Biomedical subjects

Susan Groshen

Publications and source records attributed to Susan Groshen.

At least 55 records · Page 3Linked to original sources

PubMed2004

Identification of micrometastases in histologically negative lymph nodes of early-stage cervical cancer patients.

OBJECTIVE: Despite histologically negative lymph nodes, approximately 15% of patients with early-stage cervical cancer will develop recurrence. Micrometastases have been shown to be important in staging and treatment of breast cancers and melanoma and have been identified by polymerase chain reaction analysis in cervical cancers. This study sought to estimate the frequency of micrometastases identified by immunohistochemistry in histologically negative lymph nodes and compare this to other known risk factors for recurrence of cervical cancer. METHODS: Early-stage (stages IA2, IB1, and IB2) cervical cancer patients of all histologic subtypes were identified from the surgical logs of the Los Angeles County-University of Southern California Medical Center for the period 1994-2000. One hundred thirty-two patients had histologically negative lymph nodes. Immunohistochemical assay was performed on 3,106 lymph nodes by using antibodies against cytokeratins AE-1 and CAM 5.2 in combination according to standard protocols. The stained nodes were then evaluated for the presence of micrometastases and compared against the respective clinicopathologic information in each case. RESULTS: Micrometastases were detected in 19 of 132 (15%, 95% confidence interval [CI] 9%, 22%) patients, found in 29 of the 3,106 (0.9%) lymph nodes evaluated. Vascular space invasion was seen in 50 of 132 cases (38%, 95% CI 30%, 47%) and in 8 of 19 (42%, 95% CI 21%, 66%) cases with micrometastases. Surgical margins of the resected specimen were negative in 120 of 132 cases (91%, 95% CI 84%, 95%) and in 16 of 19 (84%, 95%CI 60%, 96%) of those cases with micrometastases. Micrometastases were seen most frequently in pelvic lymph nodes (25 of 29, 86%). Patients with more than 20 lymph nodes removed were more likely to demonstrate metastasis (P <.001). There was no statistically significant association between micrometastasis and vascular space invasion or tumor volume. CONCLUSION: Micrometastases are identifiable in histologically negative lymph nodes in 15% (95% CI 9%, 22%) of early-stage cancer patients, a frequency which approximates the recurrence rate for patients with negative nodes. In this series, patients with greater numbers of lymph nodes analyzed were more likely to have lymph node micrometastasis identified. There appears to be no relationship between tumor volume and the identification of micrometastases. Although micrometastases can be identified in histologically negative lymph nodes, their presence is not strongly associated with other known factors of cervical cancer recurrence. Further research is needed to determine whether the presence of lymph node micrometastases is associated with an unfavorable prognosis. LEVEL OF EVIDENCE: II-3

Adult↗

PubMed2004

Microscopic and gross extravesical extension in pathological staging of bladder cancer.

PURPOSE: We evaluated clinical outcomes in patients with pathological microscopic (pT3a) and gross (pT3b) extravesical tumor extension with transitional cell carcinoma (TCC) of the bladder following radical cystectomy. MATERIALS AND METHODS: A total of 236 patients, including 173 males (73%) and 63 females, underwent radical cystectomy for pathological primary bladder TCC with extravesical extension (pT3), of whom 69 (29%) had pT3a and 167 (71%) had pT3b disease. At a median followup of 8.9 years (range 0 to 19.4) lymph node involvement, local and distant recurrences, and clinical outcomes were determined. RESULTS: Of the 236 patients with pT3 tumors 106 (45%) had lymph node positive disease, including 34 of 69 (49%) with pT3a and 72 of 167 (43%) with pT3b disease. The 10-year recurrence-free survival rate for patients with pT3a tumors was 48% compared with 47% for those with pT3b disease (p = 0.89). Recurrence-free survival was significantly better in patients with lymph node negative disease than in those with positive lymph nodes irrespective of the extent of extravesical involvement (pT3a vs pT3b). Local pelvic recurrence developed in 13 of the 236 patients (6%), while 84 (36%) had distant metastatic disease. Of the patients with recurrence, the type of recurrence (local or distant) was not associated with tumor stage (pT3a vs pT3b, p = 0.71). Lymph node involvement was a significant risk factor for distant tumor recurrence (p <0.001). CONCLUSIONS: Differentiating between microscopic (pT3a) and gross (pT3b) extravesical tumor involvement of TCC as outlined in the revised 1997 TNM staging system does not appear to have prognostic significance.

Adult↗

PubMed2004

Prognosis of seminal vesicle involvement by transitional cell carcinoma of the bladder.

PURPOSE: Transitional cell carcinoma (TCC) of the bladder that extends directly into contiguous organs (pT4) portends a poor prognosis. The 2002 American Joint Committee on Cancer staging system does not include seminal vesicle involvement by primary TCC of the bladder. In this analysis we evaluated the clinical outcomes and prognostic significance of seminal vesicle involvement with TCC of the bladder after radical cystectomy. MATERIALS AND METHODS: From 1971 to 2001, 1,682 patients underwent radical cystectomy and pelvic lymphadenectomy for bladder cancer. Only those tumors that involved adjacent organs through the bladder wall (pT4) were included. Overall 132 male patients with a median age of 68 years (range 36 to 98) qualified for analysis. Patients were stratified into 4 subgroups of 1) direct extravesical prostatic stromal involvement only in 37 patients (28%), 2) prostatic stroma and seminal vesicle involvement in 37 patients (28%), 3) seminal vesicle involvement only in 10 patients (8%) and 4) other contiguous pelvic organ involvement (stage pT4b) in 48 patients (36%). Overall 88 patients (67%) received some form of adjuvant therapy. At a median followup of 12.5 years (range 0 to 15.2) clinical outcomes were analyzed including overall and recurrence-free survival using Kaplan-Meier plots. RESULTS: There was no significant difference in clinical outcomes or prognosis for groups 2 and 3, thus they were combined for analysis. Five-year overall survival for any seminal vesicle involvement (10%) was significantly worse than prostatic stromal involvement only (38%) but was similar to pT4b tumors (7%, p <0.0001). The 5-year recurrence-free survival for seminal vesicle involvement (14%) was also significantly worse than prostatic stromal involvement alone (68%) but similar to that pT4b disease (25%, p = 0.01). Results were controlled for lymph node status. CONCLUSIONS: Patients with extravesical tumor extension into seminal vesicles and contiguous pelvic organs are at high risk for recurrence and progression. Involvement of the seminal vesicles by direct extension of bladder TCC portends a prognosis similar to that of pT4b disease and should, therefore, be classified as such.

Adult↗

PubMed2004

Usefulness of CA 125 as a preoperative prognostic marker for transitional cell carcinoma of the bladder.

PURPOSE: We evaluated the role of CA 125 as a prognostic marker in patients with transitional cell carcinoma (TCC) of the bladder undergoing uniform radical cystectomy with bilateral pelvic iliac lymphadenectomy. MATERIALS AND METHODS: From April 1996 to March 2001, 287 patients with a median age of 68 years (range 34 to 89) had preoperative CA 125 serum assays performed. All patients had high grade or invasive TCC and were scheduled to undergo radical cystectomy. Preoperative CA 125 was evaluated according to tumor grade and pathological subgroups (organ confined, extravesical and lymph node positive) as well as recurrence-free and overall survival. RESULTS: Of the 287 patients 31 (10.8%) demonstrated increased serum CA 125 (greater than 35 U/ml). No significant association was found between increased CA 125 and recurrence-free survival or tumor grade. However, a statistically significant association was found among pathological tumor subgroups, namely 4.9% for organ confined, 11.3% for extravesical and 21.6% for lymph node positive disease (p <0.001). Furthermore, patients with lymph node positive disease or high grade tumors (grades III/IV and IV/IV) and increased CA 125 assays demonstrated significantly worse overall survival (p <0.001). CONCLUSIONS: Increased CA 125 was seen in approximately 11% of patients with high grade or invasive TCC preoperatively. It was more commonly found in patients with locally advanced and lymph node positive disease, and it was associated with overall survival. However, recurrence-free survival was not associated with CA 125. Further studies are required to define the exact role of CA 125 in bladder cancer.

Adult↗

PubMed2003

Natural history of surgically treated bladder carcinoma with extravesical tumor extension.

BACKGROUND: The current TNM classification for bladder carcinoma stratifies extravesical extension into microscopic (pT3a) and macroscopic (pT3b) tumor involvement. The authors evaluated the outcomes of patients with pT3a and pT3b disease after radical cystectomy. METHODS: Patients (n = 129) with transitional cell carcinoma of the bladder treated with radical cystectomy alone demonstrated pathologic extravesical tumor extension: 37 (29%) had pT3a disease and 92 (71%) had pT3b disease. No patient received any adjuvant therapy. With a median follow-up of 13.6 years, the presence of lymph node involvement, margin positivity, local (pelvic) and distant disease recurrence, and clinical outcomes were determined. RESULTS: Of the 129 patients, 43 (33%) had lymph node tumor involvement: 13 of 37 patients with pT3a disease (35%) and 30 of 92 patients with pT3b disease (33%). The 10-year recurrence-free and overall survival for the entire group was 54% and 20%, respectively. No statistical difference between pT3a and pT3b disease was observed with regard to recurrence-free (P = 0.54) and overall (P = 0.66) survival. Lymph node involvement was predictive of a significantly worse 10-year recurrence-free survival (32%) compared with lymph node-negative disease (60%; P = 0.003). Local disease recurrence was reported to occur in 12 patients (9%), whereas 37 patients (29%) were reported to develop distant metastases. Among those who had disease recurrence, the type of disease recurrence (local or distant) was not found to be associated with tumor stage (pT3a vs, pT3b, P = 0.47). CONCLUSIONS: This cohort of surgically managed patients provided insight into the long-term natural history of pathologically confirmed extravesical bladder carcinoma after radical cystectomy. There was no important difference in the incidence of lymph node involvement, survival rates, and disease recurrence rates between patients with microscopic and macroscopic extravesical extension. Adjuvant protocols should be undertaken for these high-risk patients to further improve on these clinical outcomes.

Adult↗

PubMed2003

Preoperative twice-weekly paclitaxel with concurrent radiation therapy followed by surgery and postoperative doxorubicin-based chemotherapy in locally advanced breast cancer: a phase I/II trial.

PURPOSE: Preoperative chemotherapy is the conventional primary treatment in locally advanced breast cancer (LABC). We investigated the safety and efficacy of primary twice-weekly paclitaxel and concurrent radiation (RT) before modified radical mastectomy followed by adjuvant doxorubicin-based chemotherapy. PATIENTS AND METHODS: Stage IIB (T3N0) to III LABC patients were eligible. Primary chemoradiation consisted of paclitaxel, 30 mg/m(2) delivered intravenously for 1 hour twice weekly for a total of 8 to 10 weeks, and concurrent RT (45 Gy at 1.8 Gy/fraction). Modified radical mastectomy was performed at least 2 weeks after completion of chemoradiation or on recovery of skin toxicity. Postoperatively, patients who responded to paclitaxel and RT received four cycles of doxorubicin/paclitaxel, whereas patients who did not respond received doxorubicin/cytoxan. RESULTS: Forty-four patients were accrued. Toxicity from paclitaxel/RT included grade 3 skin desquamation (7%), hypersensitivity (2%), and stomatitis (2%). Postsurgery complications occurred in six patients (14%). The only grade 4 toxicity of postmastectomy chemotherapy was hematologic (10%). Grade 3 toxicities were leukopenia (24%), infection (22%), peripheral neuropathy (17%), arthralgia and pain (17%), stomatitis (12%), fatigue (10%), esophagitis (5%), and nausea (2%). Overall clinical response rate to preoperative paclitaxel and RT was 91%. Thirty-four percent of patients achieved a pathologic response in the mastectomy specimen: 16% pathologic complete responses (clearance of invasive cancer in the breast and axillary contents) and 18% pathologic partial responses (< 10 residual microscopic foci of invasive breast cancer). CONCLUSION: Twice-weekly paclitaxel with concurrent RT is a feasible and effective primary treatment for LABC. Future studies should compare primary chemoradiation to chemotherapy in LABC.

Adult↗

PubMed2003

Establishment of a nude mouse model of hepatic metastasis for evaluation of targeted retroviral gene delivery.

BACKGROUND AND OBJECTIVES: The goal of this study was to establish a reproducible nude mouse model of liver metastasis and investigate the potential of deploying targeted injectable retroviral vectors for metastatic gastrointestinal cancer. METHODS: Human cancer cells were injected into the portal vein via an indwelling catheter. The animals were sacrificed at specified time intervals, and the number of tumor nodules was counted in histologic sections of harvested livers. A group of animals received either an extracellular matrix-targeted or a nontargeted retroviral vector bearing a beta-galactosidase gene by portal vein infusion. RESULTS: The number of tumor nodules increased progressively over time at </=50 days post-infusion (r = 0.81; P < 0.0001). Transduction of tumor nodules was observed in the animals that received a matrix-targeted, but not a nontargeted, vector. CONCLUSIONS: We have established a reproducible nude mouse model of liver metastasis, and demonstrated the feasibility of gene delivery to metastatic tumor nodules in vivo by portal vein infusions of a matrix-targeted retroviral vector.

Animals↗

PubMed2003

Increased platelet Fc receptor expression as a potential contributing cause of platelet hypersensitivity to collagen in diabetes mellitus.

Recent clinical and laboratory observations support a potential role for the platelet FcgammaRIIA receptor (FcR) in collagen-mediated platelet activation associated with arterial thrombosis. Stable age- and sex-independent variation in receptor expression exists. Flow cytometry showed that 100 diabetes patients had increased mean platelet FcR expression levels compared with 201 non-diabetes patients (P < 0.001). Aggregation studies following FcR cross-linking supported a receptor role in increased activation of diabetes platelets after collagen stimulation (P = 0.018). Immunoprecipitation of collagen-stimulated and FcR-crosslinked platelets demonstrated enhanced levels of tyrosine-phosphorylated Syk in diabetic platelets. Increased platelet FcR-mediated sensitivity to collagen may contribute to cardiovascular morbidity and mortality in diabetes.

Adult↗

PubMed2003

Risk factors for patients with pelvic lymph node metastases following radical cystectomy with en bloc pelvic lymphadenectomy: concept of lymph node density.

PURPOSE: We evaluated the clinical outcomes and risk factors for progression in a large cohort of patients with lymph node metastases following en bloc radical cystectomy and bilateral pelvic lymphadenectomy. MATERIALS AND METHODS: From July 1971 through December 1997, 1,054 patients underwent radical cystectomy and bilateral pelvic-iliac lymphadenectomy for high grade, invasive transitional cell carcinoma of the bladder. Of these patients 244 (23%) with a median age of 66 years (range 36 to 90) had pathological lymph node metastases. Overall 139 of the 244 patients (57%) received some form of chemotherapy. At a median followup of greater than 10 years (range 0 to 28) outcomes data were analyzed in univariate analysis according to tumor grade, carcinoma in situ, primary bladder tumor stage, pathological subgroups, total number of lymph nodes removed and involved with tumor, and lymph node density (total number of positive lymph nodes/total number removed). In addition, the form of urinary diversion and the administration of chemotherapy were also evaluated. Multivariate analysis was then performed to analyze these variables independently. RESULTS: The incidence of positive lymph nodes increased with higher p stage and pathological subgroups. Of 669 patients 75 (11%) with organ confined primary tumors and 169 of 385 (44%) with extravesical tumor extension had involved lymph nodes. The median number of lymph nodes removed in the 244 lymph node positive cases was 30 (range 1 to 96), while the median number of positive lymph nodes was 2 (range 1 to 63). Overall recurrence-free survival at 5 and 10 years for the 244 patients with lymph node positive disease was 35% and 34%, respectively. Patients with lymph node positive disease and an organ confined primary bladder tumor had significantly improved 10-year recurrence-free survival compared with those with extravesical tumor extension (44% vs 30%, p = 0.003). The total number of lymph nodes removed at surgery was also prognostic. Patients with 15 or less lymph nodes removed had 25% 10-year recurrence-free survival compared with 36% when greater than 15 lymph nodes were removed. Recurrence-free survival at 10 years for patients with 8 or less positive lymph nodes was significantly higher than in those with greater than 8 positive lymph nodes (40% vs 10%, p <0.001). The novel concept of lymph node density was also a significant prognostic factor. Patients with a lymph node density of 20% or less had 43% 10-year recurrence-free survival compared with only 17% survival at 10 years when lymph node density was greater than 20% (p <0.001). On multivariate analysis the total number of lymph nodes involved, pathological subgroups of the primary bladder tumor, lymph node density and adjuvant chemotherapy remained significant and independent risk factors for recurrence-free and overall survival. CONCLUSIONS: Patients with lymph node tumor involvement following radical cystectomy may be stratified into high risk groups based on the primary bladder tumor, pathological subgroup, number of lymph nodes removed and total number of lymph nodes involved. Lymph node density, which is a novel prognostic indicator, may better stratify lymph node positive cases because this concept collectively accounts for the total number of positive lymph nodes (tumor burden) and the total number of lymph nodes removed (extent of lymphadenectomy). Future staging systems and the application of adjuvant therapies in clinical trials should consider applying lymph node density to help standardize this high risk group of patients following radical cystectomy.

Adult↗

PubMed2003

Computerized quantification of tissue vascularization using high-resolution slide scanning of whole tumor sections.

Assessment of tissue vascularization using immunohistochemical techniques for microvessel detection has been limited by difficulties in generating reproducible quantitative data. The distinction of individual blood vessels and the selection of microscopic fields to be analyzed remain two factors of subjectivity. In this study, we used imaging analysis software and a high-resolution slide scanner for measurement of CD31-immunostained endothelial area (EA) in whole sections of human neuroblastoma xenograft and murine mammary adenocarcinoma tumors. Imaging analysis software provided objective criteria for analysis of sections of different tumors. The use of the criteria on images of entire tumor section acquired with the slide scanner constituted a rapid method to quantify tumor vascularization. Compared with previously described methods, the "hot spot" and the "random fields" methods, EA measurements obtained with our "whole section scanning" method were more reproducible with 8.6% interobserver disagreement for the "whole section scanning" method vs 42.2% and 39.0% interobserver disagreement for the "hot spot" method and the "random fields," respectively. Microvessel density was also measured with the whole section scanning method and provided additional data on the distribution and the size of the blood vessels. Therefore, this method constitutes a time efficient and reproducible method for quantification of tumor vascularization.

Adenocarcinoma↗

PubMed2003

P7 antigen expression in human breast cancer.

PURPOSE: Evaluate p7 expression in human breast cancer and determine whether chemotherapy and radiation therapy effect a change in p7 expression. EXPERIMENTAL DESIGN: Using a p7-specific monoclonal antibody with immunohistochemistry and Western immunoblot analyses to assess p7 expression in archival, frozen breast cancer specimens both before and after therapy. RESULTS: A novel 7 kDa protein (p7), originally identified in multidrug-resistant ovarian and breast cancer cell lines, was found to be expressed in 21 of 64 (32%) primary, unselected human breast cancer specimens by immunohistochemistry with the use of a p7-specific monoclonal antibody, 1D7. P7 was observed in malignant cells but not in other types of cells in the breast tissue. Western blot analysis confirmed the 7 kDa polypeptide in p7-positive breast carcinomas identified by immunohistochemistry. P7 expression was significantly associated with breast cancers having distant metastasis and/or local recurrence (P = 0.027, Fisher's exact test). In addition, p7 expression was significantly increased in post-treatment breast cancer biopsy specimens compared with pretreatment breast cancer biopsy specimens in patients with locally advanced breast cancer after 5-fluorouracil chemotherapy and radiation therapy [2 of 15 (13%) pretreatment breast cancers compared with 8 of 15 (53%) post-treatment breast cancers; P = 0.016, McNemar's test]. CONCLUSIONS: These findings demonstrate that expression of p7 is associated with malignant tumor cells in primary breast cancers, especially those showing recurrent or metastatic disease. Its specific association with the malignant phenotype suggests it may have potential for novel target-based therapies. The markedly increased expression in patients with locally advanced disease after neoadjuvant therapy suggests a role for p7 in treatment outcome.

Antigens, Neoplasm↗

PubMed2003

Quantitative O(6)-methylguanine DNA methyltransferase methylation analysis in curatively resected non-small cell lung cancer: associations with clinical outcome.

PURPOSE: Hypermethylation of the O(6)-methylguanine DNA methyltransferase (MGMT) promoter region leads to transcriptional repression of the MGMT gene and is a common event in primary human neoplasia. The purpose of this study was to determine the frequency and clinical relevance of MGMT gene promoter hypermethylation in curatively resected non-small cell lung cancer (NSCLC). EXPERIMENTAL DESIGN: MGMT hypermethylation, expressed as the ratio between methylated MGMT to unmethylated MYOD1 in genomic DNA, was analyzed in normal and matching tumor tissue from 90 patients with NSCLC, and a control group of 10 patients without cancer using a methylation-specific fluorogenic Real-Time PCR (Taqman) system. RESULTS: Hypermethylation of the MGMT promoter was detected in 34 of 90 (38%) tumor specimens and 16 of 90 (18%) matching normal lung tissues of patients with NSCLC, and in 0 (0%) cases of the control group without lung cancer. The mean MGMT methylation level was significantly higher in tumor than in matching normal tissue (P < 0.001). MGMT methylation in normal tissue was always accompanied with MGMT methylation in matching tumor tissue. Patients without MGMT promoter hypermethylation showed a significantly better survival than patients with MGMT promoter hypermethylation (P = 0.017). Multivariate analysis revealed MGMT promoter methylation as an independent unfavorable prognostic factor (P = 0.030). CONCLUSIONS: MGMT promoter hypermethylation is a common event in patients with primary NSCLC. This epigenetic alteration is associated with inferior survival, suggesting that MGMT promoter hypermethylation might be an important biomarker for a biological aggressive disease in NSCLC.

Adult↗

PubMed2003

A phase I trial of SD-9427 (progenipoietin) with a multipeptide vaccine for resected metastatic melanoma.

PURPOSE: The melanoma tumor antigen epitope peptides MART-1(26-35 (27L)), gp100(209-217 (210M)),and tyrosinase(368-376 (370D)) were emulsified with incomplete Freund's adjuvant and administered with SD-9427 (progenipoietin), an agonist of granulocyte colony-stimulating factor and the FLT-3 receptor, to evaluate the toxicities of and immune responses to this regimen as primary end points and time to relapse and survival as secondary end points. EXPERIMENTAL DESIGN: Fifteen patients with high-risk resected stage III and IV melanoma were enrolled. Each patient received peptides + incomplete Freund's adjuvant with SD-9427 at doses of either 10, 20, or 40 microg/kg s.c. for 3 days before and 7 days after each vaccination. Immunizations were administered every month for 6 months and then administered once 6 months later. A leukapheresis to obtain peripheral blood mononuclear cells for immune analyses as well as skin testing with peptides and recall antigens was performed before and after vaccination. IFN- gamma release assay, ELISPOT, and MHC-peptide tetramer analysis were performed using peripheral blood mononuclear cells collected before and after vaccination to evaluate peptide-specific cytotoxic T-cell responses. RESULTS: Local pain and granuloma formation and fatigue of grade I or II were the most common side effects. One patient developed antibody-mediated leukopenia and transient grade III neutropenia that resolved after stopping SD-9427. Six of 12 patients tested developed a positive skin test response to one or more of the peptides. Seven of 10 patients tested demonstrated an immune response to at least one peptide when evaluated by IFN-gamma release assay and ELISPOT assay after vaccination, as did 11 of 12 patients analyzed by MHC-peptide tetramer assay. Four of 15 patients have relapsed with a median follow-up of 20 months, and 1 patient in this high-risk group has died of disease. CONCLUSIONS: SD-9427 with a multipeptide vaccine was generally well tolerated, although one patient developed reversible antibody-mediated neutropenia. These data suggest that the majority of patients with resected melanoma mount an antigen-specific immune response against a multipeptide vaccine administered with SD-9427.

Adult↗

PubMed2003

ERCC1 gene polymorphism as a predictor for clinical outcome in advanced colorectal cancer patients treated with platinum-based chemotherapy.

Excision repair cross-complementation group 1 (ERCC1) is a highly conserved protein and an essential member of the nucleotide excision repair pathway. DNA repair is an important mechanism for resistance to platinum-based chemotherapy. Previous studies have shown that ERCC1 gene expression is associated with clinical outcome to platinum chemotherapy in a variety of cancers. Recently, 2 common polymorphisms in the ERCC1 gene have been described. The first is a single nucleotide polymorphism at codon 188 of the ERCC1 gene that causes a C-->T change but codes for the same amino acid, asparagine. This polymorphism may be associated with differential ERCC1 gene expression. The second is also a signal nucleotide polymorphism in the 3'-untranslated region and may affect MRNA stability. We hypothesized that these 2 polymorphisms may be associated with clinical outcome to platinum-based chemotherapy. We assessed the relationship between these ERCC1 gene polymorphism and clinical outcome to platinum-based chemotherapy in 106 patients with advanced refractory colorectal cancer. We found a significant associated between the ERCC1 codon 118 polymorphism and clinical outcome. Patients with the C/C genotype had a median survival of 15.3 months (95% CI, 6.0-12.1) and 11.1 months (95% CI, 5.8-16.2) for those with C/T and T/T genotypes, respectively. The ERCC1 codon 118 polymorphism may be a useful predictor of clinical outcome in advanced colorectal cancer patients treated with platinum-based chemotherapy.

Adult↗

PubMed2002

Ceramide signaling in fenretinide-induced endothelial cell apoptosis.

Stress stimuli can mediate apoptosis by generation of the lipid second messenger, ceramide. Herein we investigate the molecular mechanism of ceramide signaling in endothelial apoptosis induced by fenretinide (N-(4-hydroxyphenyl)retinamide (4-HPR)). 4-HPR, a synthetic derivative of retinoic acid that induces ceramide in tumor cell lines, has been shown to have antiangiogenic effects, but the molecular mechanism of these is largely unknown. We report that 4-HPR was cytotoxic to endothelial cells (50% cytotoxicity at 2.4 microm, 90% at 5.36 microm) and induced a caspase-dependent endothelial apoptosis. 4-HPR (5 microm) increased ceramide levels in endothelial cells 5.3-fold, and the increase in ceramide was required to achieve the apoptotic effect of 4-HPR. The 4-HPR-induced increase in ceramide was suppressed by inhibitors of ceramide synthesis, fumonisin B(1), myriocin, and l-cycloserine, and 4-HPR transiently activated serine palmitoyltransferase, demonstrating that 4-HPR induced de novo ceramide synthesis. Sphingomyelin levels were not altered by 4-HPR, and desipramine had no effect on ceramide level, suggesting that sphingomyelinase did not contribute to the 4-HPR-induced ceramide increase. Finally, the pancaspase inhibitor, t-butyloxycarbonyl-aspartyl[O-methyl]-fluoromethyl ketone, suppressed 4-HPR-mediated apoptosis but not ceramide accumulation, suggesting that ceramide is upstream of caspases. Our results provide the first evidence that increased ceramide biosynthesis is required for 4-HPR-induced endothelial apoptosis and present a molecular mechanism for its antiangiogenic effects.

Acyltransferases↗

PubMed2002

Association between glutathione S-transferase P1, T1, and M1 genetic polymorphism and survival of patients with metastatic colorectal cancer.

BACKGROUND: Members of the glutathione S-transferase (GST) superfamily are important in cellular defense mechanisms. These enzymes attach reduced glutathione to electrophilic groups in a wide variety of toxic compounds, including chemotherapeutic agents. Certain polymorphisms in GSTs are associated with changes in enzyme activity, sensitivity to chemotherapy, and overall patient survival. In a retrospective study, we investigated associations between common polymorphisms in genes for several GST subclasses (GSTP1, GSTT1, GSTM1) and survival of patients with metastatic colorectal cancer receiving 5-fluorouracil (5-FU)/oxaliplatin chemotherapy. METHODS: During 1998-2000, 107 previously treated patients with advanced colorectal cancer received 5-FU/oxaliplatin combination chemotherapy. Associations between deletion polymorphisms in GSTM1 and GSTT1 genes and between a polymorphism in the GSTP1 gene that generates an Ile(105)Val in the GSTP1 protein and survival were evaluated using relative risks (RRs) of dying and the log-rank test. All statistical tests were two-sided. RESULTS: Patients heterozygous for the GSTP1 polymorphism had an RR = 0.47 (95% confidence interval [CI] = 0.27 to 0.81) compared with patients homozygous for the GSTP1 (105)Ile allele. Patients homozygous for the mutant polymorphism had an RR = 0.16 (95% CI = 0.04 to 0.63). After adjustment for performance status and tumor site, the stratified RRs were 0.28 (95% CI = 0.07 to 1.10) for patients with two (105)Val alleles and 0.64 (95% CI = 0.36 to 1.16) for those with one (105)Val allele (P =.042). Patients with the (105)Val/(105)Val genotype survived a median of 24.9 months, those with the (105)Ile/(105)Ile genotype a median of 7.9 months, and those with the (105)Ile/(105)Val genotype a median of 13.3 months (P<.001). The GSTM1 and GSTT1 genotypes were not associated with survival or clinical response. CONCLUSIONS: The GSTP1 Ile(105)Val polymorphism is associated in a dose-dependent fashion with increased survival of patients with advanced colorectal cancer receiving 5-FU/oxaliplatin chemotherapy.

Adult↗

PubMed2002

Low HER2/neu gene expression is associated with pathological response to concurrent paclitaxel and radiation therapy in locally advanced breast cancer.

PURPOSE: The objective of this study was twofold: first, to identify patients with locally advanced breast cancer (LABC) who will achieve a pathological response to a preoperative regimen of concurrent paclitaxel and radiation; and second, to explore associations between molecular markers from the original tumors and pathological response. METHODS AND MATERIALS: Patients with previously untreated LABC were eligible to receive a regimen of preoperative concurrent paclitaxel, 30 mg/m(2) twice a week for a total of 8 weeks, and radiation delivered Weeks 2--6, 45 Gy at 1.8 Gy per fraction to the breast, ipsilateral axilla, and supraclavicular nodes. At mastectomy, pathologic findings were classified as pathological complete response (pCR) = no residual invasive cells in the breast and axillary contents; pathological partial response (pPR) = presence of < or = 10 microscopic foci of invasive cells; no pathological response (pNR) = pathological persistence of tumor. For each patient, pretreatment breast cancer biopsies were prospectively analyzed by immunohistochemistry (IHC) for estrogen and progesterone (ER/PR) hormonal receptors, HER2/neu and p53 overexpression. Estrogen receptor (ER), HER2/neu, metablastin, beta-tubulin III and IV, microtubule-associated protein-4 (MAP-4), bcl-2, bax, and cyclooxygenase-2 (COX-2) gene expression were measured using real-time quantitative polymerase chain reaction (PCR). RESULTS: A total of 36 patients had pretreatment biopsies and were evaluable for the analysis of the association of molecular markers with pathological response. Pathological response in the mastectomy specimen was achieved in 12 of these 36 patients (33%). Only HER2/neu and ER gene expression were found to be significantly associated with the extent of pathological response to the regimen, i.e., tumors with low HER2/neu gene expression and negative estrogen receptors were more likely to respond to the tested regimen (p = 0.009 and p = 0.006, respectively). Conversely, p53 protein expression measured by IHC did not appear to be associated with pathological response (p = 0.67). CONCLUSION: Further studies in LABC should assess whether patient selection for treatment based on the original tumor molecular characteristics could affect their chance to achieve a pathological response.

Adult↗

PubMed2002

Thymidylate synthase gene polymorphism predicts response to capecitabine in advanced colorectal cancer.

Thymidylate synthase is a target enzyme for chemotherapeutic agents such as 5-fluorouracil and capecitabine, its oral prodrug. The human thymidylate synthase gene promoter is polymorphic, having either double or triple repeats of a 28-bp sequence. It has previously been shown that colorectal cancer patients who are homozygous for the triple tandem repeats (L/L) have significantly higher thymidylate synthase mRNA expression than those homozygous for the double repeat variant (S/S). Capecitabine is converted to 5-fluorouracil by a sequential triple enzyme pathway, with the last step catalyzed by the tumor-associated angiogenic factor thymidine phosphorylase. We have recently shown that individuals with metastatic colorectal cancer treated with 5-fluorouracil have a higher response rate if they are homozygous for the genotype S/S as opposed to S/L or L/L. Our hypothesis is that individuals homozygous for the double repeat variant (S/S) should have a better response to capecitabine than their counterparts with S/L or L/L. In this retrospective pilot study we assessed the thymidylate synthase polymorphic status of 24 patients with metastatic colorectal cancer and determined their response to capecitabine. We found that 75% (3/4) of individuals with the S/S variant responded to capecitabine, compared to 8% (1/12) and 25% (2/8) of those with the S/L and L/L variants, respectively. Our data suggest that genotyping patients for the thymidylate synthase polymorphism would be useful in identifying patients who are more likely to respond to capecitabine treatment for advanced colorectal cancer.

Antimetabolites, Antineoplastic↗