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Biomedical subjects

D G Mutch

Publications and source records attributed to D G Mutch.

At least 19 recordsLinked to original sources

Microsatellite instability, MLH1 promoter methylation, and loss of mismatch repair in endometrial cancer and concomitant atypical hyperplasia.

OBJECTIVE: MLH1 methylation is associated with the microsatellite instability (MSI) phenotype in endometrial cancer and atypical endometrial hyperplasia, a premalignant precursor to carcinoma. The observation that methylation is also seen in atypical endometrial hyperplasia without MSI suggests that methylation is an early event in endometrial tumorigenesis. Our objective was to determine if methylation is always present in MSI-positive atypical hyperplasia concomitant with MSI-positive, methylation-positive carcinoma. METHODS: We used laser capture microdissection to study MLH1 methylation and MSI in a large series of endometrial cancer cases that had previously been shown to have methylation and the MSI-high (MSI-H) phenotype. We resampled areas of carcinoma from 27 patients along with 51 foci of concomitant atypical endometrial hyperplasia. RESULTS: Consistent with previous reports, we saw MLH1 methylation in areas of atypical endometrial hyperplasia that did not show MSI. In addition, we noted that 18% of the MSI-H atypical endometrial hyperplasia DNAs lacked methylation of critical cytosines in the MLH1 promoter. Immunohistochemistry studies showed that these MSI-H unmethylated foci of atypical endometrial hyperplasia failed to express MLH1, as did regions of simple hyperplasia. CONCLUSION: Methylation of the MLH1 promoter is an early event in endometrial tumorigenesis. Given that not all MSI-positive tissues had methylation at cytosines -229 and -231, it appears that methylation may not be required for MLH1 silencing and loss of mismatch repair.

Adaptor Proteins, Signal Transducing↗

Phase I study of rubitecan and gemcitabine in patients with advanced malignancies.

BACKGROUND: Rubitecan (9-nitrocamptothecin, 9-NC, Orathecin) and gemcitabine have single-agent activity in pancreatic and ovarian carcinoma. We conducted a phase I trial to evaluate the maximum tolerated dose (MTD) and toxicities of this combination in advanced malignancies. PATIENTS AND METHODS: Twenty-one patients with refractory or recurrent malignancies were enrolled in this dose escalation trial. Dose escalation proceeded from a starting level of rubitecan at 0.75 mg/m(2)/day administered orally on days 1-5 and 8-12 in combination with gemcitabine 1000 mg/m(2) administered intravenously on days 1 and 8 of a 21-day cycle. RESULTS: The MTD was defined as rubitecan 1 mg/m(2) administered orally days 1-5 and 8-12, and gemcitabine 1000 mg/m(2) administered intravenously over 30 min days 1 and 8, given every 21 days. Dose-limiting toxicity was myelosuppression including neutropenia and thrombocytopenia. Other side effects included diarrhea, nausea, vomiting and fatigue. Five patients with stable disease were observed among 18 evaluable patients. CONCLUSIONS: The recommended phase II dose is rubitecan 1 mg/m(2) given orally on days 1-5 and 8-12 in combination with gemcitabine 1000 mg/m(2) as a 30-min intravenous infusion on days 1 and 8 of a 21-day cycle.

Adult↗

Long-term follow-up of RTOG 92-10: cervical cancer with positive para-aortic lymph nodes.

PURPOSE: The purpose of this study was to evaluate the late toxicity and efficacy of twice-daily external irradiation to the pelvis and lumbar para-aortic region with brachytherapy and concurrent chemotherapy for carcinoma of the cervix with positive para-aortic lymph nodes. PATIENTS AND METHODS: This study was designed to administer twice-daily radiation doses of 1.2 Gy to the pelvis and lumbar para-aortic lymph nodes (simultaneously) at 4-6-h intervals, 5 days per week. The total external radiation doses were 24-48 Gy to the whole pelvis, 12-36 Gy parametrial boost, and 48 Gy to the lumbar para-aortic region with an additional boost to a total dose 54-58 Gy to the positive para-aortic lymph node(s). One or two intracavitary implants were performed to deliver a minimum total dose of 85 Gy to point A. Cisplatin (75 mg/m(2); Days 1, 22, and 43) and 5-fluorouracil (1,000 mg/m(2)/24 h x 4 consecutive days, beginning on Days 1, 22, and 43) were given for two or three cycles. RESULTS: Thirty patients with clinical Stages I-IV carcinoma of the cervix with biopsy-proven para-aortic lymph node metastases were enrolled in this study. Hyperfractionated external irradiation was completed in 87% (26 of 30). Brachytherapy was given in two implants to 47% (14 of 30) and in one implant to 33% (10 of 30); 13% (4 of 30) did not receive brachytherapy, 1 patient had three implants, and 1 had five high-dose-rate implants. Radiotherapy was completed per protocol in 70%. Three cycles of chemotherapy were given to 23% (7 of 30); 73% (22 of 30) received two cycles, and 1 patient did not receive chemotherapy. The acute toxicity from chemotherapy was Grade 1 in 3%, Grade 2 in 17%, Grade 3 in 48%, and Grade 4 in 28%. Acute toxicity from radiotherapy was Grade 1 in 7%, Grade 2 in 34%, Grade 3 in 21%, and Grade 4 in 28%. Late toxicity was Grade 1 in 10%, Grade 2 in 17%, Grade 3 in 7%, and Grade 4 in 17%. Grade 5 toxicity occurred in 1 patient during the course of therapy, but none had a late Grade 5 toxicity. The median follow-up time for the 7 patients alive at the time of last follow-up was 57 months. The overall survival estimates were 46% at 2 years and 29% at 4 years. The probability of local-regional failure was 40% at 1 year and 50% at 2 and 3 years. The probability of disease failure at any site was 46% at 1 year, 60% at 2 years, and 63% at 3 years. CONCLUSION: The results suggest that twice-daily external irradiation to the pelvis and lumbar para-aortic region with brachytherapy and concurrent chemotherapy resulted in an unacceptably high rate (17%, 5 of 29) of Grade 4 late toxicity. One patient died of acute complications of therapy. The survival estimates seem no better than standard fractionation irradiation without chemotherapy.

Adenocarcinoma↗

Radiation therapy for carcinoma of the cervix with biopsy-proven positive para-aortic lymph nodes.

PURPOSE: To evaluate local tumor control, cause-specific survival, patterns of relapse, and toxicity in patients with cervical cancer and positive para-aortic lymph nodes treated with radiation therapy alone. METHODS: This is a retrospective chart review of 43 patients with cervical cancer and biopsy-proven positive para-aortic lymph nodes treated with radiation therapy treated from 1965 to 1993. There were 15 patients with clinical Stage I disease, 12 with Stage II, and 16 with Stage III. Patients were treated with external irradiation to the pelvis and para-aortic regions combined with brachytherapy. None received chemotherapy. RESULTS: The 5-year overall survival rate was 32% and the median overall survival was 2.2 years. The 5-year cause-specific survival rate was 49% and the median cause-specific survival was 2.7 years. The cause-specific survivals at 5 years were 47% for Stage I, 64% for Stage II, and 46% for Stage III. Tumor recurrence occurred in 20 patients. The sites of recurrence were in the pelvis only in 3, the pelvis and distant metastasis in 9, and distant metastasis only in 8 patients. Severe, grade 3 complications occurred in 2 patients. One patient developed an enterovaginal fistulas and 1 developed radiation myelitis. CONCLUSION: Pelvic and para-aortic irradiation and brachytherapy resulted in a 49%, 5-year, cause-specific survival. Clinical tumor stage did not effect outcome. The majority of relapses occurred at distant sites. Toxicity was acceptable. Systemic chemotherapy should be considered as adjunctive therapy for these patients.

Adult↗

Genotypic and phenotypic progression in endometrial tumorigenesis: determining when defects in DNA mismatch repair and KRAS2 occur.

We set out to determine the relative timing of loss of DNA mismatch repair and KRAS2 mutation in endometrial tumorigenesis. We studied endometrial carcinoma (CA) and synchronous atypical endometrial hyperplasia (AEH), the premalignant precursor of endometrial cancer. Carcinoma and hyperplasia were investigated for loss of mismatch repair as evidenced by microsatellite instability (MSI) and for KRAS2 mutations. Endometrial cancers previously shown to be MSI-positive were evaluated for KRAS2 codon 12 and 13 mutations. DNA was isolated from foci of AEH concomitant with, but physically remote from, the cancers by use of tissues prepared by laser capture microdissection (LCM). The AEH DNAs were then assessed for MSI and KRAS2 mutations. Of 210 endometrial CAs investigated, 51 (26%) were MSI-positive, and among those, 21 (41%) arose concomitantly with AEH. Of 41 foci of AEH (mean, two foci per patient) investigated, 34 (83%) were MSI-positive. KRAS2 mutations were seen in 5/51 (10%) MSI-positive carcinomas. From the five patients informative for both KRAS2 mutation and MSI, 10 foci of AEH were available for investigation. All 10 AEH specimens (100%) were MSI-positive, and six (60%) had the KRAS2 mutation present in the coexisting CA. The observation that some MSI-positive AEH specimens lack the KRAS2 mutation seen in the coexisting CA supports a model in which loss of DNA mismatch repair precedes KRAS2 mutation. However, in addition to the absence of KRAS2 mutations in AEH, we discovered mutations in LCM hyperplasia and carcinoma specimens that were not present in the portion of the cancers originally investigated. These discordant genotypes suggest genetic heterogeneity in endometrial hyperplasia and concomitant cancer.

Base Pair Mismatch↗

Characterization of the homeodomain gene EMX2: sequence conservation, expression analysis, and a search for mutations in endometrial cancers.

Previous loss-of-heterozygosity studies in endometrial carcinoma mapped a putative tumor suppressor gene to 10q25.3-26.1. An analysis of genomic sequences for the deletion interval showed several expressed sequence tags and the homeodomain gene EMX2, a homologue of Drosophila melanogaster empty spiracles. Expression studies showed that EMX2 transcripts are abundant in the adult uterus and that message levels seem to be inversely correlated with endometrial proliferation. EMX2 RNA was more abundant in quiescent postmenopausal endometrium than in premenopausal endometrium. We found decreased EMX2 expression in a subset of primary endometrial tumors, and four of six endometrial cancer cell lines investigated failed to express EMX2. The predicted protein showed extensive amino acid conservation with EMX2 sequences from several vertebrates. There was also considerable evolutionary conservation in the 3' untranslated region. To examine the potential function of EMX2 in endometrial tumorigenesis, we investigated 20 primary tumors and 6 endometrial cancer cell lines for mutations. Two primary tumors had mutations. Inactivation or reduced expression of EMX2 in cancers, coupled with increased expression in the quiescent endometrium, indicate that this homeodomain gene is involved in maintenance of the differentiated state.

Adenocarcinoma↗

Factors predicting subcutaneous implanted central venous port function: the relationship between catheter tip location and port failure in patients with gynecologic malignancies.

OBJECTIVE: We set out to determine the factors that predict subcutaneous implanted central venous port function. Specifically, we sought to determine whether the location of the catheter tip is correlated with port failure. METHODS: A review of all gynecologic oncology patients who underwent initial port placement between 1993 and 1998 was undertaken. The initial chest radiograph following port placement was reviewed, and the venous location of the catheter tip was recorded. Patients were followed until port removal, death, or the last documentation of port function. RESULTS: Two hundred thirty-six patients underwent port placement during the study period. The majority of patients (97%) had their port placed for intravenous chemotherapy. The median time of port duration in patients with a functional port was 21.6 months. Forty of the 236 ports (17%) were removed because of device malfunction. Catheter tips were located in the central venous system in 164 (69%) cases and outside of the central venous system in 72 (31%) cases. Removal secondary to malfunction was significantly higher when the catheter tip was located outside of the central venous system (30/72 (42%) versus 10/164 (6%), P = 0.001). By life-table analysis, ports removed for malfunction with their tips located centrally had a significantly longer median duration of functional use than those whose tips were located peripherally (78 versus 44 months, P = 0.0001). CONCLUSIONS: The rate of port removal secondary to malfunction is significantly less if the catheter tip is located in the central venous system. Confirmation of the location of the catheter tip is imperative for the long-term function of a subcutaneous implanted central venous port.

Adult↗

Prophylactic oophorectomy and ovarian cancer surveillance. Patient perceptions and satisfaction.

OBJECTIVE: To evaluate decision making, information gathering, satisfaction and regret in women at increased risk of ovarian cancer who had undergone prophylactic oophorectomy or ovarian cancer surveillance. STUDY DESIGN: Thirty women undergoing prophylactic oophorectomy (median age, 47 years) and 30 women who had undergone ovarian cancer surveillance (median age, 43) completed an in-depth telephone interview consisting of open-ended questions. RESULTS: Most commonly cited concerns before prophylactic oophorectomy included the physical discomfort of surgery and recovery (40%) and issues of immediate menopause and hormone replacement (37%). Fourteen women (47%) would have liked more information prior to surgery. Two women (7%) expressed regret about their decision. The remaining 28 women (93%) undergoing prophylactic oophorectomy expressed no regret about the decision. Nine women (37%) would have liked more information prior to considering ovarian cancer surveillance. Nearly half the women undergoing surveillance did not recall receiving any information about prophylactic oophorectomy as an option. Fifteen women (50%) expressed some regret about ovarian cancer surveillance, and three were frankly dissatisfied. CONCLUSION: Few women undergoing prophylactic oophorectomy had regret about their decision, though half these women would have liked more information prior to surgery. Many women undergoing ovarian cancer surveillance had some regret about or dissatisfaction with their decision.

Adult↗

Clinical significance of microsatellite instability in endometrial carcinoma.

BACKGROUND: The purpose of this study was to compare the clinical characteristics of endometrial carcinomas with and without microsatellite instability (MSI). METHODS: The authors prospectively acquired DNA from patients with endometrial carcinomas at Washington University Medical Center. Tumors were assigned MSI (+) status when two or more of five microsatellite repeat markers revealed novel bands in tumor DNA not present in the corresponding normal DNA. Clinical characteristics and survival data of patients with and without MSI were abstracted from patient charts. Statistical significance was calculated with the chi-square test, and survival was assessed with Kaplan-Meier methods. RESULTS: The authors found 65 of 70 (93%) patients with MSI (+) tumors to be of white race, whereas only 124 of 159 (78%) patients with MSI (-) tumors were white (P = 0.012). Advanced disease (International Federation of Gynecology and Obstetrics Stage III-IV) was observed in 9 of 70 (13%) MSI (+) patients and 44 of 159 (28%) MSI (-) patients (P = 0.017). In addition, aggressive histologic subtypes were observed less frequently in MSI (+) tumors (6/70 [8%]) than in MSI (-) tumors (30 of 159 [19%]) (P = 0.034). Race and stage were shown by multivariate analysis to be different in MSI (+) and MSI (-) patients. Recurrence and overall survival were similar in the two groups. CONCLUSIONS: Patients with MSI (+) tumors were more likely to be of white race and to present with early stage disease. Further investigation is needed to explain why patients with MSI (+) tumors have similar survival to patients with MSI (-) tumors, despite presenting at earlier stages, being of white race, and being less likely to be associated with virulent histologic subtypes.

DNA, Neoplasm↗

Atypical clustering of gynecologic malignancies: A family study including molecular analysis of candidate genes.

OBJECTIVE: We set out to determine whether hereditary nonpolyposis colorectal cancer (HNPCC) was responsible for cancer susceptibility in a family with gynecologic malignancies in three consecutive generations. METHODS: A detailed family history study, including review of medical records, was undertaken. Tumor DNAs from affected family members were evaluated for microsatellite instability (MSI). Linkage between cancer susceptibility and the candidate DNA mismatch repair genes MLH1, MSH2, MSH3, and MSH6 (GTBP) was investigated. MLH1 and MSH2 protein expression was evaluated by immunohistochemistry and MSH2 was investigated for mutation. RESULTS: Four gynecologic malignancies in the core family were confirmed. MSI was seen in six of seven cancers studied. The only MSI-negative tumor was an ovarian cancer from the proband's maternal grandmother, which arose at the age of 92. Haplotype analysis using chromosome 2p markers implicated the MSH2 gene in this family's cancer susceptibility. MSH2 protein expression was absent in an MSI-positive colon cancer from an affected family member. CONCLUSIONS: The inability to exclude linkage of MSH2 with the disease susceptibility, the presence of the MSI phenotype in cancers from family members sharing the same region of chromosome 2p, and the lack of immunodetectable MSH2 point to MSH2-associated HNPCC as a cause for this family's cancer susceptibility. Continued efforts to increase awareness of the heritability of endometrial cancer should improve our understanding of the disease, with resultant improved surveillance strategies, recommendations for surgical and chemoprophylaxis, and identification of patients at risk for malignancy as a result of HNPCC.

Adult↗

Absence of PTEN repeat tract mutation in endometrial cancers with microsatellite instability.

OBJECTIVE: PTEN, a tumor suppressor gene shown to be frequently mutated in endometrial cancers, has been suggested to be a target of microsatellite instability (MSI)-driven mutagenesis. We set out to investigate the relationship between MSI and PTEN mutation in a large series of primary endometrial carcinomas. METHODS: Thirty-nine MSI-positive endometrial cancers were evaluated by single-strand conformational variant analysis and direct sequencing to screen all nine PTEN exons for mutation. RESULTS: Fifteen specimens (38%) demonstrated 16 PTEN mutations. We observed only one alteration in the poly-adenine repeat of exon 8 that is suggested to be a target for mutation in endometrial cancers with MSI. Seven of 16 (44%) mutations in our series were deletions of >/=3 bp, a class of mutation not usually associated with tumors with defective DNA mismatch repair. To determine the significance of this high frequency of deletion, 26 additional endometrial cancers without MSI were matched with the 39 MSI-positive cancers for the prognostic factors of tumor histology, stage, grade, and patient race. The MSI-positive tumors had a significantly higher frequency of deletions involving >/=3 bp when compared with the MSI-negative group (5/11 versus 0/10, P = 0.035). CONCLUSIONS: Repeat tract mutation in PTEN is an uncommon event in MSI-positive cancers. Deletion of >/=3 bp in this gene is more common in MSI-positive cancers when compared with tumors without MSI.

DNA Mutational Analysis↗

Radical hysterectomy for cervical cancer in obese women.

OBJECTIVE: To estimate the morbidity, adequacy of surgery, and survival of obese women undergoing radical hysterectomy and pelvic lymphadenectomy. METHODS: Patients with stage I and IIa cervical cancer and a body mass index (BMI) over 30 kg/m(2) and absolute weight greater than 85 kg explored with the intent for radical hysterectomy between 1986 and 1998 were identified. Patient characteristics, surgical, pathologic, and follow-up data were extracted and survival curves were generated. RESULTS: Forty-eight obese women were identified who were explored for radical hysterectomy and pelvic lymph node dissection. The median BMI was 36 kg/m(2), and the median weight was 95 kg. Thirty-five patients (73%) had stage Ib1 disease. Despite the obesity of the study group, none had severe comorbidity. The procedure was completed in 46 patients, and abandoned in two because of metastatic disease. For patients undergoing radical hysterectomy and pelvic lymph node dissection, median blood loss was 800 mL. No patient developed fistulas. Residual tumor was present in 26 (57%) hysterectomy specimens, and margins were without disease in 45 specimens (98%). A median of 26 pelvic lymph nodes were obtained per procedure, and six patients (13%) had positive nodes. Five-year overall and disease-free survival are 84% (95% confidence interval [CI] 70.9, 97.5) and 80% (95% CI 65.2, 93.8), respectively, at a median follow-up of 36 months. CONCLUSION: In this carefully selected obese group, we demonstrate that radical hysterectomy and pelvic lymph node dissection can be performed with adequate surgical resection, acceptable morbidity, and excellent survival.

Adult↗

Lack of effect of tumor size on the prognosis of carcinoma of the uterine cervix Stage IB and IIA treated with preoperative irradiation and surgery.

PURPOSE: The purpose of this analysis was to evaluate the prognostic significance of cervical tumor size in patients with Stages Ib and IIa carcinoma of the cervix treated with preoperative irradiation and radical or conservative hysterectomy. METHODS AND MATERIALS: This study is a retrospective analysis of 177 patients. One hundred forty-one patients had Stage Ib and 36 patients had Stage IIa carcinoma of the cervix. All patients were treated with preoperative irradiation and surgery. Radiation therapy consisted of external pelvic irradiation and intracavitary brachytherapy; total doses ranged from 30 to 60 Gy to the pelvic sidewall and 60 to 70 Gy to point A. Surgery consisting of radical hysterectomy and lymph node dissection or a conservative hysterectomy and lymph node dissection was performed 4 to 6 weeks after completion of irradiation. RESULTS: The 5-year progression-free survivals were 80% for Stage Ib and 63% for Stage IIa (p = 0.03). The 5-year cumulative pelvic failure rates for Stage Ib were 16% for tumors <3 cm and 9% for tumors >3 cm (p = 0.90). The 5-year cumulative pelvic failure rates for Stage IIa were 22% for tumors <3 cm and 22% for tumors >3 cm (p = 0.75). The corresponding cumulative distant metastasis failure rates at 5 years for Stage Ib were 21% for tumors <3 cm and 21% for tumors >3 cm (p = 0.60). For patients with Stage IIa disease, the 5-year cumulative distant metastasis rates were 33% for tumors <3 cm and 36% for tumors >3 cm (p = 0.70). A multivariate analysis was performed to evaluate prognostic factors for the endpoint of progression-free survival. The variables that were analyzed were patient age, tumor histology, tumor size, clinical stage, point A and pelvic lymph node irradiation dose, and cervical tumor status and pelvic lymph node status at the time of hysterectomy. The variables that were found to be of independent significance for progression-free survival by multivariate analysis were pelvic lymph node irradiation dose (p <0.001), pelvic lymph node status at the time of hysterectomy (p = 0.01), and clinical stage (p = 0.02). Cervical tumor size at the time of diagnosis and the presence of tumor cells in the cervix in the hysterectomy specimen was not an independent prognostic factor by multivariate analysis. The overall severe complication rate was 11% for all patients. CONCLUSIONS: For this population of patients treated with preoperative irradiation and surgery, pelvic lymph node status at the time of hysterectomy and the preoperative irradiation dose to the pelvic lymph nodes are independent predictors of progression-free survival and the development of distant metastasis. The pretreatment cervical tumor size is of less importance for predicting progression-free survival and the development of distant metastasis but clinical stage is an important prognostic variable. These results are in contrast with those of surgery or irradiation alone, in which primary tumor size is a critical prognostic factor for all outcome parameters.

Adolescent↗

Pelvic radiation with concurrent chemotherapy compared with pelvic and para-aortic radiation for high-risk cervical cancer.

BACKGROUND AND METHODS: We compared the effect of radiotherapy to a pelvic and para-aortic field with that of pelvic radiation and concurrent chemotherapy with fluorouracil and cisplatin in women with advanced cervical cancer. Between 1990 and 1997, 403 women with advanced cervical cancer confined to the pelvis (stages IIB through IVA or stage IB or IIa with a tumor diameter of at least 5 cm or involvement of pelvic lymph nodes) were randomly assigned to receive either 45 Gy of radiation to the pelvis and para-aortic lymph nodes or 45 Gy of radiation to the pelvis alone plus two cycles of fluorouracil and cisplatin (days 1 through 5 and days 22 through 26 of radiation). Patients were then to receive one or two applications of low-dose-rate intracavitary radiation, with a third cycle of chemotherapy planned for the second intracavitary procedure in the combined-therapy group. RESULTS: Of the 403 eligible patients, 193 in each group could be evaluated. The median duration of follow-up was 43 months. Estimated cumulative rates of survival at five years were 73 percent among patients treated with radiotherapy and chemotherapy and 58 percent among patients treated with radiotherapy alone (P=0.004). Cumulative rates of disease-free survival at five years were 67 percent among patients in the combined-therapy group and 40 percent among patients in the radiotherapy group (P<0.001). The rates of both distant metastases (P<0.001) and locoregional recurrences (P<0.001) were significantly higher among patients treated with radiotherapy alone. The seriousness of side effects was similar in the two groups, with a higher rate of reversible hematologic effects in the combined-therapy group. CONCLUSIONS: The addition of chemotherapy with fluorouracil and cisplatin to treatment with external-beam and intracavitary radiation significantly improved survival among women with locally advanced cervical cancer.

Antineoplastic Combined Chemotherapy Protocols↗

Factors affecting long-term outcome of irradiation in carcinoma of the vagina.

OBJECTIVE: This report evaluates prognostic and technical factors affecting outcome of patients with primary carcinoma of the vagina treated with definitive radiation therapy. METHODS AND MATERIALS: A retrospective analysis was performed on records of 212 patients with histologically confirmed carcinoma of the vagina treated with irradiation. RESULTS: Tumor stage was the most significant prognostic factor; actuarial 10-year disease-free survival was 94% for Stage 0 (20 patients), 80% for Stage I (59 patients), 55% for Stage IIA (63 patients), 35% for Stage IIB (34 patients), 38% for Stage III (20 patients), and 0% for Stage IV (15 patients). All in situ lesions except one were controlled with intracavitary therapy. Of the patients with Stage I disease, 86% showed no evidence of vaginal or pelvic recurrence; most of them received interstitial or intracavitary therapy or both, and the addition of external-beam irradiation did not significantly increase survival or tumor control. In Stage IIA (paravaginal extension) and IIB (parametrial involvement) 66% and 56% of the tumors, respectively, were controlled with a combination of brachytherapy and external-beam irradiation; 13 of 20 (65%) Stage III tumors were controlled in the pelvis. Four patients with Stage IV disease (27%) had no recurrence in the pelvis. The total incidence of distant metastases was 13% in Stage I, 30% in Stage IIA, 52% in Stage IIB, 50% in Stage III, and 47% in Stage IV. The dose of irradiation delivered to the primary tumor or the parametrial extension was of relative importance in achieving successful results. In patients with Stage I disease, brachytherapy alone achieved the same local tumor control (80-100%) as in patients receiving external pelvic irradiation (78-100%) as well. In Stage II and III there was a trend toward better tumor control (57-80%) with combined external irradiation and brachytherapy than with the latter alone (33-50%) (p = 0.42). The incidence of grade 2-3 complications (12%) correlated with the stage of the tumor and type of treatment given. CONCLUSION: Radiation therapy is an effective treatment for patients with vaginal carcinoma, particularly Stage I. More effective irradiation techniques, including optimization of dose distribution combining external irradiation and interstitial brachytherapy in tumors beyond Stage I, are necessary to enhance locoregional tumor control. The high incidence of distant metastases emphasizes the need for earlier diagnosis and effective systemic cytotoxic agents to improve survival in these patients.

Brachytherapy↗

Differences in patterns of TP53 and KRAS2 mutations in a large series of endometrial carcinomas with or without microsatellite instability.

BACKGROUND: The correlation between tumor microsatellite instability (MSI) and the accumulation of mutations in KRAS2 and TP53 is uncertain. The authors evaluated the TP53 and KRAS2 genes for mutations in sporadic endometrial carcinomas with microsatellite instability (MSI) and matched MSI negative controls to determine whether defective DNA mismatch repair impacts the patterns of mutations in two genes known to be involved in endometrial tumorigenesis. METHODS: Twenty-five MSI positive endometrial tumors were matched for prognostic factors with 25 MSI negative tumors. Mutations in codon 12 and 13 of KRAS2 were assessed using a polymerase chain reaction (PCR) restriction assay. Mutations in codon 61 of KRAS2 and exons 5-8 of TP53 were evaluated using PCR amplification and single strand conformation variant (SSCV) analysis. All variants were subjected to direct DNA sequencing. RESULTS: KRAS2 and TP53 mutations were identified with equal frequency in the MSI positive and MSI negative groups. For TP53, the authors identified 5 mutations (20%) in the MSI positive specimens compared with 8 (32%) in the MSI negative group. For KRAS2, there were identified 8 mutations (32%) in the MSI positive specimens compared with 7 (28%) in the MSI negative tumors. The mutational spectra evident from sequence analysis of TP53 and KRAS2 variants were similar between MSI negative and MSI positive tumors. MSI negative tumors were more likely to have mutations in both KRAS2 and TP53 than MSI positive tumors, which were rarely mutant in both genes (P=0.046). CONCLUSIONS: Although the overall frequency of mutations in TP53 and KRAS2 is similar, MSI positive tumors are less likely to have mutations in both genes than MSI negative sporadic endometrial carcinomas. MSI positive and MSI negative endometrial carcinomas may arise through distinct genetic pathways.

DNA Repair↗