Biomedical subjects

P W Kantoff

Publications and source records attributed to P W Kantoff.

At least 19 recordsLinked to original sources

PubMed2000

Smoking and alcohol use may be risk factors for poorer outcome in patients with clear cell renal carcinoma.

OBJECTIVES: To correlate the clinical outcomes of 148 patients with clear cell renal carcinoma treated at a single institution with a variety of other factors. METHODS: Cases were derived from a consecutive series of nephrectomy specimens obtained from 1980 to 1994. A retrospective review of clinical records was performed, with tobacco use, alcohol use, recurrence, and survival noted. RESULTS: The median age of the patients was 62 years. The median follow-up was 4.4 years. Of 148 patients, 82% had localized disease (MO), and 18% had suspected metastases (M1) at the time of nephrectomy. Of 121 patients without metastases at diagnosis, T classification was assessed for 117: 48 (41%) had T1 disease, 18 (15%) T2, 46 (39%) T3, and 5 (4%) T4. The Fuhrman grade was 1 or 2 in 51% of patients and 3 or 4 in 45%. Both clinical stage and grade were significantly associated with overall survival (P <0.0001 and P = 0.0028, respectively) and recurrence-free survival (P = 0.0002 and P = 0.0011, respectively). Smoking and alcohol use history was determined in 70% and 63% of patients, respectively. In patients with Stage M0, smokers had a significantly worse overall survival rate compared with nonsmokers (P = 0.039). Also, in patients with Stage M0, a trend toward a worse recurrence-free survival rate was noted in alcohol users compared with those who never used alcohol regularly (P = 0.06). CONCLUSIONS: The prognosis of clear cell renal carcinoma depends on the pathologic stage at diagnosis and the Fuhrman grade. Smoking is a known risk factor for developing renal cancer and may be associated with increased mortality from clear cell carcinoma in patients with Stage M0. Also, regular alcohol use may decrease the recurrence-free survival rate.

Adenocarcinoma, Clear Cell↗

PubMed1999

The V89L polymorphism in the 5alpha-reductase type 2 gene and risk of prostate cancer.

5alpha-Reductase type 2, the predominant prostatic isozyme of this protein, converts testosterone to dihydrotestosterone. It has been hypothesized that individuals with greater 5alpha-reductase activity are at increased risk for prostate cancer (CaP). A single nucleotide polymorphism of the 5alpha-reductase type 2 gene (SRD5A2) gives rise to a substitution of leucine (leu) for valine (val) at codon 89 (V89L), the presence of which may affect serum androstanediol glucuronide (AAG) levels. We studied the effect of this polymorphism on the risk of prostate cancer in a prospective, nested, case-control design within the Physicians' Health Study. In all controls (n = 799), the leu allele frequency was 0.30. Among the 386 controls with plasma AAG levels available, there was no significant association between AAG levels and V89L genotype. We also detected no significant association between risk for CaP and genotype [odds ratio: val/val = 1.0 (reference), leu/val = 0.96 (95% confidence interval, 0.76-1.20), and leu/ leu = 0.84 (95% confidence interval, 0.57-1.24)]. These data do not support a moderate to large effect of the SRD5A2 V89L polymorphism on plasma AAG levels or CaP risk in this predominantly Caucasian cohort, although a small effect cannot be completely excluded.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗

PubMed1999

A phase II trial of methotrexate, cisplatin, 5-fluorouracil, and leucovorin in the treatment of invasive and metastatic urothelial carcinoma.

BACKGROUND: The current treatment of advanced urothelial carcinoma generates high response rates but is associated with poor overall survival. The current study evaluated the efficacy and toxicity of a new combination of active drugs in the treatment of urothelial carcinoma. METHODS: Twenty-four patients with muscle invasive or metastatic urothelial carcinoma were enrolled. Fifteen patients (63%) had metastatic disease whereas 9 patients had T2-T4 disease. Three patients were unevaluable for response because of significant toxicity. Patients were treated every 28 days with methotrexate, 60 mg/m(2), intravenously (i.v.) on Day 1; cisplatin, 25 mg/m(2)/day, by continuous i.v. infusion on Days 2-6; 5-flurouracil (5-FU) 800 mg/m(2)/day by continuous i.v. infusion on Days 3-6; and leucovorin, 500 mg/m(2)/day, by continuous i.v. infusion on Days 2-6. Dosage in subsequent cycles was adjusted according to toxicity. RESULTS: The median follow-up was 81 months (range, 53-97+ months). The overall response rate (complete response + partial response) for all 24 patients was 63% (95% confidence interval, 41-81%). The median survival was 65 months in the patients with muscle invasive disease and 17 months in the patients with metastatic disease. The duration of response in patients with metastatic disease was 6 months (range, 4-19 months). Toxicity was significant, with 82% of patients experiencing Common Toxicity Criteria Grade 3 or 4 neutropenia and 63% experiencing Grade 3 or 4 thrombocytopenia. However, only three patients developed febrile neutropenia and gastrointestinal and neurologic toxicity was moderate. CONCLUSIONS: The combination of methotrexate, cisplatin, 5-fluorouracil, and leucovorin represents an active regimen in the treatment of urothelial carcinoma with a moderate toxicity profile. As new drugs are found to treat urothelial carcinoma, further studies will be needed to evaluate the role of traditional agents such as 5-fluorouracil and methotrexate in new combination chemotherapeutic regimens.

Adult↗

PubMed1999

CAG repeat within the androgen receptor gene and incidence of surgery for benign prostatic hyperplasia in U.S. physicians.

BACKGROUND: CAG repeat length in exon 1 of the androgen receptor (AR) gene correlates inversely with transcriptional transactivation activity of the AR. Men with shorter AR CAG repeat lengths are at higher risk of prostate cancer. Because benign prostatic hyperplasia (BPH) is an androgen-dependent condition, we examined the hypothesis that a shorter AR gene CAG repeat length increases the risk of developing of BPH. METHODS: Among 14,916 men of the Physicians' Health Study who had provided a blood sample in 1982, we measured AR gene CAG repeat lengths for 310 men who had surgery for BPH up to 7.5 years of follow-up and 1,041 controls. RESULTS: Risk of surgery for BPH increased linearly with decreasing AR CAG repeat length (P (trend) = 0.03). Relative to men with a CAG repeat length > or = 25, men with a repeat length < or = 19 had an odds ratio of BPH surgery of 1.76 (95% confidence interval, 1.16-2.65). CONCLUSIONS: Variability in the AR gene CAG repeat influences the development of symptomatic BPH.

Humans↗

PubMed1999

The CAG repeat within the androgen receptor gene and benign prostatic hyperplasia.

OBJECTIVES: Shorter CAG repeat lengths in exon 1 of the androgen receptor (AR) gene are associated with a stronger transcriptional activity of the AR and with a higher risk of prostate cancer. Because benign prostatic hyperplasia (BPH) is an androgen-dependent condition, we examined the hypothesis that men with shorter AR gene CAG repeat lengths have an increased risk of developing BPH. METHODS: Using data from the Health Professionals Follow-up Study (HPFS), we evaluated the relationship between AR gene CAG repeat length and prevalent BPH, as defined by BPH surgery, by enlarged prostate gland detected by digital rectal examination, and by urinary symptoms as determined by the American Urological Association Symptom Index. RESULTS: The odds ratio for BPH surgery or enlarged prostate gland was 1.92 (95% confidence interval [CI] 1.22 to 3.03; P [trend] = 0.0002), comparing AR gene CAG repeat length of 1 9 or less to 25 or more. Results were similar for the end points of BPH surgery (P [trend] = 0.002) and for enlarged prostate gland (P [trend] = 0.001). For a six-repeat decrease in CAG repeat length, the odds ratio for having moderate or severe urinary obstructive symptoms from an enlarged prostate gland was 3.62 (95% CI 1.51 to 8.67; P = 0.004). CONCLUSIONS: Variability in the AR gene CAG repeat influences the development of symptomatic BPH, particularly in predicting obstructive urinary symptoms. Our findings support further study to establish the appropriate clinical relevance.

Adult↗

PubMed1999

Plasma levels of vascular endothelial growth factor are increased in patients with metastatic prostate cancer.

OBJECTIVES: Vascular endothelial growth factor (VEGF) is a cytokine that plays an important role in tumor angiogenesis. VEGF is overexpressed in many human cancers, including prostate cancer, but circulating levels of VEGF in patients with prostate cancer have not been reported. In this study, we analyzed plasma concentrations of VEGF in a cohort of patients with prostate cancer and compared them with a normal population. METHODS: Twenty-six healthy, cancer-free individuals and 80 patients with prostate cancer (54 patients with localized prostate cancer and 26 patients with metastatic prostate cancer [bone or lymph node positive]) were analyzed in this study. Blood was drawn in the same fashion from all individuals and deposited in tubes containing ethylenediaminetetraacetic acid as anticoagulant. Plasma was extracted and VEGF concentrations were determined using a quantitative sandwich enzyme immunoassay technique. RESULTS: Median plasma VEGF was 28.5 pg/mL (interquartile range 19.3 to 57.0) in patients with metastases; 7.0 pg/mL (interquartile range 0 to 26.5) in patients with localized disease, and 0 pg/mL (interquartile range 0 to 24) in controls. These differences were statistically significant (P <0.001). When compared group by group, the metastatic group had significantly higher plasma VEGF than the localized disease group and the control group (P = 0.003 and P <0.001, respectively). There was a tendency for plasma VEGF to be higher in the localized disease group than in the control group, a trend that almost reached statistical significance (P = 0.038). Using a cutoff of 18 pg/mL, the sensitivity and specificity of the test in differentiating between patients with and without metastatic disease was 81% and 71%, respectively. The odds of metastatic disease were almost 10 times greater for patients with VEGF values greater than 18 pg/mL than for those with values less than 18 pg/mL. There was no correlation between age and plasma VEGF values or between plasma VEGF and serum prostate-specific antigen (PSA). However, patients with serum PSA greater than 20 ng/mL had significantly higher plasma VEGF values than patients with serum PSA less than 20 ng/mL (P <0.001). No direct relation was found between Gleason sum and plasma VEGF, although VEGF levels were higher in patients with Gleason sums of 8 to 10 than in patients with lower Gleason sums. CONCLUSIONS: Our study indicates that patients with metastatic prostate cancer have higher plasma VEGF levels than patients with localized disease or healthy controls. A larger prospective study is needed to confirm the predictive utility of VEGF.

Aged↗

PubMed1999

Laparoscopic retroperitoneal lymph node dissection for clinical stage I nonseminomatous germ cell testicular tumors.

OBJECTIVES: To assess retrospectively whether laparoscopic retroperitoneal lymph node dissection (RPLND) in patients with clinical Stage I nonseminomatous germ cell testicular tumor (NSGCT) provides useful pathologic staging information on which subsequent management can be based. Approximately 30% of patients with clinical Stage I NSGCT will have pathologic Stage II disease. METHODS: A retrospective review of 29 patients with clinical Stage I NSGCT who underwent transperitoneal laparoscopic RPLND by a single surgeon was performed. Selection criteria included the presence of embryonal carcinoma in the primary tumor or vascular invasion. A modified left (n = 18) or right (n = 11) template was used. RESULTS: Positive retroperitoneal nodes were detected in 12 (41%) of 29 patients. Ten of these patients received immediate adjuvant platinum-based chemotherapy, and 2 patients refused chemotherapy. The nodes were negative in 1 7 (59%) of 29 patients; all but 2 patients (one with recurrence in the chest, the other with biochemical recurrence) have undergone observation. No evidence of disease recurrence has been found in the retroperitoneum of any patient (follow-up range 1 to 65 months). Prospectively, the dissection was limited if grossly positive nodes were encountered; therefore, the total number of nodes removed was significantly different if the nodes were positive or negative (14 +/- 2 and 25 +/- 3, respectively; P <0.004). Two patients required an open conversion because of hemorrhage. Complications included lymphocele (n = 1) and flank compartment syndrome (n = 1). CONCLUSIONS: Laparoscopic RPLND is a feasible, minimally invasive surgical alternative to observation or open RPLND for Stage I NSGCT. Disease outcomes are favorable to date. Longer follow-up in a larger series is necessary to determine therapeutic efficacy.

Adult↗

PubMed1999

Prognostic indicators in hormone refractory prostate cancer.

Prognostic factors in hormone refractory prostate cancer currently are of limited use to clinicians. Although studies have identified several factors that predict for poor survival in patients, most are either retrospective, or nonrandomized. Therefore, large prospective, randomized trials are needed to validate the significance of these factors. In addition, these indicators are largely descriptive of the patients' condition or the extent of disease. As more treatment options are developed for these patients, functionally relevant and prognostic molecular markers are needed to direct their care.

Biomarkers, Tumor↗

PubMed1999

Modification of BRCA1-associated breast cancer risk by the polymorphic androgen-receptor CAG repeat.

Compared with the general population, women who have inherited a germline mutation in the BRCA1 gene have a greatly increased risk of developing breast cancer. However, there is also substantial interindividual variability in the occurrence of breast cancer among BRCA1 mutation carriers. We hypothesize that other genes, particularly those involved in endocrine signaling, may modify the BRCA1-associated age-specific breast cancer risk. We studied the effect of the CAG repeat-length polymorphism found in exon 1 of the androgen-receptor (AR) gene (AR-CAG). AR alleles containing longer CAG repeat lengths are associated with a decreased ability to activate androgen-responsive genes. Using a sample of women who inherited germline BRCA1 mutations, we compared AR-CAG repeat length in 165 women with and 139 women without breast cancer. We found that women were at significantly increased risk of breast cancer if they carried at least one AR allele with >/=28 CAG repeats. Women who carried an AR-CAG allele of >/=28, >/=29, or >/=30 repeats were given a diagnosis 0.8, 1.8, or 6.3 years earlier than women who did not carry at least one such allele. All 11 women in our sample who carried at least one AR-CAG allele with >/=29 repeats had breast cancer. Our results support the hypothesis that age at breast cancer diagnosis is earlier among BRCA1 mutation carriers who carry very long AR-CAG repeats. These results suggest that pathways involving androgen signaling may affect the risk of BRCA1-associated breast cancer.

Adult↗

PubMed1999

Treatment of locally advanced prostate cancer: is chemotherapy the next step?

PURPOSE: Management of locally advanced prostate cancer remains controversial. Various single and combination modality approaches have been advocated, but an accepted standard of care remains undefined. The purpose of this review is to define the current knowledge in managing locally advanced prostate cancer and to propose new treatment approaches based on current knowledge. MATERIALS AND METHODS: A MEDLINE search to detect all relevant articles on the management of locally advanced prostate cancer was performed. A review of the staging, natural history, and prognosis of this disease was also performed. RESULTS: The lack of a clearly defined treatment approach to patients with locally advanced prostate cancer stems from multiple factors, including ambiguities in clinical staging, inadequate knowledge of the natural history of the cancer, and a dearth of comparative randomized trials evaluating efficacy of different therapies. Single modality treatment, including radical prostatectomy (RP) or external-beam radiotherapy alone, is associated with high rates of failure. The use of adjuvant hormonal ablation therapy in combination with external-beam radiotherapy has shown improvement in progression-free and overall survival, although similar improvements have not been clearly demonstrated for surgical patients treated with hormonal therapy. New advances in chemotherapy for hormone-refractory prostate cancer suggest that response rates may be as high as 50% or more, and current trials are evaluating the addition of chemotherapy to hormonal ablation in either surgery or radiation therapy in locally advanced prostate cancer. CONCLUSION: Optimal management of locally advanced prostate cancer remains undefined. Standard treatment options include RP, external-beam radiotherapy, or hormonal ablation therapy, alone or in combination. New approaches being tested include improved methods for delivering radiation or combining hormonal ablation with surgery or radiation. It is possible that other forms of systemic therapy, including chemotherapy, may become important components of multimodality treatment. Clinical trials designed to test this hypothesis are ongoing.

Actuarial Analysis↗

PubMed1999

Hydrocortisone with or without mitoxantrone in men with hormone-refractory prostate cancer: results of the cancer and leukemia group B 9182 study.

PURPOSE: Approximately 40,000 men die each year of hormone-refractory prostate cancer (HRPC). The results of treatment with chemotherapy have been disappointing to date, with no trials demonstrating a benefit with respect to survival duration. Corticosteroids and mitoxantrone each have been shown to be active agents in this disease. The purpose of this study was to demonstrate an advantage of mitoxantrone and hydrocortisone (M+H) over hydrocortisone alone with respect to survival duration. PATIENTS AND METHODS: Two hundred forty-two patients with HRPC were randomized to receive either M+H or hydrocortisone alone. Patients were monitored for survival, time to disease progression, time to treatment failure, response, and quality-of-life (QOL) parameters. RESULTS: Treatment in both arms was well tolerated. Although there was a delay in time to treatment failure and disease progression in favor of M+H over hydrocortisone alone, there was no difference in overall survival (12.3 months for M+H v 12.6 months for hydrocortisone alone). There was an indication that QOL was better with M+H, in particular with respect to pain control. CONCLUSION: M+H generated more frequent responses and a delay in both time to treatment failure and disease progression compared with hydrocortisone alone. In addition, there was a possible benefit of M+H with respect to pain control over hydrocortisone alone. No improvement in survival was observed. Although M+H could be viewed as a palliative option for patients with HRPC, new drugs and novel strategies are needed to improve survival for this disease.

Aged↗

PubMed1999

Evidence that the CAG repeat in the androgen receptor gene is associated with the age-related decline in serum androgen levels in men.

In men over 30 years old, serum levels of testosterone (T) decrease with age. A shorter polymorphic CAG repeat length in exon 1 of the androgen receptor (AR) gene is associated with higher transcription activation by the AR. We determined the number of CAG repeats for 882 men aged between 40 and 70 years from the Massachusetts Male Aging Study (MMAS). MMAS is a population-based random sample survey of men for whom baseline (1987-1989, mean age 53+/-8 years) and follow-up (1995-1997, mean age 61+/-8 years) serum hormone levels were available. Multiple linear regression was used to determine if CAG repeat length would be predictive of hormone levels at follow-up. Hormone levels measured included T, free T, albumin-bound T, dihydrotestosterone (DHT), sex hormone-binding globulin (SHBG) and luteinizing hormone (LH). The CAG repeat length was significantly associated with T (P=0.041), albumin-bound T (P=0.025) and free T (P=0.003) when controlled for age, baseline hormone levels and anthropometrics. Follow-up levels of T decreased by 0.74%+/-0.36 per CAG repeat decrement. Likewise, the percentages of free and albumin-bound T decreased by 0.93%+/-0.31 and 0.71%+/-0.32 per CAG repeat decrement respectively. These results suggest that androgen levels may be modulated by AR genotype.

Adult↗

PubMed1999

A prognostic score for hormone-refractory prostate cancer: analysis of two cancer and leukemia group B studies.

Previously, we have shown that serial measurements of prostate-specific antigen (PSA) in hormone-refractory prostate cancer (HRPC) can be used to calculate an average relative velocity (rva) of PSA. Together, the level of PSA and the rva formed a two-variable model for survival time that worked at any time during the course of HRPC. Here, we have added serial measurements of hemoglobin and weight to test whether they improve the prior model based on PSA alone. Data from two Cancer and Leukemia Group B studies (9181 and 9182) on HRPC were combined to study the relationship between survival and serial measurements of PSA, serum hemoglobin, and patient weight. Altogether, there were 348 patients who could be evaluated. We used the Cox proportional hazard model for survival time with the interval censored method to accommodate time-dependent covariates, and tests for significance were two sided. Log (PSA), rva, log (hemoglobin), and log [weight (in kg)] were all significantly related to survival time during the course of HRPC (P < 3.0 x 10(-5)). Together, they formed a prognostic score based upon the relative hazard. Higher values of this score implied higher probability of death as the next observed event. Serial measurements of PSA, hemoglobin, and weight provide a prognostic score that can be applied continuously during the course of HRPC. Changes in the score may provide a reproducible measure of treatment effect.

Antineoplastic Agents↗

PubMed1999

Docetaxel (Taxotere)-based chemotherapy for hormone-refractory and locally advanced prostate cancer.

Treatment of hormone-refractory prostate cancer (HRPC) historically has shown limited efficacy. However, taxane-based chemotherapy regimens recently have demonstrated more promising results. Several groups have reported significant efficacy and minimal toxicity in patients with hormone-refractory disease receiving estramustine plus docetaxel (Taxotere; Rhône-Poulenc Rorer, Collegeville, PA). Others have demonstrated single-agent activity of platinum compounds in HRPC. Therefore, the combination of estramustine, docetaxel, and carboplatin is currently being tested in two separate trials of HRPC. The first is a Dana-Farber/Partners Cancer Care phase I study of estramustine, carboplatin, and escalating doses of weekly docetaxel. The second study is a Cancer and Leukemia Group B multicenter phase II study evaluating the combination of estramustine, docetaxel, carboplatin, and granulocyte colony-stimulating factor. The promise of taxane-based regimens in the treatment of hormone-refractory disease has led to consideration of treating patients at high risk for developing metastatic disease earlier in their clinical course. At Dana-Farber/ Partners Cancer Care, we are evaluating neoadjuvant weekly docetaxel alone followed by surgery in patients with high-risk localized prostate cancer using pathologic response as the primary end point. Adding carboplatin to the active combination of estramustine and docetaxel may improve the response rate in HRPC. Furthermore, the use of promising chemotherapy agents earlier in high-risk localized disease may improve clinical outcomes in these patients by decreasing their risk for systemic relapse.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1998

Patient-reported symptoms after primary therapy for early prostate cancer: results of a prospective cohort study.

PURPOSE: To assess complications of therapy for early (nonmetastatic) prostate cancer. PATIENTS AND METHODS: A prospective study of a cohort of 279 men who sought treatment advice and completed required pretreatment forms. The measures were self-reported patient symptoms and other measures of quality of life before therapy and at 3 and 12 months afterward. RESULTS: Bowel and bladder symptoms were uncommon pretreatment. Patients frequently reported irritative bowel and bladder symptoms at 3 months after radiotherapy, although these subsided somewhat at 12 months. Substantial ("a lot") urinary incontinence and wearing of absorptive pads were reported by 11% and 35% at 12 months after surgery and varied little by age. Incontinence occurred after radiotherapy infrequently, and only in men more than 65 years old. Inadequate erections, present in one third of men pretreatment, were nearly universal at 3 months after surgery, although some improvement, primarily in men under 65 years of age, was evident at 12 months. Sexual dysfunction after radiotherapy increased less but continually through 12 months, suggesting that observed treatment-related differences would decline with further follow-up. CONCLUSION: External-beam radiotherapy of early prostate cancer is followed by bowel and bladder irritability, by increasingly severe sexual dysfunction and, in men aged more than 65 years, occasional urinary incontinence. Greater sexual dysfunction and urinary incontinence occur in the year following radical prostatectomy. These postsurgical complication rates from patient questionnaires are greater than have been reported in other treatment series and confirm the results of two retrospective studies of patient-reported complications.

Adult↗

PubMed1998

The androgen receptor gene GGN microsatellite and prostate cancer risk.

The androgen receptor (AR) gene contains a polymorphic GGN microsatellite in exon 1, which encodes polyglycine in the amino terminus of the AR. Previous work has shown that a polymorphic region of CAG repeats also in exon 1 is inversely related to the ability of the AR to transactivate other genes and to prostate cancer risk. We investigated whether AR gene GGN repeat length is related to prostate cancer in a nested study of 582 cases and 794 controls matched on age and smoking status in the Physicians' Health Study. DNA was prepared from archived blood. Using PCR, the region surrounding the GGN repeat was amplified. Fluorescence-labeled primers were used such that the fragment produced could be sized using polyacrylamide gels and Genescan software. We estimated odds ratios and 95% confidence intervals from logistic models controlling for the matching variables for the relation between GGN repeat length and total prostate cancer and by stage/grade and by age at diagnosis. Among controls, the most frequent GGN repeat lengths were 23 (53.5%) and 24 (34.0%), with a range of 10-29. There was no statistically significant difference in the mean GGN repeat length between cases (23.13) and controls (23.05). However, cases had a narrower spread of repeats lengths (parametric test, P = 0.03; nonparametric test, P = 0.07) than controls, with fewer extreme lengths in either direction. The risk of total prostate cancer was slightly increased for a GGN repeat length of 23 compared to all others (odds ratio, 1.20; 95% confidence interval 0.97-1.49); risk did not vary by tumor stage/grade. For every one repeat deviation in either direction from 23, the risk of prostate cancer decreased by 8% (P = 0.04). Although the AR gene GGN repeat probably plays only a modest role in prostate cancer, the observed relation of this repeat with prostate cancer risk supports the evaluation of the effect of GGN repeat length on AR transactivation.

Adult↗

PubMed1998

Management of hormone refractory prostate cancer: current standards and future prospects.

PURPOSE: Recent advances in the biology and treatment of hormone refractory prostate cancer are reviewed. MATERIALS AND METHODS: A MEDLINE literature search of secondary hormonal therapy and chemotherapy for hormone refractory prostate cancer was performed. Recent advances in the biology of hormone refractory prostate cancer, changes in the measurement of response to therapy, and testing of new drugs and combinations of drugs were reviewed. RESULTS: Historically the treatment of hormone refractory prostate cancer has been disappointing. Useful parameters to monitor clinical response have been lacking but perhaps more importantly a scarcity of apparently active drugs has contributed to these results. Recently several developments have improved the outlook for treatment of hormone refractory prostate cancer. Recognition of antiandrogen withdrawal responses has had important ramifications for clinical trial interpretation and patient care. Secondary hormonal therapies, such as alternative antiandrogens and anti-adrenal agents, are well tolerated and can provide significant clinical benefits. Combining prostate specific antigen values with quality of life and measurable disease responses has made clinical trial end points more objective and more clinically relevant for the patient. Furthermore, a better understanding of the biology of hormone refractory prostate cancer, refinements in measuring response to treatment and availability of agents with proved palliative capabilities and/or generating greater than 50% response have all lead to improvements in treatment management. In 2 randomized studies mitoxantrone in combination with steroids has demonstrated significant palliative benefit compared with steroids alone. In phase II studies more than half of patients respond to estramustine combinations with vinblastine, etoposide or paclitaxel. Other novel combinations and new drugs currently are being tested. CONCLUSIONS: Recent advances suggest that available therapies for hormone refractory prostate cancer can have a meaningful impact on the disease. Improving treatment of hormone refractory prostate cancer remains an area of active investigation.

Androgen Antagonists↗

PubMed1998

Debrisoquine hydroxylase (CYP2D6) and prostate cancer.

The p450 hepatic microsomal enzyme system metabolizes exogenous drugs and carcinogens. Debrisoquine hydroxylase (CYP2D6), one member of the p450 hemoproteins, has polymorphic expression leading to poor metabolism of debrisoquine and similar compounds in approximately 7% of Caucasians. The genetic locus for this enzyme has been characterized, and the mutations responsible for the slowed metabolism have been identified. Epidemiological studies of the CYP2D6 phenotype suggest an association between the normal or rapid metabolism phenotype and increased risk of lung and bladder cancer. Preliminary data have also suggested an association with prostate cancer (CaP). We used a PCR-based assay to investigate possible associations between the CYP2D6 B allele, the most common genetic mutation responsible for the poor metabolism phenotype, and CaP. Using genomic DNA isolated from peripheral blood, we genetically typed 571 men with CaP and 767 matched controls, all participants in the Physician's Health Study. Relative to men homozygous for the wild-type allele, heterozygotes for the B allele have an odds ratio of 1.19 (95% confidence interval, 0.94-1.51) for CaP, and men homozygous for the B allele have an odds ratio of 1.37 (95% confidence interval, 0.86-2.20). When analyzed as a trend over zero, one, or two copies of the B allele, there emerges a possible association between the B allele and an increased risk of CaP of borderline statistical significance (P = 0.07).

Adult↗