Chemo-endocrine therapy in patients with stage D2 prostate cancer

Effectiveness of Platinum-Based Chemotherapy in Patients With Metastatic Prostate Cancer: Systematic Review and Meta-analysis

BACKGROUND

Taxanes are the only cytotoxic drugs that have demonstrated a survival benefit for patients with castration-resistant prostate cancer (CRPC), but there is some evidence that platinum compounds may also benefit such patients.

METHODS

We performed a systematic search on electronic databases. We sought prospective clinical studies testing platinum compounds for CRPC. Platinum compounds could be delivered alone or in combination with other drugs. Both randomized and nonrandomized studies were included for qualitative synthesis, only randomized studies were included for meta-analyses. Clinical overall response rate (cORR), prostate-specific antigen overall response rate (sORR), progression-free survival (PFS), overall survival (OS), and toxicity were the outcomes of interest.

RESULTS

We identified 53 studies delivering platinum agents for patients with CRPC. cORR varied from 0 to 82%, while sORR varied from 2% to 100%. Response rates were higher in patients who received combination treatments rather than platinum compounds alone. Pooled data from randomized trials demonstrated a statistically significant increase in both cORR (odds ratio = 5.3; 95% confidence interval, 1.89-14.92) and sORR (odds ratio = 2.07; 95% confidence interval, 1.33-3.22) when adding platinum compounds to chemotherapy. PFS varied from 2.1 to 12 months and OS 4.2 to 28 months with platinum-containing chemotherapy. Nausea and myelosuppression were the most common adverse effects. Toxicity was manageable in most studies.

CONCLUSION

Platinum compounds are a safe and active treatment for CRPC. Response rates are higher when cytotoxic chemotherapy containing platinum agents are compared to nonplatinum chemotherapy. Data on OS and PFS are inconclusive. More research is needed to evaluate whether platinum-based chemotherapy results in a survival benefit for patients with CRPC, as well as to establish predictive biomarkers.

Randomized Comparison of Goserelin Acetate versus Mitomycin C plus Goserelin Acetate in Previously Untreated Prostate Cancer Patients with Bone Metastases

In a prospective trial conducted by the Gruppo Onco Urologico Piemontese, newly diagnosed prostate cancer patients with bone metastases were randomized to receive goserelin (3.6 mg subcutaneously every 4 weeks) or goserelin plus mitomycin at 14 mg/m2 i.v. every 6 weeks. Treatment was planned to be continued until progression. The study was interrupted because of inadequate accrual rate when 63 patients had been recruited. A long-term follow-up (median, 47 months), performed to counterbalance the limited number of patients included, revealed no difference in time to progression and overall survival between the study treatments. However, 56.5% of assessable patients allocated to the chemotherapy arm presented a ≥90% reduction of prostate-specific antigen levels compared with 36.3% in the goserelin group, and previously elevated levels normalized in 73.9% versus 45.4%. Non-progressing patients received 5-7 cycles of mitomycin C with acceptable toxicity, but the cytotoxic treatment was interrupted early in all cases within the first year due to cumulative myelotoxicity. In conclusion, the results, although inconclusive, fail to support a clear advantage in terms of cost/benefit of chemotherapy plus hormone therapy over hormone treatment alone in advanced prostate cancer with bone involvement.

Anti-tumour activity of platinum compounds in advanced prostate cancer-a systematic literature review

BACKGROUND

For men with advanced castration-resistant prostate cancer (CRPC), several treatment options are available, including androgen receptor (AR) pathway inhibitors (abiraterone acetate, enzalutamide), taxanes (docetaxel, cabazitaxel) and the radionuclide (radium-223). However, cross-resistance is a clinically relevant problem. Platinum compounds have been tested in a number of clinical trials in molecularly unselected prostate cancer patients. Advances in CRPC molecular profiling have shown that a significant proportion of patients harbour DNA repair defects, which may serve as predictive markers for sensitivity to platinum agents.

OBJECTIVE

To systematically identify and analyse clinical trials that have evaluated platinum agents in advanced prostate cancer patients.

METHODS

PubMed was searched to identify published clinical trials of platinum agents in advanced prostate cancer. The PRIMSA statement was followed for the systematic review process. Identified trials are analysed for study design, statistical plan, assessments of anti-tumour activity and the potential value of predictive biomarkers.

RESULTS

A total of 163 references were identified by the literature search and 72 publications that met the selection criteria were included in this review; of these 33 used carboplatin, 27 cisplatin, 6 satraplatin, 4 oxaliplatin and 2 other platinum compounds. Overall, anti-tumour activity varies in the range of 10%-40% for objective response and 20%-70% for PSA decline ≥50%. Response seemed highest for the combinations of carboplatin with taxanes or oxaliplatin with gemcitabine. The interpretation of the clinical data is limited by differences in response criteria used and patient populations studied.

CONCLUSION

Platinum compounds have moderate anti-tumour activity in molecularly unselected patients with advanced prostate cancer. Translational evidence of DNA repair deficiency should be leveraged in future studies to select prostate cancer patients most likely to benefit from platinum-based therapy.

A randomized comparative study of endocrine monotherapy and a combination of estramustine phosphate with the endocrine therapy in patients with untreated stage D prostate cancer

BACKGROUND

We investigated the clinical efficacy and the prolongation of survival with combination therapy of estramustine phosphate (EMP) and endocrine therapy in untreated patients with progressive prostate cancer.

METHODS

We randomly divided 57 patients with untreated stage D prostate cancer into two groups, an endocrine monotherapy group and a group receiving combination treatment, consisting of endocrine therapy plus EMP. Treatment was continued until deterioration.

RESULTS

There were no significant differences in the improvement rating for subjective/objective symptoms or in progression-free survival between the two groups. However, overall survival was significantly prolonged in the combination therapy group (log-rank test, P = 0.0394; generalized Wilcoxon's test, P = 0.0145). In particular, overall survival was significantly prolonged, compared to that in the endocrine monotherapy group, in patients in the combination therapy group who were less than 74 years old, those with a performance status (PS) of 1 to 3, a pretreatment prostate-specific antigen (PSA) level of more than 20 ng/ml, moderately or poorly differentiated carcinoma, or a partial response (PR) based on the PSA level 12 weeks after the start of treatment. There was no significant difference in the incidence of side effects between the combination therapy and the endocrine monotherapy groups.

CONCLUSION

A combination of EMP with endocrine therapy may be useful for initial treatment in younger patients (aged 73 or younger) and in patients at high risk of progressive prostate cancer.

Radiation Therapy Oncology Group P-0014: a phase 3 randomized study of patients with high-risk hormone-naive prostate cancer: androgen blockade with 4 cycles of immediate chemotherapy versus androgen blockade with delayed chemotherapy

Currently, approximately 30,000 men die annually of metastatic, hormone-refractory prostate cancer. Androgen blockade is palliative and is generally effective for an average of 2 to 3 years until a patient develops androgen-independent disease. Newer chemotherapeutic regimens can induce remissions in approximately 50% of patients; however, median survival for patients with androgen-independent disease is still 8 to 12 months. The strategy of using chemotherapy regimens after androgen blockade has been proved noncurative, and new approaches are needed to attempt to cure patients with advanced disease. It has been demonstrated in the preclinical setting that androgen withdrawal induces apoptosis in cancer cells in both the Shinogi breast cancer model and the LNCaP prostate cancer model. In both of these models, androgen withdrawal was not curative, and the tumors grew back in a hormone-independent state. It is possible that the addition of chemotherapy at the time of initial androgen ablation will improve cell kill by potentiating apoptosis, thereby killing cells that might otherwise have mutated to the androgen-independent state if allowed to continue to cycle and grow. The rationale behind Radiation Therapy Oncology Group (RTOG) P-0014 is to demonstrate in a randomized phase 3 trial that giving patients chemotherapy at the beginning of androgen blockade may improve patient survival.

Immediate vs. delayed androgen deprivation for prostate cancer

Androgen ablation has been the standard treatment of symptomatic patients with metastatic prostate cancer for more than 50 years. Within the last 15 years, the introduction of prostate-specific antigen (PSA) has induced a stage migration toward less extensive disease and a dramatic decrease in the proportion of men presenting with N+/M+ disease. Historical studies, conducted during the pre-PSA era, are therefore of limited interest in counseling modern patients. The routine use of radical therapies such as radical prostatectomy and radiotherapy has considerably expanded the problem of timing of endocrine treatment in range and complexity. Advanced disease is now diagnosed in patients with limited involvement of extraprostatic sites and even in patients presenting an isolated elevation of PSA after radical treatment. In the absence of clear guidelines, data from past literature and ongoing modern studies were compiled in the present review in an attempt to generate practical considerations.

Orchiectomy and orchiectomy plus mitomycin C for metastatic prostate cancer in patients with poor prognosis: the final results of a European Organization for Research in Cancer Therapy Genitourinary Group Trial

PURPOSE

The outcome of patients with symptomatic metastatic prostate cancer is poor and improved treatment regimens are urgently needed. Theoretically, the combination of orchiectomy and chemotherapy could reduce androgen sensitive and insensitive cells in the prostate. This European Organization for Research in Cancer Therapy Genitourinary Group randomized, multicenter phase III trial demonstrates the outcome of orchiectomy alone versus orchiectomy followed by intravenous mitomycin C.

MATERIALS AND METHODS

A total of 189 patients with metastatic prostate cancer and poor prognostic factors were randomized in this trial by 42 institutions. Of these patients 184 (97%) were eligible for study, including 90 treated with orchiectomy alone (orchiectomy only arm) and 94 treated with orchiectomy followed by 15 mg./m.2 mitomycin C in 1 week (combined treatment arm). Mitomycin C was administered every 6 weeks and treatment was continued as long as tolerance and patient compliance allowed, and no progression was observed. Objective and subjective criteria for progression were clearly defined in the protocol.

RESULTS

Patient and tumor characteristics were well balanced between the 2 treatment arms. At a median followup of 4.2 years 144 patients had died, including 112 of prostate cancer. No significant differences for time to overall (p = 0.17), subjective (p = 0.25) and objective (p = 0.08) progression were found between the 2 treatment groups. For progression-free survival no difference was noted (p = 0.67) between the 2 treatment groups but a trend in favor of orchiectomy alone was observed for overall survival (p = 0.04). Mitomycin C induced considerable hematological, gastrointestinal, renal and pulmonary toxicity leading to discontinuation in 31% of patients with pulmonary toxicity and 7% with renal deterioration. In addition, the quality of life evaluation revealed significant reduction in the combined treatment arm.

CONCLUSIONS

Based on the results of this randomized phase III study orchiectomy plus mitomycin C for metastatic prostate cancer in patients with poor prognostic factors cannot be recommended due to failure of improvement in survival and reduced quality of life parameters.