Neoadjuvant chemotherapy in high-risk localized prostate cancer: a systematic review

Background: The rate of recurrence and mortality in high-risk prostate cancer remains high. On the other hand, the use of chemotherapy in metastatic prostate cancer has improved overall survival of patients. The aim of this study was to evaluate the effect of neoadjuvant chemotherapy alone on increasing survival of patients with high risk localized prostate cancer Methods: This is a systematic review study. Databases including Scopus, Medline, PubMed, Google Scholar, Cochrane, Embase were searched. The terms used include prostate cancer, adenocarcinoma, neoadjuvant, chemotherapy, chemotherapy alone, systemic therapy. Of the various types of articles, only oiginal research studies that specifically focused on neoadjuvant chemotherapy (not chemotherapy with target therapy, immunotherapy, or hormone therapy) were identified. Inclusion criteria included study type (original research studies) and sample type (high-risk localized prostate cancer patients) and outcome type (patient survival). Results: A total of 17 original research studies were identified. All of these studies were phase one or phase two. Docetaxel was the most commonly used chemotherapy drug. Also, the most common regimen used was the use of docetaxel alone. The rate of decrease in prostate-specific antigen (PSA) (>50%) after neoadjuvant chemotherapy was reported in 24 to 58% of patients. PSA declines of less than 50% after neoadjuvant chemotherapy occurred in 40 to 100% of patients. No studies reported a complete pathologic response following neoadjuvant chemotherapy. However, the relative pathologic response and reduced tumor volume were seen in the majority of patients. All of these studies showed that neoadjuvant chemotherapy alone, in high-risk prostate cancer patients, was almost well tolerated and that the complications were mostly mild (grade 1 and 2). Grade 3 and 4 complications were negligible. A 2-year recurrence-free survival of up to 68.5% and a 5-year recurrence-free survival of up to 49% were reported. The overall 5-year survival also ranged from 35 to 48%. Conclusion: The use of neoadjuvant chemotherapy alone has not clearly increased the survival of patients with high-risk localized prostate cancer, and there is controversy in studies.