Comparative study of surgical orchidectomy and medical castration in treatment efficacy, adverse effects and cost based on a large prospective metastatic prostate cancer registry.

INTRODUCTION: Androgen deprivation therapy (ADT) remains the mainstay of treatment for metastatic prostate cancer (mPCa) but is associated with significant morbidities. Comparisons of medical castration (MC) and surgical orchidectomy (SO) have yielded varied results. We aimed to evaluate the oncological outcomes, adverse effect (AE) profiles and costs of MC and SO in patients with mPCa. METHODS AND MATERIALS: We reviewed 523 patients who presented with de novo mPCa from a prospectively maintained prostate cancer database over 15 years (2001-2015). All patients received ADT (either MC or SO) within 3 months of diagnosis. The data were analyzed with chi-square, binary and logistics regression models. RESULTS: One hundred and fifty one (28.9%) patients received SO while 372 (71.1%) patients had MC. The median age of presentation was 73 [67 -79] years old. The median prostate-specific antigen (PSA) was 280ng/ml [82.4-958]. Three hundred and thirty one patients (66.3%) had high volume bone metastasis and 57 patients (10.9%) had visceral metastasis. Clinical demographics and clinicopathological were similar across both groups. Similar oncological outcomes were observed in both groups. The proportion of PSA response (PSA <1ng/ml) was 65.6% for SO and 67.2% for MC (P = 0.212). Both therapies achieve >95% of effective androgen suppression (testosterone <50ng/dL). Time to castrate-resistance was similar (18 vs 16 months, P = 0.097), with comparative overall survival (42 vs. 38.5 months, P = 0.058) and prostate cancer mortality (80.1 vs. 75.9%, P = 0.328). Similarly, no difference was observed for the 4 AE profiles between SO and MC respectively; change in Haemoglobin (-0.75 vs. -1.0g/dL, P = 0.302), newly diagnosed Diabetes mellitus (4.6 vs. 2.9%, P = 0.281), control measured by HbA1c (0.2 vs. 0.25%, P = 0.769), coronary artery disease events (9.9 vs. 12.9%, P = 0.376) and skeletal-related fractures (9.3 vs. 7.3%, P = 0.476). After adjusting for varying governmental subsidies and inflation rates, the median cost of SO was $5275, compared to MC of $9185.80. CONCLUSION: Both SO and MC have similar oncological outcomes and AE profiles. However, SO remains a much more cost-effective form of ADT for the long-term treatment of mPCa patients.

Local and systemic morbidities of de novo metastatic prostate cancer in Singapore: insight from 685 consecutive patients from a large prospective Uro-oncology registry.

OBJECTIVE: To evaluate the incidence and management of local and systemic complications afflicting patients with de novo metastatic prostate cancer (mPCa) in Singapore. DESIGN: Retrospective analysis of a large prospective Uro-oncology registry of mPCa. SETTING: This study is carried out in a tertiary hospital in Singapore. PARTICIPANTS: We reviewed our institution's prospectively maintained database of 685 patients with mPCa over a 20-year period (1995-2014). Patients with non-mPCa or those progressed to metastatic disease after previous curative local treatments were excluded. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcome was to evaluate the systemic and local morbidity rates associated with mPCa. Local complication was defined as the need for palliative procedures to relieve urinary obstruction, worsening renal function or refractory haematuria, while systemic complication was related to radiographic evidence of skeletal-related pathological fractures. Secondary outcomes analysed were the management and overall survival patterns over 20 years. RESULTS: 237 (34.6%) patients required local palliative treatments. 88 (12.8%) patients presented with acute urinary retention, 23 patients (9.7%) required repetitive local palliative treatments. On multivariate analyses, prostate-specific antigen >100 (p=0.02) and prostate volume >50 g (p=0.03) were independent prognostic factors for significant obstruction requiring palliative procedures. 118 (17.2%) patients developed skeletal fractures, with poor Eastern Cooperative Oncology Group Performance (ECOG) status (p=0.01) and high volume bone metastasis (p<0.01) independently predictive of skeletal fractures. Altogether, 653 (95.3%) patients received androgen deprivation therapy (ADT), with the median time to castrate resistance of 21.4 months (IQR 7-27). The median overall survival was 45 months (IQR 20-63), with prostate cancer mortality of 81.4%. Improved overall survival was observed from 41.6 months (1995-1999) to 47.8 months (2010-2014) (p<0.01). CONCLUSION: Morbidities and complications arising from mPCa are more common and debilitating than we thought, often requiring immediate palliative treatments, while many necessitate repeated interventions with progression.