When performing CP for PCa involving bladder, some medical centers might claim the surgical significance or the possibility of overtreatment. However, the refractory and disappointing state after traditional therapies often reduces the patients’ QoL seriously by recurrent lower urinary tract symptoms and enduring a lifelong dependence on tubes and catheters. Improving local control and providing a better QoL to the patients are imperative clinical goals independent of the survival outcome. Up to date, CP as a treatment strategy of cT4 PCa invading into bladder, is still controversial without fully evaluation. Only limited literatures have been published [3, 4], partly because of a decreased incidence of T4 disease, but mainly due to stubborn thoughts of poor prognosis of these patients. However, data from LAPCa cohort studies showed 15-year PCSS of 60% and 10-year OS of 75% [5–7]. The oncological effectiveness of RP as part of a multi-modal treatment strategy for LAPCa remains unknown. A prospective phase III randomised controlled trial comparing RP against primary external beam radiotherapy and ADT among patients with LAPCa is currently recruiting (https://clinicaltrials.gov/ct2/show/NCT02102477). Several retrospective studies showed selected T4 patients received RP acquired better OS and PCSS than those undergoing no surgery or radiation therapy [10, 11]. In 2015, CP was performed to treat castration-resistant prostate cancer (CRPC) with infiltration of dorsal bladder by Axel Heidenreich and his colleagues . Mean OS in their patient cohort was 20.4 (1–28) months and mean symptom-free survival was 15.3 (1–25) months, covering 75% of the total survival time. The authors concluded that palliative radical CP was a challenging but feasible local treatment option in well-selected bladder invasive CRPC patients, if performed by experienced hands. In our follow-up with a median period of 42.0 months, 5-year PCSS rate of patients received CP reached 82.1%, comparable with 87.1% of previous study . Omar Fahmy et al. reported that 5-year PCSS rates of patients with LAPCa who were treated with RP, radiation therapy and hormone therapy were 94.2%, 95.7%, and 78.5%, respectively . Probably, more advanced and higher risk of tumors in the participated patients in the present study resulted into the discrepancies. The significantly lower QoL scores after surgeries suggested that CP had a role in improving quality of life in patients with PCa extending to bladder. Moreover, our results supported a role of CP in relieving pelvic symptoms, especially in ceasing dependence on tubes, which is consistent with previous reports [3, 4].
CP itself is still a technically challenging procedure. In a previous study of salvage CP for radiation failure in PCa, one early death (12.5%) occurred from a pulmonary embolism within 60 days of surgery, accompanied by 4 (50%) of rectal injury . In the present study, one immediate death occurred during surgical procedure due to severe bleeding of internal iliac artery, and only 7.4% of patients suffered postoperative rectal injury because patients with tumor invasion of rectum were excluded from the series.
Our study showed that the entered patients had frequent lymph node metastasis (66.7%). Although pN1 was a predictor of worse prognosis as shown in the present study, the median PCSS even with lymph node metastasis was 64.3 months. One of limitations in our study was lacking controlling trial of patients subjected to non-CP interventions, making it impossible to compare the effects of CP on PCa patients with conservative therapies. Jutta Engel et al  reported that RP was a strong independent predictor of survival in patients with node-positive PCa, improving OS by 24% versus those patients with aborted RP. There have been several retrospective observational studies showing dramatic improvements in PCSS in favour of RP versus non-RP in patients who were found to be lymph node metastasis . From the results of these studies and our study, CP is also suggested to be applicable in T4 PCa patients with node-positive disease. Moreover, Fizazi K et al reported upfront usage of docetaxel only improved clinical relapse-free survival for T4 patients, with no long-term survival benefit . This conclusion was further confirmed in the present study. Multivariate analysis demonstrated that PCSS was not improved by adding neoadjuvant chemotherapy versus neoadjuvant CAB. In addition, choices of combines of postoperative adjuvant therapies did not affect PCSS.
Patients entered in this study had 55.6% of high grade tumors (Gleason score ≥ 8), which are commonly considered as potent significant risk factors of poor outcomes. Nevertheless, some retrospective case series reported good outcomes after RP for patients with high grade PCa in combination with radiation plus hormonal therapy [18, 19]. In the present study, the median PCSS with Gleason score ≥ 8 was 64.1 months. However, for the patients who received CP, Gleason score ≥ 8 was a predictor of worse PCSS and PFS.
Muscle-invasive bladder cancer is a frequently occurring disease with a high mortality rate despite optimal treatment due to common involvement of nodes and high grade urothelial carcinomas [20, 21]. For the first time in the world, we assessed CP on the prognosis of PCa regarding to invasion depth of bladder wall. For the patients received CP, median PCSS of those with bladder muscle-invasion was 61.5 months, shorter than those with non muscle-invasion (68.8 months). Multivariate analysis suggested bladder muscle-invasion was an independent predictor of poor outcomes for patients who received CP.
Several limitations should be stated before conclusion. The main limitation is the small number of entered patients because of the low incidence of T4 PCa nowadays. Nevertheless, the involved patients in the present study were still more than the previous report, 17 in Kumazawa's study . Moreover, as narrated above, our study was lacking controlling trial of patients received tradition therapies due to the limited participants. Hence, comparisons of CP and conservative therapies on PCa patients were not performed. We are currently performing a multi-center randomized study with large scale cases and long-term follow-up to acquire more evidencing results.