Introduction

The impact of the zonal origin of cancer on the prognosis after radical prostatectomy has been controversial. We investigated the influence of tumor location (anterior vs. posterior) on biochemical recurrence (BCR) after laparoscopic radical prostatectomy (LRP).

Methods

We reviewed 1082 patients undergoing LRP between 2005 and 2015, among whom there were 544 patients with pathological data on the location of the index tumor who did not receive neoadjuvant/adjuvant therapy. We defined the largest lesion as the index tumor if there were several masses. BCR was defined as PSA > 0.2 ng/mL. Differences of the BCR rate between groups were examined by Kaplan-Meier analysis and the Cox proportional hazards model.

Results

There were 234 patients (43%) with an anterior tumor and 310 patients (57%) with a posterior tumor. The anterior group had less T3 disease (61 patients, 26%) than the posterior group (111 patients, 36%) and a Gleason score of 4+4 or more was less frequent in the anterior group (24 patients, 10%) than in the posterior group (60 patients, 19%), although the differences were not significant. During a median follow-up period of 5.0 years, 75 patients (14%) experienced BCR. As shown in Figure 1, there was no significant difference of the BCR rate between patients with T2 disease and those with anterior T3 disease (hazard ratio: 1.29, 95% CI: 0.58-2.92, p=0.528), while their 5-year BCR-free survival rates were 91% and 89 %, respectively. Patients with posterior T3 disease had a higher BCR rate than those with anterior T3 disease (hazard ratio: 1.88, 95% CI: 0.85-4.13, p=0.118). Their 5-year BCR-free survival rates were 90% and 79%, respectively.

Conclusions

These results indicate that anterior index tumors are more likely to have favorable pathological characteristics. Especially in patients with T3 disease, anterior tumors are associated with a lower BCR rate after LRP.

Funding

none