Outcome of adjuvant radiotherapy after radical prostatectomy for prostate cancer patients.

AIM

To examine the outcome and risk factors of biochemical failure (BCF) in Japanese prostate cancer (PCa) patients treated with adjuvant radiotherapy (RT) after radical prostatectomy (RP).

PATIENTS AND METHOD

In this study we enrolled 83 Japanese patients having clinically organ-confined PCa without neoadjuvant treatments who received conventional RT (60 Gy) after RP. All patients had extracapsular extension (ECE) and/or positive surgical margin (PSM) of the RP specimens, but no lymph node metastasis. The disease-specific, clinical failure-free, and BCF-free survivals were analyzed. Furthermore, the risk factors affecting the BCF-free survival were examined in detail.

RESULTS

The 5-year disease-specific, clinical failure-free, and BCF-free survival rates were 100, 99, and 87%, respectively. The clinicopathological factors associated with BCF were seminal vesicle invasion (SVI) (p = 0.024), perineural invasion (PNI) (p = 0.03), and pre-RT prostate-specific antigen (PSA) (p = 0.014). In the patients with PSM (n = 59), the entire surgical margin-positive patients had a significantly higher risk of BCF than the focal surgical margin-positive patients (p = 0.015). Multivariate analysis showed that SVI and pre-RT PSA were independent prognostic factors of BCF (p = 0.0142, p = 0.0225, respectively). 22% of our patients had only low-grade adverse effects.

CONCLUSION

The outcome of adjuvant RT after RP in the Japanese patients with ECE and/or PSM was excellent, and the adverse effects were mild and tolerable. However, the patients with SVI, PNI, entire surgical margin-positive specimens, or high pre-RT PSA had poor biochemical control by only adjuvant RT after RP.