Natural course of asymptomatic abnormal prostate findings incidentally detected by CT after intravesical BCG therapy

Background: Detailed information is not currently available on the incidence, natural course, and management of asymptomatic abnormal prostate findings incidentally detected by radiologic evaluations after BCG therapy for non-muscle-invasive bladder cancer patients. Methods: We identified 38 patients who were evaluated by contrast-enhanced CT scans before TUR-BT and after BCG therapy between 2006 and 2012. We evaluated the clinical courses of patients with abnormal radiologic findings of the prostate gland after BCG therapy. Results: Abnormal findings on CT scans were found in the prostate glands of 11 of the 38 patients examined (28.9%), none of whom exhibited any sign or symptom associated with prostatitis. Abnormal findings included a low attenuation area (n = 6, 15.8%), contrast enhancement (n = 3, 7.9%), and a low attenuation area and contrast enhancement in the prostate gland (n = 2, 5.3%). During the follow-up, abnormal prostate findings disappeared spontaneously in most cases without any anti-bacterial or anti-tuberculous drug treatments. No significant differences were observed in patient clinical backgrounds, with the exception of post-BCG prostate volumes, between patients with and without abnormal CT findings. Furthermore, no significant differences were noted in the incidence of the adverse effects of BCG therapy, tumor recurrence rates, or progression rates between patients with and without abnormal CT findings of the prostate gland after BCG therapy. Conclusions: Asymptomatic abnormal prostate findings incidentally detected by CT after BCG therapy are not rare, and these disappear over time during the follow-up period without any treatment.