PURPOSE: When faced with biochemical recurrence after definitive radiotherapy for prostate cancer, clinicians must determine whether the recurrence is local or systemic. Post radiotherapy prostate biopsies to detect persistent local disease are difficult to interpret histopathologically and are subject to sampling error. Our study examines outcomes for patients with a negative prostate biopsy performed for rising prostate-specific antigen (PSA) levels after prostate radiation. MATERIALS AND METHODS: We performed a retrospective review of 238 prostate cancer patients with a negative biopsy following definitive radiotherapy. Seventy-five of these patients had biochemical recurrence at the time of biopsy. A negative biopsy was defined as the absence of prostate cancer without radiation-treatment effect in the specimen. RESULTS: Patients underwent biopsy at a mean of 41 months after the completion of radiation. They had a mean PSA of 6. Patients were followed for an average of 63 months. Thirty-two patients (43%) developed metastasis, and 11 (15%) died of prostate cancer despite a negative post-radiation biopsy. Five of nine patients (56%) with sequential biopsies had a positive second biopsy. CONCLUSIONS: Patients with PSA recurrence and a negative post-radiation biopsy have a high chance of persistent local disease, progression, and death from prostate cancer. Furthermore, an initial negative biopsy does not rule-out local recurrence. Patients with biochemical recurrence after radiotherapy for prostate cancer need to be evaluated earlier for local recurrence.

Prostate-specific antigen (PSA) has been used for prostate cancer detection since 1994. PSA testing has revolutionized our ability to diagnose, treat, and follow-up patients. In the last two decades, PSA screening has led to a substantial increase in the incidence of prostate cancer (PC). This increased detection caused the incidence of advanced-stage disease to decrease at a dramatic rate, and most newly diagnosed PC today are localized tumors with a high probability of cure. PSA screening is associated with a 75% reduction in the proportion of men who now present with metastatic disease and a 32.5% reduction in the age-adjusted prostate cancer mortality rate through 2003. Although PSA is not a perfect marker, PSA testing has limited specificity for prostate cancer detection, and its appropriate clinical application remains a topic of debate. Due to its widespread use and increased over-detection, the result has been the occurrence of over-treatment of indolent cancers. Accordingly, several variations as regards PSA measurement have emerged as useful adjuncts for prostate cancer screening. These procedures take into consideration additional factors, such as the proportion of different PSA isoforms (free PSA, complexed PSA, pro-PSA and B PSA), the prostate volume (PSA density), and the rate of change in PSA levels over time (PSA velocity or PSA doubling time). The history and evidence underlying each of these parameters are reviewed in the following article.