Persistent suspicion of prostate cancer despite repeated negative prostate biopsies is a common problem in urologic practice.
In one of the largest prostate cancer screening programs, 91% of cancers were detected during the first or second biopsy. The likelihood of finding cancer at the third or fourth biopsy decreased dramatically to 14% and was even less for subsequent procedures. Some methods suggested to increase detection include taking a larger number of cores, and including biopsies of the lateral, transitional or anterior zones of the gland. After the first negative biopsy, transurethral resection of the prostate (TURP) may disclose cancer in 4% to 28% of cases.
A recent paper by P. Puppo and colleagues from Genoa, Italy examined the role of TURP together with biopsies of the peripheral zone during the same setting to improve detection of prostate cancer in men who have undergone repeated negative biopsies but still have a rising PSA.
The study is published in the May, 2006 issue of European Urology.
The study group was comprised on 43 patients, aged 53-69 years old, with a history of at least two negative biopsies for prostate cancer. Thirty-five men had an increasing PSA level and underwent repeat transrectal biopsies in which 16 to 24 cores were taken including samples of the transitional zone. Seven men (20%) were found to have prostate cancer. The remaining men were offered a TURP and biopsy of the peripheral zone in the same setting. Fourteen men accepted. At the time of surgery, the median age of the 14 patients was 61 years, the median PSA was 10.7, and the median number or prior negative biopsies was 3.5. The median prostate volume was 38 ml, the median weight of resected prostate tissue was 21.5 grams.
Analysis of the results showed that eight patients were found to have prostate cancer (57%). Six patients were found to have cancer in the TURP specimen only, one in both the TURP specimen and the transrectal specimen, and one in just the transrectal specimen. All eight patients diagnosed with prostate cancer then underwent radical prostatectomy as primary treatment. The six patients without cancer had follow-up which was at least 9 months and had at least 2 PSA levels reported. Two patients underwent repeat biopsy for a rising PSA level but no cancer was detected.
The authors suggest that combining biopsies of the far lateral prostate and TURP is a safe and useful diagnostic tool in men who have undergone repeated negative biopsies. In this series, no serous complications occurred and the detection rate for cancer was 57% after three or more consecutive negative biopsies. TURP also did not critically interfere with subsequent radical surgery, which can be performed with satisfactory results.
Eur Urol. 2006 May;49( ):873-8
Study unveils novel bladder cancer diagnostic model based on key mitochondrial genes