PATHOLOGY

Characterization of minute adenocarcinomas of prostate at radical prostatectomy
Truskinovsky AM, Sanderson H, Epstein JI
Department of Pathology, University of California, Davis, Medical Center, Sacramento, California, USA
Urology. 2004; 64: 733-7

• Objectives: To characterize minute prostate cancer seen at radical prostatectomy. With aggressive screening and more extensive biopsy sampling, we have increasingly seen these cancers at radical prostatectomy.
• Methods: We examined radical prostatectomy specimens submitted in total for minute cancer.
• Results: During the past 1.5 years, 78 prostates (5.2%) had either no cancer (2 cases) or contained between one and six foci of organ-confined carcinoma (76 cases) measuring 6 mm or less, with a Gleason score of 6 or less. The mean prebiopsy serum prostate-specific antigen level was 5.8 ng/mL, and 84.6% of the patients had undergone biopsy because of an elevated prostate-specific antigen level. Of these patients, 40% had had either benign or atypical diagnoses on prior biopsies, and 43% had only minute (0.5 mm or less) foci of carcinoma on biopsy. The radical prostatectomy specimens had a mean of two cancer foci measuring, on average, 3 mm in the greatest dimension. In 85% of the cases, the side of the positive biopsy matched the side of the carcinoma found at radical prostatectomy; 81.5% of cases had high-grade prostatic intraepithelial neoplasia immediately adjacent to the cancer.
• Conclusions: The incidence of minute carcinoma of the prostate has increased from 0.5% in 1988 to 5.2% in the current study. The patients often had moderately increased prostate-specific antigen levels and minute foci of carcinoma on biopsy. These small tumors at radical prostatectomy are usually discovered by fortuitous biopsy that is often preceded by other biopsies with noncancerous diagnoses. Patients with the above clinical and biopsy findings should be counseled about the possibility of finding only minute foci of carcinoma at radical prostatectomy and may want to consider watchful waiting.
  
  
• Editorial Comment
  The incidence of “minute” (minimal, insignificant) cancer at radical prostatectomies has substantially increased in the last years. The main reason is aggressive screening and more extensive biopsy sampling. It is important to note that “minute” (minimal, insignificant) cancer in radical prostatectomy does not mean “latent” (dorment, indolent) carcinoma. It represents a low volume (incipient) cancer that can progress either as a “latent” or a “clinical” cancer. It is important to counsel the patients about the possibility of finding only minute foci of carcinoma at radical prostatectomy including the possibility of not finding a tumor at all.
  According to the authors of the study, patients having clinical and biopsy findings for minute cancers may want to consider watchful waiting. In this respect, urologists consider age an important variable but the cut point is controversial. Carter et al. (1) informed men older than 65 years that expectant management was a reasonable option for management of cancer regardless of the presence or absence of co-morbidity. The recommended follow-up for those men managed expectantly was semiannual total and free PSA measurement with digital rectal examination, and annual surveillance transrectal ultrasound directed prostate biopsies.

Reference
1. Carter HB, Walsh PC, Landis P, Epstein JI: Expectant management of nonpalplable prostate cancer with curative intent: preliminary results. J Urol. 2002; 167: 1231-4.

Dr. Athanase Billis
Full-Professor of Pathology
State University of Campinas, Unicamp
Campinas, São Paulo, Brazil