MINIMAL OR NO CANCER IN RADICAL PROSTATECTOMY SPECIMENS - REPORT OF 13 CASES OF THE VANISHING CANCER PHENOMENON

Early detection efforts identify prostate cancer at lower clinical and pathologic stages, often resulting in smaller volumes of tumor in rad ical prostatectomy specimens. In some cases, complete sampling of the radical prostatectomy specimen for biopsy-proven adenocarcinoma reveal s minimal or no residual cancer. We evaluated the clinical and patholo gic findings in 13 such cases in an effort to document this finding, w hich we refer to as the ''vanishing cancer phenomenon.'' The mean numb er of prostate slides examined per case was 79 (range, 34-248). Carcin oma was absent in two cases, present in a single focus in eight cases, and present in two foci in three cases. Mean cancer volume in the 10 cases with residual tumor was 0.019 cc (range, 0.003-0.038); the large st single dimension of any tumor focus was 3 mm. All cancers were well differentiated or moderately differentiated in the biopsy and prostat ectomy. Our results indicate that in some cases cancer may be extremel y difficult or impossible to find in the prostatectomy specimen despit e exhaustive sampling. The incidence of this ''vanishing cancer phenom enon'' is probably increasing because more low-stage cancers are being treated by prostatectomy. The inability to identify cancer in a prost ate removed for needle biopsy-proven carcinoma may not indicate techni cal failure.