No abstract

Fifty‐four patients with prostate carcinoma, each having 2 TURP (transurethral resection of the prostate) procedures separated by 3 to 11 years, were studied to determine whether the histologic appearance of prostate carcinoma remains the same for the life of the host or whether the histological appearance changes with time. Using the M. D. Anderson (MDAH) method of grading prostate carcinoma, 19 of 26 (73%) Grade 1 lesions, 9 of 12 (75%) Grade 2 lesions, and 7 of 8 (88%) Grade 3 lesions dedifferentiated into another grade at the time of the 2nd TURP. Eight cases that were Grade 4 at the time of the 1st TURP, remained Grade 4 lesions at the time of the 2nd TURP. Although 10 Grade 1, Grade 2, and Grade 3 lesions did not change grades, 8 of these 10 cases were less differentiated at the time of the second TURP than they were at the time of the first TURP. Furthermore, no Grade 1 lesions demonstrated evidence of metastases, but 19% of Grade 2 lesions, 55% of Grade 3 lesions, and 80% of Grade 4 lesions demonstrated evidence of metastases. This study suggests that the usual course of prmprostat carcinoma is dedifferentiation and that with dedifferentiation, the likelihood of metastases increases. Cancer 52:246‐251, 1983.

A new grading system for adenocarcinoma of the prostate (MDAH System) and its simplified version, both based on the percentage of tumor that is differentiated (gland-forming) or undifferentiated (non-gland-forming), were compared with the grading systems of Mostofi and Gleason. In a study group of 182 patients with Stage C adenocarcinoma of the prostate, the MDAH system identified 84 patients (46%) as Grade 1, 75 (41%) as Grade 2--3, and 23 (13%) as Grade 4. Kaplan-Meier survival curves predicted a 91% five-year survival for Grade 1 patients, a 60% 5-year survival for Grade 2--3 patients, and a 15% five-year survival for Grade 4 patients. Wilcoxon (Gehan modification) tests showed that the survival was significantly different among Grades 1, 2--3, and 4. The MDAH System is an improvement over other grading systems in that it is a simple, low-power microscopic method that depends only on the percentage of gland formation in the tumor and further reflects the biologic behavior of the tumor as measured by the patient's survival.

Failure to express Class I and/or Class II MHC determinants is a common feature of the majority of human prostatic carcinoma cells. Absence of these recognition molecules may be associated with avoidance of immune-surveillance and contribute to the metastatic dissemination of this malignancy.