[Results of testing tumor resistance (in vitro--in vivo) in breast cancer]

Abstract

In-vitro sensitivity to cytostatics was tested in 281 carcinomas of the breast using the test method introduced by Volm. The Adriamycin 3H-uridine test system was chosen for the analysis. Altogether, 84.7% of the tumors were testable. A correlation with the subsequent in-vivo result was found in 219 of the breast cancer patients. Only 8% of the breast cancers were unequivocally sensitive to the test (uridine incorporation rate less than 55% for verification). The mean uridine incorporation rate was 577 CPM. Neither tumor size, lymph node status, nor the estrogen and progesterone receptor content of the tumor cells influenced the test result. With regard to the breast carcinoma, no relationship was found between the predictive information and the subsequent in-vivo response to chemotherapy. This applied to both short-term observation periods of three to six months as well as longer-term follow-ups. Furthermore, no connection was found between sensitivity in vitro and probability of recurrence (p = 0.69) under cytostasis. Probability of survival was higher among patients with tumors that were not sensitive to the test than among those with tumors which were (p less than or equal to 0.001). In the authors' experience the Volm chemosensitivity test only appears to furnish prognostic information about the breast carcinoma; in the light of their data the test appears rather unsuitable as an aid to deciding whether or not to institute cytostatic therapy.