gms | German Medical Science

Despite the improved survival rates associated with adjuvant therapy, the survival patients with breast, ovarian and cervical cancer remains poor. Individualized combined chemo- and radiotherapy in cancer patients is still not widely applied. In order to determine the in vitro efficacy of cytostatic drugs in combination with radiotherapy (30 to 45 Gray), it is necessary to obtain tissue samples representative for the tumor. These samples allow prediction of the in vivo responses towards radiochemotherapy. 20 samples were sent to chemosensitivity testing, obtained from patients suffering from two different gynaecological carcinomas (ovary 12, breast 8). The samples were classified in 3 stages. In stage I were 4 of the patients with ovarian carcinoma, 3 as stage II, 5 as stage III and 2 were classified as stage VI. All cases with breast cancer belong to stage II. Vinorelbine and 5-Fluorouracil appeared to be the combination with the highest effect in vitro on breast cancer (74,0 %; SD 0,13%) followed by Mitoxantron which showed partial effects (67,3 %; SD 17,7 %). On the other hand the combination of Paclitaxel and 5-Fluorouracil (3,8 %; SD 10,2 %) and Cisplatin (11,9 %; SD 12,3 %) pointed out a strong resistance. In 4 cases of ovarian malignancies Paclitaxel and Carboplatin were prescribed, in vitro the ATP-TRCA measured a tumor growth inhibition of 25,1 % (SD 15,7 %) which demonstrated the strong resistance. In 3 additional cases the combination Carboplatin/Cyclophosphamid was used, which showed in vitro an ATP-inhibition of 14,9 % (SD 15,8 %) only. Other drugs such as Novantron demonstrated higher ATP-inhibition (58,1 %; SD 13,2 %). For example an ovarian carcinoma patient at stage III was treated with the combination Carboplatin/Cyclophosphamid, which appeared in vitro with an inhibition of 40,1 %, while other tested drugs like Paclitaxel showed a higher effect on the tumor cells (75,3 %). The profiles of the tested gynaecological malignancies revealed a big heterogeneity of radiochemosensitivity results for single and drug combinations. The findings explain that the TRC-assay is able to determine the fraction of surviving cells and has proved to be an effective tool to measure the synergistic cytotoxicity by using radiochemotherapy.