Related Experiment Videos
[Human tumor clonogenic assay in human breast cancer]
Abstract:
The human tumor clonogenic assay (HTCA) developed by Hamburger and Salmon was evaluated in 135 fresh samples of breast cancer. Successful tumor colony growth (greater than or equal to 5 colonies/plate) was obtained in 100 (74%) of the 135 samples, and adequate growth for drug testing (greater than or equal to 30 colonies/plate) in 75 (56%). With regard to the success rates of growing colonies categorized by specimen source, tumor sites, histology, prior chemotherapy and estrogen receptor (ER), specimens from solid tumors and primary tumors showed higher success rates than those from pleural effusions and metastatic tumors. The effects of prior chemotherapy, histology type and ER status on the success rate of colony formation were not significant. The overall median plating efficiency was 0.012%. Higher plating efficiencies were found in pleural effusion, metastatic tumors and samples from patients with prior chemotherapy. These findings appeared to indicate that aggressiveness of disease might be related to plating efficiency. Defining a greater than or equal to 50% inhibition of colony formation (ICF) as in vitro drug sensitivity, the in vitro response rates to anticancer drugs tested were as follows: adriamycin 33%, mitomycin C 39%, 5-fluorouracil 32%, methotrexate 42%, L-PAM 31%, cisplatin 38%, vincristine 32%, vinblastine 54%. The group of patients without prior chemotherapy showed higher sensitivity in vitro compared with the group of patients who had prior chemotherapy (38% vs. 27%). Correlation between in vitro drug sensitivity (greater than or equal to 70% ICF) and clinical response in 12 patients treated with the same drugs were analyzed retrospectively. The predictive accuracy was 0% (0/1) for true positive and 91% (10/11) for resistance. Thus, overall predictive accuracy was 83%. Based on these results, HTCA appeared to be useful chemosensitivity test for evaluation of antitumor drugs for human cancers in vitro and prediction of the chemotherapeutic effect in clinical use.