Biopsy of thoracic neoplasms for assay of chemosensitivity. New indication for thoracotomy.

Eighty-six thoracic neoplasms, both primary and metastatic, were removed at thoracotomy from 86 patients and were tested for chemosensitivity in the clonogenic assay. Substantial tumor growth was achieved in 79% (67/86). Fifty-two percent (16/31) of the primary lung tumors and 45% (15/33) of the metastatic tumors were sensitive to at least one tested drug. Clinical correlations between in vitro chemosensitivity and in vivo response were possible in 20 patients. The assay was 83% accurate for predicting in vivo sensitivity and 86% accurate for predicting in vivo resistance. The value of the assay as it pertains to lung cancer has been demonstrated. On the basis of the results, thoracotomy is indicated in selected patients as a diagnostic procedure to obtain tissue for chemosensitivity testing.