The establishment of sublines with opposite chemosensitivity from a patient with pulmonary large cell carcinoma and the implementation of treatment based on tumor heterogeneity

Two sublines were established from the primary tumor of a patient with pulm onary large cell carcinoma. These two sublines had different growth charact eristics in vitro and different tumor tissue structure in nude mice, and op posite drug sensitivities. Subline 1 was sensitive to a number of drugs, wh ile its sensitivity to cisplatin (CDDP) was not very strong. In contrast, s ubline 2 was resistant to many drugs, but showed very strong sensitivity to CDDP. When the patient developed recurrence, he was first treated with CDD P-based chemotherapy based on the sensitivity of subline 2, followed by met hotrexate-based treatment on the basis of sensitivity for subline 1. Comple te remission (CR) was achieved after this alternating chemotherapy. To our knowledge, this is the first report of sublines with opposite sensitivity b eing established from the same tumor, achieving CR by the treatment of each subline.