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 pulmonary large cell carcinoma. These two sublines had different growth characteristics in vitro and different tumor tissue structure in nude mice, and opposite drug sensitivities. Subline 1 was sensitive to a number of drugs, while its sensitivity to cisplatin (CDDP) was not very strong. In contrast, subline 2 was resistant to many drugs, but showed very strong sensitivity to CDDP. When the patient developed recurrence, he was first treated with CDDP-based chemotherapy based on the sensitivity of subline 2, followed by methotrexate-based treatment on the basis of sensitivity for subline 1. Complete remission (CR) was achieved after this alternating chemotherapy. To our knowledge, this is the first report of sublines with opposite sensitivity being established from the same tumor, achieving CR by the treatment of each subline.