Size dependence of the response of Lewis lung tumors to BCNU.

The survival of Lewis lung tumor cells has been studied after a single ip dose of BCNU. In dissectible subcutaneous and intramuscular tumors and artificial lung metastases survival was measured by colony formation in soft agar and in vivo in the lung. The long-term control of small lung nodules by single doses of BCNU was studied and cell-survival estimates were inferred. The results demonstrate that the cytotoxic action of BCNU shows a strong dependence upon tumor size.