Small cell lung cancer and the influence of chemotherapy on CFUcs in bone marrow

To determine the optimal moment for the harvesting of bone marrow for autologous transplantation, the authors did serially colony forming units in culture (CFUc) counts in a group of 42 patients with small cell lung cancer (SCLC) before and after remission induction chemotherapy and subsequent maintenance chemotherapy. Disease stage did not influence the CFUc count except in patients with bone marrow metastases; this resulted in either abnormally low or abnormally high CFUc counts, probably dependent on the degree of invasion. After 2 courses of induction chemotherapy, the number of CFUcs was 3.1-fold higher than before therapy. After 4 courses, the CFUcs number was comparable to the pretreatment value. An inverse correlation was found between the degree of hematologic toxicity (expressed as leucocytes count) and the increase of CFUcs after induction chemotherapy. The number of CFUcs decreased during prolonged chemotherapy to low levels after 1 year. Harvesting of bone marrow is probably done best shortly after induction chemotherapy.