The influence of myelosuppression on the response to chemotherapy in small cell bronchogenic carcinoma.

In an attempt to clarify the relationship between myelosuppression and the response to chemotherapy, 127 cases of small cell lung cancer were reviewed. These patients received a total of four different drug combinations. The myelosuppression of the first chemotherapy course was reduced with the addition of one or two drugs to the basic Cytoxan (cyclophosphamide)-vincristine drug combination without a change in the incidence of remission. Patients with good performance status have less severe leukopenia and thrombocytopenia than those with poor performance status. Patients with complete and partial response have slightly more severe thrombocytopenia but not leukopenia than the nonresponders. It is concluded that the burden of tumor has a direct effect on the incidence of remission and myelosuppression suggesting that more severe toxicity is necessary to obtain remission in poor risk patients. Myelosuppression is required before assessing whether the patient has received an adequate amount of chemotherapeutic agent but is only a weak prognostic factor.