Patterns of response and relapse in chemotherapy of extensive squamous carcinoma of the lung

In a large study of combination chemotherapy for patients with extensive squamous carcinoma of the lung, 44 of 247 patients (18%) achieved>50% regression of tumor mass. The likelihood of response was significantly (and independently) higher for females and for fully ambulatory patients. Bone and liver were the most commonly involved metastatic sites, with documented involvement pretreatment in 32 and 16% of patients, respectively. Recurrence in the ipsilateral hemithorax after radiation therapy was the only clinical evidence of disease in 24% of the patients. There were no significant differences in response rate by individual metastatic sites, or for single compared to multiple sites. The median time to response was 4 weeks, with response noted by 8 weeks in 74%. Clinically evident relapse has occurred in 39. Among these, the primary site was the only clinical site of failure in 14, of whom 7 never received radiation therapy. The brain was the only site of initial failure in 6, only 1 of whom had preexisting evidence of brain involvement. Failure in a single area of previously evident disease or the brain accounted for 74% of recurrences in the responding group. These observations suggest that sequential, planned radiation therapy to sites of previous clinical involvement, together with 'prophylactic' whole-brain radiation, may be of benefit in the drug-responsive subpopulation of patients with extensive disease.