Background: Most studies of adjuvant chemotherapy, radiotherapy, or immunotherapy in non-small-cell lung cancer patients with complete surgical resection of disease have shown negative results. However, two studies of stage II and III disease by our Lung Cancer Study Group suggested an advantage to adjuvant therapy with cyclophosphamide, doxorubicin, and cisplatin (CAP). Purpose: Since neither of those studies had an untreated control, the Lung Cancer Study Group undertook a trial that included a control group and also offered the potential benefit of adjuvant therapy with CAP to patients with T1, N1 or T2, N0 (stage I) non-small-cell lung cancer. Methods: After complete resection, eligible patients with stage I disease were classified by known prognostic factors and randomly assigned to receive or not to receive four courses of CAP at 3-week intervals beginning on day 30 after surgery. The CAP regimen consisted of 400 mg/m2 cyclophosphamide, 40 mg/m2 doxorubicin, and 60 mg/m2 Cisplatin. Stratification by prognostic factors was as follows: histology (squamous versus nonsquamous), white blood cell count before surgery (greater-than-or-equal-to 9100/mm3 versus <9100/mm3), and Karnofsky performance status before surgery (less-than-or-equal-to 90% versus 100%). Results: Of the 269 patients entered in the study, 101 had recurrence and 127 have died. Mean time since randomization is 6.4 years; mean follow-up is 3.8 years. There were no differences in time to recurrence or overall survival (not stratified by histology) between the two groups, even when analyses were adjusted for prognostic variables. There was one treatment-related death on the CAP arm due to infection during neutropenia. Only 53% of the eligible patients received all four courses of CAP, and only 57% of such patients received all four cycles on time. In 74% of the patients, the site of initial recurrence was distant. Conclusions: The most likely explanations for the lack of efficacy of CAP are poor compliance to the protocol and relative inactivity of the regimen, compared with the activity of drug combinations used in more recent studies. On the basis of this trial, adjuvant therapy with CAP should not be recommended for patients with resected stage I lung cancer. Implications: Further trials to test adjuvant therapy are indicated, but investigators should use better antiemetics to improve patient compliance as well as more active chemotherapy regimens.
