The delivery of chemotherapy simultaneously with radiotherapy may be the optimal way to improve survival in patients with non-small-cell lung cancer (NSCLC). The median survival time of the 79 patients in a nonrandomized pilot trial (RTOG 91-06) was 19 months.
"These are by far the best results yet reported with nonoperative therapy for locally advanced non-small- cell lung cancer in a national trial," Walter J. Curran, Jr., md, said at the American Cancer Society Science Writers Seminar.
A survival benefit for simultaneous versus sequential chemotherapy/radiotherapy has been demonstrated for localized small-cell lung cancer, but, until now, such data have not existed for NSCLC, said Dr. Curran, of Thomas Jefferson University, Philadelphia, who was representing the Radiation Therapy Oncology Group (RTOG).
Sequential vs Simultaneous Therapy
The survival benefit of sequential therapy over radiotherapy alone in NSCLC has been shown in four randomized trials that focused on stage III patients with unresected, locally advanced NSCLC and good performance status.
The most recent of these, RTOG 88-08, noted an improvement in median survival from 11 to 14 months with the addition of two cycles of cisplatin(Drug information on cisplatin) (Platinol) and vinblastine(Drug information on vinblastine) given prior to thoracic radiotherapy. Almost 500 patients were enrolled in this trial.
The approach is similar to that of the CALGB 84-33 trial, for which long-term information is available on 155 patients. Five-year survival rates for the combination therapy group are 19% vs 7% for the radiation-only group, Dr. Curran said.
The advantage of simultaneous administration is to employ all active therapies immediately, with the potential for "supra-additive synergism in the regimen's antitumor activity," he explained.
The regimen of the current trial included two high-dose cycles of cisplatin and oral etoposide(Drug information on etoposide) (VePesid) concurrently with twice-daily radiotherapy. Chemotherapy and radiotherapy were begun on the same day. The 79 patients are from 30 RTOG centers.
One Major Complication
The benefit in survival, however, was gained at the cost of an increase in one major complication-severe esophagitis-which, in fact, was to be expected with a more potent therapeutic approach. Severe esophagitis (grade 3) occurred in 36% of patients, most of whom required intravenous tube feeding or hyperalimentation. More than half the patients in the study also demonstrated grade 3 or worse reversible hematologic toxicity, he said.
In contrast, severe esophagitis occurs in less than 5% of patients who receive radiotherapy alone or sequential chemotherapy/radiotherapy. "This outcome will only be worth accepting if we can significantly affect survival," Dr. Curran commented.
The results of the pilot trial were sufficiently encouraging to spawn a currently active randomized trial (RTOG 94-10 } comparing sequential to simultaneusly administered chemotherapy/radiotherapy in 600 patients . Drug protocols will include cisplatin, vinblastine, and oral etoposide.}