A previous phase III study conducted at M. D. Anderson and other sites through the North America Intergroup, showed accelerated fractionated radiotherapy (treatment in which radiation levels are increased over time) with concurrent VP-16 (etoposide) and cisplatin (platinum-based drugs) improved five-year survival rates. But this treatment often causes other side effects.
"Severe inflammation of the lining of the esophagus, also known as acute esophagitis, is a significant risk in this type of treatment," Komaki said. "Therefore, despite its long-term survival benefit, this modality has not been popular in community hospitals."
"Boosts" increase radiation levels
Researchers at M. D. Anderson and their colleagues developed this new study to find a way to increase the level of radiation during concurrent chemotherapy without increasing damage to normal tissue. Supported by NCI grant, this clinical study was then proposed to the Radiation Therapy Oncology Group (RTOG).
Patients with LSCL were treated with thoracic radiotherapy that was accelerated slowly over three weeks. The next step included two weeks of higher radiation levels twice daily, for a total of five weeks. During radiotherapy, patients received four cycles of chemotherapy.
"We gave the patients boosts of radiation twice a day in the last two weeks of treatment, when resistant cells often start to proliferate," Komaki said.
During the median follow-up time of 19 months, 41 percent of patients experienced complete response, and another 39 percent had partial response. Despite the higher radiation dose, the rate of acute severe esophagitis was significantly lower than the previous study, 18 percent, vs. 27 percent, respectively.
However, at 36.6 percent, the two-year survival rate did not improve. In addition, while local control of the disease was excellent, 80 percent, the majority of patients still deve
|Contact: Laura Sussman|
University of Texas M. D. Anderson Cancer Center