Results from a phase III trial conducted by the Radiation Therapy Oncology Group (RTOG) concluded that treatment with higher dose radiotherapy and the addition of cetuximab to concurrent chemoradiotherapy did not benefit overall survival of stage III non-small cell lung cancer patients.
The study entitled “Standard-dose versus high-dose conformal radiotherapy with concurrent and consolidation carboplatin plus paclitaxel with or without cetuximab for patients with stage IIIA or IIIB non-small-cell lung cancer (RTOG 0617): a randomised, two-by-two factorial phase 3 study” was published in The Lancet Oncology journal.
Lung cancer is the leading cause of cancer death and can be subdivided into two main types based on cell morphology: small cell lung cancer and non-small cell lung cancer (NSCLC). Between 75 to 80 percent of newly diagnosed patients are of NSCLC type and 40 percent of these have locally advanced disease (stage IIIA or IIIB).
Radiotherapy of lung cancer led to the idea that higher doses of radiation would result in an increased death of tumor cells, increasing patients’ survival chances. “This principle led several research groups, including the RTOG, to investigate in early phase trials the maximum tolerated radiotherapy dose that could be given with concurrent chemotherapy within safety limits. The results of these investigations led to a consensus to test 74 Gray in a randomized trial,” explained study author Jeffrey Bradley in a news release.
To test this hypothesis, RTOG researchers designed a phase III trial to compare the new treatment regimen with the current standard of care, assessing whether 74 Gray would result in improved overall survival for patients with stage III NSCLC, when compared to 60-Gray.
“In the setting of concurrent chemotherapy with daily radiation therapy for stage III lung cancer, the results showed that survival with 60 Gray is numerically higher than with 74 Gray, with a potential statistically significant detriment associated with the higher radiation dose,” described Dr. Bradley.
The trial further tested the hypothesis that adding cetuximab to chemoradiotherapy would lead to improved survival. However, the authors noted that “the use of cetuximab had no meaningful effect on overall survival in our trial.”