Post-Operative Radiation Therapy Adds 4 Months to Lung Cancer Survival

A recent data review on patients with non-small cell lung cancer revealed post-operative radiation therapy (PORT) prolonged survival by an average of 4 months compared to patients that did not undergo PORT. The study was led by John L. Mikell, MD, chief resident in the Department of Radiation Oncology at Emory University Winship Cancer Institute in Atlanta. The findings were presented yesterday, during this year’s Chicago Multidisciplinary Symposium in Thoracic Oncology, made possible by the American Society of Clinical Oncology (ASCO), the American Society for Radiation Oncology (ASTRO), the International Association for the Study of Lung Cancer (IASLC) and The University of Chicago Medicine.

“These results reinforce the value of PORT for non-small cell lung cancer patients with involved mediastinal lymph nodes. Our data indicates that with modern radiotherapy equipment and treatment techniques, PORT can improve survival for these patients. The data in this study, the largest, most recent cohort of patients with involved mediastinal nodes treated with chemotherapy reinforce that PORT should be considered in addition to chemotherapy following resection of non-small cell lung cancer”, said Dr. Mikell, lead author of the study, in an ASTRO news release.

Information on patients with non-small cell lung cancer from 2004 to 2006 were obtained from the National Cancer Data Base (NCDB), which is a product of the partnership between the Commission on Cancer of the American College of Surgeons and the American Cancer Society. Specifically, the researchers took note of patients with surgically resected non-small lung cancer with lymph node involvement in the mediastinum and had undergone chemotherapy. The study pooled data from 2,115 qualified records, 43% of which had received PORT, while 56.6% did not.

The study utilized a multivariable Cox proportional hazards model to determine factors that affect overall survival (OS). To decrease biased treatment selection, the study employed inverse probability of treatment weighting (IPTW) with the propensity score. A calibrated Kaplan-Meier estimator and weighted log-rank test allowed the reseachers to note those who received PORT had an OS of 42 months – 4 months longer than those who did not receive PORT.

The study also identified factors associated with lung cancer OS such as gender, history of adenocarcinoma, income, setting, a lower T state, number of examined lymph nodes, and age. The researchers did not find any direct relationship between undergoing PORT and the number of lymph notes involved.