Modern postoperative radiotherapy, or PORT, appears to provide an additional overall survival advantage in patients with N2 non–small cell lung cancer treated with complete resection and adjuvant chemotherapy, according to a review of the National Cancer Database.
The median survival was 45.2 months in 1,850 patients treated with PORT at a dose of at least 45 Gy (median 54 Gy over 43 days), compared with 40.7 months in 2,633 who were not treated with PORT. The 3- and 5-year survival rates were 59.3% vs. 55.2% and 39.3% vs. 34.8% in the groups, respectively, and on multivariable analysis, PORT was an independent predictor of improved overall survival (hazard ratio, 0.886), as was younger age, female sex, urban population, lower Charlson score, smaller tumor size, multiagent chemotherapy, and resection with at least a lobectomy, Dr. Clifford G. Robinson and his colleagues at Washington University, St. Louis, reported online Feb. 9 in the Journal of Clinical Oncology.
Patients included in the review had pathologic stage IIIA (N2) NSCLC, underwent complete resection and adjuvant chemotherapy between 2006 and 2010, and were followed for median of 22 months. Those who received neoadjuvant chemotherapy or radiotherapy, were missing data on adjuvant therapy timing, had evidence of metastatic disease, were treated with palliative intent, or had incomplete resection were excluded (J. Clin. Oncol. 2015 Feb. 9 [doi:10.1200/JCO.2014.58.5380]).
Although studies of PORT in the 1960s and 1970s showed a lack of benefit in patients with NSCLC, this was felt to be due in large part to competing cardiac and pulmonary toxicity from outdated equipment, techniques, and dosing; patients in the current study were likely treated with modern techniques, including computed tomography, simulation, and at least linear accelerator–based, three-dimensional, conformal radiotherapy, the investigators said, noting that the finding of a possible survival advantage with PORT underscores the importance of enrolling patients in randomized trials such as LungART.
Dr. Robinson is on the speakers’ bureau for ViewRay, which has paid for travel, accommodations, and other expenses. Several of his coauthors also reported receiving research funding, honoraria, and expenses, or serving as a consultant or advisor for a number of companies, including ViewRay, Varian, Traxxsson, Agennix, Lilly, Pfizer, Daiichi Sankyo, Spectrum Pharmaceuticals, Astex Therapeutics, Novartis, Genentech, Transgene, Eisai, New Link Genetics Corp., Merck, Puma, Roche, Incyte, Boehringer Ingelheim, Celgene, Wyeth, ImClone Systems, Merrimack, Bristol-Meyers Squibb, Onocyte, Astex Therapeutics, Onyx, GlaxoSmithKline, Bayer, Covidien, and Ethicon.