What is the Impact of External Beam Radiation Therapy (EBRT) Following Limited Resection of T1 or T2 Non-small Cell Lung Cancer (NSCLC)? A SEER Analysis

Abstract

Historical series and one randomized trial have guided surgeons in selecting the appropriate surgical procedure for patients presenting with localized NSCLC. Data to this point indicate that anatomical lobectomy remains the standard of care. However, many patients are still offered limited resections. The impact of post-operative EBRT in patients undergoing limited resection is unknown. The Surveillance Epidemiology and End Results (SEER) database was queried to identify patients with T1 or T2 NSCLC of squamous cell or adenocarcinoma histology who underwent primary surgical resection (wedge, segmental or lobectomy with lymph node evaluation) for the years 1998 – 2004. Demographic, clinical and pathologic data were culled and analyzed to determine the impact of radiation therapy following resection. Survival rates were estimated using the Kaplan-Meier method and significance was determined using the log-rank test (p <.05). Cox proportional hazards model was performed to determine factors significant for overall (OS) and cause-specific survival (CSS). A total of 14,149 patients meeting inclusion criteria were included. The majority of patients underwent lobectomy (n = 9,526). A total of 1,147 patients received EBRT following surgery. The median follow-up for the entire group was 1.8 years (range 1 month - 6.9 years). Lobectomy was statistically superior to wedge or segmental resection for both OS and CSS. The addition of EBRT following wedge or segmental resection did not enhance OS or CSS relative to lobectomy or compared to wedge or segmental resection without EBRT (Table). The effect of EBRT following limited resection was not influenced by the size of the tumor. Advancing age and grade, male sex, larger tumor size, limited resection, and the addition of EBRT were statistically significant negative predictors for OS.Poster Viewing Abstract 3007; TableNo EBRTLobectomySegmentalWedgep-value5-yr OS, %57.843.737<.00015-yr CSS, %70.959.252.3<.0001With EBRT5-yr OS, %33.212.5165-yr CSS,%42.915.825.6 Open table in a new tab Lobectomy remains the standard of care for management of localized NSCLC. Generally, patients receiving post-operative EBRT in this population experienced poorer OS and CSS compared to surgery alone regardless of the surgical extent. These data suggest that planned limited resection followed by EBRT is an inferior approach to lobectomy. When lobectomy is not feasible, noninvasive alternatives to surgery, including stereotactic radiation therapy, should be considered.