Risk of cardiac (CD) and pulmonary (PD) death after post-operative radiotherapy (PORT) for non-small cell lung cancer (NSCLC): Analysis of the Surveillance, Epidemiology, and End-Results (SEER) program

Abstract

6122 Background: Since radiation treatment planning and delivery techniques have evolved over time, we investigated if the risk of CD and PD after PORT for NSCLC has decreased. Methods: We selected postoperative patients with non-metastatic NSCLC diagnosed in 1980–1995 from the SEER data. To account for peri-operative mortality, patients with survival less than 6 months were excluded. Variables analyzed included age, gender, laterality, disease stage, SEER geographic region, ethnicity/race, and histology. CD and PD were calculated at 10 years and compared for patients diagnosed during 1980–83, 1984–88, 1989–91, and 1992–95. Cox proportional hazards models (CPHM) were used to calculate the hazard of CD and PD. Results: This analysis included 29,093 patients treated with observation (OB) and 8334 patients who received PORT. For the patients treated with OB, the 10 yr mortality rates for CD/PD were 17%/2%, 15%/3%, 15%/3%, and 14%/<0.1% for years of diagnosis of 1980–83, 1984–88, 1989–91, and 1992–95, respectively. For the patients who were treated with PORT, the 10 yr mortality rates for CD/PD were 21%/3%, 21%/4%, 15%/4%, and 14%/<0.1% for years of diagnosis of 1980–83, 1984–88, 1989–91, and 1992–95, respectively. CPHM showed the hazard of CD for patients treated with OB to be significantly decreasing; 1980–83 (HR=1.412; CI=1.257–1.585; p<0.0001), 1984–88 (HR=1.260; CI=1.124–1.413; p<0.0001), 1989–91 (HR=1.180; CI=1.054–1.321; p=0.0042), and 1992–95 (HR=1.00; Ref.). CPHM showed the hazard of CD for patients who received PORT to be significantly decreasing; 1980–83 (HR=1.568; CI=1.222–2.011; p=0.0004), 1984–88 (HR=1.435; CI=1.125–1.830; p=0.0036), 1989–91 (HR=0.992; CI=0.767–1.282; p=0.9504), and 1992–95 (HR=1.00; Ref.). Although PD showed a similar decreasing trend relative to year of diagnosis, CPHM did not demonstrate this to be statistically significant. Conclusions: There was a greater reduction in the CD rate in the PORT group compared to the OB group. While there appeared to be a trend in the reduction of PD, the results were not significant which may be secondary to too few events occurring. No significant financial relationships to disclose.