Causes of death in long-term lung cancer survivors: a SEER database analysis

Abstract

Background: Long-term (>5 years) lung cancer survivors represent a small but distinct subgroup of lung cancer patients and information about the causes of death of this subgroup is scarce.

Methods: The Surveillance, Epidemiology and End Results (SEER) database (1988–2008) was utilized to determine the causes of death of long-term survivors of lung cancer. Survival analysis was conducted using Kaplan–Meier analysis and multivariate analysis was conducted using a Cox proportional hazard model. Clinicopathological characteristics and survival outcomes were assessed for the whole cohort.

Results: A total of 78,701 lung cancer patients with >5 years survival were identified. This cohort included 54,488 patients surviving 5–10 years and 24,213 patients surviving >10 years. Among patients surviving 5–10 years, 21.8% were dead because of primary lung cancer, 10.2% were dead because of other cancers, 6.8% were dead because of cardiac disease and 5.3% were dead because of non-malignant pulmonary disease. Among patients surviving >10 years, 12% were dead because of primary lung cancer, 6% were dead because of other cancers, 6.9% were dead because of cardiac disease and 5.6% were dead because of non-malignant pulmonary disease. On multivariate analysis, factors associated with longer cardiac-disease-specific survival in multivariate analysis include younger age at diagnosis (p < .0001), white race (vs. African American race) (p = .005), female gender (p < .0001), right-sided disease (p = .003), adenocarcinoma (vs. large cell or small cell carcinoma), histology and receiving local treatment by surgery rather than radiotherapy (p < .0001).

Conclusion: The probability of death from primary lung cancer is still significant among other causes of death even 20 years after diagnosis of lung cancer. Moreover, cardiac as well as non-malignant pulmonary causes contribute a considerable proportion of deaths in long-term lung cancer survivors.

Keywords:

• Lung cancer
• local treatment
• survivors
• causes of death

Transparency

Declaration of funding

This study was not funded.

Declaration of financial/other relationships

O.A.-R. has disclosed that he has no significant relationships with or financial interests in any commercial companies related to this study or article.

CMRO peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Acknowledgements

As this study is based on a publicly available database without identifying patient information, informed consent was not needed.