Influenza and pneumonia-attributed deaths among cancer patients in the United States; a population-based study.

Abdel-Rahman, Omar

OBJECTIVE To assess the patterns and trends of influenza and pneumonia-attributed deaths among cancer patients in the United States. METHODS Surveillance, Epidemiology and End Results (SEER) database was accessed and cancer patients diagnosed 1975-2016 who have been included in the SEER-9 registries were included. The primary endpoint of the study is standardized mortality rate (SMR; calculated as observed/Expected (O/E) ratio for death from influenza and pneumonia among cancer patients). Competing risk analysis was additionally conducted to evaluate the impact of age on influenza/pneumonia-attributed deaths among selected tumor types. RESULTS The current study evaluates a total of 3,579,199 cancer patients (diagnosed 1975-2016) within the SEER-9 registries; and influenza and pneumonia-attributed deaths represent 1.5% of the recorded deaths for this cohort. SMR for influenza/pneumonia-attributed death within the first year following cancer diagnosis was 1.88 (1.83-1.94); while SMR for influenza/pneumonia-attributed death following the first year was 1.11 (1.10-1.12). Within the first year following cancer diagnosis, SMR from influenza/pneumonia was higher among individuals with black race (SMR for white race: 1.75 (95% CI: 1.69-1.81) while SMR for black race: 2.90 (95% CI: 2.65-3.16), lung cancer (SMR for lung cancer: 4.39 (95% CI: 4.11-4.69)), head and neck cancer (SMR for oral cavity/pharynx cancer: 4.02 (95% CI: 3.50-4.59)), lymphomas (SMR for lymphoma: 3.28 (95% CI: 2.92-3.68)), leukemias (SMR for leukemia: 3.32 (95% CI: 2.89-3.80)) and myeloma (SMR for myeloma: 3.91 (95% CI: 3.28-4.63)). Within competing risk analysis, sub-distribution hazard ratio for death from influenza/pneumonia was higher for patients ≥ 70 years versus patients <70 years: for patients with lung cancer: 1.64; 95% CI: 1.49-1.80; for patients with oral cavity/pharynx cancer: 2.13; 95% CI: 1.92-2.36; and for patients with lymphoma: 2.81; 95% CI: 2.57- 3.07). CONCLUSIONS Cancer patients are more likely to have influenza/pneumonia-attributed death compared to the general US population. This risk is higher among patients with lung cancer, head and neck cancer, and hematological malignancies.