Non-cancer-related deaths from suicide, cardiovascular disease, and pneumonia in patients with oral cavity and oropharyngeal squamous carcinoma

Objective: To study non - cancer-related mortality rates over time and examine the possible causes for several major deaths in patients with oral cavity and oropharyngeal (OC/OP) cancer. Design: Retrospective cohort analysis using the Surveillance, Epidemiology, and End Results (SEER) cancer registry data of the National Cancer Institute. Main Outcome Measure: Cause-specific mortality rates during the first year after diagnosis of OC/OP cancer were calculated for 4 cohorts (1980-1984, 1990-1994, 2000-2003, and 2004-2007). The percentage changes over time were calculated. Standardized mortality ratios (SMRs) for suicide, cardiovascular disease, and pneumonia were calculated and compared with patient demographic and clinical characteristics. Results: We analyzed data for 32 487 patients in 4 cohorts. From 1980-1984 to 2004-2007, mortality from suicide increased by 406.2% (P=.01), cardiovascular disease-related and pneumonia - related mortality decreased by 45.9% (P<.001) and 42.9% (P=.009), respectively, and rates of other non-cancer-related deaths did not change. Compared with the general population, patients diagnosed as having OC/OP cancer were at a significantly higher risk of mortality from suicide (SMR, 7.8; 95% CI, 4.6-12.4; P<.001), cardiovascular disease (SMR, 2.4; 95% CI, 2.1-2.7; P<.001), and pneumonia (SMR, 8.9; 95% CI, 6.8-11.5; P<.001) during the first year after cancer diagnosis. Risk factors for increased mortality included age of 55 to 64 years, marital status (including never married, divorced, or separated), advanced tumor stage (including regional and distant disease), treatment with radiotherapy alone, and pharyngeal tumor location. Conclusions: Suicide rates have significantly increased in patients with OC/OP cancer since 1980 to 1984. Although cardiovascular disease- and pneumonia-related deaths have significantly decreased over time, they remain higher than the general US population. Increased knowledge of risk factors associated with non - cancerrelated mortality in OC/OP cancer may lead to early intervention and enhanced overall survival.