Lung Cancer Survival Disparities in Nevada

Lung cancer is the leading cause of cancer death in both men and women in the United States. Nevada shows moderate incidence rates of lung cancer for men but high rates for women. Little is known about the lung cancer experience and survival characteristics of the nearly 2000 new cases occurring every year in the State. The purpose of this study was to measure the extent to which geographic area of residency, gender, race, health insurance, social economic status (SES) and stage at diagnosis were associated with survival in patients diagnosed with lung cancer in Nevada. This was a retrospective population-based cohort study utilizing the Nevada Central Cancer Registry (NCCR) database for incident cases of lung cancer diagnosed in the state from 2003-2010 and followed-up through December 2011. The study population included all patients with incident cases of invasive carcinoma of the lung and bronchus, site codes C34.0, C34.3, C34.8, C34.9 and morphology codes 8000-8576. Five year cumulative survival rates were computed using the life table method stratified by race and adjusted for age. Cox proportional hazards regression was performed adjusting for region, age, gender, SES, race, tumor stage, marital status, histology, and insurance types, to examine the influence of each of these determinants on lung cancer survival in Nevada. A total of 12,962 lung cancer cases were diagnosed in Nevada during 2003-2010. The fatality of this cancer was very high with 81.9 % of the cases deceased by the end of the follow-up period. The overall age-standardized 5 year survival rate for Nevada lung cancer patients was 16.44% (95%CI 15.74-17.14). Blacks had a lower combined, age adjusted 5 year survival rate of 13.63% (95% CI 10.24-16.48) compared to the rate of Whites, 16.55 % (95% CI 15.8-17.30). However, after adjustment for all confounders, Blacks did not show an increased risk of death compared to Whites, (HR 0.99, 95% CI 0.904-1.077). Asians (HR 0.80, 95% CI 0.71-0.89) and Hispanics (HR 0.84, 95% CI 0.76-0.93) exhibited better lung cancer survival over time compared to Whites. Patients from Southern and Rural Nevada had an 8.5 % (p=0.001) and 11.3 % (p=0.008) higher risk of dying respectively, compared to patients from Northwestern Nevada. This study provides much needed baseline lung cancer survival data for Nevada. There was no lung cancer survival disparity between Blacks and Whites. The apparently better survival rates of Asians and Hispanics should be interpreted with caution as it may be due to death linkage artifacts. Disparities between different parts of the state warrants further study