Exploring Demographic Differences and Outcomes in Early-Onset Colorectal Cancer.

PURPOSE: Early-onset colorectal cancer (EOCRC), defined as CRC diagnosed before age 50 years, has increased significantly worldwide. The majority of EOCRCs do not appear to be driven by genetic factors and may be influenced by environmental factors. We hypothesized that sociodemographic disparities exist in EOCRC. The purpose was of the study was to examine the geographic disparities in patients with EOCRC. METHODS: We retrospectively examined the SEER database from 1976 to 2016 to examine the geographic disparities in EOCRC. A total of 73,378 patients with EOCRC were included in the analysis. We performed univariate and multivariable analyses to evaluate overall survival (OS) and disease-specific survival (DSS). Sociodemographic factors, including the location of residence (metropolitan areas [MA] or rural areas [RA]), sex, race, insurance status, and marital status, were included in the statistical analysis. RESULTS: The incidence and mortality rates were consistently higher in RA versus MA during the study period. Multivariable analysis showed that patients living in RA had worse OS (hazard ratio [HR], 1.14; P < .01) and DSS (HR, 1.15; P < .001) compared with those living in MA. Similarly, non-Hispanic Black ethnicity and uninsured patients had significantly worse survival when compared with non-Hispanic White and insured patients, respectively. Married status showed better survival outcomes. CONCLUSION: Patients with EOCRC living in RA have worse outcomes. Understanding the mechanisms behind such socioeconomic disparities is important so that future studies can reduce these disparities.

Association between Environmental Temperature and Survival in Gastroesophageal Cancers: A Population Based Study.

BACKGROUND: Cold stress suppresses antitumor response in animal models, leading to tumor growth. Recent studies have also shown a negative correlation between the average annual temperature (AAT) and cancer incidence. We hypothesized that esophageal cancer (EC) and gastric cancer (GC) patients living in warmer climates have improved survival outcomes than those living in colder climates. METHODS: We conducted a retrospective analysis using the Surveillance, Epidemiology, and End Results (SEER) database from 1996 to 2015. We retrieved the National Centers for Environmental Information data to calculate the county-level AAT. Cox multivariate regression models were performed to measure the association between temperature (measured continuously at diagnosis and in 5-degree increments) and OS/DSS, adjusting for variables. All associations were compared at a significance level of 0.05. The OS and DSS were summarized using Kaplan-Meier methods. All statistics were performed using SAS version 9.4 (SAS Institute Inc., Cary, NC, USA). RESULTS: A total of 17,408 EC patients were analyzed. The average age of the cohort was 65 years, 79% of which were males and 21% were females. Of them, 61.6% had adenocarcinoma, and 37.6% were squamous. After adjusting for covariates, patients in regions with an AAT > 53.5 °F had an 11% improvement in OS [HR 0.89 (95% CI 0.86-0.92), p < 0.0001] and 13% in DSS [HR 0.87 (95% CI 0.84-0.90), p < 0.0001]. When the temperature was analyzed in 5 °F increments, with each increment, there was a 3% improvement in OS [HR 0.97 (95% CI 0.96-0.98), p < 0.0001] and 4% in DSS [HR 0.96 (95% CI 0.95-0.97), p < 0.0001]. Subgroup analysis of squamous and adenocarcinoma showed similar results. These findings were validated in 20,553 GC patients. After adjusting for covariates, patients in regions with an AAT > 53.5 had a 13% improvement in OS [HR 0.87 (95% CI 0.85-0.90), p < 0.0001] and 14% in DSS [HR 0.86 (95% CI 0.83-0.89), p < 0.0001]. When analyzed in 5 °F increments, with each increment, there was a 4% improvement in OS [HR 0.96 (95% CI 0.952-0.971), p < 0.0001] and 4% in DSS [HR 0.96 (95% CI 0.945-0.965), p < 0.0001]. CONCLUSION: We showed for the first time that higher environmental temperatures are associated with significant improvements in OS and DSS in patients with gastro-esophageal cancers, notwithstanding the limitations of a retrospective database analysis. Further confirmatory and mechanistic studies are required to implement specific interventional strategies.