Decreasing incidence of lung cancer and unfavorable survival prognosis: study of temporal trends in burden and survival by histology

Abstract

Lung cancer (LC) is the fourth most incident cancer in Argentina and the leading cause of cancer-related death. Survival rates are low. Sex, age, and histology play a significant role in the burden and temporal trends. We analyzed the incidence and survival of LC in Córdoba, Argentina, from 2004 to 2014, considering the effects of age, sex, and histology.

We conducted a longitudinal ecological study. Using data from the Provincial Cancer Registry, specific age-standardized LC incidence rates (ICD-10: C33-34) were calculated (per 100,000 person-years) by sex, year (2004-2014), and histological types (small cell carcinoma (SCLC), and non-small cell carcinoma (NSCLC): adenocarcinoma, squamous cell carcinoma, large cell carcinoma, and other carcinomas). Joinpoint regression models were used to analyze temporal trends, estimating annual percentage changes (APC). For survival, median survival times and estimated survival curves were calculated, and semiparametric Cox regression models were adjusted. Statistical significance was verified using logarithmic rank tests and proportional hazards tests. Software used: Joinpoint Regression Program® and Stata 17.

Between 2004 and 2014, 8,246 cases of LC were diagnosed in individuals aged 35-84. Cases were more frequent in males (72%), with the highest incidence among those aged 75-79 and 80-84, in females. The male age-standardized rate was 57.9, and the female rate was 23.6 cases per 100,000 person-years. In both sex, the temporal trend of incidence decreased (APC -3.21%, p=0.001), with a greater decline in males (APC -3.99%, p=0.011), exhibiting negative APCs in all histological subtypes, significant in squamous cell carcinoma (APC -5.8, p<0.001), and other carcinomas (APC -8.2, p=0.004). The probability of survival decreased to 32% (95% CI: 31%-34%) within just 12 months (38% for females, 30% for males). The risk of death increased proportionally with age (male HR: 1.007 (95% CI: 1.004-1.01, p=0.000); female HR: 1.005 (95% CI: 1.00-1.01, p=0.031)) and across all histological types, with relatively lower proportional risks in females and variations based on histology: for males, the highest risk was in large cell carcinoma (p=0.008) and SCLC, and for females (p=0.055).

Despite estimating a favorable trend in LC incidence since 2004, survival prognosis remains unfavorable within the first year of diagnosis, dependent on sex and histological type.