Gender differences, environmental pressures, tumor characteristics, and death rate in a lung cancer cohort: a seven-years Bayesian survival analysis using cancer registry data from a contaminated area in Italy.

Introduction: In Taranto, Southern Italy, adverse impacts on the environment and human health due to industrial installations have been studied. In the literature, associations have been reported between gender, environmental factors, and lung cancer mortality in women and men. The aim of this study was to investigate the relationships between gender, residence in areas with high environmental pressures, bronchus/lung cancer characteristics, and death rate. Methods: Data from the Taranto Cancer Registry were used, including all women and men with invasive bronchus/lung cancer diagnosed between 1 January 2016 and 31 December 2020 and with follow-up to 31 December 2022. Bayesian mixed effects logistic and Cox regression models were fitted with the approach of integrated nested Laplace approximation, adjusting for patients and disease characteristics. Results: A total of 2,535 person-years were observed. Male gender was associated with a higher prevalence of histological grade 3 (OR 2.45, 95% CrI 1.35-4.43) and lung squamous-cell carcinoma (OR 3.04, 95% CrI 1.97-4.69). Variables associated with higher death rate were male gender (HR 1.24, 95% CrI 1.07-1.43), pathological/clinical stage II (HR 2.49, 95% CrI 1.63-3.79), III (HR 3.40, 95% CrI 2.33-4.97), and IV (HR 8.21, 95% CrI 5.95-11.34), histological grade 3 (HR 1.80, 95% CrI 1.25-2.59), lung squamous-cell carcinoma (HR 1.18, 95% CrI 1.00-1.39), and small-cell lung cancer (HR 1.62, 95% CrI 1.31-1.99). Variables associated with lower death rate were other-type lung cancer (HR 0.65, 95% CrI 0.44-0.95), high immune checkpoint ligand expression (HR 0.75, 95% CrI 0.59-0.95), lung localization (HR 0.73, 95% CrI 0.62-0.86), and left localization (HR 0.85, 95% CrI 0.75-0.95). Discussion: The results among patients with lung cancer did not show an association between residence in the contaminated site of national interest (SIN) and the prevalence of the above mentioned prognostic factors, nor between residence in SIN and death rate. The findings confirmed the independent prognostic values of different lung cancer characteristics. Even after adjusting for patients and disease characteristics, male gender appeared to be associated with a higher prevalence of poorly differentiated cancer and squamous-cell carcinoma, and with an increased death rate.