A Case-control Study of Lung Cancer in Casablanca, Morocco

Objective: To evaluate etiologic risk factors for lung cancer in Casablanca, Morocco.

Methods: We conducted a hospital-based case-control study that included 118 incident lung cancer cases and 235 age-, sex- and residence-matched controls. We analyzed the data using matched univariate and matched and unmatched multivariate logistic regression analyses.

Results: Active tobacco smoking and history of chronic bronchitis were the strongest risk factors for lung cancer in the matched logistic regression model. Multivariate odds ratio (OR) and 95% confidence intervals varied from 1.79 (0.47-6.79) for former light smokers to 26.07 (6.58-103.27) for current heavy tobacco smokers at the time of disease occurrence. Combined use of hashish/kiff and snuff had an OR of 6.67 (1.65-26.90), whereas the OR for hashish/kiff (without snuff) was 1.93 (0.57-6.58). History of chronic bronchitis had an OR of 4.16 (1.76-9.85). Other slightly increased risks of lung cancer were found for exposure to passive smoking (1.36; 0.71-2.62), occupational exposures (1.75; 0.84-3.63), use of candles for lighting (1.44; 0.42-5.01), and poor ventilation of the kitchen (1.22; 0.57-2.58).

Conclusions: This study confirms known risk factors for lung cancer and uncovers potential new etiologic ones such as the role of hashish/kiff.