Breast cancer is the most frequent cancer among Moroccan women. To the best of our knowledge, this is the first study aimed to investigate the risk of breast cancer among different occupational categories in Morocco.

A case-control study was conducted in Fez region - Morocco, from February 2016 to August 2017. Cases were women newly diagnosed with histologically confirmed breast cancer at the University Hospital of Fez, and controls were healthy women recruited at one of six outpatient primary health centers randomly selected from the Fez region. Controls were matched to cases on age (± 5 years) and area of residence. Data were collected on occupational history and other breast cancer risk factors from cases and controls using a structured questionnaire. The International Standard Classification of Occupations (ISCO 08) was used to classify occupations into categories. Odds ratios and corresponding 90% confidence intervals were calculated using multiple conditional logistic regression adjusting for potential confounding factors.

A total of 300 cases and 300 controls were recruited in the study. An increased risk of breast cancer was observed for workers in elementary occupations (9) (adjusted OR=6.11, 95% CI: 3.41–10.96), particularly among women employed as Mixed crop and livestock farm workers (9213) (adjusted OR=4.26, 95% CI: 2.09–8.67).

Our findings indicate some occupational categories susceptible to the high-risks of breast cancer. Further investigations are warranted to clarify the role of chemical products involved in these occupations. Moreover, these occupational categories need more preventive actions and screening.