Colorectal Cancer: 35 Cases in Asbestos-Exposed Workers

Background: Asbestos is considered one of the major global work-related carcinogens. Some studies suggest a potential causal relationship between asbestos exposure and colorectal cancer (CRC). However, the role of asbestos in CRC carcinogenesis is still controversial. Methods: 35 claims of occupational CRC among asbestos-exposed workers were reviewed. All claims were rejected by the Italian National Institute for Insurance against Accidents (INAIL) due to the "lack of scientific evidence in the causality" between asbestos exposure and CRC; causality was finally assessed in civil trials. All cases were categorized by age, gender, industry type, task, exposure and latency periods, anatomical location, and histopathological characteristics of CRC and concomitant respiratory diseases. Results: Most workers were males aged 60 years or more and employed in occupational activities with extensive use of asbestos for over 20 years. In 31 out of 35 cases, CRC was diagnosed over 39 years after employment. Right-sided colic adenocarcinoma was diagnosed in nine cases; rectum was involved in eight cases. Respiratory comorbidities were observed in 22 workers. Conclusions: Our study provides some interesting points in the assessment of the causal relationship between asbestos exposure and CRC.