Study finds no increased risk of respiratory cancers from asbestos-free talc exposure

In a systematic review and meta-analysis, researchers found that occupational exposure to talc that is not contaminated with asbestos is not associated with an increase in the risk of lung cancer, mesothelioma, or laryngeal cancer. The findings are published in the Journal of Thoracic Oncology.

Evidence suggests a potential link between occupational talc exposure and increased risk of lung cancer and mesothelioma when talc is contaminated with asbestos, a known carcinogen. However, the findings for non-contaminated talc remained inconclusive.

To resolve this issue, researchers led by Paolo Boffetta, Stony Brook Cancer Center and Department of Family, Population and Preventive Medicine, Renaissance School of Medicine at Stony Brook University, NY, identified 13, 8, and seven publications reporting on lung cancer, mesothelioma, and laryngeal cancer, respectively. Five studies on lung cancer in talc miners and millers and three studies in other industries were included in the meta-analysis.

The meta-analysis showed:

• Lung cancer: Relative risk (RR) of 1.13 (95% CI: 0.97–1.33) among miners and millers. RR of 1.12 (95% CI: 0.79–1.57) among workers in other industries

• Mesothelioma: No cases reported among talc miners and millers in the primary analyses

• Laryngeal cancer: No association (RR = 0.98; 95% CI: 0.58–1.57)

Talc is a naturally occurring mineral that is mined from the earth and then processed into the soft, powdery substance used in products like cosmetics, ceramics, paper, and plastics. Major talc-producing regions include China, India, Brazil, the United States, France, and Italy.

Lung cancer is the second most common cancer in both men (after prostate cancer) and women (after breast cancer). It accounted in 2022 for an estimated 1,572,000 new cases and 1,233,000 deaths each year among men and 908,000 cases and 587,000 deaths among women.

Mesothelioma is a cancer of the mesothelium which is most frequently diagnosed in the pleura (known as pleural mesothelioma) but also can occur in the abdominopelvic cavity (peritoneal mesothelioma), the heart (pericardial mesothelioma), or the testes (testicular mesothelioma).

Mesothelioma was considered a very rare tumor until a large series of cases were reported in the 1960s among workers employed in asbestos mining and manufacturing.

Laryngeal cancer is one of the most prevalent types of head and neck cancer. According to GLOBOCAN 2022, its Age Standardized Rate (ASR) is only 1.9 per 100,000 and its Age-Standardized Mortality Rate (ASMR) is 1 per 100,000 globally.

“In conclusion, current epidemiological evidence does not provide support for an increased risk of lung cancer, mesothelioma, or laryngeal cancer among workers who are primarily exposed to talc that is free from asbestos contamination,” Boffetta and co-authors wrote.

However, according to the study, it is important to continue monitoring occupational groups, enhance the mineralogical characterization of talc deposits, and conduct future studies that include detailed exposure assessments and control for key confounding factors.

These steps are essential to better understand any potential low-level risks and to inform strategies for occupational health prevention.

Provided by
International Association for the Study of Lung Cancer