Cancer Research Lab

The findings from a new study suggest that exposure to a bacterial endotoxin, found in raw cotton fiber and dust, confers protection against lung cancer in textile workers.

An association between textile jobs and a reduced lung cancer risk was first noted in the 1970s. The endotoxin was thought to mediate this effect by altering the innate and acquired immune systems. However, data examining the effect of endotoxin exposure on lung cancer risk have been lacking.

Dr. George Astrakianakis, from the Occupational Health and Safety Agency for Healthcare in Vancouver, British Columbia, and colleagues used various measures to quantify endotoxin exposure in 628 female textile workers in Shanghai who developed lung cancer and in 3184 controls who did not.

The researchers report their findings in the Journal of the National Cancer Institute for March 7th.

Cumulative endotoxin exposure showed a strong, significant inverse relationship with lung cancer risk, the report indicates. This was most apparent with a 20-year lag time: the highest quintile of exposure cut the risk by 40% compared with no exposure (p = 0.002).

The researchers estimate that endotoxin exposure in this cohort of workers reduced the occurrence of lung cancer by about 7.6 cases per 100,000.

“These findings indicate that endotoxin exposure is positively associated with early-stage anticarcinogenic activity in humans,” the researchers conclude. “Biologic plausibility for this association is supported by experimental research and corroborative evidence for reduced lung cancer among endotoxin-exposure in other industries.”