The higher prevalence of peritoneal vs pleural MMs in China, especially among nonexposed young women, is unique. Initially we thought that asbestos was the main cause because 13 of 18 peritoneal MMs (72%; 95% CI, 46%-90%) from Yuyao People’s Hospital occurred in women exposed to asbestos. However, only 1 of 14 peritoneal MMs (7%; 95% CI, 0%-34%) from the ZJCH was associated with asbestos. Except for asbestos exposure, no significant demographic differences were observed between the ZJCH and Yuyao People’s Hospital, suggesting that asbestos may not be the main cause of MM in these women. These findings point to a unique opportunity to investigate other causes of peritoneal MMs in this population, aside from asbestos. In the United States and Europe, an increasing number of peritoneal MMs do not seem to be associated with asbestos, leading some authors to speculate that a subgroup of peritoneal MMs may have a different pathogenesis.

Weimin Mao, MD, PhD; Xing Zhang, PhD; Zhenying Guo, MD; Zhibin Gao, PhD; Harvey I. Pass, MD; Haining Yang, MD, PhD; Michele Carbone, MD, PhD