Breast cancer is to blame for much of the risk difference. Its rates are ticking upward in women under 50 more quickly than in older women, as are colorectal cancers (a trend also seen among men).

Correspondence to Dr Yanlei Ma, Department of Colorectal Surgery, Fudan University Shanghai Cancer Center, Shanghai 200032, China; yanleima{at}fudan.edu.cn Objective The incidence of early-onset ...