癌症死亡率男性大于女性

Overall cancer mortality rates（死亡率） are higher for men than women in the United States, according to a study published in Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research. Michael B. Cook, Ph.D., an investigator in the division of cancer epidemiology and genetics at the National Cancer Institute, and colleagues used U.S. vital rates and survival data from the SEER database for 36 cancers by gender and age. They assessed whether cancer mortality rates and cancer survival differed by gender.

"Men are more likely to die from cancer than women," said Cook. "We found this to be true for a majority of specific types of cancer."

Results showed that the cancers that had the highest male-to-female mortality rate ratios were: lip cancer (where 5.51 men died compared to 1 female); larynx（喉） (5.37-to-1); hypopharynx（咽喉） (4.47-to-1); esophagus（食管） (4.08-to-1); and urinary bladder（膀胱） (3.36-to-1). Cancers with the highest mortality rates also showed greater risk of death in men than women: lung and bronchus（支气管） (2.31-to-1); colon and rectum (1.42-to-1); pancreas (1.37-to-1); leukemia (1.75-to-1); and liver and intrahepatic bile duct (2.23-to-1).

In their analysis of five-year cancer survival, the researchers adjusted for age, year of diagnosis and tumor stage and grade, when this information was available. Cook and his team found that a person's gender did not play a major role in cancer survival.

For many cancers, men have poorer survival than women but the differences are slight. It is difficult to assign any singular root cause, but influences include differences in behavior of the tumor, cancer screening among people without symptoms, presence of other illnesses and health care seeking behaviors.

"Our research suggests that the main factor driving the greater frequency of cancer deaths in men is the greater frequency of cancer diagnosis, rather than poorer survival once the cancer occurs," said Cook. "If we can identify the causes of these gender differences in cancer incidence（发生率，影响） then we can take preventative actions to reduce the cancer burden in both men and women."