Epidemiology

HRT use seen protective for some cancers

Last Updated: 2003-07-04 4:15:15 -0400 (Reuters Health)

NEW YORK (Reuters Health) - Ever-use of hormone replacement therapy (HRT) protects against colorectal and liver cancer, but increases the risk of cancer of the gallbladder, breast, endometrium, and bladder, according to a systematic review of Italian case-control studies conducted between 1983 and 1999.

"The colon and rectum have been the tumor sites, together with breast and endometrium, that have been extensively considered in other studies," Dr. Esteve Fern�ndez of the University of Barcelona told Reuters Health. One "strength" of the current study is that it considers other tumor sites, such as the liver and gallbladder, he added.

The overall dataset included cancers of the oral cavity, pharynx, larynx, and esophagus (n=253), stomach (n=258), colon (n=886), rectum (n=488), liver (n=105), gallbladder (n=31), pancreas (n=122), breast (n = 4,713), endometrium (n=704), ovary (n=1,614), urinary bladder (n=106), kidney (n=102), thyroid (n=65); also, Hodgkin's disease (n=26), non-Hodgkin's lymphomas (n=145), multiple myeloma (n=65), and sarcomas (n=78). The control group comprised 6,976 women with nonmalignant conditions.

"There was an inverse association between ever-use of HRT and colon (OR=0.7), rectum (OR=0.5) and liver cancer (OR=0.2), with a consistent pattern of protection for duration of us," the investigators report. The data also show an excess risk associated with HRT for gallbladder (OR=3.2), breast (OR=1.1), endometrial (OR=3.0), and urinary bladder cancer (OR=2.0).

"Most of the HRT studies have been conducted in Northern European countries and the United States," Dr. Fern�ndez said. "[Our] data from a Southern European population add useful information on the risk-benefit assessment of HRT among postmenopausal women."

He added that the current results "are in agreement with previous findings from studies conducted in other populations with a different pattern of HRT use," he said. The use of HRT is lower among the Southern European population of women compared with the population in Northern European countries and the U.S.

Int J Cancer 2003; 105:408-412.