After HRT, Some Health Risks Remain
Researchers Examine Pros and Cons of Hormone Replacement Therapy
HRT and Health Risks: Findings
"We have some good news," says Rowan T.Chlebowski, MD, PhD, a medical oncologist at the Los Angeles Biomedical Research Institute in California and another study researcher. "The cardiovascular disease risk really ended once you stopped the hormones."
The risk for cardiovascular problems, including heart attacks, strokes, and lung blood clots, was comparable for the former users and the nonusers. While former HRT users had 343 such "events," nonusers had 323.
After the HRT was stopped, the risk of fractures was similar among former users and nonusers, indicating the protective effect of the hormones disappeared once they were stopped. The rates of colorectal cancer didn't differ in a significant way between the two groups, either, indicating the protective effects found with HRT against colorectal cancer disappeared, too.
The risk of breast cancer stayed elevated during the follow-up. "Women on HRT had a 27% increased risk" of breast cancer compared to nonusers, Chlebowski says. While 79 former HRT users developed breast cancer during the follow-up, 60 nonusers did. However, the differences are not statistically significant, Chlebowski says.
When looking at the breast cancer risk, say Heiss and Chlebowski, it may have been a bit too soon for the breast cancer risk to decline. "We do see a tendency toward the breast cancer risk going down," Heiss tells WebMD.
The other troubling cancer finding: "Women on HRT had a 24% greater risk of all [invasive types of] cancer compared to women on placebo," Heiss says. While 281 of the former HRT users developed cancer during the follow-up, 218 nonusers did. Still, Heiss says, "that is not overly alarming."
Chlebowski says the finding is "concerning" and warrants more study. Why other cancers, including lung cancer, were more common among former HRT users than nonusers is a mystery, he says.
Another Expert Weighs In
The new study does have some good news, says James Liu, MD, chairman of obstetrics and gynecology at MacDonald Women's Hospital, Case Medical Center, University Hospitals, Cleveland, who reviewed the findings for WebMD. Until 2001, Liu was one of the principal investigators for the Women's Health Initiative.
"The good news is that the effects for the vast majority of side effects appear to reverse," he says. "The breast cancer issue may take longer to resolve."