The use of hormone replacement therapy to treat symptoms of menopause has been among the most controversial and confusing issues in the modern medical world.

Once touted as a potential godsend for women suffering from menopause-related hot flashes, night sweats and vaginal dryness, the therapy was under investigation through the Women’s Health Initiative until July 2002, when the research was abruptly halted because an elevated number of cases of breast cancer was detected in the study participants.

In the aftermath of that announcement, women around the world worried whether the therapy had put them at increased risk of developing breast cancer — a concern that appeared to be justified when a subsequent decline in breast cancer incidence was linked to widespread cessation of the therapy.

The July 2012 issue of a journal called Climacteric — the journal of the International Menopause Society — is devoted to revisiting the Women’s Health Initiative findings 10 years later and seeks to sort out what turned out to be true and untrue about the therapy’s impact on women’s health. In more than a dozen articles focusing on hormone replacement therapy’s relationship to breast cancer, cardiovascular disease, dementia and other key conditions, the authors (some of them involved in the original Women’s Health Initiative work) conclude that for younger women undergoing the therapy close to the time of menopause, the benefits generally outweigh the risks.

A common theme among the articles is that the initial, shocking finding that the therapy increases breast cancer risk didn’t hold up under closer scrutiny; when researchers teased out the data and played out its implications, it turned out that the increased breast-cancer risk was actually quite small. Moreover, the way the data initially were presented, the current authors note, obscured the differences among age groups and distance from the time of menopause among the study subjects. Sifting through that data reveals a “window of opportunity” during which the therapy’s benefits outweigh its risks, one of the articles notes. That window occurs before a woman turns 60 and/or within 10 years after menopause. Cheryl Iglesia, immediate past chair of the American Congress of Obstetricians and Gynecologists’ committee on gynecologic practice (and an associate ob-gyn professor at Georgetown University School of Medicine) says the publication appears to provide “a nice summary” of the changing thinking about the therapy over the past decade. (Iglesia saw only a summary of the publication before this blog was filed.)

“It’s useful in helping practitioners understand that a lot of the initial fear that was brought on 10 years ago by the alert and the stopping of the research” may have caused “a lot of women [to] have been adversely affected because we didn’t understand the implications in various populations.”

In particular, Iglesia says, women who undergo premature or surgically induced menopause have been ill-served; these women are likely to benefit greatly from hormone replacement therapy at little risk but have suffered from doctors’ reluctance to prescribe such therapy in the wake of the Women’s Health Initiative study.

“The bottom line,” Iglesia says, “is that practitioners and patients need to come face to face and individualize risk” by assessing the woman’s cardiovascular health, breast-cancer risk and other factors before deciding whether to pursue hormone replacement therapy.

Here’s a summary of some of the issue’s findings regarding the therapy and various health conditions:

— The increased risk of breast cancer related to estrogen-plus-progestin therapy (but not with estrogen-only therapy) is smaller than had been reported; women whose breast-cancer risk is otherwise low and who suffer from lots of menopausal symptoms may still benefit from the therapy.

— It appears that women using hormone replacement therapy have a large reduction — 40 percent — in colorectal cancer risk.

— The therapy appears to offer substantial bone-health benefits, including a reduction in fracture risk.

— The therapy appears to increase risk of dementia, though it’s not clear how that increased risk relates to the age at which a woman starts such therapy.

— A small increased risk of stroke is associated with hormone replacement therapy initiated near menopause; that risk increases as women start therapy at older ages. It’s possible that therapy patches carry lower stroke risk than pills, but that needs more research.

— Oral hormone replacement therapy increases the risk of venous thromboembolism (formation of blood clots in veins).

Have you used hormone replacement therapy? What do you make of the research surrounding its use?