Hormone replacement therapy…timing is everything, right?

Posted by Liz on Jan 31, 2011 in breast cancer, HRT | 5 comments

Hormone replacement therapy (HRT) continues to be a hot topic in the menopausal world. And no wonder! Because the deeper we dive into the controversies, the more information we seem to learn about its dangers.

If you search for hormone replacement or HRT on this blog, you’ll find that the dialogue has nothing but consistent. And while naysayers may try to accuse me of a personal vendetta against hormones, it’s actually not the case. I started Flashfree for several reasons, the most important being that I wanted to provide enough information about menopause and aging and treatment strategies to enable women to think on their feet, consider the facts and have intelligent dialogues with their peers and practitioners before making any decisions that could affect their health and wellbeing as they grow older. Moreover, although I am a strong proponent of alternative strategies to combat the unpleasantries of dwindling hormones, I still believe strongly in the benefits of certain Western approaches to treating illness. However, I also a strong believer in integrative strategies that combine the best of our knowledge in an individualized fashion; my mantra is ‘treat the individual, not the masses.’ Hence, when I read about the history of the menopause in general and HRT in particular, what I see is disease mongering at its finest, examples of fear and loathing and mostly, a disrespect of women. And I care too much about women’s health to remain silent.

Last Friday, several of my colleagues sent me a link to the following study:

“Breast cancer risk in relation to the interval between menopause and starting hormone therapy.”

This newly-published study in the Journal of the National Cancer Institute is one of the largest to date since the findings of the now infamous Women’s Health Initiative (WHI) study linking Preempro to breast cancer. In it, investigators used observational information culled from over a million postmenopausal women in the United Kingdom to determine how type and timing of hormone therapy might influence the risk of developing breast cancer.

A bit of context is necessary for those of you who are unfamiliar with the major criticisms of WHI, namely that that the women studied were not representative of the normal menopausal population, were older, started hormone therapy later in life (i.e. >5 years from when menopause started) when their risks for disease were greater, and that the type of hormone replacement, namely the progestin component, were not taken into consideration. WHI was also criticized for not focusing on the small percentage of women in the study who took estrogen-only and were not at greater risk for breast cancer. (If you want to read more about that particular issue, check out the write up on data presented at this past year’s San Antonio Breast Cancer Conference.)

In the UK study, the average age of participants was 56.6, considerably younger than the study population in WHI. More than half (55%) of participants reported having used hormones at some point and 35% were current users, and the rest, had never used hormone therapy. Study participants were matched by socioeconomic status, childbirth information, BMI, physical activity, alcohol consumption and smoking to insure that these factors did not influence the study findings.

Overall, 15,759 breast cancers developed and were diagnosed approximately a year and a half after the last point of contact:

• Despite contentions by some experts that starting combination hormonal therapy within 5 years of menopause is safe, women between the ages of 50 and 50 who began HRT less than 5 years after menopause had the highest rates per year of breast cancer — .61% per year — that twice that of women who had never used hormones (.31%).
• Current users of estrogen also demonstrated increased breast cancer rates (.43%) who started hormones within or less than 5 years after menopause started.
• The risk of developing breast cancer was roughly 1.5 times higher among women on combination hormone therapy who started within 5 years than women who started 5 year or more from menopause.
• The risk of developing breast cancer among past users of hormonal therapy tended to decline over time after use of hormones stopped, and within 14 years, were almost equivalent to never users.

Mind you, the study is not without fault and may be criticized on the basis of the fact that it relied on observational information rather than randomized controlled results. In other words, data were collected and then analyzed based on what they inferred.  The research might also be questioned due to the fact that information about use of hormones was reported over a year before cancer was diagnosed, thereby possibly leading to mischaracterization of hormone users/non users and estimates of the risk for developing breast cancer. Nevertheless, the researchers say that taking these factors into account, breast cancer risk among hormone users regardless of type, would have increased by a factor of at least 1.2.

The key take-away message from this new study is that it’s may be impossible to define the safest parameter for using hormone therapy. For certain women, HRT may never be safe. For others who are willing to risk life-threatening conditions for fewer hot flashes, HRT may be worth the gamble. As always, ask the hard questions.

Timing is everything, right? Maybe not when it comes to hormone replacement.