Dear Dr. Roach: I am a 65-year-old with high risk for breast cancer, and I have osteoporosis. I have an annual MRI and mammogram, and I’m on Prolia twice a year. My question regards a suggestion from my oncologist to take low-dose tamoxifen for prevention of breast cancer, along with the MRI and mammogram screenings. He has said tamoxifen, in addition to Prolia, might help with my osteoporosis. I read articles on it, and no one, not even my breast surgeon, has really indicated whether I should take tamoxifen.
I am unsure who to ask, so I am reaching out to you in hopes you may know more. Could you please share your thoughts?
Anon.
Nobody knows your breast cancer risk like your oncologist does, but the data from clinical trials consistently shows that tamoxifen reduces the risk of breast cancer in high-risk women. (The studies defined high-risk as a risk greater than 3% in the next five years.)
Tamoxifen also does indeed reduce the risk of osteoporotic fractures. However, these benefits are relatively small. There were seven fewer breast cancer diagnoses and three fewer non-vertebral fractures among 1,000 women who took the medicine for three to five years. Five years is the most commonly recommended course.
There are potential harms as well. Blood clots are more likely, with about five additional cases of blood clots among the 1,000 women who were studied. There also was an increased risk of endometrial cancer — about four cases per 1,000 women.
Low-dose tamoxifen (5 mg, which can be taken as 10 mg every other day) seems to have the same benefits as the standard dose (20 mg daily) and should have lower risks, but the two have not been directly compared.
Given that the medicine has both risks and benefits, tamoxifen is most useful in women with a higher breast cancer risk; women who already have osteoporosis or are at high risk; women who are at a lower, or zero, risk for endometrial cancer (such as those who have had a hysterectomy); and women who do not have a personal or family history of blood clots.
I want to reemphasize that your oncologist has the most detailed understanding about your personal risks and benefits, and if he’s recommended it, I recommend you give it strong consideration.
Dear Dr. Roach: I am a healthy 70-year-old woman who currently takes 250 mg of Plaquenil daily for hair loss. I was recently diagnosed with the early stages of age-related macular degeneration (AMD), for which I have no symptoms. I started taking the AREDS 2 supplements that my ophthalmologist recommended.
Because Plaquenil has a connection to retinal damage, are you concerned about prescribing this drug, even if it’s at a low dose?
L.M.
Hydroxychloroquine is an antimalarial drug that is used for some rheumatic conditions, such as systemic lupus, and for some less-common types of hair loss (called scarring alopecias). I am not aware of evidence for using hydroxychloroquine for female pattern hair loss, the most common type of hair loss for women in their 70s.
Even though the risk of eye disease is small at this dose, given your history of AMD, I recommend you see an eye doctor for regular examinations (usually yearly). You should stay alert for any changes in vision and seek prompt attention if you note any.
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