The American College of Obstetricians and Gynecologists advises that selective serotonin reuptake inhibitors, or SSRIs, can safely be used to treat hot flashes in some women with breast cancer.
And women who are able to become pregnant following breast cancer treatment can do so without increasing the risk of disease recurrence, according to the college.
The advice, published online Feb. 21 in Obstetrics and Gynecology as Practice Bulletin No. 126, is part of the college’s comprehensive new clinical guideline on the gynecological management of women who are being treated for – or who have been treated for – breast cancer (Obstet. Gynecol. 2012;119:666-82).
The guideline, which cites evidence from 166 published sources, covers such diverse issues as vasomotor symptoms; vaginal atrophy; contraception and fertility; uterine evaluation; and the treatment and prevention of bone loss in the context of current treatment regimens, which may include chemotherapy, hormonal treatments, radiation, and surgery.
"More and more women are living with breast cancer, and breast cancer treatments – particularly the hormonal therapies – have gynecological side effects," Dr. Mindy E. Goldman, lead author of the guideline, said in an interview.
"Ob.gyns. need to be aware of how these drugs work and know about any of the gynecological side effects," said Dr. Goldman, who is director of women’s cancer care for the department of obstetrics, gynecology, and reproductive sciences at the University of California, San Francisco.
For managing vasomotor symptoms such as hot flashes, the guideline recommends that – because hormonal therapy is generally contraindicated in women with hormone-positive breast cancer – an SSRI, an SNRI (serotonin norepinephrine reuptake inhibitor), or gabapentin be used instead. For women on tamoxifen, an SNRI is a better choice than an SSRI, because it avoids a potential interaction.
One SNRI, venlafaxine, was shown in randomized clinical trials to provide significant relief at low doses (75 mg) among women who had been treated for breast cancer. Gabapentin, an anticonvulsant used to control neuropathic pain in breast cancer patients, also helps relieve vasomotor symptoms at low doses, and may improve sleep quality. Pregabalin, a drug in the same class as gabapentin, also was seen as helpful, as was clonidine.
None of these medicines is licensed in the United States for the treatment of hot flashes.
Because chemotherapy, ovarian suppression, and aromatase inhibitors contribute to bone loss and increase fracture risk, the guideline recommends that pharmacologic therapy with bisphosphonates be considered for women who have T scores between –1.5 and –2.0, and be strongly considered for women with T scores less than –2.0, or who have a 10-year risk greater than 20% for a major fracture, or a 10-year hip fracture risk greater than 3%. Zoledronic acid was seen as a strong option among the bisphosphonates, and although raloxifene was generally well tolerated, vasomotor symptoms are among its reported adverse effects.
The guideline also recommends annual monitoring of women whose risks of bone loss significantly change as a result of treatment (for example, premenopausal women being treated with aromatase inhibitors). And vitamin D levels should be checked in women with breast cancer.
Up to 40% of women with breast cancer have severe vaginal dryness, and the topical hormonal creams, suppositories, and vaginal rings commonly used to treat vaginal dryness and atrophy have not been shown to be safe in women with breast cancer. Preference should be given to nonhormonal vaginal moisturizers, with hormonal treatments used on a short-term basis when nonhormonal options have failed. Testosterone supplementation, in patches or creams, remains without enough breast safety data to support it.
Contraceptives that are appropriate for women with breast cancer include barrier methods, the copper intrauterine device, and sterilization. Hormonal methods are contraindicated in women with breast cancer and are considered a risk even for women who have been cancer free for 5 or more years.
One exception may be the levonorgestrel-releasing intrauterine system, in which systemic absorption of levonorgestrel is minimal. However, the system has not been thoroughly studied with regard to long-term breast risk and should be considered only on a case-by-case basis, the guideline states.
Pregnancy following breast cancer treatment has not been shown to increase the risk of recurrence or mortality, according to a recent meta-analysis cited in the guideline (Eur. J. Cancer 2011;47:74-83).
But chemotherapy can compromise fertility, and 5-year use of tamoxifen may diminish a woman’s ovarian reserve before she may safely conceive. Therefore, many women of childbearing age will have difficulty becoming pregnant after treatment, and a fertility consultation at diagnosis is recommended so that advance planning can take place.