The prevention of breast cancer

Effects of letrozole or tamoxifen coadministered with a standard stimulation protocol on fertility preservation among breast cancer patients

PURPOSE

To assess the effects of letrozole or tamoxifen coadministration on fertility preservation treatment outcomes.

METHODS

Retrospective cohort study of 118 breast cancer patients undergoing fertility preservation treatment between 2008 and 2018. Patients who received letrozole (n = 36) or tamoxifen (n = 30) were compared to controls (n = 52) who underwent standard ovarian stimulation protocols. The primary outcome measures included the number of retrieved oocytes, mature oocytes (MII), fertilization, and top-quality embryo rates. The secondary outcome measures included duration of stimulation, gonadotropin dose and peak estradiol level.

RESULTS

The number of oocytes retrieved, MII oocytes, fertilization rate, duration of stimulation, or gonadotropin dose were similar in the letrozole and tamoxifen groups, compared to controls. Top-quality embryo rate was lower in the tamoxifen group compared to controls (25% vs 39.4%, respectively, P = 0.034). The abnormal fertilization rate was higher in the letrozole group compared to controls (7.8% vs 3.60%, respectively, P = 0.015). A stepwise logistic regression analysis revealed that letrozole and peak estradiol were significantly associated with abnormal fertilization (OR 11.94; 95% CI 2.35-60.4, P = 0.003 for letrozole and OR 1.075; 95% CI 1.024-1.12, P = 0.004 per 100 unit change in estradiol).

CONCLUSIONS

There may be a negative effect of letrozole or tamoxifen on fertilization and embryo quality, in fertility preservation cycles. Further studies are needed to confirm these findings.

The Role of Non-Steroidal Anti-Inflammatory Drugs in the Chemoprevention of Breast Cancer

Epidemiological evidence suggests that non-steroidal anti-inflammatory drugs (NSAIDs) which act as cyclooxygenase (COX-2) inhibitors may reduce breast cancer incidence by up to 20%. These agents are often taken for pain relief by older women with osteoarthritis. Age is the major risk factor for breast cancer in women with 50% cases being diagnosed in those aged >65 years. NSAIDs reduce serum estradiol by 17% in post-menopausal women and since most of these who develop breast cancers have estrogen receptor positive tumours; this suggests a possible preventative role. Careful use of these agents could provide a strategy for both relief of symptoms of osteoarthritis and also breast cancer prevention. Instead of conducting a randomised trial, proof of efficacy could be from an adequately powered cohort study within the breast screening programme.

Breast cancer and fertility preservation

Many women affected with breast cancer are in their reproductive prime and at the time of their initial diagnosis have not yet started or completed their families. Improvements in outcomes for patients with breast cancer means longer survival times and oftentimes cures. Unfortunately, many of the treatments, while life-saving, are toxic to the finite supply of oocytes and diminish a woman's chance of future childbearing. After the initial shock of the cancer diagnosis has worn off, women are coming to the realization that their diagnosis is not a death sentence. Women that have not completed their families need to be informed about available options to protect their reproductive organs from the cancer treatments. The currently available options for fertility preservation should be discussed with every patient who is in their reproductive years prior to initiating any treatments. Fertility specialists should work closely with oncologists to counsel patients about the risks, if any, of the recommended treatment on their future fertility and discuss options to preserve potential fertility before starting treatments.

Fertility preservation in young women undergoing breast cancer therapy

Breast cancer accounts for one third of all neoplasms seen in reproductive-age women and affects tens of thousands of women each year in that age group. The adjuvant chemotherapy regimens used for the treatment commonly affect fertility and cause premature ovarian failure. There have been recent advances in the field of fertility preservation, which can allow many of these breast cancer survivors to have children in the future. The most established option is embryo cryopreservation; oocyte cryopreservation can be considered in single women. Both of these approaches require approximately 2 weeks of ovarian stimulation beginning with the onset of the patient's menstrual cycle. Thus, it is crucial that these patients are referred to appropriate assisted reproduction centers as soon as they are diagnosed with breast cancer. Recently developed ovarian stimulation protocols using tamoxifen and letrozole can be used to increase the margin of safety in these patients. When and if a breast cancer patient does not have time to undergo ovarian stimulation prior to chemotherapy, ovarian cryopreservation for future autotransplantation can be offered as the last resort. The benefit of ovarian protection by gonadotropin-releasing hormone analogues is unproven and unlikely, and thus this treatment should not be offered as the sole method of fertility preservation.

Angiotensin-converting enzyme gene insertion/deletion polymorphism and breast cancer risk

BACKGROUND

The renin-angiotensin system plays an important role in homeostasis and lately, its main effector, angiotensin II, has been attributed with angiogenic and growth factor actions in the breast tissue. Previous studies have shown that the insertion/deletion (I/D) polymorphism in the angiotensin-converting enzyme (ACE) gene accounts for the variability of ACE plasma concentrations. The use of ACE inhibitors and the ACE I/D polymorphism may be linked to breast cancer risk. In this study, we evaluate the relationship of the ACE I/D polymorphism with breast cancer risk in Caucasian postmenopausal women.

METHODS

The ACE I/D polymorphism was genotyped in 4,117 women participants in the Rotterdam Study. Baseline information was obtained through a questionnaire. We conducted a logistic regression and survival analysis to assess the risk of breast cancer by the ACE genotype.

RESULTS

The DD carriers showed a significantly increased risk of developing breast cancer when compared with the II carriers (odds ratio, 1.86; 95% confidence interval, 1.06-3.27; P = 0.03). This association remained after adjusting for other risk factors, including body mass index, age at menarche, age at menopause, hormone replacement therapy, and hypertension. Our survival analysis showed that the cancer-free survival was significantly reduced in DD compared with II carriers (hazard ratio, 1.80; 95% confidence interval, 1.07-3.01; P = 0.03).

CONCLUSIONS

Our results suggest that the ACE I/D polymorphism plays an important role in breast cancer risk and disease-free survival in Caucasian postmenopausal women.