A recent study published in Lancet1 by collaborative group on hormonal factors in Breast Cancer is an individual participant meta-analysis of the worldwide epidemiological evidence on type and timing of menopausal hormonal therapy (MHT) and breast cancer risk.They have taken women‘s age at first use, duration of MHT and time elapsed since she stopped MHT. The mean age of menopause and mean of starting MHT was same i.e. 50 years. Interpretation has shown an increased risk of breast cancer in developed countries.
The largest Women’s Health Initiative randomised clinical trials added to our understanding of the benefits and risks of MHT. The estimated additional risk of breast cancer based upon WHI data was three additional cases per 1000 women for five years of combined conjugated estrogen progesterone use.For conjugated estrogen alone group, the estimate was 2.5 fewer cases of breast cancer per 1000 women.
Similar to some epidemiological and observational studies, the Lancet study has shown an association between the use of MHT and breast cancer. It has elaborated the risk related to different preparations available and timing of hormonal intake which would help in counselling of menopausal women . Although obesity is considered an independent risk factor for breast cancer, MHT did not have an adverse effect in obese woman.
This study has shown an association with obesity and breast cancer. Association of obesity with other cancers is well known.Common lifestyle factors such as reduced physical activity, obesity and alcohol consumption (>2 drinks a day) are associated with similar or greater risk of breast cancer compared with MHT. The most important modifiable risk factor for postmenopausal breast cancer is weight gain during adult life; Public health messages highlighting the importance of minimising weight gain is important for prevention of breast cancer.2 In the Indian context the average age of menopause is 47.3 years and breast cancer incidence peaks at 39 to 49 years of age. A recent study from breast cancer registry from various metro cities of India has stated it be ranking topmost with a statistically significant increase in age adjusted rate over time2, 3. Many of these cancers are HER2 positive and ER/PR negative, orHER2/ER/PR all three negative (31% triple negative).4
However there is paucity of data regarding use of MHT from India, but one should not deny postmenopausal woman MHT just on the basis of anticipated fear of increased breast cancer risk. There is need of more health awareness especially in our set up where most common cancer is the breast cancer and gets diagnosed in advanced stages and associated with higher mortality. One cannot just neglect the symptomatic menopausal women for the presumed assumption of increased risk of breast cancer, the data needs to be analyzed in local risk perspective. Prescription of menopausal hormone therapy (MHT) appears to be a safe option for healthy, symptomatic women who are within 10 years of menopause or younger than age 60 years ,who do not have contraindications to MHT and are at low risk for breast cancer .Each case needs to be individualized and women must be informed the risk of breast along with beneficial effects of MHT to help her in making the final decision.Like all medicines, HT needs to be used appropriately ,judiciously and reviewed .
Thus the findings of this new study should be used as a helpful information on counselling women regarding MHT and much more serious association of obesity as a risk factor for breast cancer.
- Collaborative Group on Hormonal Factors in Breast Cancer. Type and timing of menopausal hormone therapy and breast cancer risk: individual participant metaanalysis of the worldwide epidemiological evidence. Lancet 2019
- National Cancer Registry Programme- India (Three Year Report of the Population Based Cancer Registries 2012 – 2014 & Consolidated Report of the Hospital Based Cancer Registries 2012 – 2014).
- Malvia S, Bagadi SA, Dubey US, SaxenaS.Epidemiology of breast cancer in Indian women. Asia- Pac J of clin Oncol 2017 doi : 10.1111/ajco.12661.
- Gurprataap S. Sandhu, Sebhat Erqou, Heidi Patterson, Aju Mathew. Prevalence of TripleNegative Breast Cancer in India: Systematic Review and Meta-Analysis. Journal of Global Oncology. Volume 2, Issue 6, December 2016. (412-21).