Breastfeeding and Breast Cancer Risk

  • 07 Aug, 2020
  • By UHAPO
  • 344


Breast cancer is the most common gynecological tumor among women, accounting for almost 1 in 4 cancer cases between women.[1] In India, accounts for 14% of all cancers among women.[2] 


Many clinical pieces of evidence have indicated that early age at menarche, later age at menopause, low-parity, late age at first pregnancy, excessive use of oral contraceptive and hormone replacement therapy, alcohol intake and lack of breastfeeding increases the risk of breast cancer. Although some risk reduction might be achieved with the prevention.[3]


The primary risk factors for breast cancer are not easily modifiable because they stem from prolonged endogenous hormonal exposures, although prevention through the promotion of breastfeeding, particularly with longer duration, may be beneficial. 


Importance of Breastfeeding


Breastfeeding plays a vital role in maintaining good physical and emotional health for the mother during the puerperium, the lactation period, and all her future life.


According to the National Cancer Institute, some research suggests that the risk of breast cancer is temporarily higher in the years following pregnancy and childbirth. This increased risk may be the result of hormonal changes during pregnancy. [4]


Can breastfeeding help reduce the risk of breast cancer?


In the long term, the protection offered by breastfeeding is greater for premenopausal women but also persists for postmenopausal women even after 50 years since the first lactation.


The months of pregnancy and breastfeeding will decrease the number of menstrual cycles that a woman has in her lifetime. This will reduce her exposure to hormones particularly androgens further reduces the rates of cell proliferation and differentiation.[5]


Cells with mutations arising in mammary tissues increase the risk of certain cancers. Tissue exfoliation and epithelial apoptosis at the end of the breastfeeding period may contribute to the reduction of the probability of these cells and may help in decreasing the cancer risk. [6]


Only 3% of women with breast cancer develop the condition when they are breastfeeding. [7]


It is estimated that the risk of breast cancer can be reduced by more than 4% for each year of breastfeeding.[6]


Protective effects of breastfeeding appear to be stronger, the longer a woman breastfeeds her first child and cumulative, such that increased lifetime duration of lactation over multiple children confers greater protection against breast cancer. 


Compared with women who did not breastfeed, lactating women reported:[7]


  • Seeking medical care less often.

  • A lower frequency of respiratory, cardiocirculatory, and gastrointestinal diseases.

  • Fewer symptoms related to emotional problems.


Breastfeeding also has additional short and long term effects on maternal health. (Table.1)[7]



Long term

Uterine Involution, Reduced bleeding, reduced infection, and lactational amenorrhea


Reduced adiposity, and weight, reduced postpartum depression, reduced stress, and anxiety, Improved body image

Reduced Cancer(Breast, ovarian, endometrium), endometriosis, diabetes, osteoporosis, blood pressure, and cardiovascular diseases, metabolic syndrome, rheumatoid arthritis, Alzheimer disease, and multiple sclerosis


Does breastfeeding prevent any other cancers?


The latest studies show that women who breastfeed also lower their risk of developing both endometrial and ovarian cancers. And, just like with breast cancer, the longer a woman breastfeeds, the lower her risk becomes.




Significant reductions in the risk of developing breast cancer have been observed with longer periods of breastfeeding. non-breastfeeding mothers have been shown to have a higher risk of reproductive cancers. Hence, Women should be encouraged to breastfeed their babies as it improves the quality of life for mothers. 




  1. Bray F, Ferlay J, Soerjomataram I, Siegel RL, Torre LA, Jemal A. Global cancer statistics 2018: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries. CA Cancer J Clin. 2018;68(6):394-424



  1. Breast cancer awareness month 2019, Available at: https://www.nhp.gov.in/breast-cancer-awareness-month2019_pg, last access on 14th July, 2020


  1. do Carmo França-Botelho A, Ferreira MC, França JL, França EL, Honório-França AC. Breastfeeding and its relationship with reduction of breast cancer: a review. Asian Pac J Cancer Prev. 2012;13(11):5327-5332.



  1. Reproductive history and cancer risk, available at: https://www.cancer.gov/about-cancer/causes-prevention/risk/hormones/reproductive-history-fact-sheet#q5


  1. Lactation and risk of cancer, Available at:  https://www.wcrf.org/dietandcancer/exposures/lactation-breastfeeding,


  1. Del Ciampo LA, Del Ciampo IRL. Breastfeeding and the Benefits of Lactation for Women's Health. Aleitamento materno e seus benefícios para a saúde da mulher. Rev Bras Ginecol Obstet. 2018;40(6):354-359 



  1. Lyons TR, Schedin PJ, Borges VF. Pregnancy and breast cancer: when they collide. J Mammary Gland Biol Neoplasia. 2009;14(2):87-98.