Can any one explain what is the exact link between the breastfeeding and reduce risk of breast cancer. Some researchers are of the view that breastfeeding delays the menstruation cycle which could be the link, but I was just wondering if there is any particular report published.
One of reason may be the hormone levels in estrous cycle. Both estrogen (Fillmore et al. 2010.PNAS) and progesterone (Joshi et al. 2010.Nature) have been shown to expand breast cancer stem-like cells/mammary stem cells and stem or progenitor cells might be the cellular target of breast cancer.
In addition to changes in the exposure to estrogen/progesterone during lactation, there is also quite complex association between prolactin, breastfeeding and breast cancer risk. Prolactin displays tumor-promoting effects and its blood levels are high during lactation; however, non-lactating women after previous long duration of breastfeeding reportedly tend to have low blood levels of prolactin, which may be associated with the decreased risk of breast cancer. Another possible mechanism is decreased exposure of mammary epithelium to potentially carcinogenic cholesterol beta-epoxide in lactating women.
I compared 85 breast cancer cases with 85 healthy age and marital status adjusted control in some marital factor such as breast feeding time, but there was no significant difference between the groups in term of breast feeding time.
The results of case-control studies had been inconsistent in that matter and they reported statistically significant inverse association, but also inverse association lacking statistical significance, and some reported no apparent association. The duration of breastfeeding was inversely related to the risk in some studies, while others found association only when compared ever lactating vs never lactating parous women. Anyway, causal relationship between an exposure and an outcome is better supported if there is a significant graded response to a graded exposure (in this case lower risk at longer breastfeeding vs shorter breastfeeding). Some associations were not identified due to study design, analysis employed, combined with disease heterogeneity. On the other hand, one nested case-control study that used conditional logistic regression and limited the analysis to the cases at
@ R M Bazai
Please have a look at these useful references.
Chapter Breastfeeding and Reduced Risk of Breast Cancer in Women: A ...
Article Breastfeeding and its Relationship with Reduction of Breast ...
Article Breastfeeding and Breast Cancer Risk Reduction: Implications...
Article Breastfeeding and Reduced Risk of Breast Cancer in an Icelan...
Thanks!
Hello, one reason is that lactation delays when women start menstruating again after giving birth. This reduces lifetime exposure to hormones such as estrogen, which are linked to increased risk of breast cancer.
Breast cancer is the commonest cause of cancer death in women worldwide. Rates vary about five-fold around the world, but they are increasing in regions that until recently had low rates of the disease. Many of the established risk factors are linked to oestrogens. Risk is increased by early menarche, late menopause, and obesity in postmenopausal women, and prospective studies have shown that high concentrations of endogenous oestradiol are associated with an increase in risk. Childbearing reduces risk, with greater protection for early first birth and a larger number of births; breastfeeding probably has a protective effect. Both oral contraceptives and hormonal therapy for menopause cause a small increase in breast-cancer risk, which appears to diminish once use stops. Alcohol increases risk, whereas physical activity is probably protective. Mutations in certain genes greatly increase breastcancer risk, but these account for a minority of cases.
Review Epidemiology of breast cancer
Timothy JKeya, Pia K Verkasaloa, Emily Banksa
Volume 2, Issue 3, March 2001, Pages 133-140
The longer women breast feed the more they are protected against breast cancer. The lack of or short lifetime duration of breastfeeding typical of women in developed countries makes a major contribution to the high incidence of breast cancer in these countries.
Breast cancer and breastfeeding: collaborative reanalysis of individual data from 47 epidemiological studies in 30 countries, including 50 302 women with breast cancer and 96 973 women without the disease*
Author: Group on Hormonal Factors in Breast Cancer
THe LANCET Volume 360, Issue 9328, 20 July 2002, Pages 187-195
The report offers several possible explanations for how breast-feeding lowers breast cancer risk. One reason is that lactation delays when women start menstruating again after giving birth. This reduces lifetime exposure to hormones such as estrogen, which are linked to increased risk of breast cancer.
www.medicalnewstoday.com
The studies confirm that the breastfeeding significantly reduced the breast cancer risks.
Breast feeding - Release of prolactin hormone will reduce the chance of brest lumps .
Yes, there is a strong relationship because breast cancer in lactating women is rare. Only about 3 percent of women develop breast cancer while breastfeeding
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