[Retracted] Breastfeeding and Reduced Risk of Breast Cancer: A Systematic Review and Meta-Analysis

Table 1

Characteristics of the studies considered for meta-analysis.

Characteristics	[9]	[10]	[11]	[12]	[13]
Year of study	2000	2010	2013	2000	2003
Type of study	Case–control study	Case–control study	Cohort study	Case–control study	Prospective study
Total participants	808	800	26680	2087	110604
Breast cancer cases reported	404	400	148	706	360
Breastfeeding only cases	N/A	N/A	10336	1155 (380 cases, 775 control)	57,440
Duration of lactation (cases)
0 months	32	23	N/A	173	53164
1–6 months	58	62	N/A	262	45591 (1-12 months)
7–12 months	109	112	N/A	78	45591 (1-12 months)
13–23 months	133	122	N/A	30	7265
≥24 months	72	81	N/A	10	4584
Country	China	Tunisia	Japan	Germany	Korea
Study area	Research based on association between breast cancer and lactation (China Province)	Case-control study on breastfeeding and cancer risk reduction, Tunisia	Lactation pattern and cancer risks due to hormones, Japan	Breast cancer risk and breastfeeding in women above 50 age (Germany)	Duration of lactation and breast cancer association (Korean study)
Study outcome	The study concluded that prolonged lactation leads to decrease in breast cancer risk	Inverse association was established between breastfeeding and breast cancer	A link between lactation pattern and risk of hormone-related breast cancer was established where lactation reduces chances of breast cancer but the pattern of lactation with duration was important	Reduced risk of breast cancer in breastfeeding women	Lactation leads to decrease in breast cancer in women (premenopausal)