Table 1.

Characteristics of included studies

Study (year)	Country	Age (year)	Sample size (test group)	Diagnostic method	Study design	Follow-up (year)	Adjustment for covariance
Alderman et al. [24] (1986)	USA	50–74	1520 (427)	No report	Case-control	1976–1980	Age, estrogen use, and relative weight
Hoffman et al. [16] (1993)	USA	≥ 45	348 (174)	Radiographs	Case-control	1987–1989	Age, hospital of recruitment, age group, and number of live births
Cumming et al. [12] (1993)	Australia	≥ 65	308 (174)	No report	Case-control	1990–1991	Age, body mass index, history of hormone therapy use, et..
Michaelsson et al. [11] (2001)	Sweden	50–81	4640 (1328)	No report	Case-control	1993–1995	Age, hormone therapy, parity, body mass index, etc.
Huo et al. [10] (2003)	China	≥ 50	354 (118)	Radiographs	Case-control	1994–1996	No report
Bjørnerem et al. [9] (2011)	Norway	50–94	3748 (335)	No report	Cohort	1974–2008	Age, height, body mass index, smoking, alcohol use, etc.
Crandall [15] (2017)	USA	50–79	92,980 (1185)	No report	Cohort	1993–2005	Age, race-ethnicity, smoking status, body mass index, etc.