Table 2:

Summary of associations of established risk factors with type and histology of endometrial cancer

Risk factor	Type I	Type II	Endometrioid	Serous	Carcinosarcoma	Clear cell
Obesity	+++	++	+++	++	++	++
Diabetes	+	+	+	+	NA	NA
Metabolic syndrome	+	+	+	+	+	+
Nulliparity	++	+	++	+	+	NA
Infertility	+	+
Early age at menarche	+	++	+	++	NA	NA
Late age at natural menopause	--	NA
Breastfeeding	-	NA
Combination oral contraceptives	--	--	---	NA	NA	--
Intrauterine device use	-	NA
Menopausal estrogen plus progestins	--	NA
High cumulative doses of tamoxifen				++	++
Cigarette smoking	--	--	--	--		NA
Moderate-to-vigorous physical activity	--	--
Family history	+	++

Red indicates that the factor is positively associated with risk of the particular subtype.

⁺⁺⁺indicates a strong association (RR/OR ≥5.0),

⁺⁺a moderate association (RR/OR, 2–5), and

⁺, a modest association (RR/OR <2).

Green indicates that the factor is negatively associated with risk of the particular subtype.

^---, a strong association (RR/OR ≤0.6);

^--, a moderate association (RR/OR, 0.6–0.8); and

^-, a modest association (RR/OR ≥0.8).

Blue (N/A) indicates the factor is not associated with risk of the particular subtype