Fig 3.

Age-period-cohort period relative risks among US women age ≥ 50 years (North American Association of Central Cancer Registries Incidence, 1995 to 2008). The period relative risks by (A) age at ovarian cancer diagnosis, (B) race, (C) histologic subtype, and (D) US geographic regions associated with high (West South Central) and low (Mid-Atlantic) menopausal hormone therapy frequency. For most strata, the period relative risks declined from more than 1.0 before the 2002 referent period, after which the period relative risks were less than 1.0 (see text for further details).