Figure 1: Analytical Framework (Text Description)

Ovarian Cancer Prevention

Figure 1: Analytical Framework (Text Description)

Figure 1 depicts the key questions within the context of the PICOTS (population, interventions, comparators, outcomes, timing, setting) described elsewhere in this document. Women at risk for ovarian cancer, by virtue of having at least one ovary, can use OCs for contraception or other indications at various points during their reproductive years, or use alternative methods of contraception (including no contraception). The difference in the incidence of ovarian cancer between OC users and nonusers provides an estimate of effectiveness of OCs in preventing ovarian cancer (KQ 1). Factors such as the age of starting and stopping OC use, the dose/formulation of OC, and the number and timing of intervening pregnancies (and possibly lactation) may modify this effect (KQ 2). Different subpopulations of women (e.g., based on age, family history, the presence of BRCA1/BRCA2 mutations, or parity) may have different underlying risks of ovarian cancer and/or different responses to OCs (KQ 3). OCs have other benefits, including reducing the risks of conditions such as benign ovarian cysts, endometriosis, endometrial hyperplasia, or dysfunctional uterine bleeding (KQ 4). Because these conditions can lead to hysterectomy and/or oophorectomy, they may affect ovarian cancer risk indirectly. OCs also increase the risk of certain short-term (e.g., venous thromboembolism) and long-term (e.g., breast cancer, cervical cancer) adverse outcomes (KQ 5). The model, by quantitatively estimating the balance of these benefits and risks, may suggest combinations of patient characteristics and OC usage that indicate a role for OCs in primary prevention of ovarian cancer (KQ 6). Both the systematic review and the model should provide insight into key evidence gaps needed to be filled in order to definitively characterize the potential role of OCs in ovarian cancer prevention (KQ 7, not shown in analytic framework).

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