Population attributable risk for ovarian cancer

Area of Science:

• Epidemiology
• Oncology
• Public Health

Background:

• Ovarian cancer risk is associated with several factors including parity, oral contraceptive (OC) use, age at menopause, family history, and diet.
• Quantifying the population-level impact of these risk factors is crucial for prioritizing prevention strategies.

Purpose of the Study:

• To estimate the population attributable risks (PARs) for ovarian cancer associated with key risk factors in an Italian population.
• To determine the proportion of ovarian cancer cases that could theoretically be prevented by modifying these exposures.

Main Methods:

• A case-control study was conducted in Italy from 1983 to 1991, involving 971 ovarian cancer cases and 2758 control women.
• Multivariate relative risk estimates and PARs were computed for factors including parity, OC use, family history, age at menopause, and dietary habits (green vegetable intake, fat intake).

Main Results:

• Population attributable risks were estimated as 5% for nulliparity, 12% for never using oral contraceptives, and 4% for a family history of breast or ovarian cancer.
• Later age at menopause (>50 years) accounted for 16% of cases. Low green vegetable intake (24%) and high fat intake (7%) also contributed significantly.
• Combined, these factors explained 51% of all ovarian cancer cases in the study population.

Conclusions:

• Available knowledge on risk factors could theoretically explain over 50% of ovarian cancer cases in this Italian population.
• These findings quantify the potential scope for primary prevention of ovarian cancer through lifestyle and reproductive choices.