Published case reports of a possible association between meningioma and breast carcinoma are not uncommon in the literature. Four published analytic studies have addressed this suggested association specifically. Three of these studies reported significant associations, with relative risk estimates mostly between 1.5 and 2.0. The other study reported relative risk point estimates near 1.5, but confidence intervals included 1.0. The current study was a population-based, retrospective cohort analysis that evaluated the risk of subsequent breast carcinoma in women who were diagnosed with meningioma and the risk of subsequent meningioma in women who were diagnosed with breast carcinoma.
The measure of association is the relative risk and is reported as the standardized incidence ratio (SIR). Using western Washington State cancer registry data and intercensal population estimates for western Washington State, incidence rates of second primary tumor were compared between identified meningioma and breast carcinoma cohorts and the general population for the years 1992–1998.
The risk of breast carcinoma after patients were diagnosed with meningioma (SIR) was 1.54 (95% confidence interval [95% CI], 0.77–2.75). The risk of meningioma after patients were diagnosed with breast carcinoma was 1.40 (95% CI, 0.67–2.58), and the risk of meningioma after patients were diagnosed with invasive breast carcinoma was 1.64 (95% CI, 0.79–3.02). In each combination for age groups ages > 50 years, risks were elevated, but the confidence intervals included 1.0.
These results suggest that the risk of meningioma among women who have experienced breast carcinoma and the risk of breast carcinoma among women who have experienced meningioma are elevated moderately. Shared risk factors may account for the relatively week bidirectional associations seen in this and other studies. Cancer 2002;94:1626–35. © 2002 American Cancer Society.