Lactose absorption in patients with ovarian cancer.

To determine whether lactase persistence might be related to ovarian cancer risk, in 1994-1995 the authors assessed the capacity to digest lactose by measuring breath hydrogen production after oral administration of lactose in 50 women with ovarian cancer and 100 healthy controls. All of the women came from Sassari (Sardinia), Italy, an area where the population has a high frequency of lactose malabsorption. Thirty percent of cases were lactose absorbers, as compared with 15% of controls. The odds ratio for ovarian cancer among lactose absorbers was 2.51 (95% confidence interval 1.10-5.68). These results provide some support for a role of lactose ingestion and galactose cytotoxicity in the pathogenesis of ovarian cancer.