[Risk of invasive breast cancer in Mexican population and patterns of screening and prophylaxis]

The risk of invasive breast cancer based on the Gail model in Mexican population as well patterns of screening and prophylaxis in high risk patients are unknown.

Ambulatory adult female patients assisting to the breast clinic in a tertiary referral center in Mexico City were included. Personal history of invasive or non-invasive breast cancer was an exclusion criteria. A questionnaire was applied and the 5-year and lifetime risk of invasive breast cancer based on the Gail model were calculated. Patterns of screening mammography and prophylaxis in high risk patients were identified.

One-thousand patients were included from January through June, 2002. Mean patient age was 50 years (20-85). Fifty-six percent of patients were postmenopausal. One hundred and four patients (10.4%) had at least one first-degree relative with breast cancer. From 790 patients older than 40, only 48% reported yearly screening mammogram. According to Gail model the mean calculated risk of invasive breast cancer during the following 5-years was 1.2% for the entire group (range 0-5.7%) and the mean lifetime risk was 9.3% (range 1.4-30.1%). There were 256 patients (25.6%) with a 5-year risk greater than 1.66%, proportion significantly lower than in American population. From this group only 57% reported use of annual mammogram. No patient received prophylaxis with tamoxifen.

The proportion of high risk patients in this sample of Hispanic population is lower than that reported in American, predominantly white population. Screening and prophylaxis recommendations are not followed by the majority of Hispanic patients. This cohort will be followed prospectively in order to validate the Gail model in this subgroup of patients.