Mexican women between the ages of 40 and 49 fall into the group most frequently affected with breast cancer, a decade younger than their American counterparts, according to a study recently published in Cancer.
Breast cancer is the second most common cancer in Mexico and accounts for 10.6% of all cancers and 16.4% of cancers in women. The mortality rates from breast cancer in Mexico have doubled in the past 10 years and are expected to continue to increase as a significant portion of the population in Mexico ages. If the current breast cancer rates continue, researchers predict that Mexico will need to triple its hospital resources by the year 2020.
Researchers in Mexico analyzed data from the database of the Histopathologic Registry of Malignant Neoplasms (HRMN) in Mexico City and evaluated the ages of women at the time of breast cancer diagnosis. The median age of Mexican women at the time of breast cancer diagnosis is 51, compared with a median age of 63 in the U.S. Furthermore, 45.5% of breast cancer cases in Mexico occur in women below the age of 50, whereas only 25% of breast cancer cases in the U.S. occur in women under 50.
While the study does not explain the reason for the significant age disparity among Mexican and American women with breast cancer, it does indicate a need for revising the current guidelines for breast cancer screening in order to accommodate the age difference and increase the chances of detecting breast cancer early when treatment is most likely to produce a cure. The current recommendation in Mexico is to begin annual screening with mammography at the age of 50, which leaves almost half of Mexican women unscreened and at risk. Many breast cancers in Mexico are not diagnosed until they have reached advanced stages because of a lack of information and resources. The researchers recommend beginning breast cancer screening at the age of 35.
The results of this study indicate a need for revised guidelines and a wider dissemination of information in order to increase the chances of diagnosing breast cancers at early stages when they are most treatable. Although the results of this study confirm that Mexican women are developing breast cancer at a younger age, several questions remain unanswered regarding the reasons behind the disparity between Mexican and American women. Future research may help to unravel this mystery. (Cancer, Vol. 91, No. 4, pp. 863-868, 2001)