The U.S.-Mexico border is a distinct region connecting two countries with interdependence in insuring the optimal health of the regional communities. Evidence suggests Latinas residing in the U.S.-Mexico border states have disproportionately higher breast cancer mortality rates compared to the majority of their counterparts in the interior of either country.39–42
For these reasons, reducing mortality from breast cancer through early detection has become a major priority for both governments and one of the principle objectives of the United States-Mexico Border Health Commission.42
Both the United States and Mexico now have national breast cancer screening programs that offer free/reduced-price mammographies; for instance, in the United States, there is the National Breast and Cervical Cancer Early Detection Program (NBCCEDP), which was established in 1990, and in Mexico, the first breast cancer mammography screening program was established in 2005 in Mexico City D.F. Such programs provide critical resources for breast cancer screening prevention for low-income, uninsured, and underinsured women. Variation in program availability and eligibility criteria, however, as well as the lack of awareness among providers and the community at large about the existence of these programs, may limit their potential impact.
The main findings of our study show that Mexican participants had higher levels of knowledge about breast cancer, although U.S. Latinas were more likely to have ever engaged in breast cancer EDPs. Among the risk factors included in multivariate analyses, age, education, and insurance status were significantly associated with a positive history of preventive screening behaviors.
The high levels of knowledge among Mexican study participants may be attributed to both the Mexican government and nongovernmental organizations, such as La Asociacion Mexican Contra el Cancer de Mama (Fundacion Cim*ab), that have launched widespread efforts to disseminate educational information in the fight against breast cancer since the early 2000s.43
These findings show that previous research suggesting a lack of knowledge on the part of Mexican women, including having little information about the importance of early detection,44
may underestimate the breast cancer knowledge of Mexican women living along the U.S.-Mexico border.
Even though Mexican participants were knowledgeable about breast cancer, we found low levels of mammography/breast ultrasound and CBE use. Among all Mexican participants, high knowledge level was associated with BSE only, as the majority of participants with both high and low knowledge levels reported to have never had a mammogram/breast ultrasound or CBE. One potential explanation for these results is that women's ability to undergo mammography/breast ultrasound and CBE largely depends on structural factors, including the availability of resources and insurance. In Mexico, data suggest there is an overall lack of access to screening mammography services, partly because of a shortage of units and trained personnel, and CBEs are often left out of routine clinical examinations.43–45
Second, >75% of participants in our Mexican cohort did not have insurance, which may decrease women's access to healthcare services and, therefore, potentially explain the large proportion of participants who have never obtained a mammogram/breast ultrasound or CBE.
BSEs are a method of detection that women can perform on their own once they have been properly educated on how to carry out the procedure. In the Guidelines for the Prevention, Diagnosis, Treatment, Control, and Epidemiologic Surveillance of Breast Cancer, published by the Secretaria de Salud in Mexico, there is a strong emphasis on promoting BSE as a method of secondary prevention of breast cancer; this report states it is a role of health service providers/agencies to teach BSE to all women who receive care in the health system.14
Accordingly, Mexican women may take advantage of this screening method largely because it does not rely on the presence of technology or equipment. Data support this notion, showing that approximately 90% of breast cancers diagnosed in Mexico are identified by the woman herself, with only 10% of those tumors in stage I.40,46
Further, although there is a plethora of evidence that points to BSE as ineffective in reducing breast cancer mortality in populations where the majority of cases are detected in early stages, there is little evidence available for developing countries, where cases are often detected in late stages.1
Knaul et al.1
suggest that in these instances, where the infrastructure and human resources for mammography are being developed, other options, such as BSE, may be useful screening modalities.
Among U.S. Latinas, the story is reversed; women have lower levels of breast cancer knowledge and higher levels of EDPs compared to their Mexican counterparts. Approximately 66% of U.S. Latina participants had ever had a mammogram, a finding that suggests mammography rates among U.S. border Latinas may be lower than mammogram rates observed from national data among all U.S. Latinas.47,48
Consequently, whereas the availability of breast cancer screening resources in the United States may explain the significant differences in EDPs between the U.S. and Mexican participants, breast cancer screening use among U.S. border Latinas may be lower than that see among other U.S. racial/ethnic groups.
Our findings that age, education, and insurance were all associated with breast cancer screening behaviors among U.S.-Mexico border Latinas coincide with existing literature on factors associated with the use of breast cancer screening among both U.S. and Mexican women.17,44,49–57
These factors appear to be universal in regard to predicting breast cancer screening behaviors and use among women55
and may serve as barriers to access of breast cancer screening services and cancer educational information.17,52,54,58
There are certain limitations to the current study. Our analysis focused on Mexican and U.S. Latina women seeking routine medical care at a community health center/clinic along the U.S.-Mexico border. Accordingly, our findings are most generalizable to similar, clinic-based populations and those who access medical care. Moreover, the present study had a limited total sample size (n=265) comprising 137 U.S. Latina women and 128 Mexican women, which also limits the generalizability of our findings.
Another limitation pertains to the study design. The current study was a retrospective, cross-sectional study that relied on participants' self-report, which is subject to recall bias. Specifically, information on EDPs was collected by self-report and, therefore, may not be completely accurate if participants encountered difficulties remembering their history of breast cancer screening use.
Lastly, the decision to include breast ultrasound with mammography may have affected participants' responses, particularly women who are unfamiliar with breast ultrasound. For those participants who had received a breast ultrasound as a diagnostic test, this may have caused an overestimation of mammography/breast ultrasound screening history. It is important to note that breast ultrasounds are not commonly used as the preferred breast cancer screening method in developed countries and that health promotion efforts may not typically include breast ultrasound in breast cancer prevention education. Our use of breast ultrasound was intended to enhance this binational research project, allowing us to make cross-cultural comparisons of breast cancer screening behaviors for both U.S. Latina and Mexican female populations.