Lannin DR, Mathews HF, Mitchell J, Swanson MS, Swanson FH, Edwards MS.
Influence of socioeconomic and cultural factors on racial differences in late-stage presentation of breast cancer.
JAMA 1998;279(22):1801-7.

This study evaluated how race, socioeconomic factors and cultural factors interact to influence breast cancer stage at diagnosis. All patients diagnosed with breast cancer from 1985 to 1992 at the only inpatient treatment facility in a community in North Carolina (where 95% of residents receive inpatient care when needed) were eligible for the study. Interviews were completed with 80% of those eligible; 58% of the interviews were completed within 3 months, and 90% within 3 years of the diagnosis. A randomly selected sample was chosen from women residing in the surrounding community as a control group. Interviewers were matched to patient and control groups by race.

A total of 17.4% of the patient sample presented with advanced-stage disease. Being African American (OR=3.0, 95% CI=1.9 to 4.7), having a per capita income of $10,000 or less, being unmarried, and lacking private health insurance each had a major impact on disease stage. Additionally, delaying treatment seeking due to money or transportation difficulties was associated with late-stage presentation. Among the cultural and psychosocial factors, not having a regular doctor and not seeing a regular doctor in the past year were associated with late-stage disease, as were folk beliefs about cancer incidence and progression, religious beliefs about cancer causes and treatment, beliefs about how men react to breast cancer in women, perceived risk of cancer, and knowledge about breast cancer. Folk beliefs, religious beliefs, and beliefs about fatalism and relationships with men were more common among African American women. Knowledge about breast cancer was more common in whites. Health care utilization did not vary by race. The distribution of these psychosocial and cultural factors was similar in the patient population and in the control population, indicating that these beliefs did not result from experiences related to having breast cancer or interacting with the health care team.

In multivariate models, the OR for race decreased from 3.0 to 1.8 when other socioeconomic factors were added to the model and when psychosocial variables were added to the model, and it dropped to 1.2 when all variables were added. The authors state, "It appears that both SES and cultural variables are strong confounders of race and together can largely account for the effect of race on late-stage disease presentation." It might be more accurate to consider cultural factors as mediators of the race effect.

The authors note that a previous study found that women's knowledge and beliefs had very little influence on the use of screening mammography and that the most important factor was whether it was recommended by a physician. In this study, both early and late stage cancers were most frequently found by the patient. Thus, the authors conclude, "The most important effect of the cultural beliefs is that they lead to delayed presentation once women as developed a palpable breast abnormality." They further conclude that these findings have important implications for physicians. "Physicians must be aware of the cultural and psychosocial biases of their patients and address them in a culturally sensitive way". There are also implications for cancer education and public health interventions. "By recognizing that at least part of the problem (in breast cancer diagnosis stage) is cultural, it may be possible to modify key beliefs in a way that would lead to earlier breast cancer diagnosis and still be consistent with the underlying cultural attitudes of the target population."