The relationship between menstrual factors and breast cancer according to estrogen receptor status of tumor: a case-control study in African-American women.

BACKGROUND: Exposure to estrogen is a risk factor for breast cancer. Since estrogen executes its effect through estrogen receptors (ERs), the relationship between menstrual factors, which are estrogen-related, and breast cancer may be different depending upon ER status of tumors. This case-control study aimed to examine such a relationship according to ER status of breast cancer in African-American women. METHODS: Cases were 304 African-American patients pathologically diagnosed with breast cancer during 1995-1998, who were 20-64 years old and lived in 3 Tennessee counties. Controls were 305 African-American women without breast cancer, selected through random-digit dialing and frequency matched to cases by age and county. Information on menstrual factors (age at menarche, age at menopause, time from menarche to menstrual regularity, cycle length, and length of flow) and other risk factors were collected through telephone interviews. Estrogen receptor status of tumor samples was defined based on immunohistochemical measurement. Logistic regression analysis was used to calculate odds ratios and 95% confidence interval (CI). RESULTS: Compared to women with an average cycle length less than 28 days, the risks of breast cancer for those with longer length were 0.62 (95% CI, 0.36-1.06) and 0.56 (95% CI, 0.32-1.00) for ER-positive and ER-negative tumors, respectively. The corresponding odds ratio (OR) estimates were 0.42 (95% CI, 0.20-0.86) and 0.38 (95% CI, 0.16-0.90) for postmenopausal women. Other menstrual factors were not significantly associated with breast cancer for either ER status. CONCLUSIONS: Our results did not show a different menstrual factor/breast cancer relationship in terms of ER status in African-American women, although there might be an association between menstrual cycle length and the disease.

An intervention study on screening for breast cancer among single African-American women aged 65 and older.

BACKGROUND: Older African-American women with single marital status are least likely to use screening procedures. This study aimed to evaluate a breast screening intervention program conducted in this population. METHODS: Ten public housing complexes were randomly assigned to either the intervention or the control group. African-American women aged 65 and over were recruited into the study if they were widowed, divorced, separated, or never married and did not have a history of breast cancer (n = 325). The intervention program was delivered by lay health educators at the participant's apartment and was designed to increase knowledge about breast screening, reduce psychological problems, and increase support from significant others. Breast-screening-related cognition and behavior were measured at baseline and at 1 and 2 years postintervention. RESULTS: Comparisons of the preintervention and postintervention measurements showed that while the proportion of women who had a clinical breast examination or mammogram in the preceding year was decreased at 1 year postintervention in the control group, it was increased in the intervention group. However, the differences did not reach a significant level. No consistent patterns could be found in changes of breast self-examination and variables in knowledge, attitudes, and beliefs. When analyses were restricted to women whose significant others had provided information or help on breast screening, results were better, but the differences between the intervention and control groups still did not reach statistical significance. CONCLUSIONS: These results did not suggest significant effects of an intervention program that used lay health educators to promote breast cancer screening in older single African-American women.