Lower Mammography Use is Associated with the Geographic Clustering of Late-stage Breast Cancer in Saint Louis City Min Lian, Donna B. Jeffe, Mario Schootman Departments of Medicine and Pediatrics, Division of Health Behavior Research, Washington University School of Medicine, Campus Box 8504, St. Louis, MO th APHA Conference, Nov. 3-7, 2007, Washington, DC

Background Missouri Cancer Registry ( ); Women age 50 or older; Late-stage (regional or distant) breast cancer; Clustering: St. Louis area (RR=2). Schootman, M., et al., Geographic clustering of adequate diagnostic follow-up after abnormal screening results for breast cancer among low-income women in Missouri. Ann Epidemiol, (9): p

Questions Geographic clustering of late-stage diagnosis of breast cancer: Reasons ??? Healthy Risk factors : Genetic, Environmental, Sociopsycological. Early-stage Breast cancer Late-stage Breast cancer Non-adherent to Screening guideline; Failure to follow diagnostic test; Poor health care after the diagnosis; ….

Thinking … Mammography screening rate was decreasing nationwide from : 76.4% 74.6% Ryerson AB, Miller J, Eheman CR, White MC. Use of mammograms among women aged >/= 40 years--United States, MMWR 2007;56: “Ceiling effect” ? Geographic Targeting…

Hypothesis Mammography screening may be lower among women residing within this cluster area than outside this area.

Study Purposes To compare breast cancer screening use among women living and those not living in the cluster area of late-stage breast cancer incidence. To explore possible ways to increase breast cancer screening by identifying factors associated with lower screening use.

Study Design: women age 40 or older were selected through Random-Digit Dialing (RDD) and interviewed by telephone. 35 subjects were excluded since they did not live in the City of Saint Louis.

Study Design: 2 Five groups of questions were included in the telephone interview: Mammography use and breast clinical examination 1) Mammography use and breast clinical examination; Predisposing factors 2) Predisposing factors: age, race, education, marital status, family history ; Enabling resources 3) Enabling resources: annual family income, employment status, availability of health insurance, reasons for not seeing a doctor, access to medical care, breast cancer-related knowledge, Barriers to mammogram; Personal health practices 4) Personal health practices: Cigarette smoking ; Need for medical care 5) Need for medical care: Self-rated health status (SF-12).

Table 1. Factor analysis for questions of Barriers

Table 2. Characteristics of Subjects: Within ~ Outside the cluster.

Official Guideline Mammography: 40-49: every TWO years 50+ : every ONE year; Clinical Breast Examination (CBE): 40+ : every ONE year.

Methods Self-reported home addresses were geocoded. We used a Geographic Information System (GIS) to determine whether or not the women interviewed were living within the cluster area of late-stage breast cancer; Unconditional Logistic regression was used to examine the factors associated with low screening use. The fit of models was evaluated by the Hosmer-Lemeshow goodness-of –fit test and Nagelkerke R Square.

Results Mammography CBE

Table 3. Mammography and Clustering

Table 4. CBE and Clustering

Conclusion Lower mammography screening in the cluster area in St. Louis City; Factors investigated didn’t fully explain the reason for lower mammography use in the cluster area, and further studies are necessary; Lower mammography use may be one of contributors led to the geographic clustering of late-stage breast cancer in north Saint Louis City, but not confirmed; Geographic targeting? More studies…

Acknowledgement Financial funding: CA91842, CA91734, CA98594, HS ; Siteman Cancer Center, Health Behavior and Outreach Core: Jim Struthers, Jennifer Tappenden.