Impact 2011-American Academy of Physician Assistants (AAPA)'s 39th Annual PA Conference
Jennifer Kreinbrink BS, PA-S, Grace Parish BS, PA-S, & Daniel Smith BS, PA-S
Purpose. The American Cancer Society estimates women within the United States have a one in eight lifetime risk of being diagnosed with breast cancer. To track the detection of breast cancer, the Michigan Breast Oncology Quality Initiative (MiBOQI) was established. The purpose of this study was to characterize breast cancer detection and staging in females who were part of the MiBOQI registry between the years 2006 and 2009.
Methodology. De-identified data was obtained from the MiBOQI, a multi-institutional, statewide breast cancer registry of women diagnosed and treated for breast cancer in Michigan. Characterization of women in the registry was analyzed based on method of detection, age and stage of cancer at time of diagnosis, type of treatment, ethnicity, presence of estrogen receptor and HER2NEU.
Results. 5903 females were identified between 2006 and 2009. Average age at time of diagnosis was approximately 59 years of age (YOA) with 6% <40 YOA, 20% between 40-49 YOA, 51% between 50-69 YOA, and 23% >69 YOA. A breakdown of ethnicity revealed: 78% Caucasians, 13% African American, 2% Asian, 1% Hispanic, and 5% other. Tumor identification by an abnormal mammogram occurred in 66% of cases, self-breast exam in 27%, clinician breast exam in 3%, and other indications (i.e. axillary mass) in 4%. 18% were diagnosed at stage 0, 44% at stage I, 29% at stage II, and 9% at stage III. On pathology analysis, 80% of tumors were estrogen receptor positive and 11% were HER2NEU positive. Treatment included mastectomy for 34% and conservative surgery for 65%. Adjunctive treatment included chemotherapy (14%), hormones (26%), and chemotherapy and hormones (15%). Mortality information was not available.
Discussion. The analysis of the MiBOQI data was compared to published data. Mathis and colleagues at the Mayo Clinic (Rochester) reported the average age at diagnosis was 60 YOA, and similar findings were found for all age brackets compared to the MiBOQI: <40 YOA (6% MiBOQI: 4.5% Mathis et al.), between 40-49 YOA (20% MiBOQI: 19.5% Mathis et al.), between 50-69 YOA (51% MiBOQI: 51.4% Mathis et al.), and >69 YOA (23% MiBOQI: 24.6% Mathis et al.). Comparing method of diagnosis shows: diagnosis by mammography (66% MiBOQI: 57% Mathis et al.); diagnosis by self-examination (27% MiBOQI: 29% Mathis et al.); and clinician breast exam (3% MiBOQI: 14% Mathis et al.). Similar findings regarding the stage at time of diagnosis were found except for a greater percentage of stage III in the MiBOQI subjects, 3.9% compared to 9%. According to Mathis et al., 75% of breast cancer is estrogen receptor positive and approximately 25% of breast cancers are HER2/NEU positive. Compared to the MiBOQI, a greater number of breast cancers are estrogen positive (80%) and less are HER2NEU positive (11%). There was no known comparison data available for ethnicity. Based on a review of the literature, females in the MiBOQI are slightly younger, have a greater percentage of detection by mammography, a higher percentage of estrogen positive cancers and less prevalence of HER2/NEU.