Abstract P5-09-13: Disparities in germline mutation testing: do Medi-Cal and uninsured patients with breast cancer receive genetic testing in a safety net setting?

Background: National Comprehensive Cancer Network guidelines recommend that women with breast cancer diagnosed at age ≤50 undergo cancer genetic risk assessment and that those age ≤45 undergo testing for hereditary breast and ovarian cancer (HBOC) syndromes such as BRCA. In prior studies of primarily commercially insured women, 30% of those ≤40 years of age received BRCA testing (Levy 2011), and 34% of those ≤50 years were referred for genetic assessment (Stuckey 2016). Our aim was to determine rates and predictors of genetic testing among publicly insured or uninsured women at a safety net medical center.

Methods: Women diagnosed with invasive breast cancer or ductal carcinoma in situ from 2010 through 2016 were identified from the institutional tumor registry of a Los Angeles County public hospital. Eligible for this analysis were those at high risk for HBOC syndromes as defined by 1) age ≤50 at diagnosis or 2) age ≤60 with triple negative breast cancer. Women were excluded if they received all of their cancer treatment at an outside institution. Medical records were reviewed to determine receipt of genetic testing and test results. Univariate logistic regression was used to evaluate associations between patient characteristics and receipt of testing.

Results: 307 women were included in the analysis. 92.5% (284) were age ≤50 and 54.7% (168) were age ≤45. The majority (72.1%) had Medi-Cal or Medicare and 26.1% were uninsured at diagnosis. The racial distribution was 63.8% Hispanic, 19.2% black, 11.1% Asian and 5.5% non-Hispanic white. Overall, 52.1% (160/307) underwent genetic testing and 13.1% (21/160) were found deleterious germline mutations (BRCA1=10, BRCA2=8, BRCA not specified=1, PALB2=1, TP53=1). Among women who underwent testing, 55.0% were tested for BRCA1/2 only and 36.8% received multigene panel testing; specific testing information was unavailable for the remainder. Age, race/ethnicity, and presence of metastatic disease at diagnosis were associated with differences in genetic testing rates, whereas insurance status and year of cancer diagnosis were not (Table 1).

Conclusions: In a safety net setting with mostly Medi-Cal-insured and uninsured patients, the overall rate of germline mutation testing in women with breast cancer (52.1%) was at least comparable to that in studies of commercially insured populations. Notably, testing rates in this population were significantly different when stratifying by age, race, and cancer stage. These findings highlight subgroups in this underserved population who warrant additional attention to assessment of their cancer genetic risk.

 Total (N=307)Number tested% testedP valueAge at diagnosis   P<0.001<30 years11872.7 30-39 years654569.2 40-49 years1819552.5 ≥50 years501224.0 Race/ethnicity   P=0.011Non-Hispanic white17635.3 Asian341955.9 Black592135.6 Hispanic19611458.2 Unknown100.0 Stage at diagnosis   P=0.007Non-metastatic28515554.4 Metastatic22522.7 Insurance   P=0.594Uninsured804758.8 Medi-Cal/Medicare*22311149.8 Private insurance2150.0 Unknown2150.0 Year of diagnosis   P=0.0982010421740.5 2011472348.9 2012462656.5 2013602948.3 2014392461.5 2015392153.8 2016342058.8 *1 patient had Medicare; the remainder had Medi-Cal

Citation Format: Pan K, Yan JE, Huynh KT, Peng KA, Ozao-Choy J, Dauphine C, Park S, Dickson PI. Disparities in germline mutation testing: do Medi-Cal and uninsured patients with breast cancer receive genetic testing in a safety net setting? [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-09-13.

Abstract PD3-01: Automated, low-cost palpable breast lump triage for economically-developing countries

Background: According to GLOBOCAN, 1.7 million women were diagnosed with breast cancer and 445,000 died from the disease in 2012. Breast cancer is the most common cause of cancer death among women worldwide and the numbers are disproportionately high for women in developing countries. Furthermore, breast cancer is more common in young women (age 44 and under) in these countries than in industrialized countries. Shifts in lifestyle typical of industrialized societies are thought to be causing a rise in breast cancer incidence while technical advances in detection, diagnosis, and treatment are not reaching these areas of the world. In developing countries, breast cancer commonly presents in women as a palpable mass and a low-cost solution for breast cancer triage would be beneficial. Ultrasound has been shown to perform very well on palpable masses, is non-ionizing, and affordable, portable systems are available. In the ACRIN 6666 clinical study of asymptomatic women, adding screening ultrasound to mammography significantly increased breast cancer detection in women with elevated cancer risk and dense breasts, and more invasive cancers were seen by ultrasound alone than by mammography alone.

Method: We propose a novel computer-aided diagnosis (CADx) tool for breast cancer triage using a low-cost ultrasound imaging device that will automatically distinguish among (1) suspicious lesions to be sent for biopsy, (2) benign findings that need no additional follow-up and (3) probably benign findings with recommended 6-month follow-up. A validation study at USC Norris Cancer Center and Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center was performed in order to assess the performance of the triage software compared to the standard-of-care and biopsy-confirmed cancers and false positives. The Study machine was the GE Logiq e ultrasound imaging device, which is FDA-approved for small body parts. Lesions that were assessed as BI-RADS 2 by radiologists were determined to be benign while any lesion assessed as BI-RADS 4a or higher was sent for biopsy. This study cohort included women 61 years of age or younger with a palpable mass. The triage software was compared to the performance by radiologists using conventional standard-of-care for palpable masses.

Results: The original milestone for this study was to achieve a sensitivity of 85% while reducing the number of benign lesions going to biopsy by 40%. The validation study showed an actual sensitivity of 100% while reducing the number of benign lesions going to biopsy by 69%. To date, the images collected during the validation study include 152 lesions in total, 22 biopsy-proven cancers and 130 benign lesions; 63 benign lesions were categorized as BI-RADS 4a or higher by a radiologist and sent for biopsy.

Conclusions: The validation study showed that adding automated breast cancer triage software to a low-cost portable ultrasound imaging device is a realistic approach for regions of the world with limited access to highly trained radiologists and diagnostic equipment.

Funding: NIH Grant #UH2EB019889.

Citation Format: Love SM, Berg WA, Podilchuk C, Hovanessian-Larsen LJ, Dauphine C, Jairaj A, Barinov L, Hulbert W, Cen S, Eshraghi L, Mammone R. Automated, low-cost palpable breast lump triage for economically-developing countries [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr PD3-01.