Influence of health insurance status on inclusion of HER-2/neu testing in the diagnostic workup of breast cancer patients

OBJECTIVE: . To assess the prevalence of HER-2/neu testing in a community-based health care system shortly after the approval of several laboratory kits for HER-2/neu testing for diagnostic purposes by the US Food and Drug Administration and to discern the best discriminating variables for inclusion of the test in the diagnostic workup of breast cancer patients. DESIGN: A retrospective cross-sectional study was designed to analyze data for the period beginning 1 January 1999 and ending 31 December 2000. SETTING: Henry Ford Health System, the largest health care system in southeastern Michigan, is a comprehensive, self-contained system. STUDY PARTICIPANTS: Four hundred and fifty-one women diagnosed with primary invasive breast cancers were consecutively sampled from the tumor registry of the Henry Ford Health System. RESULTS: The proportion of women tested for HER-2/neu increased by 2-fold during year 2 of the observation. Absence of estrogen receptors (OR = 1.96, 95% CI 1.15-3.21), physicians with specialty in surgery (OR = 6.21, 95% CI 2.88-13.33, P = 0.0001), and having a capitated insurance (OR = 1.59, 95% CI 1.06-2.44, P = 0.027) were associated with HER-2/neu testing. CONCLUSION: Absence of estrogen receptors was the only pathological characteristic associated with HER-2/neu testing. The effect of specialization in surgery on the increased likelihood of HER-2/neu testing can be explained mostly by the 'patient volume effect'. The observed disparity in the delivery of innovative diagnostic approaches to cancer patients was influenced by the type of health insurance. Implementation of institutional policies can improve in providing universal quality of care for all patients regardless of their health insurance.