Differences in clinicopatholgic characteristics and risk of mortality between the triple positive and ER+/PR+/HER2-breast cancer subtypes

Purpose This study compared the demographic and clinicopathologic characteristics and risk of mortality between the triple positive (TP) and ER+/PR+/HER2- breast cancer subtypes. Methods Cases of first primary female invasive TP and ER+/PR+/HER2- breast cancer were obtained from the California Cancer Registry. Logistic regression analysis was used to compare differences in factors associated with the TP versus the ER+/PR+/HER2- subtype. Cox regression was used to compute the adjusted risk of breast cancer-specific mortality of the TP versus ER+/PR+/HER2-. Results The odds of TP versus ER+/PR+/HER2- were higher with advanced stage, high grade, low SES, 45 years of age (OR 1.48; CI 1.40-1.55), black (OR 1.11; CI 1.02-1.21), Asian/Pacific Islander (OR 1.15; CI 1.09-1.22), and uninsured (OR 1.42; CI 1.15-1.73). Unadjusted survival analysis indicated worse survival for the TP when compared with the ER+/PR+/HER2- subtype. However, adjusted risk of mortality for the TP subtype was not statistically significantly worse than the ER+/PR+/HER2- subtype. Conclusions Young age, advanced stage and grade, low SES, black and API race, and lack of health insurance are more common in the TP subtype than in the ER+/PR+/HER2- subtype. However the risk of mortality between these two subtypes is similar.