Discordance in hormone receptor status among primary, metastatic, and second primary breast cancers: biological difference or misclassification?
A considerable proportion of discordance in hormone receptor status can be attributed to misclassification in receptor assessment, although the accuracy of receptor assays was excellent. Biopsy of recurrent tumors for receptor retesting should be conducted after considering feasibility, cost, and previous ER/PR status.
Three of 4 patients were candidates for IC per A.S.P.E.N. guidelines. PICUs might have to prioritize performing IC in patients who are<2 years of age, malnourished (underweight/overweight) on admission, or PICU stay of>5 days. Future studies should determine the cost-benefit ratios of performing IC in PICU patients.