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Some breast tumors change hormonal status throughout the course of disease

September 28, 2011

A study presented to the  2011 European Multidisciplinary Cancer Congress suggests that some breast tumors change hormonal status throughout the course of the disease - from the primary tumor to relapse.  This finding suggests that decisions about treatment should not be based on a single biopsy of the primary tumor.

Dr. Linda Lindström and colleagues studied breast cancer patients in the Stockholm healthcare region who had a recurrence of the disease between January 1, 1997 and December 31, 2007.  119 patients had information on estrogen receptor (ER) status in several relapses.  33.6% of these patients had changes in status between the different sites of relapse (local, loco-regional and metastases): 16% of patients changed from ER positive to negative, 12.6% changed from negative to positive, and 5% altered back and forth throughout tumour progression.  On the other hand, 36.1% of the patients were stable ER positive, and 30.3% were stable ER negative.   With regard to progesterone receptor (PR) status, 30.2% of patients changed status, with the majority going from positive to negative.  15% of patients changed HER-2 status from primary tumor to relapse.

These findings have important implications for disease management as breast cancer patients that relapse may not be receiving appropriate treatment.  Regular biopsies to determine breast tumor markers may prevent innappropriate treatment and may aid in selecting effective treatments.  Next, the researchers plan to conduct a prospective cohort study and examine clinical markers in a group of breast cancer patients throughout their disease progression.