Impact of metastatic estrogen receptor and progesterone receptor status on survival

Hormone responsive breast cancer is usually determined by the presence of estrogen receptors (ER) or progesterone receptors (PR) on primary invasive breast cancers. Adjuvant and metastatic hormone therapy are recommended based on primary ER and PR determination. Little information is available to determine if primary hormone receptors correlate with metastatic disease and if survival is influenced by metastatic receptor status. We retrospectively compared primary to metastatic tumor ER and PR content from 200 metastatic breast cancer patients. ER and PR analyses were available in both primary and metastatic disease in 200 and 173 patients, respectively. There was a correlation between both the ER and PR in the primary and metastatic lesion (p < 0.001). However, in 60 of 200 (30%) patients, discordance between primary and metastatic ER was noted. Tumors from 68 of 173 (39.3%) showed discordance for PR. In 39 (19.5%) patients, the ER primary status was positive and metastatic status was negative and in 21 (10.5%) patients, the primary status was negative and metastatic status was positive. Survival from the time of metastatic diagnosis was calculated. Those patients with ER positive primary and metastatic tumors (Positive/Positive) or only the metastatic lesion (Negative/Positive) had similar median survival (1131 and 1111 days, respectively). However, patients with tumors that changed from positive primary to negative metastasis (Positive/Negative) experienced significantly shorter median survival (669 days, p < 0.05). Likewise, median survival (580 days) was significantly shorter for patients with primary and metastasis ER negative (Negative/Negative, p < 0.001) compared to Positive/Positive (p < 0.001) or compared to Negative/Positive (p < 0.02). The changes in PR status were not associated with a change in survival. We found a significant discordance between hormone receptor content of primary versus metastatic breast cancer. The ER status of the metastatic lesion was a better predictor of survival. Therefore, optimal metastatic treatment cannot be determined solely on primary ER and PR analysis.