Is initially metastatic breast carcinoma different from recurrent metastatic breast carcinoma?

We read with great interest the article by Largillier et al. [1] in which they analyzed prognostic factors in 1038 women with metastatic breast cancer. They did not show the importance of metastasis-free interval as a prognostic factor predicting survival from time of metastatic occurrence in their studies on contrary to other studies stating that early recurrence is an independent predictor of survival [2–4]. There are two groups of metastatic breast cancer patients as recurrent metastatic breast carcinoma and initially metastatic breast carcinoma. Studies showed that initially metastatic breast carcinoma has an equivalent outcome in term of overall survival compared with recurrent metastatic breast carcinoma [5, 6]. Since patients with initially metastatic breast carcinoma are chemoand hormonenaive patients, they are expected to respond to treatment more effectively than patients with recurrent breast cancer. Therefore, survival from time of metastatic occurrence should be better in initially metastatic breast carcinoma. Although definition and inclusion of these patients were not described in detail in Largillier et al. [1] study, these group of patients may affect the prediction of metastases-free interval as a significant prognostic factor if they were included into patient groups who have metastases-free interval <24 months.