Primary systemic chemotherapy of breast cancer: indication and predictive factors

Primary systemic chemotherapy has become a standard of care for operable breast cancer patients who are candidates for adjuvant chemotherapy. Induction of pathological complete response (pCR) is one of the main goals of primary systemic chemotherapy because patients with pCR have shown a better prognosis. The definition of pCR has varied across clinical trials. It would be ideal for all researchers to use the same terminology in describing pathologic response. Identification of accurate predictive factors of pCR to primary systemic chemotherapy is urgent, because patients with a low chance of pCR and clinical response should be spared unnecessary toxicity. Early response to primary systemic chemotherapy might be correlated with a high probability of a pCR. Therefore, evaluation of early response is useful to avoid unnecessary toxicity without potential benefit from chemotherapy.