PIP: This letter is in response to Kiang et al who reported a markedly higher response rate to chemotherapy in estrogen-receptor-positive metastatic breast cancer, as compared to that in receptor-negative tumors. Lippman et al have previously reported opposite findings. Both reports reflect a total lack of uniformity in the type of chemotherapy used for individual patients. Also, the reports have limited their conclusions to response rates and made no definite statement on the duration of response to chemotherapy. Due to conflicting results available at present, it is extremely important that the estrogen-receptor status of a patient not influence decisions about chemotherapy. It is concluded that clarification of the true relation between estrogen receptors and response to chemotherapy will require prospective investigation in patients with breast cancer, whose receptors are determined immediately before chemotherapeutic intervention and who are treated with 1 uniform and optimum chemotherapy regimen.