You will be shown biomedical passages and your task is to the answer the provided question. Provide a concise and accurate response and do not include any additional text in the response other than the answer.

Question: In which breast cancer patients can palbociclib be used?

Context: Women with hormone receptor-positive, human epidermal growth factor receptor 2- negative breast cancer-the most common subtype-have new options as palbociclib and similar drugs debut.
We aimed to assess the safety and efficacy of palbociclib in combination with letrozole as first-line treatment of patients with advanced, oestrogen receptor-positive, HER2-negative breast cancer.
hormone receptor-positive, human epidermal growth factor receptor 2-negative