Evaluating Dose Timing (Morning vs Evening) of Endocrine-based Therapies in Metastatic Breast and Prostate Cancers

To join the study, you need to be at least 18 years old and have advanced breast cancer that's hormone-sensitive, meaning it responds to hormone treatments, or have advanced prostate cancer that's hormone-sensitive. For breast cancer, you would need to be starting a specific combination of hormone therapy and a medicine called a CDK4/6 inhibitor (like Ribociclib or Palbociclib). For prostate cancer, you would be taking a certain type of hormone treatment called an androgen receptor pathway inhibitor (like enzalutamide, apalutamide, or abiraterone acetate) along with other hormone therapy.

It's important that you don't have any medical reasons that would prevent you from taking your medication at either a morning or evening time. For breast cancer, if your treatment plan includes a medicine called abemaciclib, you wouldn't be able to join because it needs to be taken twice a day, which wouldn't work with the study's specific timing focus. Similarly, for prostate cancer, if your plan includes darolutamide (also a twice-a-day medicine) or a chemotherapy drug called docetaxel with your hormone treatment, you wouldn't be eligible. You also need to be able to understand the study and fill out questionnaires as part of it.

If you decide to take part, you'll be randomly put into one of two groups: a morning group or an evening group. This means you'll be told whether to take your specific cancer medication either in the morning or in the evening. You will have regular contact with the study team, and you'll be asked to fill out questionnaires about how you're feeling and your quality of life. The study will also involve standard medical check-ups and assessments, similar to what you'd have during regular cancer treatment, to monitor your health and how the treatment is working. The exact number of visits and the full duration of your participation will be discussed in detail by the study staff.