Identifying, monitoring, and treating women for breast precancer or cancer

method of screening a patient for postmenopausal hormone replacement therapy (HRT), said method comprising the steps of:

• introducing a portion of a catheter into a breast duct of the patient;
• performing ductal lavage including the step of retrieving biological material from within the breast duct through said introduced portion of the catheter;
• obtaining a ductal fluid sample from said breast duct;
• examining the ductal fluid sample for the presence of at least one precancerous or cancerous ductal epithelial cell;
• and
• wherein HRT is contradistinguished if the patient has a precancerous or cancerous ductal epithelial cell in the ductal fluid sample.

A method of screening a patient for postmenopausal hormone replacement therapy (HRT), said method comprising the steps of:

• introducing a portion of a catheter into a breast duct of a patient;
• performing ductal lavage on said breast duct including the steps of infusing a fluid into the duct through said introduced portion of the catheter and obtaining a ductal fluid sample from a breast duct of the patient including retrieving biological material from within the breast duct through said introduced portion of the catheter;
• examining the ductal fluid sample for the presence of at least one precancerous ductal epithelial cell;
• and
• wherein HRT is contradistinguished if the patient has a precancerous ductal epithelial cell in the ductal fluid sample.