Can you repeat taxotere?

After failing with adriamycin, my moms metastatic breast cancer was successfully treated with 8 rounds of taxotere. She was then on arimidex for a year and a half, it failed, now megace for 3 months but it is not working. She will be starting on navelbine soon. I realize that we are running out of options for her treatment. My question is, can she be treated again with taxotere and save the navelbine for the future, or is it assumed that her cancer is already resistant to the taxanes? Also, are there hormonal treatments left to try after tamoxifen, arimidex and megace? My mom is 53 and has been fighting this since she was 40. Other than the cancer, she is in perfect health.....thank you

[CCF-RN,MSN-JS]

Dear Dawn44, In metastatic breast cancer after having progressive disease after 3 different types of hormone therapy trying a chemotherapy that has shown some activity against breast cancer is usually the next step in trying to control the disease.  Resistance to a prior treatment is a concern and does influence the recommendation of future chemotherapy.   The type of chemotherapy recommended would be something such as navelbine, which has shown activity in the treatment of metastatic breast cancer, and has a different mechanism of action than the taxanes.  The hope is to be able to work on the cancer cells from a different angle and again the aim of therapy is the control of the disease.

In regards to other hormone therapies, the three types your mother has had each have some differences in terms of how they work. There are other agents, which fall within the same