Treatment Options for Triple Negative Metastatic Breast Cancer

[JulieSpokane]

Thank you for this site!  My 37 year old sister was diagnosed in April, 2006 with stage III ER-/PR-/Her2- invasive ductal carcinoma.  She underwent 4 rounds preadjuvant AC, mastectomy in July, 2006, adjuvant Taxotere (had a local recurrence along mastectomy line that was resected) during 3rd round of Taxotere.  Then radiation (lifetime max dose) which ended in Jan, 2007.  Had another local recurrence along mastectomy line in June, 2007 with another local resection of tissue, but no systemic treatment.  Had 2 lung spots picked up by CT scan in Oct 2007, but did not show on PET scan.  Was rescanned in Jan, 2008 with no changes in size of spots.  However, in May, 2008, these spots grew, now showed up on PET, and recent biopsy shows metastatic (still triple negative) breast cancer in the lung.  Treatment is to commence next week, but I am concerned about the plan.  Questions are as follows:
1.  Is the current recommended treatment plan of Taxol and Avastin the best right now, since she did not respond to the taxane drug in the first place ... cancer grew while on Taxotere.
2.  What about one of the platinum drugs ... Is there ever a regime that includes Taxol+Cisplatin/Carboplatin and Avastin?
3.  What about Abraxane + Avastin?
4.  After she finishes chemo, is there any "maintenance" regime for her .. ie maintenance Avastin, or somehting I read about disphosphanates/bisphosphinate (sp??)

Your help would be greatly appreciated!  Thank you, JulieSpokane

[Fernando Roque, MD]

Hi.  Triple negative breast cancer is a subtype which is resistant to hormonal therapy and  Herceptin (used to treat Her2 positive disease).  It is however, theoretically responsive to chemotherapy regimens containing either a platinum drug, an anthracycline (Doxorubicin in AC regimen) or taxanes (Taxol or Taxotere).  Of the three drugs I've mentioned above, anthracyclines and taxanes are the more potent ones for breast cancer.  Platinum drugs are usually "add-on" drugs in the regimen (example: Carboplatin-Paclitaxel combination) and not the "primary" drug in the combination.  

Your sister's problem lies in the fact that her disease has recurred after using regimens containing anthracyclines (AC) and taxanes (Taxotere).  This implies that her cancer already has some resistance to these two types of drugs.  I think the combination of Taxol and Avastin is still a good combination to use.  Taxanes don't usually have cross-resistance.  This means that even if her tumor is resistant to Taxotere, it doesn't automatically follow that it will be resistant to Taxol, so it's still worth trying.  Avastin is a drug which can help overcome a tumor's resistance to chemotherapy, by reorganizing the blood vessels in the tumor so that the chemotherapy drug can more easily diffuse into the mass.  So combining it with Taxol can make it more effective, even if the tumor has already shown some resistance to another drug from the same class (Taxotere).

In my opinion, Abraxane only offers an advantage to Taxol in terms of lowering the incidence of adverse effects.  But I don't think it's going to provide an efficacy advantage over Taxol as a third-line drug.  

There is a new drug, Ixabepilone (Ixempra) which has been approved for use in situations where the breast cancer has progressed or recurred after both anthracycline and taxane chemotherapy.  This is to my mind, another good option to take, if you do not wish to have the Taxol-Avastin combination.