About 4 weeks ago my wife was diagnosed with moderately differentiated metaplastic spindle cell carcinoma with focal squamous differentiation in the left breast. A tumor mass (2.7 x 2.1 x 1.6 cm) was removed surgically at Mayo Clinic ~2 weeks ago. 5 lymph nodes were biopsied and were negative for cancer cells. All tissues were negative for ER, PR, and Her2. My research indicates that when this type of cancer metastasizes, it rarely utilizes the lymph system and therfore the node finding does not offer assurance of no metastases.
There is some literature suggesting that the presence of EGFR is common for this cancer type, but this was not evaluated at Mayo. If present, does this receptor indicate the use of a particular drug or hormone therapy. I have found little to suggest that a well-defined post-surgery strategy exists for treating metaplastic carcinoma of the breast. Is this indeed the case? Are there accurate diagnostics that would show the presence of metastases now that the tumor has been removed? Is the lung the most common site for metastases? What should be monitored most closely in the future to detect metastases?
Any information or recommendations would be greatly appreciated.