No response to TCHP. What now?

Khanniganslp9

Has anyone had NO response to TCHP.

At diagnosis my tumor was estimated to be 2cm by US, mammogram and by physical palpitation. I completed 5 cycles of Neoadjuvent TCHP in April. In May I had an MRI which showed "complete response" or NED. On June I had the mastectomy and the tumor was alive and well and was 5cm with 80% lobular and 20% ductal features, grade 1, no node involvement, ER+ 95%, PR 5%. They say lobular tumors can be difficult to see or palpitate and can be completely hidden even on MRI. My pathology report notes no evidence of response to chemo (no tissue necrosis and no scarring of tissue). I am HER2 positive, though my second opinion oncologist says I "barely meet criteria" for HER2 positivity - FISH.

Any ideas on what this all means? Am I not really HER2 positive? Do I need more chemo to attack the micrometastasis? If so, what regimen given my unusual profile and the fact that I was already non responsive to TCHP?

toomuch

khannigansip9- Are you saying that the initial IHC came back 1+ or 2+ for Her2 but the FISH was negative? It's my understanding that if the FISH is negative than the tumor is not considered Her2 + and generally is not treated with Herceptan. However, there is a current study that's looking at using Herceptan in Her 2 low patients so in the future we may learn that getting Herceptan is still beneficial.

In general ILC tumors have a lesser response to neoadjuvant chemo then IDC. Your tumor was highly estrogen positive so antihormonals will be an important component of your treatment. There have been some studies that have shown that ILC may respond better to AI's then Tamoxifen. If you are premenapausal, you may want to discuss ovarian suppression and an AI with your MO.