Primary right breast cancer(DCIS) with left axillary node metastasis, confusing cancer staging and treatment plan

[na2020]

My Mom has been diagnosed with a tumor in her right breast about 2cm and there are 2 cancer containing lymph nodes in the left axilla based on FNAC and PET-CT with no sign of spread elsewhere in the body.

Tata memorial is redoing the FNAC of left axillary nodes and biopsy of the right breast tumor. The current diagnosis is Stage IV breast cancer with oligometastases. The treatment plan is curative with stage 3 like outcome starting with 2 cycles of chemo followed by surgery and then chemo and radiation if needed.

Earlier consultant suggested Surgery followed by Chemo with a Stage 2 diagnosis based on possibility of a occult primary cancer in left breast.

Another consultant suggested ER PR and HER2 tests of both lymph nodes and primary right to see the relationship between tumour.

My question is if the ER PR HER2 status can tell the relationship and be useful to decide a better treatment plan thogh TATA people are not going for this test despite asking.