@estenbaf do you want to post a new discussion? Are you saying your daughter has invasive lobular cancer, 3cm?

Testing will tell her if her tumor is estrogen positive, progesterone positive and HER2 negative. In that case (ER+ and HER2-) a genomic test called the Oncotype will be done. The report will tell your daughter whether chemo is of benefit and also what the risk of recurrence might be with or without anti-hormone medications.

IF ER- or HER2+ the Oncotype won't be done.

According to the info below most lobular cancers are hormone positive and respond well to treatment. Lobular can be hard to find because it does not form clumps or masses.
https://www.healthline.com/health/breast-cancer/lobular-breast-cancer-prognosis-survival#prognosis
Let us know when you have more information. We cannot give medical advice but we can share our own experiences.