Hello @nayade ,

It sounds like good news for your friend, a cancer likely caught early (8mm is very small). [I'd wish that the surgeon had done a sentinel lymph node biopsy but maybe the doctors determined clean lymph nodes some other way.] And you didn't mention the HER2 status so what I note below is if the cancer was E+, P+ and HER2 negative. I'm not a doctor so the following is just from what I learned from my post-lumpectomy journey.

Lumpectomies came about when women demanded that doctors review the usual 'automatic mastectomy' decision for breast cancer. The resulting lumpectomies were a compromise so the 'rule of thumb' developed that "radiation-plus-lumpectomy" was an alternative to complete mastectomies for selected cases of breast cancer. According to my oncologist, they have still have equivalent statistics for success. So the rule of thumb remains that patients having lumpectomies have (or at least consider) post-surgical radiation.

There are differences in the kind and frequency of radiation though. The oncology radiologist I saw offered a series of 5 sessions, every other day, with the whole cycle complete in 9 days. Not every facility has the technology to provide that it though. And some doctors do not routinely recommend radiation for older patients.

If you friend can get a second treatment opinion, she can ask that doctor about radiation choices and the tamoxifen. If she is postmenopausal, she can also ask about aromatase inhibitors which are the drugs most commonly prescribed in the United States (but not always, again) for E+, P+, HER2- small tumors caught early. But there are a lot of other factors that an oncologist considers when making recommendations as well and maybe tamoxifen is the best idea.

There is no clear "universal protocol" that I know of just the usual 'standard recommendations' which people frequently get a second opinion to confirm or question. Doctors can have different opinions which are, both, valid but just based on differing perspectives. That's why a second opinion, if possible, can be very reassuring.