Does microscopic ENE warrant post-mastectomy radiotherapy if all other factors are low risk?

With respect to ENE, I first look at axillary surgery. If the patient has SLN+ and microscopic ENE, I do typically offer PMRT even with other low-risk factors. While the IBCSG trial evaluates micrometastases, it's important to remember 90% received lumpectomy, and therefore, most received whole brea...