Would you recommend anti-hormonal therapy in a patient with DCIS that is ER/PR positive between 1-9%?

In general terms, I consider tumors with ER and PR expression <10% as hormone receptor negative. Our analysis of outcomes for these patients at our institution suggest thy do just as well (or as poorly) as those with ER 0% and PR 0%.

Therefore, I do not recommend the use of endocrine therapy of patients with tumors that are ER/PR between 1 and 9%, whether they are invasive or non-invasive.