Discussion
tamoxifen-associated endometrial cancers, tumors, ER-positive breast
ENDOMETRIAL CANCER, RECURRENCE, DCIS, TUMORS, LOCALIZED DISEASE
We previously demonstrated that among patients who did not receive RT in our institution (National Taiwan University Hospital [NTUH] cohort), ER-negative status was significantly correlated with a higher IBTR rate [In addition to ER-negative status in tumors, we previously reported that age < 40 years was significantly associated with the risk of IBTR in breast DCIS patients who underwent BCS alone [For patients with low-risk DCIS who underwent BCS alone in the ECOG E5194 and RTOG 9804 trials [Nevertheless, tamoxifen has an estrogenic effect on the endometrium and has been reported to increase the risk of endometrial cancer; tamoxifen-associated endometrial cancers are a localized disease with rare morbidity [In conclusion, this prospective study aims to evaluate whether low-dose tamoxifen administration is not inferior to RT in decreasing local recurrence in women aged > 40 years with low-risk characteristics and ER-positive breast DCIS who have undergone BCS. If this study confirms its primary endpoint, it will provide an important alternative for clinical physicians to recommend adjuvant low-dose tamoxifen for patients with low-risk breast DCIS who do not want to receive adjuvant RT because of potential side effects. Moreover, the cost of low-dose tamoxifen is lower than that of RT. We believe that this non-inferior trial will be helpful in prospective clinical practice in patients with specific low-risk breast DCIS.