Abstract
To report long-term outcomes of a novel nipple-sparing approach in patients with DCIS or early-stage breast cancer that would not be eligible for nipple sparing mastectomy due to multifocality/multicentricity or tumor less than 2 cm from the nipple-areola complex (NAC).
We conducted a phase I pilot study approved by Institutional IRB. Eligible patients had a biopsy confirming DCIS or invasive breast cancer, and a surgical recommendation for mastectomy due to extent of disease, with tumor at least 1 cm from the NAC. Nipple sparing mastectomy (NSM) was performed after negative shave biopsy behind the nipple was obtained at time of surgery, followed by immediate reconstruction per plastic surgeon's preference. NAC RT was administered 5 to 8 weeks postoperative. A 3+3 dose-escalation design was used to test RT doses of 25, 30, 35 Gy in 10 fractions, given BID, 6 hours apart with electrons. Dose-limiting toxicity (DLT) was specified as RT-related NAC loss or any grade 4/5 AE up to 1-month from end of RT. Adverse events were assessed using CTCAE. v 4.0. Patients completed cosmesis and satisfaction assessment at standard follow up visits.
From 2010-2017, 18 women were treated on the study, 6 per dose level. Median age was 45.5 (range 30-63). 100% of patients were White, of those 44.5% were Hispanic. 17% had DCIS and 83% had invasive breast cancer (all ER+, 14 pStage T1N0, 1 pStage T1N1mi). Endocrine therapy was given to all ER+ invasive breast cancer patients. With a median F/U of 80.5 months, there was no RT-related DLT or grade 4/5 AEs (73 G1, 15 G2, 6 G3). All grade 3 AEs were related to the surgery (infection, pain, allergy to tape). There was no local recurrence in the NAC, with 100% of nipple preservation with longer follow up. Two patients developed metastases 2 years after diagnosis (bone, liver). 1 DCIS patient developed a second ipsilateral breast cancer away from the NAC, later found to have BRCA2+ mutation. Patient reported cosmesis at last visit was 72% excellent, 16.5% good, and 5.5% poor. Physicians score worse cosmesis compared to patients with 39% scored excellent and 61% good. Patient reported satisfaction with nipple sparing treatment was high, with 94% of patients choosing this treatment again.
This novel approach of nipple preserving therapy using delayed adjuvant NAC RT after nipple sparing mastectomy, resulted in 100% nipple preservation without compromise of local control, in this specific patient population not eligible for nipple sparing mastectomy alone. This study supports further exploration of nipple preservation with a broader inclusion criterion.