Background: When the conservative treatment is not recommended, Nipple Sparing Mastectomy (NSM) is proposed more and more frequently for the surgical treatment of breast cancer. The risk of local recurrence behind the nipple areolar complex (NAC) is the main limiting factor of the NSM procedure. To minimize such risk, we proposed in 2002 a intraoperative radiotherapy of the preserved NAC.
Patients and methods: From March 2002 to November 2006, 579 cases (in 570 patients) of NSM were performed for carcinoma. The median follow up time was 19 months (Range: 1-60). The subcutaneous mastectomy was performed through an incision removing a portion of the skin overlying the tumour. An extemporaneous histological examination was performed on the retroareolar glandular tissue. If the histology was positive the patient was not considered eligible. Then an intraoperative radiotherapy with electrons (ELIOT) of 16 Gy in one shot was delivered on the NAC area. An immediate breast reconstruction was done using implants in most cases and in several cases a musculocutaneous flaps, usually in large breast. The number of local recurrences was recorded and the correlation between their occurrence and the clinical and histological criteria were analysed using the Gray test statistical method in a competing framework.
Results: In 516 cases the negative retroareolar frozen section biopsy was confirmed by the final histology, while in 63 cases, the final histology showed foci of carcinoma. Seven out of these 63 cases underwent a secondary NAC removal. In the 56 cases which preserved areolas we did not observe any local recurrence after 19 months follow up. The probability of retro areola positive histology increases with the tumour size. and was not related to the nodal status. The rate of local relapses was 0.9% per year. We didn't find any significant difference in the local relapse rate according to different patient's and tumour's features. Most relapses were located close to the tumour bed but never in the NAC area.
Conclusion: Our study confirms that the local recurrence rate in the NSM completed with local radiotherapy on the NAC is not higher than the usual rate observed in the literature and the preservation of the NAC does not increase the risk. The absence of local recurrence in the region where a portion of glandular tissue has been purposely preserved is a good argument in favour of ELIOT.