Abstract P4-14-03: Nipple-sparing mastectomy and intra-operative nipple biopsy: To freeze or not to freeze?

Background: Advances in breast cancer screening and treatment have fostered the use of surgical procedures that increasingly optimize cosmetic outcome, while ensuring oncologic safety remains the primary concern of the oncologic surgeon. The role of nipple-sparing mastectomy (NSM) for risk-reducing surgery and breast cancer is evolving. It can be difficult to demonstrate involvement of the nipple-areolar complex (NAC) preoperatively, and and in this report we examine the utility of intraoperative subareolar frozen section (FS).

Methods: Records of patients undergoing NSM at the NYU Langone Medical Center from 2006–2011 were reviewed retrospectively. Use of subareolar FS was at surgeon's discretion.

Results: 237 NSM were performed (146 prophylacytic, 91 theraputic). FC was not utilized in 58 mastectomies (28 prophylactic), with 2 (+) on paraffin. Among the remaining 180 mastectomies, 11 biopsies were (+)(7.2%); 5 subareolar biopsies were (+) on FS and paraffin histologic slides (PS)(2.8%); 6 were negative on FS and (+) on PS. Among the 3 prophylactic NSM with (+) subareolar biopsies there was 1 (+) FS, 1 (−) FS, and 1 with no FS performed. There were no false (+) FS. Four of the 5 patients with (+)FS underwent simultaneous excision of the NAC. The 5th patient had atypia on FS and DCIS on PS, and returned to the OR during the same hospitalization for removal of NAC. The remaining patients underwent subsequent excision of the NAC either during planned 2nd stage reconstruction or following completion of chemotherapy. 8 NAC were free of disease and 5 were positive for in situ or invasive disease. There has been no local recurrence in these patients to date.

Conclusions: The rate of NAC involvement is low, 5.5% in this series, and FS, while utilized in the majority of these cases, detected only 46% of subareolar disease. While FS can direct intraoperative decision making, the predictive power is low, and these considerations must be addressed in preoperative patient discussions. Furthermore, among those patients with (+) subareolar biopsies, only 39% had residual disease on NAC excision. Thus, optimal oncologic management of the NAC must still be considered an unresolved issue.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P4-14-03.

Abstract P4-17-07: Reconstructive Outcomes of Nipple-Sparing Mastectomy: A Five Year Experience

Background: Nipple-sparing mastectomy (NSM) has gained popularity, but remains contoversial as the procedure's reconstructive outcomes and oncologic safety are still somewhat uncertain.

Methods: We retrospectively reviewed the New York University-Langone Medical Center experience with NSM from 2006–2011. Outcomes measured include post-operative complications, breast cancer recurrence, presence of cancer at the nipple-areolar complex, and nipple-areolar complex viability.

Results: Our data include patients who underwent NSM from 2006–2011. In total, the records of 235 (145 prophylactic, 90 theraputic) NSM at NYULMC were reviewed. Our reconstructive dta included all forms of reconstruction, including 144 tissue expanders, 74 microvascular free flaps, 16 immediate implants, and 1 combination latissimus dorsi flap with implant. Mean follow-up time was 19 months. No differences existed between the theraputic and prophylactic breast patients.

The major complication rate of 4.3% (10/235) included 4 intraoperative hematoma evacuations, 1 flap anastomosis revision, and 3 explanted implants. One patient expired 4 months following surgery secondary to progression of disease. The microvascular free flap loss rate for this group was 0. Minor complications in 6.8% of patients consisted of implant exchange for asymmetry, operative revision of partial flap necrosis, intravenous antibiotics for infection, and 1 non-operative hematoma.

In total, 5.9% of nipples were resected due to malignant or premalignant disease. There were 3 positive intraoperative biopsies with 9 additional biopsies positive on final pathology. To date, there have been no recurrences involving the nipple-areolar complex. The viability rate for the remaining nipples was 93.2% with1.7% of nipples undergoing complete necrosis, 3.8% partial necrosis, and 1.3% undergoing epiderolysis.

Conclusions: This experience with NSM demonstrates the in a carefully selected cohort, oncologic safety and reconstructive outcome are comparable to the current standard of total mastectomy.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P4-17-07.

P2-16-09: Nipple-Areolar Sparing Mastectomy: Utility of the Lateral Inframammary Incision in Immediate Implant-Based Reconstructions

Purpose: Nipple and/or areola-sparing mastectomy as a therapeutic or prophylactic procedure for breast cancer is rapidly gaining popularity as the literature continues to support it safety. The lateral inframammary fold (IMF) approach provides adequate exposure and eliminates visible scars on the anterior surface of the breast, making this incision cosmetically superior to radial or periareolar approaches.

Methods: We reviewed 58 consecutive nipple and/or areola-sparing mastectomies performed through a lateral IMF incision with immediate implant-based reconstruction, with or without tissue expansion, between June 2008 and February 2011. Prior to incision, breasts were lightly tumesced with dilute anesthetic solution with epinephrine. Sharp dissection, rather than electrocautery, was used as much as possible to minimize thermal injury to the mastectomy flap. When indicated, acellular dermal matrix was placed as an inferolateral sling. Subsequent fat grafting to correct contour deformities was performed in select patients. Three-dimensional (3D) photographs assessed changes in volume, antero-posterior projection, and ptosis. Retroareolar/nipple tissue underwent routine intraoperative frozen section analysis in cancer cases.

Results: Mean patient age was 44 years, and mean follow-up time was 14 months. Depending upon the judgment of the oncologic surgeon, 44 (76%) mastectomies were nipple/areola-sparing, and 14 (24%) were areola-sparing. Thirteen mastectomies (22%) were therapeutic, the remaining 45 mastectomies (78%) were prophylactic. Five of the nine sentinel lymph node biopsies (56%) were performed through the lateral IMF incision without the need for a counter-incision. Acellular dermal matrix was used in 44 (76%) breasts. Average permanent implant volume was 313 cc (range 170 to 750 cc), and average fat grafting volume was 90 cc (range 36 to 177 cc). Mastectomy flap necrosis, requiring operative debridement, occurred in three breasts (5%). One of these breasts required a salvage latissimus dorsi myocutaneous flap to complete the reconstruction. Of the 44 nipple/areola sparing mastectomies, three (7%) required operative debridement and reconstruction for partial nipple necrosis. No statistically significant differences existed between therapeutic and prophylactic mastectomies for developing partial skin or nipple necrosis (p = 0.65). Morphologic outcomes using 3D scan measurements showed reconstructed breasts were larger, more projected, and less ptotic (196 vs. 248 cc, 80 vs. 90 mm, 146 vs. 134 mm, p < 0.01 for each parameter).

Conclusion: Excellent results can be achieved with immediate implant-based reconstruction of nipple and/or areola-sparing mastectomy through a lateral IMF incision. NAC survival is reliable, and complication rates are low.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P2-16-09.

Groucho-dependent and -independent repression activities of Runt domain proteins

Runt domain proteins are transcriptional regulators that specify cell fates for processes extending from pattern formation in insects to leukemogenesis in humans. Runt domain family members are defined based on the presence of the 128-amino-acid Runt domain, which is necessary and sufficient for sequence-specific DNA binding. We demonstrate an evolutionarily conserved protein-protein interaction between Runt domain proteins and the corepressor Groucho. The interaction, however, is independent of the Runt domain and can be mapped to a 5-amino-acid sequence, VWRPY, present at the C terminus of all Runt domain proteins. Drosophila melanogaster Runt and Groucho interact genetically; the in vivo repression of a subset of Runt-regulated genes is dependent on the interaction with Groucho and is sensitive to Groucho dosage. Runt's repression of one gene, engrailed, is independent of VWRPY and Groucho, thus demonstrating alternative mechanisms for repression by Runt domain proteins. Unlike other transcriptional regulatory proteins that interact with Groucho, Runt domain proteins are known to activate transcription. This suggests that the Runt domain protein-Groucho interaction may be regulated.