Lack of prognostic impact of sentinel node micro-metastases in endocrine receptor-positive early breast cancer: results from a large multicenter cohort☆.

BACKGROUND: Prognostic impact of lymph node micro-metastases (pN1mi) has been discordantly reported in the literature. The need to clarify this point for decision-making regarding adjuvant therapy, particularly for patients with endocrine receptor (ER)-positive status and HER2-negative tumors, is further reinforced by the generalization of gene expression signatures using pN status in their recommendation algorithm. PATIENTS AND METHODS: We retrospectively analyzed 13 773 patients treated for ER-positive breast cancer in 13 French cancer centers from 1999 to 2014. Five categories of axillary lymph node (LN) status were defined: negative LN (pN0i-), isolated tumor cells [pN0(i+)], pN1mi, and pN1 divided into single (pN1 = 1) and multiple (pN1 > 1) macro-metastases (>2 mm). The effect of LN micro-metastases on outcomes was investigated both in the entire cohort of patients and in clinically relevant subgroups according to tumor subtypes. Propensity-score-based matching was used to balance differences in known prognostic variables associated with pN status. RESULTS: As determined by sentinel LN biopsy, 9427 patients were pN0 (68.4%), 546 pN0(i+) (4.0%), 1446 pN1mi (10.5%) and 2354 pN1 with macro-metastases (17.1%). With a median follow-up of 61.25 months, pN1 status, but not pN1mi, significantly impacted overall survival (OS), disease-free survival (DFS), metastasis-free survival (MFS), and breast-cancer-specific survival. In the subgroup of patients with known tumor subtype, pN1 = 1, as pN1 > 1, but not pN1mi, had a significant prognostic impact on OS. DFS and MFS were only impacted by pN1 > 1. Similar results were observed in the subgroup of patients with luminal A-like tumors (n = 7101). In the matched population analysis, pN1macro, but not pN1mi, had a statistically significant negative impact on MFS and OS. CONCLUSION: LN micro-metastases have no detectable prognostic impact and should not be considered as a determining factor in indicating adjuvant chemotherapy. The evaluation of the risk of recurrence using second-generation signatures should be calculated considering micro-metastases as pN0.

Breast cancer robotic nipple sparing mastectomy: evaluation of several surgical procedures and learning curve.

BACKGROUND: Few studies of robotic nipple sparing mastectomy (NSM) were reported. We report feasibility of robotic NSM and determine standard surgical procedure and learning curve threefold. METHODS: A cohort of patients with robotic NSM for breast cancer was analyzed. Complications and post-operative hospitalization stay were reported. The same technic was used for all patients except for skin and nipple areolar complex (NAC) dissection. Differences between three surgical procedures of NAC dissection were analyzed: group 1, dissection with robotic scissors using coagulation; group 2, dissection with robotic scissors without coagulation; and group 3, dissection with non-robotic scissors and then robotic dissection. We explored possible effect of learning curve among patients from group 1 with the same surgical procedure. RESULTS: Twenty-seven NSM with immediate breast reconstruction for breast cancers, 22 invasive and 5 in situ, were performed, with robotic latissimus dorsi-flap (RLDF) only in 17 cases, RLDF and breast implant in 6 cases, and implant alone in 4 cases. Repartition according to 3 surgical procedure groups was 16, 5, and 6 patients. Mean time of surgery and anesthesia decrease according to groups 1 to 3. Among 16 patients from group 1, time of surgery and anesthesia decreased with learning curve. Post-operative hospitalization decreased from group 1 to 3. We reported a total of 11 complications, with significant difference between groups (10 for group 1). Skin complications were higher for group 1 in comparison with groups 2-3 (p = 0.02). CONCLUSION: Robotic NSM can be performed with a brief learning. Standardized technique is proposed with non-robotic scissors superficial dissection and then dissection with robot.

Pathological complete response in invasive breast cancer treated by skin sparing mastectomy and immediate reconstruction following neoadjuvant chemotherapy and radiation therapy: Comparison between immunohistochemical subtypes.

CONTEXT: Even if neoadjuvant chemotherapy (NACT) and oncoplastic techniques have increased the breast conserving surgery rate, mastectomy is still a standard for multifocal or extensive breast cancers (BC). In the prospect of increasing breast reconstruction, an alternative therapeutic protocol was developed combining NACT with neoadjuvant radiation therapy (NART), followed by mastectomy with immediate breast reconstruction (IBR). The oncological safety of this therapeutic plan still needs further exploration. We assessed pathological complete response (pCR) as a surrogate endpoint for disease free survival. METHODS: Between 2010 and 2016, 103 patients undergoing mastectomy after NACT and NART were recruited. After CT and RT were administrated, a completion mastectomy with IBR by latissimus dorsi flap was achieved 6 to 8 weeks later. pCR was defined by the absence of residual invasive disease in both nodes and breast. Histologic response was analyzed for each immunohistochemical subset. RESULTS: pCR was obtained for 53.4% of the patients. This pCR rate was higher in hormonal receptor negative (HER2 and triple negative) patients when compared to luminal tumours (69.7% vs 45.7%, p=0.023). DISCUSSION: The pCR rate found in this study is higher than those published in studies analyzing NACT (12.5%-27.1%). This can be explained by the combination of anthracycline and taxane, the use of trastuzumab when HER2 was overexpressed but also by RT associated to NACT. CONCLUSION: Inverting the sequence protocol for BC, requiring both CT and RT, allows more IBR without diminishing pCR and should therefore be considered as an acceptable therapeutic option.