Omission of axillary lymph node dissection in patients with ypN+ breast cancer after neoadjuvant chemotherapy: A retrospective multicenter study (KROG 21-06).

BACKGROUND: We evaluated the impact of omitting axillary lymph node dissection (ALND) on oncological outcomes in breast cancer patients with residual nodal disease after neoadjuvant chemotherapy (NAC). METHODS: The medical records of patients who underwent NAC followed by surgical resection and had residual nodal disease were retrospectively reviewed. In total, 1273 patients from 12 institutions were included; all underwent postoperative radiotherapy. Axillary surgery consisted of ALND in 1103 patients (86.6%) and sentinel lymph node biopsy (SLNBx) alone in 170 (13.4%). Univariate and multivariate analyses of disease-free survival (DFS) and overall survival (OS) were performed before and after propensity score matching (PSM). RESULTS: The median follow-up was 75.3 months (range, 2.5-182.7). Axillary recurrence rates were 4.8% in the ALND group (n = 53) and 4.7% in the SLNBx group (n = 8). Before PSM, univariate analysis indicated that the 5-year OS rate was inferior in the ALND group compared to the SLNBx group (86.6% vs. 93.3%, respectively; P = 0.002); multivariate analysis did not show a difference between groups (P = 0.325). After PSM, 258 and 136 patients were included in the ALND and SLNBx groups, respectively. There were no significant differences between the ALND and SLNBx groups in DFS (5-year rate, 75.8% vs. 76.9%, respectively; P = 0.406) or OS (5-year rate, 88.7% vs. 93.1%, respectively; P = 0.083). CONCLUSIONS: SLNBx alone did not compromise oncological outcomes in patients with residual nodal disease after NAC. The omission of ALND might be a possible option for axillary management in patients treated with NAC and postoperative radiotherapy.

Axillary Lymph Node Dissection Does Not Improve Post-mastectomy Overall or Disease-Free Survival among Breast Cancer Patients with 1-3 Positive Nodes.

PURPOSE: Axillary lymph node dissection (ALND) may be avoidable for breast cancer patients with 1-2 positive lymph nodes (LN) after breast-conserving therapy. However, the effects of ALND after mastectomy remain unclear because radiation is not routinely used. Herein, we compared the benefits of post-mastectomy ALND versus sentinel node biopsy (SNB) alone for breast cancer patients with 1-3 metastatic LNs. MATERIALS AND METHODS: A total of 1,697 patients with pN1 disease who underwent mastectomy during 2000-2015 were identified from an institutional database. Outcomes were compared using the inverse probability of treatment weighted method. RESULTS: Patients who underwent SNB tended to have smaller tumors, a lower histology grade, a lower number of positive LNs, and better immunohistochemical findings. After correcting all confounding factors regarding patient, tumor, and adjuvant treatment, the SNB and ALND groups did not differ in terms of overall survival (OS) and disease-free survival (DFS), distant metastasis and locoregional recurrence. The 10-year DFS and OS rates were 83% and 84%, respectively, during a median follow-up period of 93 months. CONCLUSION: ALND did not improve post-mastectomy survival outcomes among patients with N1 breast cancer, even after adjusting for all histopathologic and treatment-related factors.

Evaluation of the Prognostic Stage in the 8th Edition of the American Joint Committee on Cancer in Patients with Breast Cancer and Internal Mammary Lymph Node Metastasis.

BACKGROUND/AIM: This study evaluated the prognostic value of the 8th edition of American Joint Committee on Cancer (AJCC) cancer staging system for patients with internal mammary lymph node (IMN) metastases. MATERIALS AND METHODS: Of the patients with breast cancer who were treated between 2009 and 2013, 66 were diagnosed as cN3b. We restaged the patients and analyzed the prognostic value of the prognostically staged groups. RESULTS: With a median follow-up of 53.9 months, the 5-year overall survival rates of patients with IIIA, IIIB, and IIIC stages were 100%, 95%, and 50% (p=0.001), while the progression-free survival rates were 100%, 83%, and 50% (p=0.005). CONCLUSION: Despite the small number of patients, the prognostic stage provided accurate information for IMN metastasized breast cancer, which will lead to more accurate prognosis predictions and optimal treatment selection.

Impact of pathologic diagnosis of internal mammary lymph node metastasis in clinical N2b and N3b breast cancer patients.

PURPOSE: To analyze the prognostic role of pathologic confirmation of internal mammary lymph nodes (IMNs) for breast cancer patients who received neoadjuvant chemotherapy. METHODS: Of the patients who were treated with neoadjuvant chemotherapy, surgery, and radiation therapy between 2009 and 2013, 114 women had suspicious IMNs and FNAB was attempted. Clinical IMN metastasis was diagnosed by 18F-FDG PET/CT positivity or pathologic confirmation (N = 70). Patients were divided into the FNAB(+) or FNAB(-) IMN group. RESULTS: The pathologic confirmation rate was 57% (40 of 70 patients). Rates were 74% in US-positive, 70% in MRI-positive, and 55% in PET-positive patients. Nodal stage was cN2b (6%) or cN3b (94%). Five-year progression-free survival (PFS) was significantly worse in patients with FNAB(+) IMN metastasis than FNAB(-) IMN metastasis (61% vs. 87%, P = 0.03). FNAB(+) IMN patients showed worse distant metastasis and regional recurrence-free survival without statistical significance (69% vs. 86%, P = 0.06, and 81% vs. 96%, P = 0.06). With median follow-up of 50.5 months (13.0-97.0 months), overall survival at 5 years was 77%, and PFS was 72%. CONCLUSIONS: Patients with FNAB-proven IMN metastasis had worse treatment outcomes compared to patients with clinically diagnosed IMN metastasis in cN2b/N3b breast cancer.

Inter- and intra-observer variability in contouring of the prostate gland on planning computed tomography and cone beam computed tomography.

PURPOSE: To investigate inter-/intra-observer variability in defining the prostate by use of planning computed tomography (PCT) and cone beam CT (CBCT) with magnetic resonance image (MRI) as guidance prior to the introduction of an adaptive radiotherapy for prostate cancer. MATERIAL AND METHODS: We reviewed PCT and firstly acquired CBCT datasets of each ten patients with prostate cancer. Three physicians independently delineated the prostate based on PCT and CBCT with MRI as guidance, allowing determination of inter-physician variability. Two physicians repeated prostate contouring three times in total to investigate intra-physician variability. We compared delineated prostate volumes in terms of the generalized conformity index (CI(gen)), maximum variation ratio (MVR), and center of mass (COM). RESULTS: There were no significant inter-/intra-observer differences in the estimation of prostate volume on both PCT and CBCT. For both inter- and intra-observer variability in contouring the prostate gland, there were no significant differences in MVR between PCT and CBCT. The CI(gen) for inter-observer variability was 0.74 by PCT and 0.69 by CBCT. The CI(gen) for intra-observer variability on PCT and CBCT was 0.84 and 0.81 for observer 2 and 0.76 and 0.73 for observer 3. COM analyses showed that the greatest inter-/intra-observer variability was in the measurement of the prostate apex and base. With respect to CI(gen) and COM analysis for the inter-observer variability, more precise delineation of the prostate was possible on PCT than CBCT. More precise contouring in terms of both CI(gen) and COM was demonstrated by observer 2 than observer 3. CONCLUSIONS: Despite some ambiguity in apex and base level, there was a good consistency in delineating the gland on CBCT plus MRI-guided modification both among/within observer(s), without any significant difference from the consistency in defining the prostate on PCT. This study provides a framework for future studies of CBCT imaging of the prostate.