Impact and Outcomes of Routine Microstaging of Sentinel Lymph Nodes in Breast Cancer: Significance of the pN0(i+) and pN1mi Categories
ABSTRACT BackgroundIn 2003, the American Joint Committee on Cancer (AJCC) initiated the 6th edition staging criteria, including pN0(i+) and pN1mi
categories for breast cancer. However, the clinical significance of these categories is debated in the literature.
MethodsA prospective registry was used to identify patients staged with sentinel lymph node (SLN) biopsy. SLN evaluation included
routine serial sectioning and immunohistochemical stains. SLN biopsies performed before January 2003 were restaged according
to the AJCC’s 6th edition criteria.
ResultsOf 954 SLN biopsies identified, on review, 491 N0i-, 86 N0i+, 73 N1mi, 146 N1a, 29 N2a, and 11 N3a patients were available
for analysis with a median follow-up of 45.4 months. Significant prognostic and therapeutic differences existed between the
groups. Differences in overall survival (OS) and recurrence-free survival (RFS) were only noted when the size of the metastases
reached the N1a level. There were no statistically significant differences in OS or RFS between N0(i−) and N0(i+) or N1mi
disease. Cases that were N0(i+) or N1mi were more likely to have other poor prognostic factors and to receive more aggressive
ConclusionSLN biopsy allows a more sensitive evaluation of lymph nodes for metastatic cells. This has led to the increased identification
of very small axillary metastases. While the new microstaging categories are not yet clearly associated with a significantly
decreased OS or DFS in this series, they are associated with other poor prognostic factors and more local/regional and systemic
therapy. Further analysis of the microstaging categories is needed.
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ABSTRACT: To examine treatment patterns, recurrence, and survival outcomes in patients with pN0(i+) breast cancer. Subjects were 5999 women with AJCC (6th edition) pT1-3, pN0-N1a, M0 breast cancer diagnosed between 2003 and 2006. Of these, 4342 (72%) had pN0, 96 (2%) had pN0(i+), 349 (6%) had pNmic (micrometastases >0.2 mm to ≤2 mm), and 1212 (20%) had pN1a (1-3 positive macroscopic nodes) disease. Treatment characteristics and 5-year Kaplan-Meier local recurrence, regional recurrence (RR), locoregional recurrence (LRR), and overall survival were compared between nodal subgroups. Multivariable analysis was performed using Cox regression modeling. A 1:3 case-match analysis examined outcomes in pN0(i+) cases compared with pN0 controls matched for similar tumor and treatment characteristics. Median follow-up was 4.8 years. Adjuvant systemic therapy use increased with nodal stage: 81%, 92%, 95%, and 94% in pN0, pN0(i+), pNmic, and pN1a disease, respectively (P<.001). Nodal radiation therapy (RT) use also increased with nodal stage: 1.7% in pN0, 27% in pN0(i+), 33% in pNmic, and 63% in pN1a cohorts (P<.001). Five-year Kaplan-Meier outcomes in pN0 versus pN0(i+) cases were as follows: local recurrence 1.7% versus 3.7% (P=.20), RR 0.5% versus 2.2% (P=.02), and LRR 2.1% versus 5.8% (P=.02). There were no RR events in 26 patients with pN0(i+) disease who received nodal RT and 2 RR events in 70 patients who did not receive nodal RT. On multivariable analysis, pN0(i+) was not associated with worse locoregional control or survival. On case-match analysis, LRR and overall survival were similar between pN0(i+) and matched pN0 counterparts. Nodal involvement with isolated tumor cells is not a significant prognostic factor for LRR or survival in this study's multivariable and case-match analyses. These data do not support the routine use of nodal RT in the setting of pN0(i+) disease. Prospective studies are needed to define optimal locoregional management for women with pN0(i+) breast cancer.International journal of radiation oncology, biology, physics 09/2013; DOI:10.1016/j.ijrobp.2013.07.028 · 4.59 Impact Factor
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ABSTRACT: To compare the outcome of patients with invasive breast cancer, who had isolated tumor cells (ITC) in sentinel lymph nodes, pN0(i+), to patients with histologically negative nodes, pN0. We retrospectively studied 1,273 patients diagnosed with T1-T3 breast cancer from 1999 to 2009. Patients were divided into 2 populations: 807 patients treated with breast-conserving surgery (BCS) and radiotherapy (RT), 85(10.5 %) with pN0(i+) and 722(89.5 %) with pN0. And the other population had 466 patients treated with mastectomy without post-mastectomy radiation therapy (PMRT), 80(17.2 %) with pN0(i+),and 386(82.8 %)with pN0. All patients underwent sentinel node biopsy, and the presence of ITC was determined. Patients with axillary dissection only or neoadjuvant chemotherapy were excluded. Among the 1,273 patients studied; 87.3 % received adjuvant systemic therapy. Kaplan-Meier, Cox regression, and log-rank statistical tests were used. Median patient age was 55.7 years. Median follow-up was 69.5 months. The 5- and 10-year cumulative incidence of Loco-regional recurrence (LRR) for patients treated with BCS and RT was 1.6 and 3.5 % for 85 pN0(i+) patients, and 2.4 and 5 % for 722 pN0 patients, respectively. For patients treated with mastectomy without PMRT, 5- and 10-year LRR rates were 2.8 and 2.8 % for 80 pN0(i+) patients, and 1.8 and 3 % for 386 pN0 patients, respectively. There were no statistically significant differences in LRR (p = 0.9), distant recurrence (p = 0.3) ,and overall survival (p = 0.5) among all groups. On multivariate analysis, ITC were not associated with increased risk of LRR, distant recurrence and overall survival. Grade (p = 0.003) and systemic therapy (p = 0.02) were statistically significantly associated with risk of LRR. Sentinel node ITC have no significant impact on LRR, distant recurrence and overall survival in breast cancer patients. Additional treatments such as axillary dissection, chemotherapy, or regional radiation should not be given solely based on the presence of sentinel node ITC.Breast Cancer Research and Treatment 06/2014; 146(2). DOI:10.1007/s10549-014-3027-2 · 4.20 Impact Factor
- The Breast Journal 11/2013; 19(6):680-2. DOI:10.1111/tbj.12191 · 1.43 Impact Factor