The importance of extracapsular extension of axillary lymph node metastases in breast cancer

PURPOSE: To evaluate the prognostic value of extracapsular extension (ECE) of axillary lymph node metastases in 221 patients with axillary lymph node-positive, T1-T2 breast cancer treated at Dokuz Eylul University Hospital, Department of Radiation Oncology. PATIENTS AND METHODS: The clinical records of patients with axillary node-positive, pathological stage II-III breast cancer examined at Dokuz Eylul University Hospital, Department of Radiation Oncology, between 1991-1999 were reviewed. All patients underwent modified radical mastectomy (MRM) or wide excision with axillary node dissection. Axillary surgery consisted of level I-II dissection. The number of lymph nodes dissected from the axilla was equal to or more than 10 in 92% of the patients. All 221 patients had pathological T1-T2 tumors. The number of involved lymph nodes was four or more in 112 51% patients and less than four in the remaining 109 (49%). In 127 (57.5%) patients, extracapsular extension was detected in axillary lymph nodes. Tangential radiotherapy fields were used to treat the breast or chest wall. Lymphatic irradiation was performed in 215 (97%) patients with fields covering both the supraclavicular and axillary regions. Median radiotherapy dose for lymph nodes was 5000 cGy in 25 fractions. The following factors were evaluated: age, menopausal status, histological tumor type, pathological stage, number of involved axillary lymph nodes, and extracapsular extension. The chi-square test was used to compare proportions of categorical covariates between groups of patients with and without ECE. Survival analyses were estimated with the Kaplan-Meier method. The Cox regression model was used for the analysis of prognostic factors. RESULTS: The median follow-up for the survivors was 55 months (range, 19-23). The median age was 52 years (range, 28-75). In patients with extracapsular extension the percentages of pathological stage III (22% vs 4.3%, P < 0.0001 and involvement of four or more axillary nodes (25.5% vs 69.3%, p < 0.0000) were higher. Multivariate analysis revealed a significant correlation between the presence of ECE and disease-free survival (DFS) (P = 0.04) as well as distant metastases-free survival (DMFS) (P = 0.002), but there was no significant correlation between ECE and overall survival (OS). Only an elevated number of involved axillary lymph nodes significantly reduced the overall survival (P = 0.001). CONCLUSION: The rate of extracapsular extension was found to be directly proportional to the number of axillary lymph nodes involved and the stage of disease. Extracapsular extension had significant prognostic value in both univariate and multivariate analysis for DFS and DMFS but not OS. The reason for ECE not affecting OS might be related to the much more dominant prognostic effect of the involvement of four or more axillary nodes on OS. Studies with more patients are needed to demonstrate that ECE is a likely independent prognostic factor for OS.     

腋淋巴结阳性乳腺癌结外侵犯的临床意义

目的 探讨乳腺癌患者淋巴结外侵犯(ECE)的临床意义.方法 回顾性分析1230例腋窝淋巴结阳性乳腺癌,观察ECE与临床病理指标之间关系及对患者预后的影响.结果 腋窝淋巴结阳性乳腺癌患者中,ECE阳性率为39.5%.绝经前和绝经后患者ECE的发生率分别为35.5%和47.5%(P＜0.001).ECE阳性组和阴性组的肿瘤直径分别为5.11±2.53 cm和3.90±1.80 cm(P＜0.001),肿瘤直径越大,ECE阳性比例越高(P＜0.001).ECE阳性患者和ECE阴性患者的阳性淋巴结数目分别为16.96±12.16和5.24±6.60(P＜0.001),随腋窝阳性淋巴结数目增多,ECE阳性率明显增加(P＜0.001).ECE的发生与ER、PR状态无显著相关(P=0.706).ECE足乳腺癌患者局部或区域复发的危险因素(P＜0.001),复发时间差异无统计学意义(P=0.559).ECE阳性组和ECE阴性组的远处转移时问分别为30.0个月和37.5个月(P=0.006).首发骨、皮肤和远隔淋巴结组及内脏转移组的ECE阳性率分别为60.4%和42.0%(P=0.001).ECE阳性患者的无转移生存时间、无局部或区域复发生存时间及总生存时间均小于ECE阴性患者.预后单因素和多因素分析显示,ECE是影响乳腺癌患者无转移生存时间、无局部或区域复发生存时间及总生存时间的独立危险因素.结论 乳腺癌患者ECE的发生与肿瘤直径和受累淋巴结数日呈正相关;ECE是乳腺癌局部或区域复发和远处转移的危险因素;ECE是影响乳腺癌患者无转移生存时间、无局部或区域复发生存时间及总生存时间的危险因素.     

Occult axillary lymph node metastases are of no prognostic significance in breast cancer

The significance of occult metastases in axillary lymph nodes in patients with carcinoma of the breast is controversial. Additional sections were cut from the axillary lymph nodes of 477 women with invasive carcinoma of the breast, in whom no metastases were seen on initial assessment of haematoxylin and eosin stained sections of the nodes. One section was stained with haematoxylin and eosin, and one using immunohistochemistry with two anti-epithelial antibodies (CAM5.2 and HMFG2). Occult metastases were found in 60 patients (13%). The median follow-up was 18.9 years with 153 breast cancer related deaths. There was no difference in survival between those with and those without occult metastases. Multivariate analysis, however, showed that survival was related to tumour size and histological grade. This node-negative group was compared with a second group of 202 patients who had one involved axillary node found on initial assessment of the haematoxylin and eosin sections; survival was worse in the patients in whom a nodal metastasis was found at the time of surgery. Survival was not related to the size of nodal metastases in the occult metastases and single node positive groups. Some previous studies have found a worse prognosis associated with occult metastases on univariate analysis, but the evidence that it is an independent prognostic factor on multivariate analysis is weak. We believe that the current evidence does not support the routine use of serial sections or immunohistochemistry for the detection of occult metastases in the management of lymph node negative patients, but that the traditional factors of histological grade and tumour size are useful.     

Ultrasound detection of axillary lymph node metastases in breast cancer

Presence or absence of lymph node metastases is the most accurate prognostic indicator in breast cancer. Clinical examination is unreliable in detecting involved nodes. Preoperative ultrasound scan of the axilla has been performed in 140 consecutive women with breast cancer. The sensitivity for involved nodes was 66% which was significantly higher than clinical examination (42%) (P = less than 0.01). However ultrasound gave more false positives than clinical examination and thus no overall improvement in prognostic information was achieved.     

Diagnosis of axillary lymph node metastases in patients with breast cancer

Summary The diagnosis of axillary (AX) metastases remains a challenge in the management of breast cancer and is a subject of controversy. Clinical node staging clearly is limited in the assessment of AX lymph nodes. AX mammography, ultrasonography, and computed tomography (CT) do not provide histologic information. Although nuclear magnetic resonance imaging may have considerable value in the diagnosis of AX metastases, it does not detect micrometastases. The use of biologic markers in the assessment of AX metastases remains a subject of investigation. On the other hand, biopsy of selected AX nodes or tissue with examination of histology or cytology generally would not identify a significant percentage of patients with AX node involvement. Sentinel lymph node biopsy, however, might be potentially useful for assessing AX metastases, although it remains investigational. In order to simplify diagnosis and reduce morbidity and mortality, alternatives to AX dissection must be sought and imaging and staging modalities refined. We present a review of the literature pertaining to the diagnosis of AX metastases in patients with breast cancer and a discussion of some current areas of controversy.     

Intraoperative assessment of axillary lymph node metastases in operable breast cancer

The diagnostic value of intraoperative histologic examination of frozen sections of axillary lymph nodes was investigated in 243 patients with operable breast cancer. One to six hard or enlarged axillary nodes were sampled from the axillary pad which was derived from a partial axillary dissection (including level 1 and 2 nodes). Half of these nodes were histologically examined using frozen sections during surgery. After a total axillary dissection, both the axillary nodes in the partial axillary dissection and the nodes dissected at level 3 were histologically examined on permanent section. A mean of four nodes were sampled (range: 1 to 6). Axillary dissection yielded a mean of 22 nodes (range: 6 to 60). Axillary sampling detected the presence of metastases in 65 of 84 (77%) patients with positive axillary lymph nodes. In the patients in whom the axillary involvement was not identified by axillary sampling, however, the extent of axillary involvement was limited to levels 1 and 2. Therefore, a partial axillary dissection may be justified for patients in whom axillary involvement is not found on frozen section of nodes from axillary sampling, whereas a total axillary dissection should be performed for patients in whom axillary involvement is found by these procedures.     

Occult axillary lymph node metastases do not have prognostic significance in early stage breast cancer

BACKGROUND:

Axillary lymph node status is one of the most powerful prognostic indicators in patients with breast cancer and has implications for adjuvant treatment. It has been demonstrated that enhanced histologic evaluation of axillary lymph nodes, including serial sectioning of paraffin tissue blocks and immunohistochemical (IHC) staining, increases the rate of detection of occult metastases. The clinical significance of occult lymph node metastases has been the subject of debate.

METHODS:

In the current study, the authors identified 267 patients who underwent axillary lymph node dissection (ALND) between 1987 and 1995 and were lymph node negative according to a routine pathologic evaluation, which included the complete submission of all lymph nodes and an examination of 1 hematoxylin and eosin (H&E)‐stained section per paraffin block. Patients did not receive systemic chemotherapy or hormone therapy. All of the dissected lymph nodes from these patients were re‐evaluated by intensified pathologic methods (serial sectioning with H&E levels plus IHC). Occult metastases were categorized by detection method and size. The clinical significance of the occult metastases was determined.

RESULTS:

Thirty‐nine patients (15%) who had lymph node‐negative results on routine evaluation of their ALND specimens had occult metastases identified. Eight of these patients (20%) had macrometastases >2.0 mm, 15 (40%) had micrometastases (range, >0.2 mm to ≤2 mm), and 16 (40%) had isolated tumor cells (≤0.2 mm). The presence of occult metastases and the size of metastases did not affect recurrence‐free or overall survival.

CONCLUSIONS:

The presence of occult metastasis did not have clinical significance in this cohort of patients with early stage breast cancer. Cancer 2011;. © 2011 American Cancer Society.     

乳腔镜辅助腋窝淋巴结清扫术治疗早期乳腺癌患者的效果分析

目的探讨早期乳腺癌患者采用乳腔镜辅助腋窝淋巴结清扫术的治疗效果。方法选取2015年6月至2018年6月间咸阳市彬州市人民医院收治的86例早期乳腺癌患者,根据采用的治疗方法不同进行分组。采用乳腔镜辅助腋窝淋巴结清扫术治疗的43例患者纳入观察组,采用常规腋窝淋巴结清扫术治疗的43例患者纳入对照组。比较两组患者的淋巴结清扫数量、手术时间、术中出血量、住院费用、术后引流量、术后6个月关节活动度、并发症和术后6个月复发率。结果两组患者淋巴结清扫数量比较,差异无统计学意义(P> 0. 05)。观察组手术时间和住院费用高于对照组,术中出血量和术后引流量低于对照组,差异均有统计学意义(均P <0. 05)。观察组术后6个月肩关节外旋、前屈、内旋、后伸、外展、内收活动度高于对照组(P <0. 05)。观察组并发症发生率为2. 3%,低于对照组的18. 6%,差异有统计学意义(P <0. 05)。观察组术后6个月复发率为2. 3%,与对照组的4. 6%比较,差异无统计学意义(P> 0. 05)。结论早期乳腺癌采用乳腔镜辅助腋窝淋巴结清扫术治疗,能减少术中出血量、术后引流量,保护腋窝重要神经、血管,降低并发症发生率,安全可靠,但住院费用较高,临床应结合患者病情和经济条件选取合适的术式。     

Prognostic significance of occult axillary lymph node metastases after chemotherapy‐induced pathologic complete response of cytologically proven axillary lymph node metastases from breast cancer

BACKGROUND:

Primary systemic chemotherapy has been a standard of care for the management of locally advanced breast cancer (LABC) patients and has increasingly been used for patients with large operable breast cancer. Pathologic complete response (pCR) of axillary lymph node metastases predicted an excellent probability of long‐term disease‐free and overall survival. Although the clinical significance of occult lymph node metastases in patients with breast cancer was extensively studied, their prognostic value in patients with LABC after primary chemotherapy was not known. This study evaluated the detection rate and clinical significance of occult lymph node metastases in lymph nodes that contained metastatic carcinoma at the time of initial diagnosis and converted to negative based on routine pathologic examination after primary systemic chemotherapy.

METHODS:

Fifty‐one patients with LABC and cytologically involved axillary lymph nodes that converted to negative after preoperative chemotherapy were identified from 2 prospective clinical trials. All lymph node sections were reviewed, 1 deeper level hematoxylin and eosin‐stained section of each lymph node was obtained and immunohistochemical staining for cytokeratin (CK) was performed. A total of 762 lymph nodes were evaluated for occult metastases. Kaplan‐Meier survival curves were used for calculating disease‐free and overall survival times.

RESULTS:

Occult axillary lymph node metastases were identified in 8 of 51 (16%) patients. In 6 patients, occult metastases were found in only 1 lymph node. In 7 patients, only isolated CK‐positive cells were identified. In all cases, occult carcinoma cells were embedded within areas of fibrosis, foreign body giant cell reaction, and extensive histiocytosis. Patients with occult lymph node metastases tended to have a higher frequency of residual primary breast tumors than those without occult metastases (4 of 8 vs 7 of 43, respectively). There was no statistically significant difference in disease‐free or overall survival times between patients with and without occult metastases after a median follow‐up 63 months.

CONCLUSIONS:

Persistent occult axillary lymph node metastases were not uncommon in patients with axillary lymph node‐positive LABC who experienced a pCR in involved lymph nodes after preoperative chemotherapy. However, such occult metastases did not adversely affect the good prognosis associated with axillary lymph node pCR. Therefore, routine lymph node CK evaluation was not recommended after primary chemotherapy. Cancer 2009. © 2009 American Cancer Society.     

乳腺癌腋窝淋巴结声像图联合免疫组织化学与淋巴结转移的相关性研究

背景与目的：乳腺癌腋窝淋巴结转移对于乳腺癌患者的预后及治疗方案的选择有重要的指导意义。本研究旨在探讨乳腺癌腋窝淋巴结声像图表现联合免疫组织化学与腋窝淋巴结转移的相关性。方法：回顾性分析应用超声检出的366例乳腺癌患者共计728枚腋窝淋巴结的声像图表现,采用单因素分析、多因素logistic回归及受试者工作特征(receiver operating characteristic,ROC)曲线分析的方法,分别检验乳腺癌腋窝淋巴结皮质最大厚度、长短径之比、皮髓质之比和淋巴结血流特征,联合乳腺癌术后免疫组织化学结果,研究其与病理学腋窝淋巴结转移的相关性。结果：依据单因素分析,腋窝淋巴结皮质最大厚度、长短径之比、血流特征以及乳腺癌病灶p53的阳性表达率与淋巴结转移有关(P<0.05)。依据多因素分析及ROC分析,腋窝淋巴结皮质最大厚度是判定腋窝淋巴结转移的最佳指标。腋窝淋巴结皮质最大厚度大于3 mm的患者,其乳腺癌病灶的p53阳性表达率(42.78%)明显高于皮质最大厚度小于等于3 mm的患者(25.82%),差异有统计学意义(P<0.01)。结论：乳腺癌腋窝淋巴结声像图表现联合免疫组织化学评价腋窝淋巴结转移,对乳腺癌的临床诊疗方法选择具有重要价值。     

Predicting axillary lymph node metastases in breast carcinoma patients

Routine axillary dissection is primarily used as a means of assessing prognosis to establish appropriate treatment plans for patients with primary breast carcinoma. However, axillary dissection offers no therapeutic benefit to node negative patients and patients may incur unnecessary morbidity, including mild to severe impairment of arm motion and lymphedema, as a result. This paper outlines a method of evaluating the probability of harbouring lymph node metastases at the time of initial surgery by assessment of tumour based parameters, in order to provide an objective basis for further selection of patients for treatment or investigation. The novel aspect of this study is the use of Maximum Entropy Estimation (MEE) to construct probabilistic models of the relationship between the risk factors and the outcome. Two hundred and seventeen patients with invasive breast carcinoma were studied. Surgical treatment included axillary clearance in all cases, so that the pathologic status of the nodes was known. Tumour size was found to be significantly correlated (P < 0.001) to the axillary lymph node status in the multivariate analysis with age (P = 0.089) and vascular invasion (P = 0.08) marginally correlated. Using the multivariate model constructed, 38 patients were predicted to have risk of nodal metastases lower than 20%, of these only 4 (10%) patients had lymph node metastases. A comparison with the Multivariate Logistic Regression (MLR) was carried out. It was found that the predictive quality of the MEE model was better than that of the MLR model. In view of the small sample size, further verification of this model is required in assessing its practical application to a larger population.     

临床腋淋巴结阳性乳腺癌患者行全腋窝淋巴结清扫的应用探讨

背景与目的:临床腋淋巴结阳性乳腺癌患者常规行全腋窝淋巴结清扫,本研究探讨改良根治术时采用改进L3组淋巴结清扫方式的临床应用及意义.方法:322例临床腋淋巴结阳性的乳腺癌患者中,154例采用改进的L3组淋巴结清扫方式,168例行常规Auchinclos改良根治术,对两种手术方式所用时间和术后不良反应进行比较,同时随访观察患者的无病生存率.结果:两种手术方式所用手术时间、术后不良反应差异无统计学意义(P＞0.05),行改进术式患者腋下淋巴结总数及L3组淋巴结数较常规术式多,两组差异有统计学意义(P＜0.05),L3组淋巴结未转移患者5年无病生存率为68.6％,L3组淋巴结转移患者5年无病生存率为35.7％,差异有统计学意义(P＜0.05).结论:对临床腋淋巴结阳性乳腺癌患者行L3组淋巴结清扫具有一定的临床应用价值,采用改进的淋巴结清扫方式,便于L3组淋巴结的清扫.     

The prognostic significance of total lymph node number in patients with axillary lymph node-negative breast cancer.

AIM: In node-negative breast cancer patients, several factors for survival have been evaluated and currently, some of them are accepted for their prognostic and/or predictive values after validation in the separate data sets. The prognostic significance of increases in the number of pathologically detectable axillary lymph nodes in the node-negative patients could not been established clearly. To address this question, we have reviewed our patients' records. METHODS: A retrospective cohort study was conducted in pathologically node-negative patients who underwent modified radical mastectomy for stage I and II breast cancer. Survival and multivariate prognostic factor analyses were carried out to determine whether the number of tumour-free lymph nodes in complete axillary dissection material in addition to known factors was significant for the outcomes. RESULTS: Two hundred and seventy consecutive patients were eligible to enter the trial. The median observation time and the median number of tumour-free lymph nodes were 61 (from 30 to 120) months and 18 (from 10 to 44), respectively. The cohort was divided into the groups according to the number of nodes. The 5-year event-free and overall survivals were 92.5 and 98.3% for patients who had 18 lymph nodes or less, and 70 and 86.7% for those who had more than 18 negative nodes, respectively (P < 0.00001). Multivariate analysis for event-free survival demonstrated that the number of lymph nodes (Relative risk: 3.2 and 95% confidence interval: 1.7 to 5.9) in addition to the pathological tumour size and age was the most important independent prognosticator. In similar, multivariate analysis for overall survival showed that the number of lymph nodes together with the tumour size was the significant indicator (RR of cancer-specific dying in patients who had more than 18 nodes: 3.1 and 95% CI: 1.2 to 8.5). CONCLUSION: The increases in number of tumour-free lymph nodes are clinically important and this parameter should be taken into consideration in the breast cancer patients without metastatic lymph nodes.     

Lack of efficacy of lymphoscintigraphy in detecting axillary lymph node metastases from breast cancer

Preoperative detection of metastases in regional lymph nodes should constitute a fundamental step towards a better management of breast cancer. The National Cancer Institute of Milan has traditionally been engaed in this particular problem, that is, the search for a new imaging technique for detecting lymph nodal metastases from breast cancer. In 1984 axillary lymphoscintigraphy was performed on 26 patients with operable breast cancer by periareolar injection of 100 μCi of ^99mTc sulphur microcolloid. The regional lymph nodes were identified as spot areas and a comparison was made between the number of primary draining axillary lymph nodes and their pathological examination. In only 2 of the 26 patients have more than 3 spot areas been revealed by axillary scintiscan, but this finding did not correspond to metastatic invasion. The lymphoscintigraphy pattern of the other 24 patients did not suggest any pathological condition. From our experience the method does not appear to help either a precise diagnosis of breast disease or the definition of the extent of mammary cancer.     

PET—C畛断乳腺癌及其腋窝淋巴结转移的价值

目的探讨PET—CT对诊断乳腺癌及腋窝淋巴结转移情况的临床价值。方法选取行PET—CT检查的乳腺肿瘤患者40例，根据术后病理检查结果评价PET—CT对原发病灶定性和判断腋窝淋巴结转移情况的准确性并与腋窝淋巴结清扫情况进行比较；检验原发肿瘤病灶病理直径大小与超声、PET—CT诊断的一致性及其与标准化摄取值（SUV）值的相关性。结果PET—CT对乳腺癌的定性诊断准确率95％、灵敏度94％、特异度100％；根据腋窝淋巴结清扫术情况，PET—CT诊断腋窝淋巴结转移准确率88．2％、灵敏度89．2％、特异度83．3％；肿瘤病灶病理直径大小与PET-CT诊断相关性最高（P〈0．05），与SUV则无相关性（P〉0．05）。结论PET—CT对乳腺癌及腋窝淋巴结转移的诊断与病理诊断基本相符，灵敏度、特异度较高，两者诊断原发病灶大小的一致性最佳，可为取舍腋窝淋巴结清扫术和选择合理治疗方案提供有益参考。     

Prognostic Significance of Axillary Lymph Node Micrometastases and Microvessel Count in Breast Cancer

Objective  To investigate the influence of axillary lymph node micrometastases and the microvessel count on the prognosis of patients with breast cancer. Methods  Forty-eight patients with breast cancer, who had no tumor cells in their regional lymph nodes based on conventional histopathologic examination, were re -examined with immunohistochemical LSAB techniques. H&E, anti-EMA, CK 19 and FVIII factor staining was used to identify tumor cells in both lymph nodes and tumor tissues and to count the mtcrovessels. A total of 882 lymph nodes were examined. Results  Immunostaining-positive tumor cells were found in 9.0 %( 79/882) of the dissected lymph nodes. The positive rates were not significantly different between a surviving group and a deceased group (P>0.05). The microvessel count was significantly higher in group that had died (P<0.001). Conclusion  The lymph node micrometastases did not show any correlation with patients’ survival, but the microvessel density had a negative correlation with the survival period in breast cancer patients who had negative axillary lymph nodes.     

Prognostic significance of axillary lymph node micrometastases and microvessel count in breast cancer

Objective To investigate the influence of axillary lymph node micrometastases and the microvessel count on the prognosis of patients with breast cancer. Methods Forty-eight patients with breast cancer, who had no tumor cells in their regional lymph nodes based on conventional histopathologic examination, were re -examined with immunohistochemical LSAB techniques. H&E, anti-EMA, CK 19 and FVIII factor staining was used to identify tumor cells in both lymph nodes and tumor tissues and to count the mtcrovessels. A total of 882 lymph nodes were examined. Results Immunostaining-positive tumor cells were found in 9.0 %( 79/882) of the dissected lymph nodes. The positive rates were not significantly different between a surviving group and a deceased group (P>0.05). The microvessel count was significantly higher in group that had died (P<0.001). Conclusion The lymph node micrometastases did not show any correlation with patients’ survival, but the microvessel density had a negative correlation with the survival period in breast cancer patients who had negative axillary lymph nodes.     

Basal breast cancer molecular subtype predicts for lower incidence of axillary lymph node metastases in primary breast cancer

BACKGROUND: Axillary lymph node involvement remains the most important prognostic factor in early-stage breast cancer. We hypothesized that molecular classification based on breast cancer biology would predict the presence of nodal involvement at diagnosis, which might aid treatment decisions regarding the axilla. PATIENTS AND METHODS: From a clinically annotated tissue microarray of 4444 early-stage breast cancers, expression of estrogen receptor (ER), progesterone receptor (PgR), HER2, epidermal growth factor receptor, and cytokeratin 5/6 was determined by immunohistochemistry. Cases were classified by published criteria into molecular subtypes of luminal, luminal/HER2 positive, HER2 positive/ER negative/PgR negative, and basal. Risk of axillary nodal involvement at diagnosis was determined in 2 multivariable logistic regression models: a "core biopsy model" including molecular subtype, age, grade, and tumor size and a "lumpectomy model," which also included lymphovascular invasion. Luminal was used as the reference group. After internal validation of findings in 2 independent sets, we conducted combined analysis of both. RESULTS: In the core biopsy model, the molecular subtypes had a predictive effect for nodal involvement (P= .000001), with the basal subtype having an odds ratio for axillary lymph node involvement of 0.53 (95% CI, 0.41-0.69). Tumor grade (P=5.43 x 10(-12)) and size (P=8.52 x 10(-35)) were also predictive for nodal involvement. Similar results were found in the lumpectomy model, where lymphovascular invasion was also predictive (P=2.74 x 10(-115)). CONCLUSION: These results indicate that the basal breast cancer molecular subtype predicts a lower incidence of axillary nodal involvement, and including biomarker profiles to predict nodal status at diagnosis could help stratification for decisions regarding axillary surgery and locoregional radiation.