Surgical sentinel lymph node biopsy in early breast cancer. Could it be avoided by performing a preoperative staging procedure? A pilot study

Gamma probe and ultrasound-guided fine needle aspiration cytology of the sentinel node (GULF) trial

PURPOSE

Sentinel lymph node biopsy (SLNB) was introduced as a minimally invasive technique for nodal staging. Since associated morbidity is not negligible, it is highly relevant to pursue a more minimally invasive alternative. The purpose of this study was to prospectively evaluate the sensitivity of fine needle aspiration cytology (FNAC) with combined gamma probe and ultrasound (US) guidance in comparison with the gold standard histology of the sentinel node (SN) after SLNB for detecting metastasis.

METHODS

The study was designed as a prospective, multicentre, open-label, single-arm trial enrolling patients with newly diagnosed cutaneous melanoma or breast cancer between May 2015 and August 2017. Sample radioactivity was measured using a Mini 900 scintillation monitor. After FNAC, all patients underwent SLNB. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were estimated.

RESULTS

Accrual was terminated early following an unplanned interim analysis indicating that a FNAC sensitivity of at least 80% could not be achieved. In total 58 patients of the originally planned 116 patients underwent FNAC with gamma probe and US guidance. There were no true-positive FNAC results, 14 false-negative results and one false-positive result, and thus the sensitivity, specificity, PPV and NPV of FNAC were 0%, 98%, 0% and 75%, respectively. At least 75% of the FNAC samples had a radioactivity signal higher than the background signal.

CONCLUSION

FNAC with gamma probe and US guidance is not able to correctly detect metastases in the SN and is therefore not able to replace SLNB. Gamma probe-guided US is a highly accurate method for correctly identifying the SN, which offers possibilities for future research.

Gamma probe and ultrasound guided fine needle aspiration cytology of the sentinel node (GULF) trial - overview of the literature, pilot and study protocol

BACKGROUND

Sentinel node (SN) biopsy (SNB) detects clinically occult metastases of breast cancer and melanoma in 20-30%. Wound infections, seroma and lymph edema occur in up to 10%. Targeted ultrasound (US) of the SN, (with fine needle aspiration cytology (FNAC) if appropriate) has been investigated as a minimally invasive alternative, but reported sensitivity rates are too low to replace SNB. Our hypothesis is that the use of a handheld gamma probe concomitant with US may improve sensitivity. Our aim is to provide an overview of the current literature on preoperative nodal staging of clinical N0 melanoma patients, report on a pilot, and present a study protocol for a minimally invasive alternative to the SNB: Gamma probe and Ultrasound guided Fine needle aspiration cytology of the sentinel node (GULF trial).

METHODS

The GULF trial is a multicenter open single arm observational trial. Newly diagnosed cT1b-4N0M0 cutaneous melanoma or cT1-3N0M0 breast cancer patients, aged >18 years, presenting for SNB are eligible. 120 patients will be included for preoperative targeted gamma probe guided US and FNAC of the SN. Afterwards all patients proceed to surgical SNB. Primary endpoint is the sensitivity of FNAC. Secondary endpoints include SN identification rate and the histopathological compatibility of Core Needle Biopsy and FNAC vs. SNB. Secondary endpoints were investigated in a pilot with 10 FNACs and marker placements, and 10 FNACs combined with Core Needle Biopsy.

RESULTS

A pilot in 20 patients showed that SN identification rate was 90%, supporting the feasibility of this technique.

DISCUSSION

There is broad experience with US (in combination with FNAC) prior to SNB, but sensitivity and specificity are too low to completely abandon SNB. Promising alternative techniques potentially will replace SNB in the future but more evidence is needed in the form of prospective studies. Accurate identification of the SN for US-FNAC has been proven feasible in our pilot. When adequate sensitivity can be reached, US-FNAC provides a minimally invasive alternative for the surgical SNB procedure.

TRIAL REGISTRATION

The GULF trial is registered in the Netherlands Trial Registry (NTR), ID: NRT5193 . May 1st 2015.

Prediction of axillary lymph node metastases in breast cancer patients based on pathologic information of the primary tumor

BACKGROUND

Axillary lymph nodes (ALN) are the most commonly involved site of disease in breast cancer that has spread outside the primary lesion. Although sentinel node biopsy is a reliable way to manage ALN, there are still no good methods of predicting ALN status before surgery. Since morbidity in breast cancer surgery is predominantly related to ALN dissection, predictive models for lymph node involvement may provide a way to alert the surgeon in subgroups of patients.

MATERIAL AND METHODS

A total of 1325 invasive breast cancer patients were analyzed using tumor biological parameters that included age, tumor size, grade, estrogen receptor, progesterone receptor, lymphovascular invasion, and HER2, to test their ability to predict ALN involvement. A support vector machine (SVM) was used as a classification model. The SVM is a machine-learning system developed using statistical learning theories to classify data points into 2 classes. Notably, SVM models have been applied in bioinformatics.

RESULTS

The SVM model correctly predicted ALN metastases in 74.7% of patients using tumor biological parameters. The predictive ability of luminal A, luminal B, triple negative, and HER2 subtypes using subgroup analysis showed no difference, and this predictive performance was inferior, with only 60% accuracy.

CONCLUSIONS

With an SVM model based on clinical pathologic parameters obtained in the primary tumor, it is possible to predict ALN status in order to alert the surgeon about breast cancer counseling and in decision-making for ALN management.

[Evolution of sentinel lymph node biopsy in breast cancer--axillary staging in the past 15 years at the Uzsoki Street Hospital]

INTRODUCTION

Sentinel biopsy technique was performed in Europe in 1996.It was a great improvement in the surgical treatment of breast cancer, it decreased the number of patients suffering from early and late morbidity following axillary lymph node dissection (ALND). In our paper we demonstrate the evolution of sentinel biopsy technique (SLNB), as well as the changes in our policy on axillary treatment in line with the European trends.

METHODS

The authors of this article give an overview and analyse the relevant literature concerning sentinel lymph node biopsy and data of patients on whom sentinel lymph node biopsy was performed from 01/01/2001 to 31/12/2012.

RESULTS

Between 2001 and 2013 we performed 3756 breast operations, 2742 of those were done for malignant disease. Altogether we performed 744 sentinel lymph node biopsies in the Uzsoki teaching Hospital. The proportion of SLNB patients is increasing, it was 24.6% between 2001-2006 and 29.2% between 2007-2012, respectively. The indication of SLNB is widening, there might be justification of the technique even by multifocal or multilocular disease, in male patients, after former breats surgery or even in pregnant patients.

CONCLUSION

Histological examination of sentinel lymph node and its effect on complex treatment of breats cancer may place the role of surgical axillary staging in a brand new aspect in the near future perhaps.

Preoperative axillary imaging with percutaneous lymph node biopsy is valuable in the contemporary management of patients with breast cancer

BACKGROUND

ACOSOG Z11 and other studies showing little benefit to axillary dissection (ALND) for early-stage breast cancers with limited nodal disease have led to questioning the value of preoperative axillary imaging ± ultrasound-guided needle biopsy (USNB). Data are lacking on the value of this approach in identifying cases that fall outside Z11 guidelines.

METHODS

We studied 988 consecutive patients with invasive breast cancers who underwent operation including axillary surgery in 2010-2011.

RESULTS

Preoperative axillary ultrasonography (AUS) was performed in 92% and breast/axillary magnetic resonance imaging (MRI) in 51%; 82 (33.5%) of 245 patients with suspicious lymph nodes (LN) were USNB-positive. Regarding nodal status, AUS, MRI, and USNB had negative and positive predictive values of 78%, 76%, 70% and 54%, 58%, 100%, respectively. AUS/MRI visualization of one versus multiple abnormal LNs visualized predicted >2LN+ on final pathology (13.5%/15.1% % vs 30.8%/32.6%, P < .009). Among USNB-LN+ T1/T2 patients, 51.6% had 1-2 LN+ while 60% with multiple and 31% with one AUS-abnormal LN(s) had > 2LN+, P = .001.

CONCLUSION

In our contemporary series, preoperative AUS±USNB streamlined surgical care for 29% of node-positive patients. Two-thirds of T1/T2 USNB-LN+ patients with multiple AUS-suspicious LNs had >2LN+, suggesting they should undergo ALND without SLNB. AUS±USNB helps identify node-positive breast cancer patients who fall outside Z11 guidelines.