Biopsy-proven Node-positive Breast Research Articles

Sentinel node biopsy after neoadjuvant therapy: Relevance of sentinel node micrometastases, isolated tumor cells, and value of immunohistochemistry.

52 Background: Sentinel node biopsy (SNB) is used in breast cancer patients that present with clinically negative nodes. In this setting, most guidelines do not support the use of immunohistochemistry (IHC) and recommend against completion node dissection (CND) when only isolated tumor cells (pN0(i+)) or micrometasases (pN1mi) are identified. When SNB is used after neoadjuvant therapy (NAT), the relevance of ypN0(i+) and ypN1mi sentinel nodes (SNs) and the value of IHC are not well established. The goals of this study are to determine if CND should be recommended in the presence of ypN0(i+) or ypN1mi SNs and if IHC should be used to evaluate SNs after NAT. Methods: From March 2009 to December 2012, 152 women with biopsy proven node positive breast cancer were accrued to the multicentric prospective SN FNAC trial. After NAT, SNB was followed by a CND in all participants. SNs were cut in serial slices no thicker than 2 mm. Hematoxylin and eosin stains (H and E) were done on all slices, and if negative, IHC was used. The size of the largest SN metastasis and the primary method of identification (H and E or IHC) were recorded. ypN0(i+), ypN1mi and ypN1 SNs were considered as positive. Pathology was centrally reviewed. Results: 145 women were eligible for the trial. Axillary pathologic complete response rate = 34% (49/145). SNB success rate = 88% (127/145). False negative rate = 8.4% (7/83). If ypN0(i+) SNs are classified as node negative, the false negative rate is increased to 13.3% (11/83). For patients with ypN0(i+) (n=7), ypN1mi (n=8) and ypN1 (n=61) SNs, the rates of non-SN involvement are 57%, 38% and 56% respectively (p=NS). 40% (27/68) of positive SNBs are primarily detected by IHC. This is increased to 64% (9/14) for the identification of SN metastases ≤ 2mm. Conclusions: After NAT, particularly when presenting with biopsy proven node positive breast cancer, patients with ypN0(i+) and ypN1mi SNs have a significant rate of non-SN involvement. In the absence of evidence to show that a CND can be safely avoided, efforts should be made to identify even minimal amounts of disease when SNBs are done following NAT. IHC is useful to increase the detection of small SN metastases in this setting. Clinical trial information: NCT00909441.

Sentinel node biopsy following neoadjuvant chemotherapy in biopsy proven node positive breast cancer: The SN FNAC study.

1018 Background: A significant and increasing proportion of patients (>30%) with biopsy proven node positive breast cancer will obtain a pathological complete response (pCR) in the axilla after neoadjuvant chemotherapy (NAC). If sentinel node biopsy (SNB) can accurately identify these patients, they could potentially avoid the morbidity of an axillary node dissection. The primary aim of this study is to evaluate the identification rate (IR), false negative rate (FNR) and accuracy of SNB in this setting. The accuracy of post NAC axillary ultrasound and clinical examination are evaluated as secondary endpoints. Methods: Patients with biopsy proven node positive breast cancer (T0-3, N1-2, M0) treated with NAC were eligible to participate in this multi-centre prospective trial. Following NAC, axillary ultrasound and clinical examination results were obtained. At time of surgery, all participants underwent both a SNB and a completion node dissection. A SNB IR greater than 90% and a FNR of less than 10% were pre-determined as being optimal. Results: From September 2009 to December 2012, 153 patients were accrued to the study. 7 patients were not eligible and 5 patients had not yet undergone surgery at the time of analysis. Axillary pCR rate = 34.0% (48/141). SNB IR = 87.2% (123/141), 95% CI [81.7%-92.7%] and FNR = 9.9% (8/81), 95% CI [3.4%-16.4%]. If only one sentinel node was removed, FNR = 19.0%(4/21); if there were 2 or more sentinel nodes, FNR = 6.6% (4/61) (p < 0.0001). Accuracy of SNB, axillary ultrasound and clinical examination were 93.5%, 63.2%, and 45.5% respectively. Conclusions: SNB following NAC in biopsy proven node positive breast cancer is associated with a suboptimal IR. FNR (less than 10%) and accuracy of SNB in this study are comparable to that of patients that present with clinically negative nodes. The FNR decreases when more than one sentinel node is identified. However, in an era where regional nodal radiation is increasingly used, the relevance of leaving residual disease in the undissected axilla after NAC is unknown and remains to be investigated. Clinical trial information: NCT00909441.

Role of axillary ultrasound after neoadjuvant chemotherapy in women with node-positive breast cancer (T1-4, N1-2, M0) at initial diagnosis (ACOSOG Z1071).

1107 Background: The role of axillary ultrasound (AUS) after neoadjuvant chemotherapy (NAC) to assess for residual nodal disease in patients presenting with node positive breast cancer remains unclear. ACOSOG Z1071 is a prospective multi-institutional trial evaluating sentinel node biopsy in patients with biopsy proven node positive breast cancer (T0-4, N1-2, M0) receiving NAC. Herein we report on the secondary objective evaluating the correlation of lymph node (LN) features on AUS with residual nodal disease. Methods: AUS images from diagnosis and after NAC were centrally reviewed for cortex size, LN size and LN morphology. Morphologic features were defined as: type I, no visible cortex, type II, < 3 mm hypoechoic cortex, type III, > 3mm hypoechoic cortex, type IV, generalized lobulated hypoechoic cortex, type V, focal hypoechoic cortical lobulation, and type VI, totally hypoechoic node with no hilum. Type I and II are considered normal. Results: Surgical and imaging data are available on 294 patients. Median age was 50 years (range 23-93 years), mean initial tumor size 3cm (0 to 15cm) and clinical stage II in 64.5% and III in 35.5%. The maximum LN diameter decreased after NAC (mean 22mm pre-NAC to 14mm post-NAC)(p<0.0001); however, there was no significant difference after NAC between the pathologically N+ (13mm, range 5-46mm) and N0 cases (12mm, range 3-32mm)(p=0.13). LN cortical thickness correlated with residual nodal disease after NAC (p-value = 0.04). Using a cutoff point of cortical thickness of 3 mm, the sensitivity was 33% (48/145) and specificity 80% (66/82). AUS morphological features after NAC was associated with false negative rate 62%, false positive rate 28%, sensitivity 38%, and specificity 72%. Conclusions: AUS after NAC is useful to assess nodal response. Cortical thickness was the best predictor of residual nodal metastasis. LN size and morphological features do not reliably exclude residual nodal metastasis in patients after NAC. [Table: see text]