Extracapsular extension of the sentinel lymph node metastasis: a predictor of nonsentinel node tumor burden

A systematic review on the significance of extracapsular lymph node involvement in gastrointestinal malignancies

AIMS

The impact of extracapsular lymph node involvement (LNI) has been studied for several malignancies, including gastrointestinal malignancies. Aim of this study was to assess the current evidence on extracapsular LNI as a prognostic factor for recurrence in gastrointestinal malignancies.

METHODS

The Cochrane Database of systematic reviews, the Cochrane central register of controlled trials, and MEDLINE databases were searched using a combination of keywords relating to extracapsular LNI in gastrointestinal malignancies. Primary outcome parameters were incidence of extracapsular LNI and overall five-year survival rates.

FINDINGS

Fourteen manuscripts were included, concerning seven oesophageal, three gastric, one colorectal, and three rectal cancer series with a total of 1528 node positive patients. The pooled incidence of extracapsular LNI was 57% (95% CI: 53-61%) for oesophageal cancer, 41% (95% CI: 36-47%) for gastric cancer, and 35% (95% CI: 31-40%) for rectal cancer. In nine of the 14 studies a multivariate analysis was performed. In eight of these nine studies extracapsular LNI was identified as an independent risk factor for recurrence.

CONCLUSION

Extracapsular LNI is a common phenomenon in patients with gastrointestinal malignancies. It identifies a subgroup of patients with a significantly worse long-term survival. This systematic review highlights the importance of assessing extracapsular LNI as a valuable prognostic factor. Pathologists and clinicians should be aware of this important feature.

Extracapsular lymph node involvement in node-positive patients with adenocarcinoma of the distal esophagus or gastroesophageal junction

In adenocarcinoma of the esophagus or gastroesophageal junction, little attention has been paid to the biologic significance of extracapsular lymph node involvement (LNI). In the present study, a consecutive series of 251 patients with lymph node dissemination were reviewed. All patients underwent esophagectomy for adenocarcinoma and were prospectively followed. A total of 1562 positive lymph nodes were reexamined. Extracapsular LNI was identified in 456 lymph nodes (29%) in 166 patients (66%). Extracapsular LNI was confined to one lymph node in 63 patients (38%). The occurrence of extracapsular LNI increased significantly with the depth of invasion, presence of positive resectable truncal nodes, number of resected nodes, number of positive nodes, and lymph node ratio. The median potential follow-up period was 58 months (range, 12-143 months). In this period, 178 patients died of recurrent disease. The pattern of recurrence was comparable between patients with and without extracapsular LNI (P = 0.938). The median survival in patients with extracapsular LNI was 15 months (95% confidence interval, 12-18 months) compared with 41 months (95% confidence interval, 19-64 months) in those without extracapsular LNI (P < 0.001). Median survival of patients with 2 or more lymph nodes was 12 months (95% confidence interval, 8-15 months). Multivariate analysis demonstrated that T-stage, extracapsular LNI, and lymph node ratio were independent prognostic factors. The presence of extracapsular LNI identifies a subgroup with a significantly worse long-term survival. Together with the T-stage and the lymph node ratio, extracapsular LNI reflects a particularly aggressive biologic behavior and has significant prognostic potential.

The significance of one positive axillary node

AIMS

The aim of this study was to identify a subgroup of patients with breast cancer that can safely avoid axillary dissection.

METHODS

Using data collected by the Eindhoven Cancer Registry, we compared the clinico-pathological features of 489 patients with only one positive lymph node to those of 817 patients with more than one positive lymph node in the axilla. All patients underwent complete axillary dissection, not preceded by a sentinel node biopsy.

RESULTS

Tumour size greater than 1cm, harvesting more than 15 axillary lymph nodes at histopathological examination, metastasis size larger than 2mm, extranodal extension, and nodal involvement of the axillary apex are independently associated with the occurrence of more than one metastatic axillary lymph node.

CONCLUSION

No subgroup could be identified in which axillary dissection can always be omitted. However, tumour size<1cm, finding a micrometastasis rather than a macrometastasis, and especially not finding extranodal extension were independently associated with finding only one positive axillary lymph node.

Predictors of tumour involvement in remaining axillary lymph nodes of breast cancer patients with positive sentinel lymph node

AIMS

To characterize the various clinicopathologic features in cases of breast cancer with positive sentinel lymph nodes (SLNs), in order to determine factors that might help in predicting the involvement of the non-SLNs.

METHODS

A retrospective database review was performed of 726 breast cancer patients with stage 0-II, in whom SLNs were successfully identified. One hundred eighty-five of these patients showed positive SLNs, and subsequently underwent axillary lymph node dissection (ALND). These cases were divided into two groups based on the presence or absence of metastases in the non-SLNs, i.e. positive non-SLNs (NSLN+; 81 cases) and negative non-SLNs (NSLN-; 104 cases).

RESULTS

Multivariate analysis revealed that a larger size of the primary tumour (>2.0cm), presence of lymphatic invasion, larger size of the largest SLN metastasis (>2mm), and a 100% metastatic rate in the SLNs (number of positive SLNs/number of harvested SLNs) were significantly associated with NSLN+. Among the cases in which all the four factors were present, 73% (30/41) were found to have NSLN+.

CONCLUSION

We found four independent predictors in relation to non-SLN metastasis. Although these factors might be useful for determining the need of additional ALND, it would seem that even the presence of all of these four factors in combination may be insufficient to safely omit ALND. Thus, until further evidence is accumulated from the results of large clinical trials, ALND would still be recommended for patients with SLN metastasis.

Evaluation of a breast cancer nomogram for prediction of non-sentinel lymph node positivity

AIMS

This study evaluates the breast cancer nomogram (BCN), an online tool developed by Memorial Sloan-Kettering Cancer Center to determine the rate of non-SLN positivity, in an independent cohort of SLN positive patients.

MATERIAL AND METHODS

Available data between 02/2000 and 06/2004 in two prospective databases, 749 cases had successful SLN biopsy including 149 axillary-SLN metastases study cases. These cases had accurately graded tumours up to 9 cm in size and CAD with a minimum total 10 nodes removed. Histopathological assessment of nodes included hematoxylin and eosin staining and/or immunohistochemistry. Computerized BCN was used to estimate probability of non-SLN positivity and compared with actual probability after grouping into deciles.

RESULTS

The trend of actual probability in various decile groups was comparable to the predicted probability. An area under the receiver operating characteristic curve was 0.75 as compared to 0.76 in the original study.

CONCLUSION

Although this study is small, the results are encouraging and suggest the nomogram is a useful tool to estimate the likelihood of positive axillary non-SLN. However, variations in pathological assessment between centres are the major impediment to widespread application of BCN. If SLN positive patients decline the standard recommendation of CAD or entry into clinical trials evaluating the significance of CAD then the BCN could help in decision making.

Staged sentinel lymph node biopsy before mastectomy facilitates surgical planning for breast cancer patients

BACKGROUND

In patients with breast cancer who choose mastectomy with immediate reconstruction, the sentinel lymph node (SLN) status on permanent histology may complicate treatment if a metastasis is found. The purpose of this study was to determine how performing an SLN biopsy (SLNB) before the definitive operation would influence subsequent surgical procedures.

METHODS

Our SLN database was searched for patients who underwent staged SLNB with subsequent mastectomy between 2001 and 2004.

RESULTS

Twenty-five patients with 27 breast cancers underwent SLNB before mastectomy. Of them, 9 of 27 (33%) were node positive. All 9 patients underwent modified radical mastectomy. Three node-positive patients did not undergo immediate reconstruction. Of the remaining 6 node-positive patients, 5 underwent reconstruction with autologous tissue rather than a tissue expander. In contrast, 6 of 16 (37%) node-negative patients underwent reconstruction with a tissue expander.

CONCLUSIONS

Staged SLNB assists in selecting the appropriate operation in patients who are considering immediate reconstruction.

Nonsentinel node metastasis in breast cancer patients: assessment of an existing and a new predictive nomogram

BACKGROUND

The accurate prediction of nonsentinel node (NSN) metastasis in breast cancer patients remains uncertain.

METHODS

The medical records of 574 breast cancer patients from 2 different institutions (Mayo Clinic and University of Michigan) with sentinel lymph node biopsy examination and completion axillary lymph node dissection were reviewed for multiple clinicopathologic variables. The Memorial Sloan Kettering Cancer Center nomogram performance for prediction of NSN metastases was assessed. A new model was developed with clinically relevant variables and possible advantages.

RESULTS

The Memorial Sloan Kettering Cancer Center nomogram predicted the likelihood of NSN metastasis with an area under the receiver operating characteristic curve of .72 and .86. For predicted probability cut-off points of 5% and 10%, the false-negative rates were 0% and 14% (Mayo), and 17% and 11% (Michigan). A new model was developed with similar area under the curve but lower false-negative rates for low-probability subgroups.

CONCLUSIONS

Predictive models for NSN tumor burden are imperfect.

Sentinel lymph nodes and breast carcinoma: analysis of 70 cases by frozen section

BACKGROUND

The sentinal node biopsy (SNB) is a reliable method for determining the status of the regional lymph nodes in patients with breast cancer. SNB technology is evolving rapidly, but no standardization has yet been accomplished. The aim of this study is to discuss the accuracy of this procedure and the optimal method for identifying micrometastases.

METHODS

We collected data from 70 women with primary invasive breast carcinoma who underwent SNB for breast cancer. We examined two frozen sections levels from each half of each lymph node, as well as a cytology imprint before arriving at the frozen section diagnosis. Immunohistochemistry with pancytokeratin (AE1/AE3) was done on the paraffin sections. For the association between the lymph node size and the possibility of metastases, Student's t test was used and a P value of less than 0.05 was regarded as significant.

RESULTS

The number of patients with metastases in SNB was 19, from which 15 cases were correctly diagnosed in frozen sections/imprints and four cases were false negative. The axillary toilet from all cases with SNB metastases smaller than 2 mm showed no additional positive nodes. Lymph node diameter showed a significant association with sentinel node status (P<0.0001).

CONCLUSION

Frozen section examination of SNB from patients with breast carcinoma is both specific (100%) and sensitive (79%). Diagnosis of lobular carcinoma can be difficult, and may require immunohistochemistry with cytokeratin for diagnosis. Small metastases in a non-optimal frozen section may be difficult to discern. Cytology imprints add nothing to the diagnosis.

Predictors of non-sentinel lymph node metastasis in breast cancer patients

In many patients, the sentinel lymph node (SLN) is the sole site of regional nodal metastasis. This subgroup of patients would not be expected to benefit from completion axillary lymph node dissection (CALND). This study evaluated the factors that may determine the likelihood of additional positive nodes in the axilla in the presence of sentinel node metastasis. A total of 618 breast cancer patients underwent SLN biopsy based on lymphoscintigraphy, intraoperative gamma probe detection, and blue dye mapping using 99mTc-nanocolloid and Patent Blue V injected peritumourally. This was followed by standard axillary node clearance at the same operation. Of the 201 patients with a positive SLN, 105 (52%) patients had no further positive nodes in the axilla, 96 (48%) patients had additional metastasis in non-sentinel lymph nodes (NSLN) upon CALND. In patients with a positive SLN, increasing tumour size and tumour grade significantly increased the frequency of additional positive nodes on univariate analysis. The number of SLNs removed and the number of negative SLNs were significant negative predictors. Increasing tumour burden in the sentinel nodes (determined by the number of positive SLNs) was significantly associated with increasing likelihood of positive NSLNs. Multivariate analysis revealed that the rest of the axilla is more likely to be positive if there are more positive than negative SLNs removed and more likely to be negative otherwise. A group of cases from one centre (Cardiff) were subjected to further detailed analysis. Tumour burden in the positive SLN was assessed by measuring the size of metastasis, percentage replacement of the SLN by tumour and by documenting extracapsular extension (ECE) around the SLN. Of the 64 patients with a positive SLN, 34 (53%) patients had no further positive nodes in the axilla, 30 patients (47%) had additional metastasis in NSLNs upon CALND. Increasing tumour burden in the SLN was associated with additional positive nodes in the axilla. Multivariate analysis revealed that size of the SLN metastasis is the most important predictor of involvement of only the SLN. Overall, in patients with a positive SLN, the difference in the number of positive and negative SLNs removed and size of the metastasis in the SLN, all predicted the frequency of additional positive nodes.