Clinical implications of immunohistochemically demonstrated lymph node micrometastasis in resectable pancreatic cancer

Preoperative risk factors for para-aortic lymph node positivity in pancreatic cancer

PURPOSE

This study aimed to identify the preoperative risk factors for para-aortic lymph node (PALN) positivity, including micrometastasis, in pancreatic cancer.

METHODS

Medical records of patients with pancreatic cancer who underwent curative resection were retrospectively reviewed, and the relationships between preoperative risk factors and PALN positivity were identified. Clinicopathological and prognostic factors for overall survival were analyzed. Micrometastasis was investigated by immunohistochemistry.

RESULTS

400 patients were enrolled. PALN positivity by hematoxylin and eosin staining, micrometastasis, and negative were found in 46 (11%), 32 (8%), and 322 (81%) patients, respectively. The median overall survival times of patients with PALN positivity, including micrometastasis, was 22.5 months. Multivariate logistic regression identified borderline or locally advanced status (p=0.037), elevated preoperative carbohydrate antigen (CA) 19-9 level (p<0.001), larger tumor size ≥30 mm (p=0.001) and larger PALN size ≥10 mm (p=0.019) as independent preoperative risk factors of PALN positivity. Multivariate overall survival analysis demonstrated borderline or locally advanced status (p=0.013), elevated preoperative CA19-9 level (p<0.001) and PALN positivity (p=0.048) were independent poor prognostic factors.

CONCLUSIONS

Borderline or locally advanced status, elevated preoperative CA19-9 level, and larger tumor and PALN size were risk factors for PALN positivity, and thus, they may contribute to the optimization of preoperative treatments for patients with potential PALN positivity.

Prognostic Significance of Lymph Node Metastasis and Micrometastasis Along the Left Side of Superior Mesenteric Artery in Pancreatic Head Cancer

BACKGROUNDS AND OBJECTIVES

Although metastasis in lymph nodes along the left side of superior mesenteric artery (SMA-LNs-lt) is sometimes found, survival benefit of SMA-LN-lt dissection for pancreatic head cancer is still unclear. The purpose of this study is to evaluate the prognostic significance of SMA-LN-lt metastasis and micrometastasis.

METHODS

A total of 166 patients with pancreatic head cancer who underwent pancreatectomy with lymphadenectomy including SMA-LNs-lt between 2002 and 2017 were reviewed retrospectively. Micrometastasis was evaluated by immunohistochemistry.

RESULTS

Twenty patients (12%) had SMA-LN-lt metastasis detected by hematoxylin and eosin (HE) staining, and eight patients (5%) had micrometastasis. Patients with SMA-LN-lt HE-positive or micrometastasis group experienced significantly shorter overall survival (OS) than those without (p = .015). In multivariate analysis, SMA-LN-lt HE-positive or micrometastasis (p = .034), portal vein resection (p = .002), histologic grade 2/3 (p = .046), LN metastasis (p = .002), and lack of adjuvant chemotherapy (p < .001) were independent risk factors. Within a subset of SMA-LN-lt HE-positive or micrometastasis group, lack of adjuvant chemotherapy (p = .003) was the independent poor prognostic factor.

CONCLUSIONS

In pancreatic head cancer, the rate of SMA-LN-lt HE-positive and micrometastasis was found in 12% and 5%, respectively. Adjuvant chemotherapy may contribute to improvement of prognosis in patients with LN metastasis including SMA-LN-lt metastasis and micrometastasis.

Pathomorphological features of metastatic lymph nodes as predictors of postoperative prognosis in pancreatic cancer

To investigate the pathological features of metastatic lymph nodes (LN) in pancreatic ductal adenocarcinoma (PDAC) and to determine factors with prognostic implications.Metastatic LN status is a proven significant factor for predicting postoperative prognosis in pancreatic cancer patients. However, the effective prognostic criteria regarding metastatic LNs for such disease remain unknown.We retrospectively reviewed 98 patients with R0/1 resection for PDAC. All metastatic LNs were evaluated for the pathomorphological features of metastasis and analyzed in terms of postoperative outcomes. Various morphological patterns of metastasis were assessed in 440 positive LNs and then classified into 4 groups: common type, direct type (continuously invaded by the main tumor), scatter type (multiple tumor clusters among the normal LN tissues), and isolated tumor cell (ITC).The pathological stage was defined as stage IIA in 10% and IIB in 90% patients. Common-type metastasis was noted in 55% positive LNs of 75% node-positive patients; direct type in 36% LNs of 69% patients; scatter type in 5% LNs of 14% patients; and ITCs in 5% LNs of 18% patients. Significant difference was noted only in recurrence-free survival (RFS) but not in overall survival (OS) in the common-type; only in OS but not in RFS for the scatter type; and neither in RFS nor OS for both direct type and ITC. Multivariate analysis revealed that only LN ratio and curability were independent predictive factors of poor.The tumor distribution patterns in metastatic LNs are the postoperative prognostic factors in pancreatic cancer.

Systematic review of the clinical significance of lymph node micrometastases of pancreatic adenocarcinoma following surgical resection

OBJECTIVES

The aim of this study is to perform a systematic review of the clinical impact of lymph node micrometastasis in pancreatic adenocarcinoma following surgical resection.

METHODS

A systematic review was conducted and published literature were searched using "pancreas or pancreatic" and "cancer or carcinoma or neoplasm", and "micrometastasis or micrometastses" in the PubMed, EMBAE, and Web of Science.

RESULTS

Thirteen publications with 726 patients and 3701 lymph nodes were included in this systematic review. The detection method was immunohistochemical stains or polymerase chain reaction. The pooled proportion of patients with positive lymph node micrometastasis was 43.1% (95% Confidence interval (CI) 0.254-0.628). The pooled proportion of positive lymph node micrometastasis (number of positive lymph node micrometastasis/total number of lymph nodes examined) was 10.8% (95% CI 4.8-22.6). Among the conventional H &E negative patients, the reported 5-year survival rates of the patients without lymph node micrometastases vs. those with lymph node micrometastases in the ranged from 50% to 61% and from 0% to 36%, respectively Patients with lymph node micrometastasis showed poorer survival (Hazard ratio 4.29, 95% CI 1.27-14.41).

CONCLUSIONS

The presence of lymph node micrometastasis is associated with poorer survival. Lymph node micrometastasis is applicable to stratify the risk of recurrence and the need for adjuvant therapy of post-resection patients with pancreatic adenocarcinoma in the conventional H & E lymph node negative patients.

Para-aortic lymph node sampling in pancreatic head adenocarcinoma

BACKGROUND

The significance of positive para-aortic nodes in patients with resectable pancreatic carcinoma is unclear. This study sought to evaluate the accuracy of intraoperative detection and prognostic significance of these lymph nodes in patients with resected adenocarcinoma of the pancreatic head.

METHODS

From 2000 to 2010, para-aortic node sampling was performed prospectively in all patients before pancreatoduodenectomy. Frozen sections were created and nodes categorized as positive or negative for metastases. Surgeons were blinded to the frozen-section results. This was followed by standard histopathological assessment of corresponding paraffin-embedded, haematoxylin and eosin-stained material. Nodes considered uninvolved by this analysis were examined immunohistochemically for micrometastases.

RESULTS

A total of 111 consecutive patients were included, with a median follow-up of 20·8 (range 1·5-126) months. The 1-, 2- and 5-year overall survival (OS) and disease-free survival (DFS) rates were 73·6, 54·0 and 24·7 per cent, and 51·8, 28·1 and 18·8 per cent respectively. Para-aortic node involvement was always associated with peripancreatic lymph node metastasis, and was detected by frozen-section analysis in 12 patients and by haematoxylin and eosin staining in 17. Sensitivity and specificity of frozen-section examination for detecting para-aortic lymph node metastases were 71 and 100 per cent respectively. Median OS for patients with and without para-aortic node involvement on frozen-section analysis was 9·7 versus 28·5 months respectively (P = 0·012), and 15·7 versus 27·2 months (P = 0·050) when assessed by haematoxylin and eosin staining. Median DFS for patients with and without para-aortic node involvement on frozen-section examination was 5·6 versus 12·9 months respectively (P = 0·041), and 8·4 versus 12·9 months (P = 0·038) for haematoxylin and eosin analysis. The presence of micrometastases in para-aortic nodes was not significantly associated with altered OS or DFS.

CONCLUSION

Para-aortic node sampling with frozen-section examination detects distant lymphatic involvement reliably. It should be performed systematically. When metastases are found, they should be considered a contraindication to pancreatic resection.

High expression of S100A11 in pancreatic adenocarcinoma is an unfavorable prognostic marker

S100A11 is a member of S100 protein family, and our previous study showed that S100A11 is one of the up-regulated proteins that have not been reported to be associated with pancreatic carcinoma. The purpose of this study was to investigate the relation between S100A11 expression and the clinicopathological variables and clinical outcome in patients with pancreatic adenocarcinoma. Immunohistochemistry analysis was performed for S100A11 in 78 pairs of specimens of human pancreatic adenocarcinoma tissues and adjacent nontumorous tissues. The univariate and multivariate survival analyses were also performed to determine its prognostic significance. S100A11 expression in pancreatic adenocarcinoma (62/78) was significantly higher than that in the adjacent nontumorous tissues (19/78) (P = 0.000). High expression of S100A11 was associated with the lymph node metastasis and histological differentiation (P = 0.003 and 0.004, respectively). Univariate analysis showed that S100A11 expression was associated with poor prognosis (P = 0.0000). Multivariate analysis using the Cox regression model indicated that age ≥ 65 years, CA19-9 ≥ 1,000 U/ml and positive S100A11 were independent prognostic indicators of pancreatic adenocarcinoma (P = 0.002, 0.004 and 0.001, respectively). These results suggested that S100A11 might be a significant tumor marker for pancreatic adenocarcinoma and an unfavorable predictor for prognosis of patients who have undergone surgical resection.