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

Abstract

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.

Resectable pancreatic ductal adenocarcinoma: association between preoperative CT texture features and metastatic nodal involvement

“…Lymph node metastases is considered a grave prognostic sign in PDAC. Tumor size and lymph node involvement are significantly correlated with OS [2,20,21]. Previous study showed that tumor size was found to be an important predictor of lymph node status and predicted odds of positive nodes tend to increase with increasing tumor size [22].…”

Peritumoral lymph nodes in pancreatic cancer revisited; is it truly equivalent to lymph node metastasis?

“…27 In a Japanese single institution study of 98 PDAC patients, PTLNI was found in 27 patients (27.6%). 28 They reported that there was no statistically significant difference in survival outcomes between patients with PTLNI and patients without LN metastasis. The current study demonstrated that PTLNI group had similar survival outcomes compared to N0 patients in terms of median disease-free survival duration and rate.…”

“…Several studies have investigated the effect of PTLN invasion on the prognostic outcome. [24][25][26][27][28] The first study in the literature on PTLN was published in 2010 by Massachusetts General Hospital group. 24 They reviewed 517 patients who underwent pancreatic resection for PDAC and found direct invasion in at least 20% of patients with one or two LN metastases.…”

Impact of Neoadjuvant Chemoradiation on Pathologic Response in Patients With Localized Pancreatic Cancer

“…As such, it is not surprising that treatment response (CR/nCR) in the primary tumor is uncommon, regardless of the type of neoadjuvant therapy delivered. However, PC metastases lose the characteristic stromal component and may even be difficult to distinguish from liver, lung, or ovarian neoplasms (41,42). In a well-vascularized environment which is depleted of the immunosuppressive stroma, PC metastases may become susceptible to both chemotherapeutic agents as well as chemoradiation.…”