[Significance of occult lymphatic tumor spread in pancreatic cancer]

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.

The lymphatic system and pancreatic cancer

This review summarizes current knowledge of the biology, pathology and clinical understanding of lymphatic invasion and metastasis in pancreatic cancer. We discuss the clinical and biological consequences of lymphatic invasion and metastasis, including paraneoplastic effects on immune responses and consider the possible benefit of therapies to treat tumors that are localized to lymphatics. A review of current techniques and methods to study interactions between tumors and lymphatics is presented.

Clinical and pathologic prognostic factors for curative resection for pancreatic cancer

BACKGROUND

Pancreatic cancer is the fifth leading cause of cancer-related deaths in the world. Operative resection is the only therapeutic option with curative potential for this disease.

OBJECTIVE

The aim of the present study was to correlate clinical and pathologic parameters with survival in patients submitted to pancreatic resection for pancreatic adenocarcinoma.

METHODS

Surgical resection with curative intent (R0 and R1 resections) was performed in 65 pancreatic cancer patients between 1990 and 2006. The overall results of surgical treatment were retrospectively analyzed and compared with the clinicopathologic features of these patients.

RESULTS

Pylorus-preserving pancreatoduodenectomy was performed in 37 patients (56.9%), classic resection in 35.4%, distal pancreatectomy in 4.6% and total pancreatectomy in 3.6%. The inhospital mortality was 5% (three patients). Postoperative complications occurred in 28 patients (43%). Mean survival and five-year survival rate after curative resection were 27 months and 9.0%, respectively. Sex, TNM stage, tumor differentiation, neural invasion, tumor size and involvement of resection margin were significant prognostic factors on univariate analysis. Multivariate analysis showed tumor differentiation and neural invasion as prognostic factors.

CONCLUSION

Patients with pancreatic cancer, even those with poor prognostic factors should be given the opportunity of surgical resection with curative intent.

Surgical management of carcinoma of the head of pancreas: extended lymphadenectomy or modified en bloc resection?

Pancreatoduodenectomy for the treatment of periampullary cancer was described over 70 years ago. The technique has evolved in an attempt to improve the dismal prognosis for patients with pancreatic cancers. Radical regional resection has been proposed to decrease the incidence of local recurrence as well as to improve survival. These extended resections have failed to show a significant survival benefit in prospective randomized controlled studies. Furthermore, extended pancreatic resections may be associated with increased morbidity. The concept of modified en bloc resection has been advocated and is soundly based on anatomical and pathological principals. This procedure is a modification of the radical regional resection previously described. It involves resection of the peripancreatic retroperitoneal tissue and lymph nodes en bloc with the head of pancreas, in order to achieve an R0 resection but without the morbidity associated with an extended lymphadenectomy. Conceptually, this procedure may be the most appropriate technique for the management of pancreatic head cancers although the ultimate effect on long-term survival can only be judged after further clinical studies.

Pancreatic cancer: a generalized disease--prognostic impact of cancer cell dissemination

BACKGROUND

Pancreatic ductal adenocarcinoma is the fifth leading cause of death among all malignancies, leading to approximately 40,000 deaths each year in Europe. The annual incidence rate for all types of pancreatic cancer is approximately nine new cases per 100,000 people, ranking it as the 11th among all cancers. Stage, grade and resection margin status are currently accepted as the most accurate pathologic variables predicting survival. All classification systems fail prognostically to distinguish between different stages. Even in patients with seemingly early tumours (T1, N0), the likelihood of relapse is high. This reflects the shortcomings of the pathologic staging to sufficiently discriminate patients with a high risk to develop tumour recurrence from those that carry a lower risk.

RESULTS

On the other hand, none of the currently used systems includes or takes into consideration the role of disseminated tumour cells neither in the lymph nodes nor in the bone marrow. Occult residual tumour disease is suggested when either bone marrow or lymph nodes, from which tumour relapse may originate, are affected by micrometastatic lesions undetectable by conventional histopathology. For detection, antibodies against tumour-associated targets can be used to detect individual epithelial tumour cells both in lymph nodes and in bone marrow. The clinical significance of these immunohistochemical analyses is still controversial. Various monoclonal antibodies are still in use for micrometastatic detection, thus contributing to the incongruity of data and validity of results. These assays have been rarely used in patients with pancreatic carcinoma.

CONCLUSION

The presence or absence of lymph-node metastases can predict the likelihood of survival for most, if not all, patients with pancreatic ductal adenocancer and the likelihood that metastases will develop at distant sites.

Morphological and immunohistochemical characterization of isolated tumor cells by p53 status in gastrointestinal tumors

BACKGROUND AND AIMS

Isolated tumor cells (ITCs) in cancer patients are retrieved mostly using immunohistochemistry with antibodies directed against antiepithelial antigens (for example Ber-EP4), which are supposed not to be present in metastatic-free tissue. To date, there has been ongoing controversy whether those cells have biologic significance and are linked with tumor progression and impaired patient's prognosis. Therefore, the aim of this study was to further characterize Ber-EP4-positive cells in various tissues, with special emphasis on their tumorigenic origin.

MATERIALS AND METHODS

The frequency and prognostic impact of ITCs in lymph nodes displayed by means of monoclonal antibody Ber-EP4 were evaluated in retrospective (n = 292) and prospective (n = 100) collectives of various gastrointestinal carcinomas free of metastatic disease in conventional histopathology (pN0). Furthermore, the frequency of ITCs in the peritoneal cavity and bone marrow was analyzed in case of absence of overt distant metastasis (pM0) in the prospective collective. Ber-EP4-immunoreactive cells were further characterized for tumorigenic origin using morphological criteria and immunohistochemical double staining for Ber-EP4 and p53.

RESULTS

Ber-EP4-positive cells could be revealed in lymph nodes in 44.3% of pN0-gastrointestinal carcinomas, in the peritoneal cavity in 19%, and in the bone marrow in 10%. In lymph nodes, BerEP4-immunoreactive cells exhibited a metastatic-atypical morphology in 59%; however, it was always typical for true tumor cells in the peritoneal cavity or bone marrow. The cumulative 5-year survival rate was adversely affected by Ber-EP4-immunoreactive cells in uni- and multivariate analysis, irrespective of the underlying cell morphology (68% for Ber-EP4 negative, 41% for Ber-EP4 positive with atypical and typical morphology each). In the case of a p53-positive primary tumor, 70% of the corresponding ITCs also overexpressed p53, while the remainder was deemed p53 negative (p = 0.002).

CONCLUSION

ITCs detected by the antiepithelial antibody Ber-EP4 are present in a substantial proportion of apparently tumor-free lymph nodes. These cells impair patients' prognoses, irrespective of the underlying cell morphology. As approximately one third of Ber-EP4-positive cells in p53-positive primary tumors do not overexpress p53; their true tumorigenic origin needs to be further investigated.

Strong prognostic value of nodal and bone marrow micro-involvement in patients with pancreatic ductal carcinoma receiving no adjuvant chemotherapy

AIM: To study the prognostic value of adjuvant chemo-therapy in patients with pancreatic, ductal adenocar-cinoma.

METHODS: Lymph nodes from 106 patients with resectable pancreatic ductal adenocarcinoma were systematically sampled. A total of 318 lymph nodes classified histopathologically as tumor-free were examined using sensitive immunohistochemical assays. Forty-three (41%) of the 106 patients were staged as pT_1/2, 63 (59%) as pT_3/4, 51 (48%) as pN₀, and 55 (52%) as pN₁. The study population included 59 (56%) patients exhibiting G_1/2, and 47 (44%) patients with G₃ tumors. Patients received no adjuvant chemo- or radiation therapy and were followed up for a median of 12 (range: 3.5 to 139) mo.

RESULTS: Immunostaining with Ber-EP4 revealed nodal microinvolvement in lymph nodes classified as “tumor free” by conventional histopathology in 73 (69%) out of the 106 patients. Twenty-nine (57%) of 51 patients staged histopathologically as pN₀ had nodal microinvolvement. The five-year survival probability for pN0-patients was 54% for those without nodal microinvolvement and 0% for those with nodal microinvolvement. Cox-regression modeling revealed the independent prognostic effect of nodal microinvolvement on recurrence-free (relative risk 2.92, P = 0.005) and overall (relative risk 2.49, P = 0.009) survival.

CONCLUSION: The study reveals strong and independent prognostic significance of nodal microinvolvement in patients with pancreatic ductal adenocarcinoma who have received no adjuvant therapy. The addition of immunohistochemical findings to histopathology reports may help to improve risk stratification of patients with pancreatic cancer.