Clinical and molecular characterization of patients with cancer of unknown primary in the modern era.

BACKGROUND: On the basis of historical data, patients with cancer of unknown primary (CUP) are generally assumed to have a dismal prognosis with overall survival of less than 1 year. Treatment is typically cytotoxic chemotherapy guided by histologic features and the pattern of metastatic spread. The purpose of this study was to provide a clinical and pathologic description of patients with CUP in the modern era, to define the frequency of clinically actionable molecular alterations in this population, to determine how molecular testing can alter therapeutic decisions, and to investigate novel uses of next-generation sequencing in the evaluation and treatment of patients with CUP. PATIENTS AND METHODS: Under Institutional Review Board approval, we identified all CUP patients evaluated at our institution over a recent 2-year period. We documented demographic information, clinical outcomes, pathologic evaluations, next-generation sequencing of available tumor tissue, use of targeted therapies, and clinical trial enrollment. RESULTS: We identified 333 patients with a diagnosis of CUP evaluated at our institution from 1 January 2014 through 30 June 2016. Of these patients, 150 had targeted next-generation sequencing carried out on available tissue. Median overall survival in this cohort was 13 months. Forty-five of 150 (30%) patients had potentially targetable genomic alterations identified by tumor molecular profiling, and 15 of 150 (10%) received targeted therapies. Dominant mutation signatures were identified in 21 of 150 (14%), largely implicating exogenous mutagen exposures such as ultraviolet radiation and tobacco. CONCLUSIONS: Patients with CUP represent a heterogeneous population, harboring a variety of potentially targetable alterations. Next-generation sequencing may provide an opportunity for CUP patients to benefit from novel personalized therapies.

A novel KLF6-Rho GTPase axis regulates hepatocellular carcinoma cell migration and dissemination.

The presence of invasion into the extra-hepatic portion of the portal vein or the development of distant metastases renders hepatocellular carcinoma (HCC) patients ineligible for the only potential curative options for this malignancy-tumor resection or organ transplantation. Gene expression profiling of murine HCC cell lines identified KLF6 as a potential regulator of HCC cell migration. KLF6 knockdown increases cell migration, consistent with the correlation between decreased KLF6 mRNA levels and the presence of vascular invasion in human HCC. Concordantly, single-copy deletion of Klf6 in a HCC mouse model results in increased tumor formation, increased metastasis to the lungs and decreased survival, indicating that KLF6 suppresses both HCC development and metastasis. By combining gene expression profiling and chromatin immunoprecipitation coupled to deep sequencing, we identified novel transcriptional targets of KLF6 in HCC cells including VAV3, a known activator of the RAC1 small GTPase. Indeed, RAC1 activity is increased in KLF6-knockdown cells in a VAV3-dependent manner, and knockdown of either RAC1 or VAV3 impairs HCC cell migration. Together, our data demonstrate a novel function for KLF6 in constraining HCC dissemination through the regulation of a VAV3-RAC1 signaling axis.

Heparanase promotes lymphangiogenesis and tumor invasion in pancreatic neuroendocrine tumors.

Heparan sulfate proteoglycans are an important and abundant component of the extracellular matrix, which undergo substantial remodeling throughout tumorigenesis via the enzymatic activity of heparanase. Heparanase has been shown to be upregulated in many human cancers; however, its specific functions in human pancreatic neuroendocrine tumors (PanNETs) and spontaneous mouse models of cancer have not been evaluated. Here, we investigated the role of heparanase in PanNETs using patient samples and the RIP1-Tag2 (RT2) PanNET-transgenic mouse model. High heparanase expression significantly correlated with more advanced tumor stage, higher tumor grade and the presence of distant metastasis in PanNET patients. We genetically manipulated heparanase levels in the RT2 model using heparanase-transgenic mice, which constitutively overexpress heparanase, and heparanase-knockout mice. Heparanase was found to have a critical role in promoting tumor invasion, through both macrophage and cancer cell sources in the tumor microenvironment. In addition, elevated heparanase levels significantly increased peritumoral lymphangiogenesis in vivo and promoted the trans-differentiation of macrophages into lymphatic endothelial cell-like structures in culture. Conversely, we found that heparanase deletion led to increased angiogenesis and pericyte coverage. Together, these data identify important roles for heparanase in regulating several critical aspects of tumorigenesis, demonstrating that heparanase represents a potential therapeutic target for PanNET patients.

Pancreatic adenocarcinoma in a young patient population--12-year experience at Memorial Sloan Kettering Cancer Center.

BACKGROUND: There is a dearth of data in a younger population of patients with pancreatic ductal adenocarcinoma (PAC) regarding epidemiology, genetics, prognosis, and outcome. This report examines a large cohort of patients with PAC

Intraductal papillary mucinous neoplasms of the pancreas: clinical and pathological features and diagnostic approach.

Pancreatic intraductal papillary mucinous neoplasms (IPMNs) are mucin-producing neoplasms with a frequent papillary architecture that arise within the pancreatic ducts and are increasingly being recognised. Because they exhibit a spectrum of dysplasia ranging from low grade to high grade and may also have associated invasive carcinoma, and because they are clinically detectable, they are now intensively studied. There is marked overlap between IPMNs and pancreatic intraepithelial neoplasia (PanIN), such that the distinction between these two lesions is nearly impossible in certain cases. In addition, IPMNs sometimes can be confused with other primary cystic lesions of the pancreas. As a result, the correct diagnosis of IPMN can be challenging. This review addresses the clinical and pathological features of IPMNs, emphasising their diagnostic criteria, differential diagnosis and biological behaviour. Problematic issues in the pathological evaluation of IPMNs are discussed.

A phase II trial of neoadjuvant cisplatin-fluorouracil followed by postoperative intraperitoneal floxuridine-leucovorin in patients with locally advanced gastric cancer.

BACKGROUND: The aim of the study was to evaluate the efficacy and toxicity of neoadjuvant chemotherapy with intravenous (i.v.) cisplatin and fluorouracil (5-FU), surgery and postoperative intraperitoneal (i.p.) floxuridine (FUdR) and leucovorin (LV) in patients with locally advanced gastric cancer. PATIENTS AND METHODS: Preoperative staging was confirmed by laparoscopy (LAP). Two cycles of i.v. cisplatin (20 mg/m(2)/day, rapid infusion) and 5-FU (1000 mg/m(2), continuous 24-h infusion), given on days 1-5 and 29-34, were followed by a radical gastrectomy and a D2 lymphadenectomy. Patients having R0 resections were to receive three cycles of i.p. FUdR (1000 mg/m(2)) and LV (240 mg/m(2)), given on days 1-3, 15-17 and 29-31. Intraperitoneal chemotherapy was begun 5-10 days from surgery. RESULTS: Thirty-eight patients were treated. Both preoperative and postoperative chemotherapy were well tolerated. T stage downstaging (pretreatment LAP versus surgical pathological stage) was seen in 23% of patients. The R0 resection rate was 84%. Neither an increase in postoperative morbidity nor operative mortality was noted. With a median follow-up of 43.0 months, 15 patients (39.5%) are still alive (median survival 30.3 months). Good pathologic response, seen in five patients (15%), was associated with better survival (P = 0.053). Peritoneal and hepatic failures were found in 22% and 9% of patients, respectively. Quality of life seemed to be preserved. CONCLUSIONS: Neoadjuvant cisplatin/5-FU followed by postoperative i.p. FUdR/LV can be safely delivered to patients undergoing radical gastrectomy and D2 lymphadenectomy. The R0 resection and the survival rates are encouraging. An association between pathologic response and patient outcome was suggested.

Small-cell carcinoma of the gastrointestinal tract: a retrospective study of 64 cases.

Small-cell carcinoma (SmCC) of the gastrointestinal tract is a very rare and aggressive malignancy. To better define its clinicopathological features, the records of all patients with this disease seen at Memorial Sloan Kettering Cancer Center between 1980 and 2002 (n=64) were reviewed. The most common primary tumour locations were in the large bowel and oesophagus. Predisposing medical conditions for non-small-cell cancers, positive family cancer history, and metachronous tumours were common. In all, 37% had mixed tumour histology and 48% presented with extensive disease, according to the Veterans' Administration Lung Study group (VALSG) staging system used for small-cell lung cancer. Treatment outcome in limited disease (LD) suggested a role for surgery and chemotherapy. Platinum-based regimens resulted in a 50% response rate. The 2-year survival was 23% and two prognostic factors were identified, the extent of disease according to the VALSG system (P<0.01) and TNM stage (P=0.03). Anatomic location had no clinical impact. In conclusion, SmCC from various gastrointestinal sites can be viewed as one clinical entity. Mixed tumour histology is common and may affect therapy. Surgery, combined with chemotherapy, should be considered for LD. The value of the VALSG system was implied and possible differences from small-cell lung cancer were noted.

MUC1 and MUC2 in pancreatic neoplasia.

MUCs are glycoproteins with various roles in homeostasis and carcinogenesis. Among other actions, MUC1 may inhibit cell-cell and cell-stroma interactions and function as a signal transducer, participating in cancer progression. In contrast, MUC2 is normally found only in goblet cells, where it contributes to the protective barrier function of these cells. Recently, a tumour suppressor role has been demonstrated for MUC2, and both MUC1 and MUC2 appear to have important roles in pancreatic neoplasia. MUC1 appears to be a marker of aggressive phenotype and may facilitate the vascular spread of carcinoma cells. In contrast, MUC2 is rarely detectable in aggressive pancreatic tumours, but is commonly expressed in intraductal papillary mucinous neoplasms (IPMNs), which are rare, indolent tumours, in intestinal IPMNs, and in indolent colloid carcinomas. MUC2 appears to be not only a marker of this indolent pathway, but also partly responsible for its less aggressive nature. Thus, in pancreatic neoplasia, MUC1 and MUC2 have potential diagnostic and prognostic value as markers of aggressive and indolent phenotypes, respectively, and have potential as therapeutic targets.

Neuroendocrine carcinomas of the colon and rectum.

PURPOSE: This study was designed to review experience with neuroendocrine carcinomas of the colon and rectum at a single institution, with emphasis on the pathology and clinical characteristics of this uncommon malignancy. METHODS: A study group of patients was identified from a prospective colorectal service database. Pathology was reviewed and neuroendocrine tumors were classified by a single pathologist. Medical records were retrospectively reviewed. RESULTS: From March 1975 to September 1998, 38 patients with neuroendocrine carcinomas were identified from the colorectal service database comprising 6495 patients (0.6 percent). These neuroendocrine carcinomas did not include carcinoid tumors. Average patient age was 57 years (range, 29-86 years). There were 17 males (44.7 percent) and 21 females (55.3 percent). Tumors were located as follows: 17 colon, 14 rectum, 6 anal canal, and 1 appendix. The diagnosis of neuroendocrine carcinoma was suggested preoperatively from tissue biopsy in 59.3 percent (16/27) of patients evaluable. Pathology was reviewed and tumors were categorized as small cell carcinoma (n = 22) or large cell neuroendocrine carcinoma (n = 16). Most tumors (20/25 evaluable, 80 percent) stained positive by means of immunohistochemistry for neuroendocrine markers, including chromogranin (18/19), synaptophysin (10/15), and/or neuron-specific enolase (14/15). Metastatic disease was detected at the time of diagnosis in 69.4 percent of the patients (25/36). Tumors were advanced at the time of diagnosis, with American Joint Committee on Cancer (AJCC) Stage I (n = 6), Stage III (n = 7), and Stage IV (n = 25) tumors. As a group, these tumors had a poor prognosis, with a median survival of 10.4 months. One-year, two-year, and three-year survival was 46 percent, 26 percent, and 13 percent, respectively. There was no significant difference in survival based on pathologic subtypes. Median follow-up time was 9.4 months (range, 0.6-263.7 months). CONCLUSIONS: Neuroendocrine carcinomas of the colon and rectum are uncommon, comprising less than 1 percent of colon and rectal cancers. Pathologically, these tumors are poorly differentiated carcinomas with distinctive cytoarchitectural features and are often immunoreactive for markers of neuroendocrine differentiation. The prognosis for high-grade neuroendocrine carcinomas is poor, as most patients have metastatic disease at the time of diagnosis.

Distinctive molecular genetic alterations in sporadic and familial adenomatous polyposis-associated pancreatoblastomas : frequent alterations in the APC/beta-catenin pathway and chromosome 11p.

Pancreatoblastomas are unusual malignant neoplasms of the pediatric pancreas that may also rarely affect adults. The molecular pathogenesis of pancreatoblastomas is unknown. They are clinicopathologically distinct from adult pancreatic ductal adenocarcinomas, but their occasional occurrence in patients with Beckwith-Wiedemann syndrome and the case presented here of a pancreatoblastoma in an adult patient with familial adenomatous polyposis (FAP) suggests that they might bear a genetic similarity to other infantile embryonal tumors such as hepatoblastomas. We analyzed a series of nine pancreatoblastomas for mutations common to other embryonal malignancies including somatic alterations in the adenomatous polyposis coli (APC)/beta-catenin pathway and chromosome 11p, using immunohistochemistry for beta-catenin, 5q and 11p allelic loss assays, and direct DNA sequencing of exon 3 of the beta-catenin gene and the mutation cluster region of the APC gene. In addition, we analyzed the pancreatoblastomas for alterations found in adult-type pancreatic ductal adenocarcinomas including mutations in the K-ras oncogene and the p53 and DPC4 tumor suppressor genes, using direct DNA sequencing of exon 1 of K-ras and immunohistochemistry for p53 and Dpc4. Allelic loss on chromosome 11p was the most common genetic alteration in pancreatoblastomas, present in 86% (six of seven informative cases). Molecular alterations in the APC/beta-catenin pathway were detected in 67% (six of nine), including five neoplasms with activating mutations of the beta-catenin oncogene and the one FAP-associated tumor with biallelic APC inactivation (germline truncating mutation combined with loss of the wild-type allele); seven neoplasms showed abnormal nuclear accumulation of beta-catenin protein. In contrast, loss of Dpc4 protein expression was present in only two cases (one diffuse and one focal), and no alterations in the K-ras gene or p53 expression were detected. Our findings indicate that pancreatoblastomas are genetically distinct from the more common pancreatic ductal adenocarcinomas, but bear a close molecular pathogenesis to hepatoblastomas. In addition, pancreatoblastoma may represent an extracolonic manifestation of FAP.

Expression of thyroid transcription factor-1 and other markers in sclerosing hemangioma of the lung.

CONTEXT: Sclerosing hemangioma of the lung is well characterized histologically, but the line of differentiation expressed by the tumor cells has been unclear. Despite the implication by its name of a vascular neoplasm, sclerosing hemangioma is considered by most authorities to be an epithelial tumor, possibly related to the pulmonary epithelium. OBJECTIVES: To determine the line of differentiation of the tumor cells with immunohistochemistry and to review the related literature. DESIGN: Nine cases of histologically typical pulmonary sclerosing hemangioma were studied with pan-epithelial (epithelial membrane antigen [EMA] and CAM 5.2), endothelial (CD31), neuroendocrine (chromogranin A), and pulmonary epithelial markers (thyroid transcription factor-1 and PE10). Staining intensity was separately evaluated in the pale cells of the solid areas and the cells lining the papillary structures. RESULTS: Both cell types were positive for thyroid transcription factor-1 and EMA in all cases (100%). Thyroid transcription factor-1 showed diffuse strong staining, and EMA staining varied from focal weak to diffuse strong. The pale cells showed focal staining for keratin (CAM 5.2) in 2 (28%) of 7 cases, and for PE10 in 5 (62%) of 8 cases. The papillary lining cells were at least focally positive with CAM 5.2 and PE10 in all cases (100%). Reactions for chromogranin and CD31 were negative in both cell types in every case. The number of PE10- or CAM 5.2-positive papillary lining cells was less than the number of EMA-positive papillary lining cells. CONCLUSION: The uniform positivity for EMA is consistent with the notion that the tumor cells of sclerosing hemangioma are epithelial, and the strong thyroid transcription factor-1 positivity suggests differentiation toward pulmonary epithelium. The papillary lining cells expressing EMA as well as PE10 or CAM 5.2 likely represent entrapped metaplastic alveolar epithelium, whereas the papillary lining cells expressing only EMA more likely constitute true neoplastic cells similar to those in the solid areas.

Pancreatic intraepithelial neoplasia: a new nomenclature and classification system for pancreatic duct lesions.

Proliferative epithelial lesions in the smaller caliber pancreatic ducts and ductules have been the subject of numerous morphologic, clinical, and genetic studies; however, a standard nomenclature and diagnostic criteria for classifying these lesion have not been established. To evaluate the uniformity of existing systems for grading duct lesions in the pancreas, 35 microscopic slides with 35 representative duct lesions were sent to eight expert pathologists from the United States, Canada, and Europe. Kappa values for interobserver agreement could not be calculated initially because more than 70 different diagnostic terms were used by the eight pathologists. In several cases, the diagnoses rendered for a single duct lesion ranged from "hyperplasia," to "metaplasia," to "dysplasia," to "carcinoma in situ." This review therefore demonstrated the need for a standard nomenclature and classification system. Subsequently, during a working group meeting, the pathologists agreed to adopt a single standard system. The terminology pancreatic intraepithelial neoplasia (or PanIN) was selected, and diagnostic criteria for each grade of PanIN were established (http://pathology.jhu.edu/pancreas_panin). This new system was then evaluated by having the eight pathologists rereview the original 35 cases. Only seven different diagnoses were rendered, and kappa values of 0.43, 0.14, and 0.42 were obtained for PanINs 1, 2, and 3 respectively. Cases assigned other diagnoses (e.g., squamous metaplasia) collectively had a kappa value of 0.41. These results show both the potential of the classification system, and also the difficulty of classifying these lesions even with a consistent nomenclature. However, even when there is lack of consensus, having a restricted set of descriptions and terms allows a better understanding of the reasons for disagreement. It is suggested that we adopt and apply this system uniformly, with continued study of its reliability and use, and possibly further refinement. The acceptance of a standard classification system will facilitate the study of pancreatic duct lesions, and will lead ultimately to a better understanding of their biologic importance.

Colloid (mucinous noncystic) carcinoma of the pancreas.

In the past, colloid (mucinous noncystic) carcinoma (CC) of the pancreas had been included under the category of ordinary ductal adenocarcinoma, a tumor with a dismal prognosis, or was frequently misdiagnosed as mucinous cystadenocarcinoma. The clinicopathologic features of CC have not yet been well characterized, because most cases on record have been parts of studies on either mucinous cystic neoplasms (MCN) or intraductal papillary mucinous neoplasms (IPMN), with which colloid carcinomas are frequently associated. To determine the clinicopathologic characteristics of CC, 17 pancreatic tumors composed predominantly (>80%) of CC (defined as nodular extracellular mucin lakes with scanty malignant epithelial cells) and in which the invasive carcinoma measured larger than 1 cm were studied. Ten of these were originally classified as mucinous ductal adenocarcinoma and four as mucinous cystadenocarcinoma. The mean age of the patients was 61 years; 9 were men and 8 were women. The mean size of the CC was 5.3 cm (range, 1.2-16 cm). In more than half of the patients, CC represented the invasive component of an IPMN (in nine cases) or MCN (in one case). The tumors were composed of well-defined pools of mucin with sparse malignant cells in various patterns of distribution. Signet-ring cells floating in the mucin (but not as individual cells infiltrating stroma, a characteristic finding of signet-ring cell adenocarcinomas) were commonly identified and were prominent in five cases. Perineurial invasion was noted in six cases and regional lymph node metastases in eight. Mutation in codon 12 of the k-ras gene was detected in only 4 of 12 cases studied and p53 mutation in 2 of 9. Immunohistochemical and histochemical mucin stains suggested luminalization of the basal aspects of the cells. Five-year survival was 57%. At an overall mean follow up of 57 months, 10 patients were alive with no evidence of disease (median, 79 mos), including four with lymph node metastasis, three others with perineurial invasion, and another with vascular invasion. Four patients died of disease (18, 18, 25, and 26 mos), and three died of thromboembolism (with persistent disease) at 2, 5, 10 months. All seven patients who died with or of tumor had undergone incisional biopsy of the tumor either before the operation or intraoperatively, whereas none of the patients who were alive had incisional biopsy. When compared with 82 cases of resectable ordinary ductal adenocarcinoma on whom follow-up and staging information was complete, it was found that the patients with CC present with larger tumors (p = 0.03) but lower stage (p = 0.01). The prognosis of CC is significantly better: 2-year and 5-year survival are 70% versus 28% and 57% versus 12%, respectively (p = 0.001). In conclusion, pancreatic CC may occur with or without an identifiable IPMN and MCN component, and should be distinguished from mucinous cystadenocarcinoma, ordinary ductal adenocarcinoma, and signet-ring cell adenocarcinoma. CC of the pancreas is associated with a significantly better prognosis than ordinary ductal adenocarcinoma. In addition to its distinctive morphologic and clinical characteristics, CC of the pancreas also appears to have a low incidence of mutation in codon 12 of the k-ras gene. In cases with a clinical suspicion of colloid carcinoma, the possibility that an incisional biopsy may contribute to thromboembolic complications or even dissemination of the tumor may need to be considered. The luminalization of the basal aspects of the tumor cells may be the cause of stromal mucin accumulation that characterizes colloid carcinoma and may act as a containing factor.

Results of total pancreatectomy for adenocarcinoma of the pancreas.

HYPOTHESIS: Total pancreatectomy for infiltrating ductal adenocarcinoma is not superior to pancreaticoduodenectomy or distal pancreatectomy. DESIGN: A retrospective analysis of a prospective database of patients. SETTING: Memorial Sloan-Kettering Cancer Center, New York, NY. PATIENTS: All patients (n = 488) undergoing pancreatic resection. MAIN OUTCOME MEASURES: Duration of operation, estimated blood loss, complications, length of stay, number of positive lymph nodes, presence of a positive margin, and survival times were analyzed. RESULTS: Thirty-five patients were identified who underwent total pancreatectomy, 28 of whom had adenocarcinoma. Median length of stay was 32 days; 19 (54%) developed postoperative complications, of which 63% were infectious. Thirty-day mortality was 3% (1 patient). Median survival was 9.3 months (range, 0.6-172 months). There was no significant difference between patients with and without adenocarcinoma in terms of duration of operation, estimated blood loss, complications, length of stay, or number of readmissions. In patients with adenocarcinoma, margin or nodal status were not significant survival variables. Patients undergoing total pancreatectomy for adenocarcinoma had a significantly worse overall survival than those undergoing total pancreatectomy for other reasons (P<.001), or compared with a contemporaneous cohort with adenocarcinoma undergoing pancreaticoduodenectomy (n = 409) and distal pancreatectomy (n = 51) (7.9 vs 17.2 months; P<.002). CONCLUSIONS: Total pancreatectomy can be performed safely with low mortality; survival is predicted by the underlying pathologic findings: patients undergoing total pancreatectomy for adenocarcinoma have a uniformly poor outcome. Those undergoing total pancreatectomy for benign disease or nonadenocarcinoma variants can have long-term survival. In patients who require total pancreatectomy for ductal adenocarcinoma, the survival is so poor as to bring into question the value of the operation.

Carcinoid tumors of the extrahepatic bile ducts: a study of seven cases.

The authors report seven patients with carcinoid tumors of the extrahepatic bile ducts (EHBDs). All patients were women, with an average age at diagnosis of 49.8 years (range, 37-67 yrs). The most common presenting symptom was painless jaundice with or without pruritus. Although one patient had peptic ulcer disease before the onset of obstructive jaundice, none had systemic endocrine manifestations. These neoplasms were most often located in the common bile duct. Grossly, the carcinoid tumors were usually nodular and poorly demarcated, and ranged from 1.1 to 2.7 cm in size. Only one of the neoplasms was polypoid. Microscopically, the tumors had a trabecular or nesting pattern with occasional tubule formation, and were composed of relatively small cells with granular chromatin. All of the neoplasms expressed chromogranin and two expressed synaptophysin. Three expressed serotonin and two of the three were also immunoreactive for pancreatic polypeptide or somatostatin. Two tumors were focally positive for gastrin and one of these two tumors was also positive for serotonin and pancreatic polypeptide. All seven carcinoid tumors showed no immunoreactivity for p53, and assays for p53 loss of heterozygosity analysis were negative in two, suggesting that p53 mutations do not play a role in the pathogenesis of EHBD carcinoids. A mutation in codon 12 of K-ras was found in one carcinoid tumor whereas two of two showed immunoreactivity for Dpc4 protein. In view of the small number of carcinoids studied, the importance of these findings in the pathogenesis of these tumors is unclear. Ultrastructural examination of three of the tumors revealed numerous membrane-bound, round neurosecretory granules. Clinically, these lesions had an indolent course. Even in the presence of lymph node metastases (noted in two patients), all of the patients remained disease free 2 to 11 years (average follow up, 6.6 yrs) after segmental resection or pancreaticoduodenectomy (Whipple's procedure). Because carcinoid tumors of the EHBD are of low malignant potential, they should be separated from the more common adenocarcinomas in this location.

Analysis of 154 actual five-year survivors of gastric cancer.

Gastric cancer patients in the United States have a poor prognosis with a collective 5-year survival rate of less than 15%. We identified a subset of actual 5-year survivors (long-term survivors) and analyzed clinicopathologic variables predictive of recurrence and survival beyond the 5-year mark. A review of our prospective database from July 1985 to February 1993 revealed 154 patients who were long-term survivors and 280 patients who died of disease prior to 5 years (short-term survivors) following curative resection (R0). Tumor (T) stage, nodal (N) status, tumor location, and median number of positive nodes were compared between the two groups. Univariate and multivariate analysis of disease-free and greater than 5-year disease-specific survival was performed within the long-term survivors. Among the long-term survivors, 29% were classified as "early gastric cancers" (T1NX). The median number of positive nodes (0 vs. 5; P <0.001) and percentage of lesions that were T1/T2 (60% vs. 19%; P <0.001), node negative (58% vs. 15%; P <0.001), or proximal (40% vs. 65%; P <0.001) was significantly different in long-term survivors vs. short-term survivors, respectively. Of the 154 five-year survivors, gastric cancer recurred in 23, and 13 patients (8%) died of the disease at a median of 84 months from the original diagnosis. On univariate and multivariate analysis of prognostic factors in the long-term survivors, only the Lauren histologic classification predicted disease-specific and disease-free survival with diffuse histologic types faring significantly less well. T stage and N status are powerful prognostic factors of outcome within the first 5 years after curative resection of gastric carcinoma. However, the Lauren histologic type emerges as the dominant predictor of outcome once a patient with gastric cancer has survived for 5 years or more.

Alpha-fetoprotein production by pancreatic tumors exhibiting acinar cell differentiation: study of five cases, one arising in a mediastinal teratoma.

Five cases of pancreatic neoplasms accompanied by production of alpha-fetoprotein (AFP) and serum elevation of this marker are presented, and the better-documented cases of this phenomenon from the literature are reviewed. Four of the cases originated in the orthotopic pancreas, whereas the fifth arose in the pancreatic component of a mediastinal teratoma. The patients were children or young adults. AFP production in pancreatic tumors is closely linked to acinar differentiation, most cases representing either pancreatoblastoma or acinar cell carcinoma. The distinction between these 2 tumors may be difficult because of the many morphologic and immunohistochemical features they share.

Lymph node micrometastases do not predict relapse in stage II colon cancer.

BACKGROUND: Over one third of patients with stage II colonic adenocarcinoma experience tumor recurrence. Because effective adjuvant therapy is now available, it is important to identify subsets of patients at higher risk for relapse who may benefit from early treatment. Immunohistochemistry has been used to detect microscopic metastases in histologically uninvolved mesenteric lymph nodes, but the prognostic significance of minimal nodal involvement has not been established. METHODS: Hematoxylin and eosin (H&E)-stained recuts of 900 mesenteric lymph nodes from 55 patients (range, 2-47; mean, 16.4 nodes per case) with resected pT3 or pT4, N0, M0 (TNM stage II) colonic adenocarcinomas were re-examined for the presence of metastases and then stained immunohistochemically for keratin using the AE1:AE3 antibody. Twenty-seven patients did not experience recurrence of tumor within 5 years following resection (no evidence of disease [NED]); 28 patients relapsed during the same time frame. Lymph nodes from 10 patients having colonic resections for nonneoplastic disorders also were stained as controls. Keratin-positive cells and cell clusters were quantified in the lymph nodes, and comparisons were made between patients with and without tumor relapse. RESULTS: In the relapse group, four patients had positive nodes already identified on the H&E-stained recuts and had to be excluded from further analysis. Sixteen additional patients had keratin-positive cells; thus, 16 of 24 (67%) had micrometastases. In the NED group, one patient had a positive node on H&E staining and 22 additional patients had keratin-positive cells, so 22 of 26 (84%) patients had micrometastases. In the patients who had micrometastases, there was a mean of 3.5 and 4.6 positive nodes in the relapse and NED groups, respectively, and a mean of 11.3 and 12.4 keratin-positive cells or clusters in the relapse and NED groups, respectively. No keratin-positive cells were found in the 1 to 21 (mean, 9.1) nodes per case studied in the control patients. CONCLUSIONS: Micrometastases to histologically uninvolved mesenteric lymph nodes commonly are detected in patients with pT3 or pT4 colonic adenocarcinomas on recuts stained immunohistochemically for keratin. Nodal micrometastases detected by immunohistochemical staining are not useful for identifying stage II patients at higher risk for relapse.