Immunohistochemical analysis of molecular biological factors in intraductal papillary-mucinous tumors and mucinous cystic tumors of the pancreas

BACKGROUND: To investigate the malignancy and differentiation of intraductal papillary-mucinous tumors (IPMTs) and mucinous cystic tumors (MCTs) of the pancreas, clinicopathologic characteristics and immunohistochemical features were analyzed. METHODS: The clinicopathologic characteristics and immunohistochemical features of 24 patients with IPMT and 8 with MCT who underwent pancreatic resections at our hospital were examined. Immunohistochemical features analyzed included expression of p53 protein, proliferating cell nuclear antigen, integrins, interleukin-1 receptor type I, and hormone-associated receptors, and the factors correlated with malignancy were identified by multiple logistic regression. RESULTS: Among the IPMTs, there were 16 intraductal papillary adenomas, 5 intraductal papillary adenocarcinomas, and 3 moderate dysplasias. Among the MCTs, there were 6 mucinous cyst adenomas and 2 mucinous cyst adenocarcinomas. Multivariate analysis revealed that of the clinicopathologic characteristics, only the presence of mural nodules (odds ratio (OR) 7.12, P = 0.044) was independently correlated with the malignancy of IPMTs, and that of the immunohistochemical features, only alpha integrin subunit expression was independently correlated with malignancy of pancreatic mucinous tumors (OR 15.6, P = 0.036), especially IPMTs (OR 35.7, P = 0.012). CONCLUSION: These results indicate that alpha-containing integrin expression can be a significant marker of malignancy in pancreatic mucinous tumors.     

Immunohistochemical analysis of molecular biological factors in intraductal papillary-mucinous tumors and mucinous cystic tumors of the pancreas

Background: To investigate the malignancy and differentiation of intraductal papillary-mucinous tumors (IPMTs) and mucinous cystic tumors (MCTs) of the pancreas, clinicopathologic characteristics and immunohistochemical features were analyzed. Methods: The clinicopathologic characteristics and immunohistochemical features of 24 patients with IPMT and 8 with MCT who underwent pancreatic resections at our hospital were examined. Immunohistochemical features analyzed included expression of p53 protein, proliferating cell nuclear antigen, integrins, interleukin-1 receptor type I, and hormone-associated receptors, and the factors correlated with malignancy were identified by multiple logistic regression. Results: Among the IPMTs, there were 16 intraductal papillary adenomas, 5 intraductal papillary adenocarcinomas, and 3 moderate dysplasias. Among the MCTs, there were 6 mucinous cyst adenomas and 2 mucinous cyst adenocarcinomas. Multivariate analysis revealed that of the clinicopathologic characteristics, only the presence of mural nodules (odds ratio (OR) 7.12, P?=?0.044) was independently correlated with the malignancy of IPMTs, and that of the immunohistochemical features, only α[Formula: See Text] integrin subunit expression was independently correlated with malignancy of pancreatic mucinous tumors (OR 15.6, P?=?0.036), especially IPMTs (OR 35.7, P?=?0.012). Conclusion: These results indicate that α[Formula: See Text]-containing integrin expression can be a significant marker of malignancy in pancreatic mucinous tumors.     

Possible Oncogenesis of Mucinous Cystic Tumors of the Pancreas Lacking Ovarian-Like Stroma

Background/Aims: Clinicopathological features and postoperative results from mucinous cystic tumors of the pancreas (MCTs) were reviewed. MCTs with ovarianlike stroma (MCTs-OLS+; n = 6) and those lacking ovarianlike stroma (MCTs-OLS–; n = 4) were compared to elucidate the oncogenesis of MCT without OLS. Patients and Methods: Ten patients with MCT were studied. Results: The 6 MCTs-OLS+ cases occurred in females and were located in the body and tail of the pancreas. The mean tumor size was 6.5 cm (range 2–11 cm). The majority (5/6) of MCTs-OLS+ were multilocular and exhibited tiny loculi on the cyst wall and septum characteristic of MCTs-OLS+. Pathological classifications were adenoma in 4 patients and noninvasive adenocarcinoma in 2 patients. All 6 patients were alive without tumor recurrence 6–124 months after tumor resection. Of the 4 MCTs-OLS– cases, 2 were males and 2 females; MCTsOLS– were located in the tail of the pancreas. The mean tumor size was 6.9 cm (range 4–8.4 cm). Invasive cancer in the pancreatic parenchyma or extrapancreatic tissue was recognized in all 4 patients, and the pathological classification of epithelia of the cyst wall were adenocarcinomas. These findings were also compatible with common invasive ductal carcinomas of the pancreas with secondary retention cyst on pseudocyst. All patients died of the disease (15, 27, 31 and 80 months after resection, respectively). Whether or not OLS is specific for MCTs of the pancreas should be clarified in future studies. Conclusion: The results of our study led to three hypotheses regarding the oncogenesis of MCTs-OLS–: (1) MCTs in which OLS disappears during the development of invasive carcinoma; (2) advanced cancer derived from intraductal papillary mucinous tumor of the pancreas, and (3) invasive ductal carcinoma of the pancreas with secondary cyst.     

Clinicopathologic study of intraductal papillary-mucinous tumors and mucinous cystic tumors of the pancreas

BACKGROUND/AIMS: We analyzed clinicopathologic and imaging findings of intraductal papillary-mucinous tumors (IPMTs) and mucinous cystic tumors (MCTs) of the pancreas to evaluate the difference between IPMTs and MCTs, and to identify the signs indicative of malignancy in IPMTs. METHODOLOGY: Clinicopathological features of 20 patients with IPMT and six patients with MCT of the pancreas were studied. RESULTS: The patients with IPMT comprised 16 males and four females with a mean age of 62.9 years. Eighty percent of IPMTs were located in the pancreatic head, and the mean tumor size was 38.6mm. Recurrence was observed in one patient, who died of IPM adenocarcinoma. In contrast, all patients with MCT were females, with a mean age of 53.0 years. None of the MCTs arose in the pancreatic head, and the mean tumor size was 42.7mm. One patient died of MC adenocarcinoma, but all of the others survived without recurrence. The difference in gender, location of the tumor, and connection to the pancreatic duct reached statistical significance between IPMTs and MCTs. A significant connection to the pancreatic duct and high level of serum carbohydrate antigen 19-9 (CA19-9) was observed in the adenocarcinoma and moderate dysplasia groups of IPMT. CONCLUSIONS: The main duct type and an elevation of serum CA19-9 level suggested malignancy in IPMTs.     

Patient- and Cyst-Related Factors for Improved Prediction of Malignancy within Cystic Lesions of the Pancreas

Background and Aims: Early diagnosis of cancer in pancreatic cysts is important for timely referral to surgery. The aim of this study was to develop a predictive model for pancreatic cyst malignancy to improve patient selection for surgical resection. Methods: We performed retrospective analyses of endoscopic ultrasound (EUS) and pathology databases identifying pancreatic cysts with available final pathological diagnoses. Main-duct intraductal papillary mucinous neoplasms (IPMNs) were excluded due to the clear indication for surgery. Patient demographics and symptoms, cyst morphology, and cyst fluid characteristics were studied as candidate riskfactors for malignancy. Results: 270 patients with pancreatic cysts were identified and analyzed (41% men, mean age 61.8 years). Final pathological diagnoses were branch-duct IPMN (n = 118, 50% malignant), serous cystadenoma (n = 71), pseudocyst (n = 37), mucinous cyst adenoma/adenocarcinoma (n = 36), islet cell tumor (n = 4), simple cyst (n = 3), and ductal adenocarcinoma with cystic degeneration (n = 1). Optimal cut-off points for surgical resection were cyst fluid carcinoembryonic antigen (CEA) ≥3,594 ng/ml, age >50, and cyst size >1.5 cm. Cyst malignancy was independently associated with white race (OR = 4.1, p = 0.002), weight loss (OR = 3.9, p = 0.001), cyst size >1.5 cm (OR = 2.4, p = 0.012), and high CEA >3,594 (OR = 5.3, p = 0.04). In white patients >50 years old presenting with weight loss and cyst size >1.5 cm, the likelihood of malignancy was nearly sixfold greater than in those patients who had none of these factors (OR = 5.8,95% CI = 2.1-16.1, p = 0.004). Conclusions: Riskfactors other than cyst size are important for determination of malignancy in pancreatic cysts. Exceptionally high cyst fluid CEA levels and certain patient-related factors may help to better predict cyst malignancy and the need for surgical treatment.     

Colorectal Mucinous Adenocarcinoma: The Clinicopathologic Features and Significance of p16 and p53 Expression

Purpose This study was designed to examine the clinicopathologic features and p53 and p16 expressions in colorectal mucinous adenocarcinoma and colorectal signet-ring cell carcinoma. Methods The clinicopathologic features of 36 patients with colorectal mucinous adenocarcinoma and colorectal signet-ring cell carcinoma were analyzed and compared with 228 patients with colorectal adenocarcinomas. The p53 and p16 expressions in the colorectal mucinous adenocarcinoma and colorectal signet-ring cell carcinoma were studied by immunohistochemistry. Results Colorectal mucinous adenocarcinoma and colorectal signet-ring cell carcinoma accounted for 14 percent of colorectal cancer. The median age at presentation was 67 years. Family history of colorectal cancer in their first-degree relatives was seen in 14 percent of these patients. Fifty-six percent of the carcinomas were located in the proximal colorectum, most commonly in the transverse colon. Two patients had ulcerative colitis. Compared with the usual colorectal adenocarcinoma, colorectal mucinous adenocarcinoma and colorectal signet-ring cell carcinoma was found more often in proximal colorectum (P = 0.002), larger (P = 0.05), and in advanced stages (P = 0.018). Forty-four percent (n = 16) of the colorectal mucinous adenocarcinoma and colorectal signet-ring cell carcinoma showed p53 expression. All the patients with colorectal mucinous adenocarcinoma and colorectal signet-ring cell carcinoma with a positive family history of colorectal adenocarcinoma had tumors that showed p53 expression (P = 0.012). Seventy-eight percent (n = 28) of the tumors showed p16 expression. The median survival of the patients with these tumors was 23 months. The survival of these patients with colorectal mucinous adenocarcinoma and colorectal signet-ring cell carcinoma was poorer if the lesions were of advanced stages (P = 0.023) or with family history of colorectal cancer (P = 0.0015). Also, patients with colorectal mucinous adenocarcinoma and colorectal signet-ring cell carcinoma that did not express p16 and p53 had better survival than other patients (P = 0.04). Conclusions Colorectal mucinous adenocarcinoma and colorectal signet-ring cell carcinoma had distinctive clinicopathologic features. Tumor staging, family history of colorectal cancer, and status of p53 and p16 expressions might predict prognosis in these patients. Supported by a grant from the Queensland Cancer Fund. Presented at the Health and Medical Research Conference of Queensland, Brisbane, Queensland, Australia, November 3 to 4, 2005     

p53 protein expression in intraductal papillary mucinous tumors (IPMT) of the pancreas as an indicator of tumor malignancy

BACKGROUND/AIMS: Intraductal papillary mucinous tumors, as a cystic disease in the pancreas, clinically has a more indolent and favorable course than invasive ductal pancreas carcinoma. However, some cases of intraductal papillary mucinous tumors show invasive and rapid progression like ductal pancreas carcinoma and the prognosis of such patients is sometimes poor. In the current study, we carried out immunohistochemical staining of intraductal papillary mucinous tumor tissues for p53 and investigated whether positive staining indicates tumor malignancies and has a prognostic value for intraductal papillary mucinous tumors. METHODOLOGY: Nineteen (19) patients who underwent pancreatic resection under the diagnosis of intraductal papillary mucinous tumors at the Chiba University Hospital between April 1992 and December 1996 were studied. We performed immunohistochemical staining of p53 as well as of PCNA, Ki-67 and Bcl-2 using their respective antibodies. Pathological findings revealed that 9 cases were intraductal papillary adenoma, 9 were intraductal papillary adenocarcinoma, and one was invasive ductal papillary adenocarcinoma. RESULTS: p53 expression could only be detected in the 1 case with invasive ductal papillary adenocarcinoma. Significant association could not be found between histological features and immunohistochemical staining of PCNA, Ki-67 and Bcl-2. CONCLUSIONS: p53 protein expression could be detected after progression to invasive type of intraductal papillary mucinous tumors. The present results demonstrate that p53 expression might be an indicator of invasive progression in intraductal papillary mucinous tumors, and might represent a surgical indicator of intraductal papillary mucinous tumors.     

Endoscopic ultrasound characteristics of mucinous cystic neoplasms of the pancreas

OBJECTIVE: Mucinous cystic neoplasms of the pancreas have a more favorable prognosis than ductal adenocarcinoma. Management of a subgroup, intraductal papillary-mucinous neoplasms, is controversial. Endoscopic ultrasound (EUS) with fine-needle aspiration biopsy may emerge as the imaging modality of choice. There are few studies describing the EUS features of these tumors. METHODS: A total of 35 consecutive cases of cystic tumors of the pancreas with an established pathological diagnosis were analyzed for characteristic EUS features. RESULTS: Mucinous cystadenocarcinomas (n = 14) were more likely to be characterized by hypoechoic cystic/solid mass or complex cyst and were frequently associated with a dilated main pancreatic duct. Benign mucinous duct ectasia (n = 6) were characterized by a dilated main pancreatic duct in conjunction with hyperechoic thickening of the duct wall. The two cases of intraductal mucinous hyperplasia additionally showed a hypoechoic mass. Intraductal papillary carcinoma (n = 11) had features in common with mucinous cystadenocarcinoma but also had echogenic foci in the mass and intraductal hyperechoic lesions. The two cases of microcystic cystadenoma showed either a mixed hypoechoic solid/cystic mass or a complex cyst without the additional features seen in mucinous cystadenocarcinoma. CONCLUSIONS: EUS features seem to exist that may help to differentiate cystic neoplasms from adenocarcinoma of the pancreas and, thus, to establish the preoperative diagnosis of cystic tumors of the pancreas.     

Clinicopathologic review of 41 cases of pancreatic mucinous cystic neoplasms]

BACKGROUND/AIMS: Intraductal papillary mucinous neoplasms (IPMN) and mucinous cystic neoplasms are included in mucin-producing pancreatic tumors. The reports about IPMN are not uncommon but those about the mucinous cystic neoplasms are relatively few. The aims of this study were to define the natural history of resected mucinous cystic neoplasms of the pancreas and to identify the findings which suggest malignancy. METHODS: The authors retrospectively evaluated the clinical outcomes of 41 patients with mucinous cystic neoplasms who were surgically resected at Asan Medical Center between 1995 and 2004. RESULTS: Women (n=33) were more frequently affected than men (n=8). Thirty three patients (80.6%) had adenoma, 1 (2.4%) borderline malignancy, 1 (2.4%) carcinoma in situ, and 6 (14.6%) invasive mucinous cystadenocarcinoma. The most frequent symptom was abdominal pain (39%). About half of the enrolled patients were asymptomatic. Unilocular type (79%) was more frequent than the multilocular type (21%) on gross morphology. The tumor size of invasive mucinous cystic neopolasms was larger than that of non-invasive mucinous cystic neoplalsms (p=0.01). Abdominal pain was more frequent in invasive mucinous cystic neoplasms (p=0.026). On gross morphology, mural nodules were detected in 4 of 6 patients with invasive mucinous cystic neoplasms. However, they were not detected in any patients with non-invasive mucinous cystic neoplasms. Recurrence developed in none of the 35 patients with non-invasive mucinous cystic neoplasms, however 2 of the 6 patients with invasive mucinous cystic neoplasms died within 5 years. CONCLUSIONS: Clinical predictors of invasive mucinous cystic neoplasms are suggested to be tumor size and abdominal pain. The prognosis of the non-invasive mucinous cystic neoplasms is excellent when curative resection is performed.     

Pancreatic Cystic Neoplasms: Predictors of Malignant Behavior and Management

Background/Aim:

Pancreatic cystic neoplasms are being increasingly identified with the widespread use of advanced imaging techniques. In the absence of a good radiologic or pathologic test to preoperatively determine the dianosis, clinical characteristics might be helpful. The objectives of this analysis were to define the incidence and predictors of malignancy in pancreatic cysts.

Patients and Methods:

Patients with true pancreatic cysts who were treated at our institution were included. Patients with documented pseudocysts were excluded. Demographic data, clinical manifestations, radiological, surgical, and pathological records of those patients were reviewed.

Results:

Eighty-one patients had true pancreatic cyst. The mean age was 47 ± 15.5 years. There were 28.4% serous cystadenoma, 21% mucinous cystadenoma, 6.2% intraductal papillary tumors, 8.6% solid pseudopapillary tumors, 1.2% neuroendocrinal tumor, 3.7% ductal adenocarcinoma, and 30.9% mucinous cystadenocarcinoma. Malignancy was significantly associated with men (P = 0.04), older age (0.0001), cysts larger than 3 cm in diameter (P = 0.001), presence of solid component (P = 0.0001), and cyst wall thickening (P = 0.0001). The majority of patients with malignancy were symptomatic (26/28, 92.9%). The symptoms that correlated with malignancy included abdominal pain (P = 0.04) and weight loss (P = 0.0001). Surgical procedures were based on the location and extension of the lesion.

Conclusion:

The most common pancreatic cysts were serous and mucinous cysts. These tumors were more common in females. Old age, male gender, large tumor, presence of solid component, wall thickness, and presence of symptoms may predict malignancy in the cyst.     

EUS in the evaluation of pancreatic cystic lesions

BACKGROUND: The differential diagnosis in pancreatic cystic lesions is often difficult despite the availability of various modern imaging modalities. This study assessed the role of EUS in the following: (1) discrimination of pseudocysts from pancreatic cystic tumors, (2) differential diagnosis between serous cystadenoma and mucinous cystic tumor, and (3) prediction of accompanying malignancy in intraductal papillary mucinous tumor. METHODS: EUS findings in 75 patients with pancreatic cystic lesions (58 cystic tumors, 17 pseudocysts) were evaluated. In the comparison of pseudocysts and cystic tumors, the latter included intraductal papillary mucinous tumor, mucinous cystic tumors, and serous cystadenomas, but not solid-pseudopapillary tumors. RESULTS: In univariate analysis, pseudocysts exhibited echogenic debris and parenchymal changes more often than cystic tumors did (respectively, 29% vs. 6%, p < 0.05; and 65% vs. 4%, p < 0.001). In contrast, septa and mural nodules were found more frequently in cystic tumors than pseudocysts (respectively, 69% vs. 12%, p < 0.001; 56% vs. 12%, p < 0.01). Multivariate analysis revealed that parenchymal changes (odds ratio [OR] = 83.59; p < 0.01); septa (OR = 30.75; p < 0.05); and mural nodules (OR = 21.38; p < 0.05) were independent predictors of differentiation between pseudocysts and cystic tumors. Serous cystadenoma exhibited diverse EUS features, as well as a honeycomb appearance. Mural nodules were found more often in mucinous cystic tumors than in serous cystadenomas (p < 0.05). There were no factors that predicted malignancy in intraductal papillary mucinous tumor. CONCLUSIONS: EUS is a useful complementary imaging method for differentiation of pancreatic cystic lesions.     

Carcinoma arising in congenital choledochal cysts

BACKGROUND/AIMS: Congenital choledochal cyst is almost always associated with pancreaticobiliary maljunction and is sometimes associated with biliary carcinoma. This study aimed to investigate the clinicopathological features and surgical treatment of choledochal cyst associated with carcinoma arising in the cyst wall. METHODOLOGY: Relationship of the clinicopathological findings and surgical treatment of 8 patients with histologically proven carcinoma that had developed in the choledochal cyst wall were examined to determine mode of tumor spread, multicentric tumor origins, and coincidence with other neoplastic lesions. RESULTS: Papillary adenocarcinoma (n = 5) had different clinicopathological features than tubular adenocarcinoma (n = 3). Radiologically, papillary adenocarcinoma presented as an eccentrically located polypoid mass in the cyst, while with tubular adenocarcinoma, there was evidence of bile duct stenosis with irregular thickening of the bile duct wall. Papillary adenocarcinoma was associated with extensive superficial spread (n = 1), synchronous (n = 2), or metachronous (n = 2) multicentric tumors. Pancreatoduodenectomy with (n = 1) or without (n = 1) hepatic lobectomy, and repeated resection by hepatic lobectomy (n = 2) were performed for these circumstances of tumors. Extensive or repeated resections allowed 3 patients to live longer than 2 years. Tubular adenocarcinoma was associated with scirrhously infiltrative spread and a poor prognosis. CONCLUSIONS: Papillary adenocarcinoma frequently occurs in the choledochal cyst wall. Since aggressive resection offers survival benefits in papillary adenocarcinoma arising in the choledochal cyst wall, the presence of superficial spread and multicentric tumors should be identified and taken into account when planning surgery. Patients require close monitoring so that recurrent carcinoma of the remnant bile duct can be identified early.     

Dukes B colorectal cancer: distinct genetic categories and clinical outcome based on proximal or distal tumor location

PURPOSE: The aim of this study was to determine whether tumor location proximal or distal to the splenic flexure is associated with distinct molecular patterns and can predict clinical outcome in a homogeneous group of patients with Dukes B (T3-T4, N0, M0) colorectal cancer. It has been hypothesized that proximal and distal colorectal cancer may arise through different pathogenetic mechanisms. Although p53 and Ki-ras gene mutations occur frequently in distal tumors, another form of genomic instability associated with defective DNA mismatch repair has been predominantly identified in the proximal colon. To date, however, the clinical usefulness of these molecular characteristics remains unproven. METHODS: A total of 126 patients with a lymph node-negative sporadic colon or rectum adenocarcinoma were prospectively assessed with the endpoint of death by cancer. No patient received either radiotherapy or chemotherapy. p53 protein was studied by immunohistochemistry using DO-7 monoclonal antibody, and p53 and Ki-ras gene mutations were detected by single strand conformation polymorphism assay. RESULTS: During a mean follow-up of 67 months, the overall five-year survival was 70 percent. Nuclear p53 staining was found in 57 tumors (47 percent), and was more frequent in distal than in proximal tumors (55 vs. 21 percent; chi-squared test, P < 0.001). For the whole group, p53 protein expression correlated with poor survival in univariate and multivariate analysis (log-rank test, P = 0.01; hazard ratio = 2.16; 95 percent confidence interval = 1.12-4.11, P = 0.02). Distal colon tumors and rectal tumors exhibited similar molecular patterns and showed no difference in clinical outcome. In comparison with distal colorectal cancer, proximal tumors were found to be statistically significantly different on the following factors: mucinous content (P = 0.008), degree of histologic differentiation (P = 0.012), p53 protein expression, and gene mutation (P = 0.001 and 0.01 respectively). Finally, patients with proximal tumors had a marginally better survival than those with distal colon or rectal cancers (log-rank test, P = 0.045). CONCLUSION: In this series of Dukes B colorectal cancers, p53 protein expression was an independent factor for survival, which also correlated with tumor location. Eighty-six percent of p53-positive tumors were located in the distal colon and rectum. Distal colon and rectum tumors had similar molecular and clinical characteristics. In contrast, proximal neoplasms seem to represent a distinct entity, with specific histopathologic characteristics, molecular patterns, and clinical outcome. Location of the neoplasm in reference to the splenic flexure should be considered before group stratification in future trials of adjuvant chemotherapy in patients with Dukes B tumors.     

A 10-Year Outcomes Evaluation of Mucinous and Signet-Ring Cell Carcinoma of the Colon and Rectum

PURPOSE Most studies examining mucinous or signet-ring cell colorectal cancers are single institution reports. This study used a national cancer registry to analyze the epidemiology and survival outcomes of these two subtypes of colorectal cancer compared with adenocarcinoma tumors.METHODS All patients diagnosed with mucinous (n = 16,991), signet-ring cell (n = 1,522), or adenocarcinoma (n = 146,115) colorectal cancer in the Surveillance, Epidemiology, and End Results database (1991–2000) were evaluated. Analyses were performed to obtain age-adjusted incidence rates, stage at presentation, tumor grade, and five-year relative survival for each subtype.RESULTS Mucinous were slightly more common in females (53.4 percent). Incidence rates per 100,000 persons were: mucinous, 5.5; signet-ring cell, 0.6; and adenocarcinoma 46.6. The annual percent change during ten years was stable for mucinous, increased for signet-ring cell (4.8 percent; P < 0.05), and decreased for adenocarcinoma (−1.1 percent; P < 0.05). Fewer mucinous (18 percent) and signet-ring cell (21 percent) tumors were located in the rectum compared with adenocarcinoma (29 percent). Signet-ring cell presented at later stage (III/IV, 80.9 percent) more often than mucinous (52.8 percent) and adenocarcinoma (49.5 percent), and also had worse tumor grade (high grade: signet-ring cell, 73.5 percent; mucinous, 20.9 percent; adenocarcinoma, 17.5 percent). Relative five-year survival was worse for signet-ring cell than mucinous or adenocarcinoma.CONCLUSIONS We present a large population-based review of colorectal cancer subtypes by analyzing national data from the past decade. Although the incidence of colorectal adenocarcinoma is decreasing in the United States, mucinous and signet-ring cell subtypes are stable and increasing, respectively. Importantly, it seems that the signet-ring cell subtype has worse outcomes, whereas survival rates for mucinous tumors are similar to adenocarcinomas.Read at the meeting of The American Society of Colon and Rectal Surgeons, Dallas, Texas, May 8 to 13, 2004.Supported in part by a Limited Project Grant from The American Society of Colon and Rectal Surgeons Research Foundation.     

Expression of integrins in tumour tissue of a patient with cancer of the Vater's ampulla complicated by pancreas divisum

We present herein a rare case where cancer of the Vater's ampulla was complicated with pancreas divisum. Endoscopic retrograde cholangiopancreatography demonstrated the pancreas divisum and stenosis of the common channel due to the tumorous lesion of the Vater's ampulla. Magnetic resonance cholangiopancreatography demonstrated that the Wirsung duct and Santorini duct were unconnected. The biopsy specimen at the upper gastrointestinal endoscopy revealed moderately differentiated tubular adenocarcinoma. The patient was diagnosed with cancer of the Vater's ampulla complicated with pancreas divisum, and underwent a pylorus-preserving pancreaticoduodenectomy. Immunohistochemical examination showed that the p53 protein and the alpha5beta1-integrin were expressed in tumour cells, and the proliferating cell nuclear antigen test was positive. Furthermore, the alpha5beta1-integrin was expressed in chronic pancreatitis tissue. We demonstrate that there is a risk that pancreas divisum will co-exist with malignant disease in the pancreaticobiliary area, causing a potential risk of complicating malignant diseases in the pancreas.     

Appendiceal mucocele with concomitant colonic cancer

PURPOSE: Mucocele of the appendix is an uncommon disorder, usually found incidentally during ultrasonography or radiographic studies. We report two cases of combined appendiceal mucocele and colonic cancer. METHODS: The two cases were analyzed for the clinicopathologic characteristics such as history, presentation, laboratory data, radiologic and endoscopic studies, pathology, and p53 immunoreactivity. RESULTS: Two patients were diagnosed with an appendiceal mucocele by ultrasound of the abdomen, together with computed tomography. Colonoscopic examination subsequently revealed synchronous colonic adenocarcinoma in both patients. Ileocecal resection following endoscopic polypectomy and a right hemicolectomy was performed for each patient. An appendiceal mucocele was histologically diagnosed as a mucinous cystadenoma. Immunohistochemical detection of abnormally high level of p53 protein was observed in colonic adenocarcinomas of both patients, whereas both appendiceal cystadenomas were negative for p53. CONCLUSIONS: To be remembered is the high frequency of concomitant gastrointestinal tumors in patients with appendiceal mucocele, especially caused by mucinous neoplasms. A total colonoscopic surveillance will afford earlier diagnosis of synchronous colonic cancers in these patients.     

Oncoproteins and proliferation markers in synovial sarcomas: a clinicopathologic study of 19 cases

PURPOSE: The objective of this study was to evaluate synovial sarcomas for the expression of oncogenic proteins (Her2/neu, EGFR, Bcl-2, p53) and proliferation markers (Ki-67, Topoisomerase 2alpha), as possible markers of prognostic significance. METHODS: From 17 patients with synovial sarcomas 19 tumors (15 primary, 2 recurrent, and 2 metastatic) were selected on the basis of characteristic histology, the expression of at least one epithelial marker, and/or the presence of t(X;18). Adequate follow-up was available in all cases. RESULTS: The tumors were tested immunohistochemically and were found to express multiple oncogenic proteins. Four of 19 synovial sarcomas (21%) demonstrated nuclear over-expression of p53 protein; 18 of 19 tumors (94%) stained positive for Bcl-2; and 13 of 19 tumors (68%) were immunoreactive with EGFR. Of particular interest was the frequent expression of Her2/neu, an oncogenic protein more commonly observed in epithelial neoplasms. Ten of 19 tumors (52%, 7 monophasic and 3 biphasic) showed positive cytoplasmic and membranous staining with Her2/neu (HercepTest, DAKO). The staining intensity ranged from 1+ to 2+. Cellular expression of Her2/neu was independent of EGFR positivity and showed no association with proliferative activity of the tumors. FISH analysis of eight positive cases showed no evidence of Her2/neu gene amplification. Among the non-metastatic tumors, we found a significant correlation between Ki-67 and Topoisomerase 2alpha. Spearman's correlation co-efficient was 0.86 with P=0.001 ( n=17). CONCLUSIONS: In this relatively small series of cases, we found no definite correlation between the over-expression of Her2/neu and clinical outcome. The over-expression of p53 was significantly associated with clinical outcome (Fisher's exact test, P=0.02).     

Mutated p53 protein expression and proliferative activity in advanced gastric cancer.

BACKGROUND/AIMS: When the DNA of cells is damaged, wild-type p53 protein induces the expression of p21 (Waf1/Cip1/Sdi1), and regulates the progression of the cell cycle by inducing G1 arrest. Thus, wild type p53 or p21 protein negatively regulates cancer cell proliferation. However, in tumor with loss of expression of functional wild-type p53 protein by mutation or allelic deletion of the gene for p53, whether the proliferative activity of cancer cells might be accelerated or not is unclear. In this study, we investigated the correlation between the level of expression of mutated p53 protein and the proliferative activity of cancer cells in advanced gastric cancer. METHODOLOGY: Ninety-seven samples from patients with gastric cancer that had invaded the serosa without lymph node metastasis (t3, n0, stage II) were investigated by immunohistochemical staining with a monoclonal antibody against p53 and against p21, and with the monoclonal antibody Ki-67. DNA ploidy patterns were analyzed by flow cytometry. The immunoreactivity against p53 and the proliferative activity of cancer cells were scored in terms of a labeling index (LI; percentage of immunostained cells) in each case. Moreover, the prognostic values for 93 surviving patients were evaluated by univariate and multivariate analysis. RESULTS: The mean p53 LI was 24% (range: 0-82.4%) and the mean Ki-67 LI was 23.1% (range: 0-70.7%) in 97 tumors. The expression of p21 protein was detected in 30 of 97 tumors (30.9%) and DNA aneuploidy was detected in 36 of 97 tumors (37.1%). There was significant correlation between the p53 LI and the Ki-67 LI (r = 0.61, t = 7.456, p < 0.001) in 97 tumors. Although, no significant difference was detected, the mean p53 LI (18.3%) of 30 tumors with expression of p21 protein was lower than that of 67 tumors without expression of p21 protein (26.6%, p = 0.096). However, no significant correlation between expression of p21 protein and Ki-67 LI was observed. The p53 LI was not an independent prognostic factor in 93 surviving patients by multivariate survival analysis (p = 0.069). However, the 5-year survival rate of 50 patients with a low level of p53 LI (p53 LI (< or = 10%, 78.3%) was significantly better than that of 43 patients with a high level of p53 LI (p53 LI > 10%, 62.1%, p = 0.045). CONCLUSIONS: Accumulation of mutated p53 protein might suppress the expression of p21 protein in gastric adenocarcinoma, and cancer cells with overexpression of mutated p53 protein might have a high proliferative activity.     

c-erbB-2 、bcl-2和p53在结直肠肿瘤中的表达及其临床意义

背景：c-erbB-2、bcl-2和突变型p53在结直肠腺瘤癌变过程中相互调节并发挥重要作用。目的：探讨结直肠肿瘤中c-erbB-2、bcl-2和D53蛋白的表达及其临床意义。方法：取42例结直肠腺癌、10例腺瘤和10例正常结直肠黏膜组织，以免疫组化方法检测其中c-erbB-2、bcl-2和p53蛋白的表达，分析其表达与腺癌临床病理特征的关系。结果：c-erbB-2、bcl-2和p53蛋白在腺癌、腺瘤和正常黏膜组织中的表达差异均有统计学意义（P〈0．05），bcl-2蛋白在腺癌组织中的表达低于腺瘤组织，c-erbB-2和p53蛋白在腺癌组织中的表达高于腺瘤和正常黏膜组织。c-erbB-2蛋白的表达随腺癌分化程度的降低而增高，bcl-2蛋白的表达随腺癌分化程度的降低而降低：c-erbB-2和p53蛋白的表达与淋巴结转移和Dukes分期呈正相关。腺癌组织中bcl-2与p53蛋白的表达呈负相关（rs=-0．301，P〈0．05）。结论：c-erbB-2与结直肠癌的进展、分化和转移相关。腺癌组织中p53高表达和bcl-2相对低表达提示两者可能参与了结直肠癌的发生、发展过程，bcl-2过表达可能在结直肠癌发生的早期起作用。     

Risk of malignancy in serous cystic neoplasms of the pancreas

BACKGROUND: In contrast to mucinous cystic neoplasms of the pancreas, which are known to have considerable malignant potential, the serous variant is generally thought to be benign. There are, however, several reports of malignancy in serous cystic neoplasms of the pancreas. AIMS: To assess the risk of malignancy of serous cystic tumors of the pancreas and to investigate specific clinical and histological features. METHODS: Clinical and pathological characteristics of benign and malignant serous cystic neoplasms of the pancreas were investigated by a review of the literature and documented by a case of a serous cystadenocarcinoma and immunohistochemical analysis of a series of serous cystadenomas. Reviewing the literature prevalence, age and sex distribution of serous cystic neoplasms were analyzed. RESULTS: The prevalence of cancer among serous cystic neoplasms reported since 1989 was 3%. Serous cystadenoma of the pancreas present at an earlier age (61 years) than serous cystadenocarcinoma (66 years; p = 0.056) and are symptomatic in the majority of patients.Pathological examination of the primary tumor was not able to distinguish cystadenoma from cystadenocarcinoma in 38% of cases. In 25% the diagnosis of cancer was established only after growth of metachronous metastases. In the present case, nuclear atypia, papillary structures, proliferation marker Ki-67 and p53 protein were increased in the primary tumor and/or metachronous metastasis. CONCLUSION: Serous cystic neoplasms of the pancreas do have malignant potential with a risk of malignancy of 3% and should be surgically treated if the operative risk is acceptable. Routine analysis of genetic and proliferation markers may improve diagnosis of malignancy in these tumors.