Effect of Transfection with p53 Gene on Malignancy of Human Hepotacellular Carcinoma Cell Lines

Mutations in p53 gene occur in more than 50% of human tumor cells. Introduction of exogenous wild type p53 gene into tumor cells in vitro often leads to the reduction of the latter‘s malignancy and tumor formation ability in nude mice. QGY-7703 and SMMC-7721 are two human hepatoceUular carcinoma cell lines established in China. Researchers in our laboratory had investigated their p53 backgrounds in the earlier works.     

Point mutation of 5＇ noncoding region of BCL-6 gene in primary gastric lymphomas

AIM: To investigate the mutations of the 5' noncoding region of BCL-6 gene in Chinese patients with primary gastric lymphomas. METHODS: PCR and direct DNA sequencing were used to identify BCL-6 gene mutations in the 5' noncoding region in 29 cases of gastric diffuse large B-cell lymphoma (DLBCL) and 18 cases of gastric mucosa-associated lymphoid tissue (MALT) lymphoma as well as 10 cases of reactive hyperplasia of lymph node (LRH). RESULTS: Six of 29 gastric DLBCLs (20.7%), 4 of 18 gastric MALT lymphomas (22.2%) and 1 of 10 LRHs(10%) were found to have mutations. All mutations were single-base substitutions and the frequency of single-base changes was 0.20×1O~(-2)-1.02×1O~(-2)per bp. CONCLUSION: Point mutations in the 5' noncoding region of BCL-6 gene are found in Chinese patients with primary gastric DLBCLs and MALT lymphomas, suggesting that they may, in some extent, participate in the pathogenesis of primary gastric DLBCLs and MALT lymphomas.     

Association of the Platelet Glycoprotein Ia C807T Gene Polymorphism With Risk of Myocardial Infarction in Chinese

Objectives To investigate the relationship of the GPIa C807T dimorphism to the risk of myocardial infarction （MI） in Chinese. Methods We did a case-control study including 100 patients and 110 controls with same race. An allele-specific polymerase chain reaction （PCR） was used for genotyping of C807T polymorphism. Results An apparent association was found between the T807 allele and MI among individuals younger than the mean age of 60 years （odds ratio, 2. 49 ; 95 % confidence interval, 1.08 - 6.22 ）. The T807 allele remained an independent risk factor for MI when age, sex, smoking, hypertension, diabetes, bodymass index, LDL-cholesterol and HDL-cholesterol were adjusted by logistic regression. Conclusions GPIa T807 appears to be an independent risk factor for MI.     

Transfection of IL-2 and／or IL-12 genes into spleen in treatment of rat liver cancer

METHODS: A retroviral vector GCIL12EIL2PN encoding human IL-2 (hIL-2) and mouse IL-12 (raiL-12) fused gene and its packaging cell were constructed. The packaging cell lines contained of IL-2 and/or IL-12 genes were injected intrasplenically to transfect splenocyte at different time.The therapeutic effect, immune function and toxic effect were evaluated.RESULTS: The average survival times of the 4 groups using IL genes at days 1, 3, 5 and 7 after tumor implantation were 53.3±3.7, 49.3±4.2, 31.0±2.1 and 24.3±1.4 d respectively in IL-2/IL-12 fused gene group, 25.0±2.5, 23.5±2.0,18.3±2.4 and 12.0±1.8 d respectively in IL-2 gene treatment group, and 39.0+4.8, 32.0+3.9, 23.0+2.5 and 19.4+2.1 d respectively in IL-12 gene treatment group (P<0.01, n=-10).In the IL-12/IL-2 fused gene treatment group, 30% of rats treated at days 1 and 3 survived more than 60 d and serum raiL-12 and hIL-2 levels were still high at day 3 after treatment. Compared with IL alone, NK cell activity was strongly stimulated by IL-2/IL-12 gene. Microscopy showed that livers were infiltrated by a number of lymphocytes.CONCLUSION: IL-2 and/or IL-12 genes injected directly into spleen increase serum IL-2 and IL-12 levels and enhance the NK cell activity, which may inhibit the liver tumor growth. The therapy of fused gene IL-2/IL-12 is of low toxicity and relatively high NK cell activity. Our data suggest that IL-2/IL-12 fused gene may be a safe and efficient gene therapy for liver tumor. The gene therapy should be administrated as early as possible.     

Is p53 gene mutation an indicatior of the biological behaviors of recurrence of hepatocellular carcinoma？

AIM: To evaluate mutant p53 gene in primary hepatocellular carcinoma and to investigate the correlation between it and the recurrence of hepatocellular carcinoma. METHODS: Mutations of p53 gene were examined using anti-human p53 monoclonal antibody and immunohistochemical staining in 79 resected hepatocellular carcinomas. The correlations among variables of p53 positivity and invasiveness, disease free interval and survival were studied. In addition, in those who developed recurrence, the correlation among p53 positivity, clinical features and post-recurrence survival were also studied. RESULTS: Of these 79 cases, 64 (81 %) had p53 mutation. Those patients with mutant p53 positivity had significantly more tumor recurrence (76.6 % vs 40.0 %, P=0.0107). However, the COX proportional hazards model showed that p53 overexpression had only weak correlations with recurrence free interval and survival time (P=0.088 and 0.081), which was probably related to the short duration of follow-up. The invasiveness variables may be predictors of HCC recurrence. On univariate analysis, more patients with mutant p53 positivity had vascular permeation (78.1 vs 40.0 %, P=0.0088, O.R. (odds ratio) =5.3), grade II-IV differentiation (98.4 vs 80.0 %, P=0.0203, O.R. =15.7), no complete capsule (82.8 vs 53.3 %, P=0.0346, O.R. =4.2) and daughter nodules (60.9 vs. 33.3 %, P=0.0527, O.R. =3.1) than patients with negative p53 staining. On multivariate analysis, only vascular permeation and grade of differentiation remained significant (P=0.042 and 0.012). There was no statistically significant correlation between the status of p53 in the primary lesion and the clinical features of recurrent hepatocellular carcinomas examined, including extrahepatic metastasis (P=0.1103) and the number of recurrent tumors (P=1.000) except for disease over more than one segment in the extent of recurrent tumors (P=0.0043). The post-recurrence median survival was lower in patients in whom p53 mutation had been detected in the primary lesion with a weak significance (3.42 months vs 11.0 months, P=0.051). CONCLUSION: Our findings suggest that p53 mutation correlates significantly with invasiveness including vascular permeation, grade of cellular differentiation, incomplete capsule and multinodular lesions. Hepatocellular carcinomas with p53 mutations had more tumor recurrence and p53 mutation may also influence disease recurrence interval and survival time. Hepatocellular carcinomas with p53 mutations recur more extensively with a shorter survival. Therefore, p53 mutation in the primary lesion is useful as an indicator of the biological behavior of recurrent hepatocellular carcinomas.     

Phase Ⅰ／Ⅱ enzyme gene polymorphisms and esophageal cancer risk： A meta-analysis of the literature

AIM: Phase I/II enzymes metabolize environmental carcinogens and several functional polymorphisms have been reported in their encoding genes. Although their significance with regard to esophageal carcinogenicity has been examined epidemiologically, it remains controversial. The present systematic review of the literature was performed to clarify associations. METHODS: Eligible studies were case-control or cohort studies published until September 2004 that were written in any language. From PubMed and a manual review of reference lists in relevant review articles, we obtained 16 studies related to the CYP1A1 Ile-Val substitution in exon 7, CYP1A1 MspI polymorphisms, CYP2E1 Rsal polymorphisms, GSTM1 null type, GSTT1 null type and GSTP1 Ilel04Val. All were of case-control design. Summary statistics were odds ratios (ORs) comparing heterozygous-, homozygous-non-wild type or these two in combination with the homozygous wild type, or the null type with the non-null type for GSTM1 and GSTT1, A random effect model was used to estimate the summary ORs. A meta-regression analysis was applied to explore sources of heterogeneity. RESULTS: Individuals with the Ile-Val substitution in CYP1A1 exon 7 had increased esophageal cancer risk, with ORs (95%CI) compared with lie/lie of 1.37 (1.09-1.71), 2.52 (1.62-3.91) and 1.44 (1.17-1.78) for Ile-Val, Val/Val genotype and the combined group. No significant association was found between esophageal cancer risk and the other genetic parameters. CONCLUSION: A significant association exists between the CYP1A1 Ile-Val polymorphism and risk of esophageal cancer. Polymorphisms that increase the internal exposure to activated carcinogens may increase the risk of esophageal cancer.     

Detection of aberrant methylation of RARβ2, GSTP1 and DAPK gene in prostate cancer and its clinical significance

Objective To explore hypermethylation of RARβ2, GSTP1 and DAPK gene in prostate cancer tissues, and to explore its correlation with clinicopathological features of prostate cancer and its diagnostic value. Methods Hypermethylation of RARe2, GSTP1 and DAPK gene was detected by nested methylation-specific PCR (NMSP) in 57 prostate cancer (PCa) tissues and 35 benign prostate hyperplasia (BPH) tissues. The correlation between hypermethylation and clinicopathological features of prostate cancer and its diagnostic value were analyzed. Results The hypermethylation frequencies of RARβ2, GSTP1 and DAPK gene in PCa were significantly higher than those in BPH (RARβ2: 52.6% vs. 0% GSTP1: 61.4% vs. 2.9%;DAPK: 43.9% vs. 8.6%;all P<0.01). The methylation rate of RARβ2 gene was directly correlated with distinct Gleason scores and clinical stage (4～7 score vs. 8～10 score: 34.8% vs. 64.7%;stage B, C vs. stage D: 37.0% vs. 66.7%;x2=4.927 and 5.004, P=0.026 and 0.025). The methylation rate of GSTP1 gene was significantly different in patients with different Gleason scores (4～7 score vs. 8～10 score: 43.5% vs. 73.5%;x2 =11.530, P=0.001), but had no difference in patients with distinct clinical stage (stage B, C vs. stage D: 51.9% vs. 70.0%;x2=1.975, P=0.16) . There was no difference in DAPK gene methylation rate among patients with different Gleason scores and distinct clinical stage (4 ～7 score vs. 8～10 score: 39.1% vs. 50.0%;stage B, C vs. stage D: 33.3% vs. 53.3%;x2= 1.290 and 2.309, both P～0.05). GSTP1 gene showed the highest sensitivity of 61.4% (35/57)with specificity of 97.1%(34/35), while RARβ2 gene had the highest specificity of 100% (35/35) with the sensitivity of 52.6% (30/57). The sensitivity and specificity of DAPK gene were 43.9% and 91.4% (25/57 and 32/35), respeetively. When the hypermethylation of RARβ2, GSTP1 and DAPK gene were detected together, the diagnostic sensitivity was increased, but the specificity was decreased. Conclusions The aberrant methylation of RARβ2, GSTP1 and DAPK gene is correlated with tumorigenesis and progression of prostate cancer, which may be used as an effective diagnostic marker for prostate cancer.     

Clinical Survey of Matrine in Treating Serum HBeAg Positive Patients and the Rate of Negative conversion

There is growing evidence that abnormal methylation of CpG island in the promoters of tumor suppressor genes can contribute to cancer formation and progression by providing an alternative means to mutational inaction. Our previous studies have shown that the CpG island methylator phenotype (CIMP) may be responsible for most aberrant tumor suppressor genes methylation in colorectal cancer,     

Clinical usefulness of K-ras gene mutation detection and cytology in pancreatic juice in the diagnosis and screening of pancreatic cancer.

BACKGROUND: The significance of K-ras codon 12 mutation in pancreatic juice is still unclear. Although considerable controversy surrounds this question, the diagnostic utility of K-ras in patients with clinical suspicion of pancreatic cancer (PC) and in PC-risk patients remains unknown. OBJECTIVE: To study prospectively the utility of the K-ras gene mutation and cytology in the diagnosis and screening of PC, and to assess its contribution to clinical decision making. METHODS: Pancreatic juice samples obtained from 90 patients were evaluated prospectively. Group I (n = 40) comprised patients with clinical suspicion of PC; group II (n = 50) comprised 49 patients with chronic pancreatitis and one patient proceeding from a PC family screening. The K-ras mutation was detected by means of artificial restriction fragment length polymorphisms (RFLP) in DNA after polymerase chain reaction (PCR) amplification. RESULTS: In group I, of those patients with a definitive diagnosis of PC, malignant cells were found in 27% and K-ras mutation in 44%. In five cases, molecular analysis contributed to diagnosis (4/11 with negative cytology and 1/2 with insufficient cytological material). K-ras mutation revealed an early tumour in one patient, and was the only sample available for diagnosis in another. In group II, the K-ras gene mutation was detected in 8/49 patients (16%) with chronic pancreatitis, one of whom developed PC (2%). CONCLUSIONS: K-ras mutation analysis of pancreatic juice may complement cytological evaluation in the diagnosis of PC, in spite of its limited contribution to clinical decision making. The presence of K-ras mutation in chronic pancreatitis classifies a subgroup of PC-risk patients who should be evaluated carefully by long-term follow-up.     

Early detection of pancreatic cancer in patients with chronic pancreatitis: diagnostic utility of a K-ras point mutation in the pancreatic juice

OBJECTIVE: Point mutations of the K-ras oncogene at codon 12 have been described several months before the onset of pancreatic cancer in isolated cases of chronic pancreatitis (CP). The aim of this study was to evaluate the interest of a prospective follow-up of patients with CP and K-ras mutations at codon 12 in the detection of early pancreatic cancer. METHODS: From February 1996 to March 1998, 36 patients (mean age 52.6 yr, 31 men, five women) with CP (alcoholic: 61.1%, pancreas divisum: 5.6%, autoimmune: 5.6%, unknown origin: 27.7%) were included and then prospectively monitored (median duration of 22 months) for detection of pancreatic carcinoma. K-ras point mutations were examined by two-step polymerase chain reaction combined with restriction enzyme digestion in pancreatic juice collected during endoscopic retrograde pancreatography. RESULTS: Ten patients (27.8%) were positive for K-ras mutation. Patients with and without the mutation were not different with respect to age and sex ratio. K-ras mutations were homogeneously distributed according to the etiology (alcoholic vs nonalcoholic) and morphological characteristics (ductal stricture or mass vs none) of CP. A pancreatic carcinoma was discovered at an invasive stage in two patients, respectively at 7 and 17 months after disclosure of a K-ras mutation, versus none in patients without the mutation (p < 0.02). CONCLUSIONS: Presence of a K-ras gene mutation is not rare in patients with CP and represents an increased risk of developing pancreatic cancer. However, its utility for the detection of early pancreatic cancer remains doubtful in clinical practice.     

Does detection of K-ras mutations in pancreatic juice influence clinical decision making?

The majority of patients with pancreatic cancer harbour mutations in the K-ras gene. This oncogene may be detected in material obtained at endoscopic retrograde cholangiopancreatography (ERCP), such as bile and pancreatic juice. Since a formal tissue diagnosis may be difficult to establish in pancreatic cancer, detection of K-ras in these materials is an attractive approach to diagnosis. A variety of molecular techniques has been used to detect K-ras, and frequency of the mutation may vary between different populations. In this issue of the European Journal of Gastroenterology and Hepatology, Boadas et al. collected pancreatic juice following secretin stimulation at the time of ERCP, and detected K-ras in 44% of patients with pancreatic cancer. They found the mutation in 16% of patients with chronic pancreatitis. Presence of the mutation, therefore, is not specific enough to recommend its use in the clinical diagnosis of pancreatic cancer. Chronic pancreatitis patients with the mutation may be at higher risk of developing pancreatic cancer than those patients without the mutation, but there is no clear consensus on management and follow-up of these patients.     

PCR—MASA检测胰腺癌外周血K—ras基因点突变的研究

目的 了解胰腺癌外周血中K—ras基因点突变检测的临床价值。方法 采用PCR—MASA法检测胰腺癌患外周血中K—ras基因点突变。结果胰腺癌外周血标本中K—ras基因点突变率为38．1％(8／21)，而所有被检测的急、慢性胰腺炎、胰岛素瘤、壶腹癌、十二指肠乳头癌、胆管癌及胆石症患外周血标本均无K—ras基因突变。结论 (1)PCR—MASA方法简捷、特异、敏感，扩增产物只需常规电泳、染色即可观察结果，无需酶切、杂交、放射性和非放射性显影；(2)对外周血标本检测K—ras基因第12位密码子有无突变，具有临床实用性，有助于判断胰腺病变良恶性及胰腺癌的早期诊断。     

Detection of K-ras point mutation and telomerase activity during endoscopic retrograde cholangiopancreatography in diagnosis of pancreatic cancer

AIM: To study the value of monitoring K-ras point mutation at codon 12 and telomerase activity in exfoliated cells obtained from pancreatic duct brushings during endoscopic retrograde cholangiopancreatography (ERCP) in the diagnosis of pancreatic cancer. METHODS: Exfoliated cells obtained from pancreatic duct brushings during ERCP were examined in 27 patients: 23 with pancreatic cancers, 4 with chronic pancreatitis. K-ras point mutation was detected with the polymerase chain reaction and restriction fragment-length polymorphism (PCR-RFLP). Telomerase activity was detected by PCR and telomeric repeat amplification protocol assay (PCR-TRAP-ELISA). RESULTS: The telomerase activities in 27 patients were measured in 21 exfoliated cell samples obtained from pancreatic duct brushings. D450 value of telomerase activities in pancreatic cancer and chronic pancreatitis were 0.446+/-0.27 and 0.041+/-0.0111, respectively. Seventy-seven point eight percent (14/18) of patients with pancreatic cancer and none of the patients with chronic pancreatitis showed telomerase activity in cells collected from pancreatic duct brushings when cutoff value of telomerase activity was set at 2.0. The K-ras gene mutation rate (72.2%) in pancreatic cancer was higher than that in chronic pancreatitis (33.3%) (P<0.05). In considering of both telomerase activities and K-ras point mutation, the total positive rate was 83.3%(15/18), and the specificity was 100%. CONCLUSION: Changes of telomerase activities and K-ras point mutation at codon 12 may be an early event of malignant progression in pancreatic cancer. Detection of telomerase activity and K-ras point mutation at codon 12 may be complementary to each other, and is useful in diagnosis of pancreatic cancer.     

Diagnosis of pancreatic cancer by cytology and measurement of oncogene and tumor markers in pure pancreatic juice aspirated by endoscopy

BACKGROUND/AIMS: Cytological examination of pancreatic juice is useful in the diagnosis of an occult cancer of the pancreas. The early diagnosis of pancreatic carcinoma using traditional radiographic or ultrasonographic methods is extremely difficult. METHODOLOGY: In order to detect an early pancreatic cancer, cytological examination, measurement of tumor marker, and detection of K-ras point mutation were performed using the samples of pure pancreatic juice aspirated endoscopically in patients who had symptoms or findings that suggested pancreatic disease. RESULTS: By routine ERP-cytology, positive cytologic results were obtained in 15 (4%) out of 359 patients without a mass. With the aid of intra-operative cytodiagnosis, all 15 occult neoplasms of the pancreas were successfully resected. One patient died from another disease without evidence of recurrence. However, the other patients were alive with no evidence of recurrence for an average of 5.5 years following surgery. The patients who had negative ERP-cytology results were observed, but no further cases of pancreatic cancer were found. The CEA levels in the pure pancreatic juice were significantly higher in patients with pancreatic cancer than in those with pancreatitis. K-ras point mutation at codon 12 was detected not only in cases of pancreatic cancer, but also in cases of chronic pancreatitis as well as control subjects. CONCLUSIONS: Cytological examination of pancreatic juice is useful in the diagnosis of an early and potentially curable in situ cancer of the pancreas. The CEA levels in the pure pancreatic juice provided useful information for differentiating the pancreatic cancer from chronic pancreatitis. K-ras point mutation at codon 12 in pancreatic juice was considered to be useful in identifying patients at high risk for the development of pancreatic cancer.     

Differential diagnosis of pancreatic cancer and focal pancreatitis by using EUS-guided FNA

BACKGROUND: Despite advances in diagnostic imaging techniques, the differentiation between pancreatic cancer and focal pancreatitis remains difficult. This study evaluated the effectiveness of EUS-guided FNA in the differential diagnosis between pancreatic cancer and focal pancreatitis, with particular reference to detection of the K-ras point mutation. METHODS: The study included 62 consecutive patients with pancreatic ductal cancer and 15 patients with focal pancreatitis demonstrated as a pancreatic mass lesion by EUS. RESULTS: Sensitivity, specificity, overall accuracy, positive predictive value, and negative predictive value of cytopathologic diagnosis were 82%, 100%, 86%, 100%, and 58%, respectively. Sensitivity, specificity, overall accuracy, positive predictive value, and negative predictive value of histopathologic diagnosis were 44%, 100%, 55%, 100%, and 32%, respectively. The K-ras point mutation was found in 74% of pancreatic cancers and 0% of focal pancreatitis lesions. No complication of EUS-guided FNA was observed. CONCLUSIONS: EUS-guided FNA is useful for the differential diagnosis of pancreatic mass lesions caused by pancreatic cancer and focal pancreatitis. Analysis for the K-ras point mutation in specimens obtained by EUS-guided FNA may enhance diagnostic accuracy in indeterminate cases.     

Telomerase activity in pure pancreatic juice for the diagnosis of pancreatic cancer may be complementary to K-ras mutation

BACKGROUND: The usefulness of K-ras mutation in pancreatic juice for the diagnosis of pancreatic cancer is questionable. Telomerase is positive in pancreatic cancer but rarely in benign pancreatic diseases. We conducted this study to determine the usefulness of K-ras mutation and telomerase activity in pancreatic juice for the diagnosis of pancreatic cancer. METHODS: Pancreatic juice collected during endoscopic retrograde cholangiopancreatography was examined in 31 patients: 12 with pancreatic cancer, 11 with chronic pancreatitis, and 8 control patients. The K-ras gene was detected by using the restriction fragment length polymorphism method. Telomerase activity was detected by using the telomeric repeat amplification protocol. RESULTS: K-ras mutation was positive in 75% (9 of 12) of pancreatic cancers and in 27% (3 of 11) of cases of chronic pancreatitis but in none of the control patients. Telomerase activity was detected in 92% (11 of 12) of pancreatic cancers and in 18% (2 of 11) of cases of chronic pancreatitis. The diagnostic value in pancreatic cancer was comparable between K-ras mutation and telomerase when evaluated separately. However, by combining these 2 methods, the specificity rose to 100%. CONCLUSIONS: For the diagnosis of pancreatic cancer, telomerase activity in pancreatic juice may possibly be complementary to K-ras mutation because it may decrease the rate of false-positive diagnosis.     

Telomerase activity in pure pancreatic juice for the diagnosis of pancreatic cancer may be complementary to K-ras mutation

Background: The usefulness of K-ras mutation in pancreatic juice for the diagnosis of pancreatic cancer is questionable. Telomerase is positive in pancreatic cancer but rarely in benign pancreatic diseases. We conducted this study to determine the usefulness of K-ras mutation and telomerase activity in pancreatic juice for the diagnosis of pancreatic cancer. Methods: Pancreatic juice collected during endoscopic retrograde cholangiopancreatography was examined in 31 patients: 12 with pancreatic cancer, 11 with chronic pancreatitis, and 8 control patients. The K-ras gene was detected by using the restriction fragment length polymorphism method. Telomerase activity was detected by using the telomeric repeat amplification protocol. Results: K-ras mutation was positive in 75% (9 of 12) of pancreatic cancers and in 27% (3 of 11) of cases of chronic pancreatitis but in none of the control patients. Telomerase activity was detected in 92% (11 of 12) of pancreatic cancers and in 18% (2 of 11) of cases of chronic pancreatitis. The diagnostic value in pancreatic cancer was comparable between K-ras mutation and telomerase when evaluated separately. However, by combining these 2 methods, the specificity rose to 100%. Conclusions: For the diagnosis of pancreatic cancer, telomerase activity in pancreatic juice may possibly be complementary to K-ras mutation because it may decrease the rate of false-positive diagnosis. (Gastrointest Endosc 2000;51:708-13.)     

Pancreatic intraductal sampling during ERCP in patients with chronic pancreatitis and pancreatic cancer: cytologic studies and k-ras-2 codon 12 molecular analysis in 47 cases.

BACKGROUND: A preoperative tissue diagnosis of pancreatic cancer is desirable but difficult to obtain. METHODS: Pancreatic brush cytology, salvage cytology, and collection of pancreatic juice were attempted prospectively during ERCP in 34 patients with pancreatic cancer and 11 with chronic pancreatitis. K-ras-2 codon 12 was analyzed for presence and type of point mutations. RESULTS: Brush cytology coupled with salvage cytology had a sensitivity of 74%. The addition of cytologic analysis of pancreatic juice did not substantially improve sensitivity (76%). K-ras-2 was mutated in both cancer (87%) and pancreatitis (40%). The specificity for cytology was 100% and for K-ras-2 mutations 60%. Combining cytology with mutation analysis increased sensitivity to 93% but reduced the positive predictive value. The negative predictive value never exceeded 75%. None of the patients with chronic pancreatitis had cancer develop (median follow-up 60 months). CONCLUSIONS: Pancreatic ductal brushing with salvage cytology is useful in the diagnosis of cancer, whereas cytologic analysis of pancreatic juice can be abandoned. At present, K-ras-2 mutation is not useful for differentiating pancreatic cancer from chronic pancreatitis or the identification of patients with chronic pancreatitis at risk for malignant transformation.