Clinical validity of detecting K-ras mutations for the diagnosis of exocrine pancreatic cancer: a prospective study in a clinically-relevant spectrum of patients.

The diagnostic utility of detecting K-ras mutations for the diagnosis of exocrine pancreatic cancer (EPC) has not been properly studied, and few reports have analysed a clinically relevant spectrum of patients. The objective was to evaluate the clinical validity of detecting K-ras mutations in the diagnosis of EPC in a large sample of clinically relevant patients. We prospectively identified 374 patients in whom one of the following diagnoses was suspected at hospital admission: EPC, chronic pancreatitis, pancreatic cysts, and cancer of the extrahepatic biliary system. Mutations in the K-ras oncogene were analysed by PCR and artificial RFLP in 212 patients. The sensitivity and specificity of the K-ras mutational status for the diagnosis of EPC were 77.7% (95% CI: 69.2-84.8) and 78.0% (68.1-86.0), respectively. The diagnostic accuracy was hardly modified by sex and age. In patients with either mutated K-ras or CEA > 5 ng/ml, the sensitivity and specificity were 81.0% (72.9-87.6) and 62.6% (72.9-87.6), respectively. In patients with mutated K-ras and CEA > 5 ng/ml the sensitivity was markedly reduced. In comparisons with a variety of non-EPC patient groups sensitivity and specificity were both always greater than 75%. In this clinically relevant sample of patients the sensitivity and specificity of K-ras mutations were not sufficiently high for independent diagnostic use. However, it seems premature to rule out the utility of K-ras analysis in conjunction with other genetic and 'omics' technologies.

In pancreatic ductal adenocarcinoma blood concentrations of some organochlorine compounds and coffee intake are independently associated with KRAS mutations.

While KRAS activation is a fundamental initiating event in the aetiopathogenesis of pancreatic ductal adenocarcinoma (PDA), environmental factors influencing the occurrence and persistence of KRAS mutations remain largely unknown. The objective was to test the hypothesis that in PDA there are aetiopathogenic relationships among concentrations of some organochlorine compounds (OCs) and the mutational status of the KRAS oncogene, as well as among the latter and coffee intake. Incident cases of PDA were interviewed and had blood drawn at hospital admission (N = 103). OCs were measured by high-resolution gas chromatography with electron capture detection. Cases whose tumours harboured a KRAS mutation had higher concentrations of p,p'-dichlorodiphenyltrichloroethane (DDT), p,p'-dichlorodiphenyldichloroethene (DDE) and polychlorinated biphenyls (PCBs) 138, 153 and 180 than cases with wild-type KRAS, but differences were statistically significant only for p,p'-DDT and PCBs 138 and 153. The association between coffee intake and KRAS mutations remained significant (P-trend < 0.015) when most OCs where accounted for. When p,p'-DDT, PCB 153, coffee and alcohol intake were included in the same model, all were associated with KRAS (P = 0.042, 0.007, 0.016 and 0.025, respectively). p,p'-DDT, p,p'-DDE and PCB 138 were significantly associated with the two most prevalent KRAS mutations (Val and Asp). OCs and coffee may have independent roles in the aetiopathogenesis of PDA through modulation of KRAS activation, acquisition or persistence, plausibly through non-genotoxic or epigenetic mechanisms. Given that KRAS mutations are the most frequent abnormality of oncogenes in human cancers, and the lifelong accumulation of OCs in humans, refutation or replication of the findings is required before any implications are assessed.

Lifetime history of alcohol consumption and K-ras mutations in pancreatic ductal adenocarcinoma.

BACKGROUND: In pancreatic ductal adenocarcinoma (PDA), evidence on the etiopathogenic role of alcohol consumption in the occurrence of K-ras mutations is scant, and the role of alcohol in pancreatic carcinogenesis is not well established. We analyzed the relation between lifetime consumption of alcohol and mutations in codon 12 of the K-ras oncogene in patients with PDA. METHODS: Incident cases of PDA were prospectively identified and interviewed face-to-face during hospital admission about lifetime alcohol consumption and other lifestyle factors. Logistic regression was used to compare PDA cases (N = 107) with mutated and wild-type K-ras tumors (case-case study). RESULTS: Mutated cases were moderate or heavy drinkers more frequently than wild-type cases: the odds ratio adjusted by age, sex, smoking, and history of pancreatitis (ORa) was 3.18 (95% confidence interval: 1.02-9.93; P = 0.046). Total grams of alcohol and years of consumption were higher in mutated than in wild-type cases: the ORa for lifetime alcohol consumption over 507,499 g was 3.35 (95% CI: 0.81-13.88); and for more than 40 years of alcohol consumption it was 4.47 (95% CI: 1.05-19.02). Age at onset of alcohol consumption and years of abstinence were also associated with the presence of K-ras mutations. There were no significant differences in alcohol dependency. CONCLUSIONS: Alcohol consumption is weakly associated with an increased risk of having a K-ras mutated PDA. To confirm or to refute the hypothesis that ethanol, acetaldehyde or other alcohol-related substances might influence the acquisition or persistence of K-ras mutations in the pancreatic epithelium, large and unselected studies are warranted.

CYP1B1 polymorphisms and k-ras mutations in patients with pancreatic ductal adenocarcinoma.

The frequency of CYP1B1 polymorphisms in pancreatic cancer has never been reported. There is also no evidence on the relationship between CYP1B1 variants and mutations in ras genes (K-, H- or N-ras) in any human neoplasm. We analyzed the following CYP1B1 polymorphisms in 129 incident cases of pancreatic ductal adenocarcinoma (PDA): the m1 allele (Val to Leu at codon 432) and the m2 allele (Asn to Ser at codon 453). The calculated frequencies for the m1 Val and m2 Asn alleles were 0.45 and 0.68, respectively. CYP1B1 genotypes were out of Hardy-Weinberg equilibrium; this was largely due to K-ras mutated PDA cases. The Val/Val genotype was over five times more frequent in PDA cases with a K-ras mutation than in wild-type cases (OR = 5.25; P = 0.121). In PDA, polymorphisms in CYP1B1 might be related with K-ras activation pathways.

A single-nucleotide polymorphism in the aromatase gene is associated with the efficacy of the aromatase inhibitor letrozole in advanced breast carcinoma.

PURPOSE: To evaluate the efficacy of treatment with the aromatase inhibitor letrozole in breast cancer patients segregated with respect to DNA polymorphisms of the aromatase gene CYP19. PATIENTS AND METHODS: Postmenopausal patients (n = 67) with hormone receptor-positive metastatic breast cancer were treated with the aromatase inhibitor letrozole. PCR allelic discrimination was used to examine three single-nucleotide polymorphisms (SNP) in DNA obtained from breast carcinoma tissue. Two SNPs analyzed (rs10046 and rs4646) were located in the 3' untranslated region and one (rs727479) was in the intron of the aromatase CYP19 gene. The primary end point of treatment efficacy was time to progression (TTP). RESULTS: Median age was 62 years and median number of metastatic sites was 2. Observed allelic SNP frequencies were rs10046, 71%; rs4646, 46%; and rs727479, 63%. Of the 67 patients, 65 were evaluable for efficacy. Median TTP was 12.1 months. We observed no relationship between TTP and the rs10046 or rs727479 variants. In contrast, we found that TTP was significantly improved in patients with the rs4646 variant, compared with the wild-type gene (17.2 versus 6.4 months; P = 0.02). CONCLUSION: In patients with hormone receptor-positive metastatic breast cancer treated with the aromatase inhibitor letrozole, the presence of a SNP in the 3' untranslated region of the CYP19 aromatase gene is associated with improved treatment efficacy. Testing for the CYP19 rs4646 SNP as a predictive tool for breast cancer patients on antiaromatase therapy deserves prospective evaluation.

R-CHOP-14 in patients with diffuse large B-cell lymphoma younger than 70 years: a multicentre, prospective study.

Several studies have shown that adding rituximab to CHOP (cyclophosphamide, doxorubicin, vincristine, prednisolone) or reducing the interval between chemotherapy cycles from 3 weeks to 2 weeks improves survival in patients with diffuse large B-cell lymphoma (DLBCL). These studies prompted our group (GOTEL) to evaluate prospectively in a pilot study the feasibility and efficacy of R-CHOP-14 in patients with DLBCL. Patients (<70 years) with stage II bulky or stage III or IV DLBCL and no significant comorbidities were included in the study. Rituximab was administered on day 1 before chemotherapy. R-CHOP was given every 14 days. All patients received filgrastim (5 microg/kg) from days 4 to 10. From May 2002 to August 2004, 80 patients were recruited. Median age was 53 years and 58 patients were <60 years. According to the age-adjusted international prognostic index (aaIPI), 13 patients (16%) had low-risk disease, 31 (39%) low-to-intermediate risk, 27 (34%) high-to-intermediate risk and 9 (11%) high-risk disease. Grade 3-4 neutropenia was observed in 15 patients (17.5%) and grade 3-4 infections in 13 patients (16%). After therapy, 58 patients (73%) achieved CR-CRu (95% CI: 55-90%). With a median follow-up of 26 months, progression-free survival (PFS) and overall survival (OS) at 30 months were 72% and 86%, respectively. Administration of R-CHOP-14 is feasible and effective in patients <70 years.

Food and nutrient intakes and K-ras mutations in exocrine pancreatic cancer.

BACKGROUND: No studies have investigated the relation between K-ras mutations and dietary factors in exocrine pancreatic cancer (EPC), and fewer than 10 studies have done so in other neoplasms. PATIENTS AND METHODS: Incident cases of EPC were prospectively identified, and interviewed face-to-face during hospital admission. Food and nutrient intakes were measured with a food frequency questionnaire. Logistic regression was used to compare EPC cases (n = 107) with and without K-ras mutations (case-case study). RESULTS: K-ras mutations were more common among daily consumers of milk and other dairy products than among non-daily consumers: the odds ratio adjusted by total energy, age, sex, smoking, alcohol and coffee consumption (ORa) was 5.1 (95% CI 1.1 to 24.5, p = 0.040). For all dairy products, including butter, the ORa for the medium and upper tertiles of intake were 5.4 and 11.6, respectively (p for trend = 0.023). The ORa for regular coffee drinkers further adjusted by dairy consumption was 4.7 (95% CI 1.1 to 20.7, p = 0.043). K-ras mutated cases reported a lower intake of vitamin E (ORa = 0.2, p for trend = 0.036), polyunsaturated fats and omega 3 fatty acids (ORa = 0.2; p for trend <0.03). CONCLUSIONS: Results support the hypothesis that in EPC exposure to specific dietary components or contaminants may influence the occurrence or persistence of K-ras mutations.

Quality of life for oncology patients during the terminal period. Validation of the HRCA-QL index.

AIM: The evolution of performance status, disability, and quality of life (QL) according to the Hebrew Rehabilitation Center for Aged QL (HRCA-QL) index for cancer patients through their terminal period is described. The assessment of HRCA-QL validity and reliability is also described. DESIGN: A total of 200 cancer patients were followed up from the onset of their "terminal phase" until they died. Information on symptoms, performance, disability and QL were collected by patient's oncologists in hospital and by their family practitioners and community nurses when the patient was at home. Health measures were: the HRCA-QL index, Karnofsky performance status (KPS) and the Independence in Activities of Daily Living (IADL) index. RESULTS: The three indices were acceptable for a fair number of patients at the start of the terminal phase. Almost two-thirds had a KPS > or =60. With respect to the IADL index, the patients were independent in five of the six functions, with 80% having a HRCA-QL equal to or greater than 4. The median duration of the terminal period was 59 days. All three indices declined progressively, with marked deterioration in the last 2 weeks. The HRCA-QL index was highly correlated with KPS and the IADL index, had good internal consistency and showed an acceptable test-retest and inter-rater reliability. The HRCA-QL index was reactive to clinical changes. CONCLUSIONS: All three scales confirmed that terminal patients experience a progressive loss of performance, increase in dependence and deterioration of QL as they approach the end of life. Based in these results, we consider the HTCA-QL index valid for use in terminal cancer patients.

Generalizing molecular results arising from incomplete biological samples: expected bias and unexpected findings.

PURPOSE: In molecular epidemiology, obtaining biological samples for all subjects targeted for study is frequently hampered by ethical, clinical, and logistic factors. The extent to which the incompleteness of biological samples could cause bias is rarely analyzed in depth. Here we report some expected bias and some unexpected findings during a study on mutations in the K-ras gene in exocrine pancreatic cancer (EPC). METHODS: In this case-case study, all patients registered with EPC between 1980 and 1990 at two general hospitals were retrospectively identified from the hospital tumor registries. Their clinical records were abstracted and paraffin-embedded samples retrieved from pathology records. DNA was amplified, and mutations in codon 12 of the K-ras gene were detected using the artificial RFLP technique. RESULTS: Results on the mutations (RM) were obtained for 51 of the 149 cases of EPC (34.2%). There were no significant differences on the availability of RM by age, gender, and tumor stage at diagnosis, but RM were over five times more likely to be available from one of the hospitals. Subjects with RM were more likely to have received a treatment with curative intent (OR = 11.56, 95% CL: 2.88-46.36). The existence of RM was positively associated with the availability of information on alcohol use and family history of cancer. Subjects with RM tended to belong to higher occupational groups and to smoke less than subjects without RM. Unexpectedly--given that in EPC K-ras mutations have consistently been found unrelated to age, gender, tumor stage, and other clinical factors-, cases with a K-ras mutation were more likely than wild-type cases to have information on tobacco and alcohol use (OR = 3.29, p = .21), medical history (OR = 4.46, p = .41), and family history of cancer (OR = 4.80, p = .01). The relationship between completeness of clinical records and K-ras mutations among cases with RM could not be accounted by age, gender, and occupational group. CONCLUSIONS: Simple tests of age and gender distributions among subjects with and without available clinical information and molecular results may not rule out selection and information bias. Studies using biologic specimens are even more in need than classic studies to explain clearly the process followed to include and exclude subjects. Additional caution is needed when generalizing molecular results arising from incomplete biological specimens.