Assessment of K-ras mutation: a step toward personalized medicine for patients with colorectal cancer

Physical confinement promotes mesenchymal trans-differentiation of invading transformed cells in vivo

Metastasis is tightly linked with poor cancer prognosis, yet it is not clear how transformed cells become invasive carcinomas. We previously discovered that single KRasV12-transformed cells can invade directly from the epithelium by basal cell extrusion. During this process, cells de-differentiate by mechanically pinching off their epithelial determinants, but how they trans-differentiate into a migratory, mesenchymal phenotype is not known. Here, we demonstrate that basally extruded KRasV12-expressing cells become significantly deformed as they invade the zebrafish body. Decreasing the confinement that cells experience after they invade reduces the percentage of KRasV12 cells that trans-differentiate into mesenchymal cell types, while higher confinement increases this percentage. Additionally, increased confinement promotes accumulation of internal masses over time. Altogether, our results suggest that mechanical forces drive not only de-differentiation of KRasV12-transformed epithelial cells as they invade but also their re-differentiation into mesenchymal phenotypes that contribute to distant metastases.

Microbial cancer therapeutics: A promising approach

The success of conventional cancer therapeutics is hindered by associated dreadful side-effects of antibiotic resistance and the dearth of antitumor drugs' selectivity and specificity. Hence, the conceptual evolution of anti-cancerous therapeutic agents that selectively target cancer cells without impacting the healthy cells or tissues, has led to a new wave of scientific interest in microbial-derived bioactive molecules. Such strategic solutions may pave the way to surmount the shortcomings of conventional therapies and raise the potential and hope for the cure of wide range of cancer in a selective manner. This review aims to provide a comprehensive summary of anti-carcinogenic properties and underlying mechanisms of bioactive molecules of microbial origin, and discuss the current challenges and effective therapeutic application of combinatorial strategies to attain minimal systemic side-effects.

Mast Cells, microRNAs and Others: The Role of Translational Research on Colorectal Cancer in the Forthcoming Era of Precision Medicine

Colorectal cancer (CRC) is a heterogeneous disease, molecularly and anatomically, that develops in a multi-step process requiring the accumulation of several genetic or epigenetic mutations that lead to the gradual transformation of normal mucosa into cancer. In fact, tumorigenesis is extremely complex, with many immunologic and non-immunologic factors present in the tumor microenvironment that can influence tumorigenesis. In the last few years, a role for mast cells (MCs), microRNAs (miRNAs), Kirsten rat sarcoma (KRAS) and v-raf murine sarcoma viral oncogene homologue B (BRAF) in cancer development and progression has been suggested, and numerous efforts have been made to thoroughly assess their correlation with CRC to improve patient survival and quality of life. The identification of easily measurable, non-invasive and cost-effective biomarkers, the so-called "ideal biomarkers", for CRC screening and treatment remains a high priority. The aim of this review is to discuss the emerging role of mast cells (MCs), microRNAs (miRNAs), KRAS and BRAF as diagnostic and prognostic biomarkers for CRC, evaluating their influence as potential therapy targets in the forthcoming era of precision medicine.

Probiotic Lactobacillus salivarius Ren prevent dimethylhydrazine-induced colorectal cancer through protein kinase B inhibition

Probiotics are known to be a potential agent for colorectal cancer (CRC) inhibition, but the precise mechanisms by which probiotic exert anti-tumorigenic effects remain to be explored. Lactobacillus salivarius (LS) Ren was isolated from centenarians living in Bama of China, which showed an anticancer potent in animal model of oral cancer. Here, we investigated the effect of LS on colorectal carcinogenesis and its putative mechanism. Oral administration of LS effectively suppressed the formation of dimethylhydrazine (DMH)-induced CRC in both initial and post-initial stages. Significant antiproliferation and proapoptotic effects were observed with inhibition of tumor formation by dietary intake of LS. Besides, LS metabolites inhibited growth, arrested cell cycle, and induced apoptosis of HT-29 cells. Furthermore, upon the treatment of LS, protein kinase B (AKT) phosphorylation and the downstream proteins of cyclinD1 and cyclooxygenase-2 (COX-2) were significantly downregulated in both in vivo and in vitro tests. These results showed that LS inhibited the colorectal carcinogenesis through suppressing AKT signaling pathway, resulting in suppressing cell proliferation and inducing cell apoptosis. Our findings suggest that this probiotic may act as a prophylactic agent for CRC prevention. Key points • LS effectively prevented rat colorectal carcinogenesis induced by DMH. • LS modulated the proliferation and apoptosis in both in vivo and in vitro. • LS inhibited AKT phosphorylation and expressions of downstream cyclinD1 and COX-2.

Apoptosis, necroptosis and autophagy in colorectal cancer: Associations with tumor aggressiveness and p53 status

OBJECTIVE

Cleaved caspase-3 (CC3), phosphorylated-mixed-lineage kinase domain-like protein (p-MLKL), and microtubule-associated protein-1 light chain-3B (LC3B) have pivotal functions in apoptosis, necroptosis, and autophagy, respectively. In vitro studies have shown that interaction of these proteins are complex and their roles in cancer can be influenced by many factors. However, these findings are not adequately assessed in human tissues. Here, we determined CC3, p-MLKL, and LC3B expression in colorectal cancers (CRCs), and assessed their associations with clinicopathological parameters, and with KRAS and p53 status.

METHODS

We immunohistochemically assessed 113 CRC specimens for levels of CC3, p-MLKL, LC3B, and p53. KRAS gene status was analyzed using the Scorpion- amplification refractory mutation system.

RESULTS

High levels of CC3 (CC3^High) and LC3B (LC3B^High) were detected in 38% and 35% of the 113 CRCs, respectively, but no or only a few p-MLKL-positive cells were observed in any of the tumors. CC3^High was significantly associated with high pT status (P = 0.03), vascular invasion (P = 0.03) and high pStage (P = 0.04) and was marginally associated with lymph node (P = 0.06) and distant metastases (P = 0.06). LC3B^High was also significantly associated with high pT status (P = 0.02) and lymphatic invasion (P = 0.002), and was marginally associated with nerve plexus invasion (P = 0.06). In combined analysis, compared with CC3^Low/LC3B^Low tumors, tumors that were either CC3^High, LC3B^High, or both were significantly associated with high pT status (P = 0.0007), lymphatic invasion (P = 0.03), vascular invasion (P = 0.003), distant metastasis (P = 0.04) and high pStage (P = 0.04). LC3B^High was significantly associated with a mutant-type expression pattern of p53 (P = 0.003).

CONCLUSION

To the best of our knowledge, this is the first study to examine the combination of CC3/LC3B and p-MLKL expression in clinical CRC samples and to correlate these expression data with clinicopathological parameters and EGFR and p53 status. Our results suggest that necroptosis is a rare process in CRC, apoptosis and autophagy are upregulated in aggressive CRCs, and p53 mutation may lead to the upregulation of autophagy.

Dipeptidyl peptidase-4 inhibitors: Anti-diabetic drugs with potential effects on cancer

Dipeptidyl peptidase (DPP- 4) inhibitors belong to the oral antidiabetic drugs. They are used for the treatment of Type 2 Diabetes mellitus. DPP-4 is an enzyme which puts down the action of hormone, incretin. Incretins belong to the group of hypoglycaemic gastrointestinal hormones. Some studies show that DPP-4 inhibitors causes cancer and some study show that they have anticancer property. This review sheds light on the role of the different types of DPP-4 inhibitors in cancer therapy.

Zeptomole Biosensing of DNA with Flexible Selectivity Based on Acoustic Levitation of a Single Microsphere Binding Gold Nanoparticles by Hybridization

A novel scheme for DNA sensing at the zeptomole level is presented, based on the levitation of a single microsphere in a combined acoustic-gravitational (CAG) field. The levitation of a microsphere in the field is predominantly determined by its density. Capture and reporter probe DNAs are anchored on poly(methyl methacrylate) microsphere (PMMA) and gold nanoparticles (AuNPs), respectively, and a target DNA induces the binding of AuNPs on PMMA. This interparticle sandwich DNA-hybridization induces density increase in PMMA, which is detected as a shift in the levitation coordinate in the CAG field. The reporter DNAs are designed based on base-pair (bp) number selectivity, which is evaluated using direct interparticle hybridization between DNA-bound PMMA and complementary DNA-anchored AuNPs. Interestingly, the bp-number selectivity can be enlarged by lowering the reactant concentrations. Thus, the threshold bp, at which no density change is detected, can be adjusted by controlling the reactant concentrations. This strategy is extended to the sensing of HIV-2 DNA and single nucleotide polymorphism (SNP) detection of the KRAS gene by sandwich hybridization. In SNP detection, the present method selectively distinguishes wild-type DNA from mutant DNA differing by one nucleotide in the 21-nucleotide sequence by optimizing the lengths of probe DNAs and particle concentrations. This approach allows the detection of 1000 DNA molecules.

Major challenges related to tumor biological characteristics in accurate mutation detection of colorectal cancer by next-generation sequencing

Next-generation sequencing (NGS) has been used in mutation detection of colorectal cancer (CRC). We here interrogated 747 CRC samples to detect mutations in 22 cancer-related genes by using NGS, and to explore some key challenges related to tumor biology. RAS mutations (KRAS or NRAS mutations), RAS/BRAF/PIK3CA mutations (mutations in KRAS, NRAS, BRAF or PIK3CA) and mutation burden (mutations in any of the 22 detected genes) were observed in 53.0% (396/747), 57.1% (431/747) and 84.2% (629/747) of specimens, respectively. Higher mutation frequencies were observed in biopsy specimens with ≥20% tumor cellularity than those with <20% tumor cellularity, but these differences were not observed in resection samples. Intratumor mutational heterogeneity was estimated by mutant allele frequency and tumor cellularity, and more likely to occur in PIK3CA mutant tumors. No significant differences of mutation frequencies were detected between primary and metastatic tumors. Additionally, specimens after chemotherapy showed lower mutation frequencies compared with specimens without chemotherapy. Together, our findings demonstrate that poor tumor cellularity, tumor heterogeneity and adjuvant therapy may confound the molecular diagnosis of CRC, and should be highlighted with prospective quality assessment during tissue process.

Phase II trial of capecitabine plus erlotinib versus capecitabine alone in patients with advanced colorectal cancer

Aim & methods: Capecitabine monotherapy as palliation for advanced colorectal cancer (CRC) is generally well tolerated. Adding erlotinib, an EGFR-tyrosine kinase inhibitor, might improve efficacy versus capecitabine alone. 82 patients received capecitabine alone (Arm 1) or capecitabine with erlotinib (Arm 2). Results: Median time-to-progression (TTP) in Arm 1 was 7.9 months versus 9.2 in Arm 2. In KRAS-wild type (WT) patients TTP was 8.4 and 11.7 months in Arms 1 and 2, respectively. In KRAS-mutated patients TTP was 7.4 and 1.9 months in Arms 1 and 2, respectively (p = 0.023). Arm 2 KRAS-WT patients, left-sided primaries, had an overall survival of 16.0 versus 12.1 months in right-sided primaries. Conclusion: Adding erlotinib to capecitabine increased TTP by 3.2 months in KRAS-WT patients. This study suggests that erlotinib harms patients with KRAS-mutated advanced CRC while it may provide benefit to those with KRAS-WT CRC. Further study of EGFR-tyrosine kinase inhibitors in patients with left-sided KRAS-WT CRC is warranted.

Targeted therapies for colorectal cancer: Current status and future perspectives

Colorectal cancer (CRC) is a common malignant tumor of the digestive system. At present, traditional chemotherapy is often combined with targeted drugs to treat patients with metastatic colon cancer, in order to increase the response rate, prolong the progression free survival and overall survival, and improve the quality of life of patients. In this paper, we describe the molecular targets for targeted therapy of CRC and their distribution in CRC, which include vascular endothelial growth factor, epidermal growth factor receptor, cyclooxygenase-2, matrix metalloproteinase, receptor tyrosine kinase, PD-1/PD-L1, RAS, BRAF and so on. In addition, we review current targeted therapies for CRC, including antibody drugs, small molecule targeted drugs, fusion proteins, immune therapy and so on. This paper will provide a reference for individualized treatment of CRC.

Polyp Genetics

The genetic events involved in the transformation of normal colonic epithelium to neoplastic polyps to invasive carcinoma, as initially proposed by Fearon and Vogelstein, form the foundation of our understanding of colorectal cancer. The identification of the polyp as the precursor lesion to colorectal cancer is the basis of many of our current practices for screening, surveillance, and prevention. The last three decades have seen a veritable explosion in our understanding of the molecular events involved in the pathogenesis of colorectal cancer. It is now clear that there are multiple genetic pathways in the polyp to carcinoma sequence. Some polyps previously thought to be nonneoplastic have now been shown to have malignant potential. Finally, increased understanding of the sequence of genetic events has led to the development of targeted therapeutics. The clinical translation of these scientific advances has made a significant impact on the management of patients with colorectal cancer. Accordingly, it is imperative that all clinicians caring for these patients have an understanding of the genetics of colorectal polyps and cancer. In this article, we review the etiology and genetic pathways to carcinoma associated with a range of polyps of the colon and rectum.

Early onset of colorectal cancer in a 13-year-old girl with Lynch syndrome

Lynch syndrome is the most common inherited colon cancer syndrome. Patients with Lynch syndrome develop a range of cancers including colorectal cancer (CRC) and carry a mutation on one of the mismatched repair (MMR) genes. Although CRC usually occurs after the fourth decade in patients with Lynch syndrome harboring a heterozygous MMR gene mutation, it can occur in children with Lynch syndrome who have a compound heterozygous or homozygous MMR gene mutation. We report a case of CRC in a 13-year-old patient with Lynch syndrome and congenital heart disease. This patient had a heterozygous mutation in MLH1 (an MMR gene), but no compound MMR gene defects, and a K-RAS somatic mutation in the cancer cells.

K-ras Mutation in Colorectal Cancer, A Report from Southern Iran

There are very few studies about K-ras mutations in colorectal cancer (CRC) from developing countries such as Iran. It is therefore essential to conduct studies to learn about the molecular signature of such tumors, allowing the determination of an appropriate management plan. In the present study, we aimed to determine the frequency and types of K-ras mutations among patients with CRC in Iran. Formalin-fixed paraffin-embedded specimens of 100 cases of CRC were collected from hospitals affiliated with Shiraz University of Medical Sciences (June 2011 to June 2013). All of the H&E slides were examined and proper slide with a minimum of necrosis and maximum of well-preserved tumor cells (at least 70% tumor in each slide) were selected. Recurrent, metastatic, and post chemotherapy cases were excluded from the study. Mutation of codons 12 and 13 of K-ras gene by PCR was performed, followed by direct sequencing by Sanger method. From 100 eligible cases (55 male and 45 females with mean age of 59 years), 32% had mutant K-ras gene; the most common substitution was 12G>C followed by 12G>A and 13G>A, respectively. It is found that K-ras mutation rate, among the selected population of the southern province of Iran, was as high as 32% (codon 12: 71.8% and in codon 13: 25% and one in both codons: 3.1%).

Prevalence of K-Ras mutations in hepatocellular carcinoma: A Turkish Oncology Group pilot study

Hepatocellular carcinoma (HCC) is the fifth most common male-predominant type of cancer worldwide. There is no effective treatment regimen available for advanced-stage disease and chemotherapy is generally ineffective in these patients. The number of studies on the prevalence of K-Ras mutations in HCC patients is currently limited. A total of 58 patients from 6 comprehensive cancer centers in 4 metropolitan cities of Turkey were enrolled in this study. Each center committed to enroll approximately 10 random patients whose formalin-fixed paraffin-embedded tumor tissues were available for K-Ras, exon 2 genotyping. Two methods were applied based on the availability of adequate amounts of tumor DNA. In the first method, the samples were processed using TheraScreen. The genomic DNA was further used to detect the 7 most frequent somatic mutations (35G>A; 35G>C; 35G>T; 34G>A; 34G>C; 34G>T and 38G>A) in codons 12 and 13 in exon 2 of the K-Ras oncogene by quantitative polymerase chain reaction (PCR). In the second method, the genomic DNA was amplified by PCR using primers specific for K-Ras exon 2 with the GML SeqFinder Sequencing System's KRAS kit. The identified DNA sequence alterations were confirmed by sequencing both DNA strands in two independent experiments with forward and reverse primers. A total of 40 samples had adequate tumor tissue for the mutation analysis. A total of 33 (82.5%) of the investigated samples harbored no mutations in exon 2. All the mutations were identified via a direct sequencing technique, whereas none were identified by TheraScreen. In conclusion, in our patients, HCC exhibited a remarkably low (<20%) K-Ras mutation rate. Patients harboring K-Ras wild-type tumors may be good candidates for treatment with epidermal growth factor inhibitors, such as cetuximab.

Can Serum be Used for Analyzing the KRAS Mutation Status in Patients with Advanced Colorectal Cancer?

Purpose

KRAS mutations have been used widely as prognostic or predictive marker in patients with advanced colorectal cancer (CRC). However, it may be difficult to obtain a tumor tissue for analyzing the status of KRAS mutation in large proportion of patients with advanced disease.

Materials and Methods

We obtained pairs of tumor and serum samples from 65 patients with advanced CRC, between March 2008 and July 2011. KRAS mutation status from the tumor samples was analyzed by genomic polymerase chain reaction and direct sequence, and KRASmutation status from the serum samples was determined by a genomic polymerase chain reaction–restriction fragment length polymorphism assay.

Results

KRAS mutations were detected in the serum samples of 26 patients and in the tumor samples of 31 patients. KRAS mutation status in the serum and tumor samples was consistent in 44 of the 65 pairs (67.7%). There was a significant correlation between the mutations detected in the serum sample and the mutations detected in the matched tumor sample (correlation index, 0.35; p < 0.004). Twenty-two of the 57 patients (38.5%) received anti-epidermal growth factor receptor therapy as any line therapy. There was no significant difference in the overall survival (OS) in accordance to the status of KRASmutations in both the serum and tumor samples (p > 0.05). In a multivariate analysis, liver metastasis and no cytoreductive operation were independent prognostic factors for decreased OS.

Conclusion

The serum sample might alternatively be used when it is difficult to obtain tumor tissues for analyzing the status of KRAS mutation in patients with advanced CRC.

[Clinical relevance of the K-ras oncogene in colorectal cancer: experience in a Mexican population]

BACKGROUND

Colorectal cancer is frequent in the developed countries, with a cancer-specific mortality rate of 33%. Different biomarkers are associated with overall survival and the prediction of monoclonal treatment effectiveness. The presence of mutations in the K-ras oncogene alters the response to target therapy with cetuximab and could be an independent prognostic factor.

AIMS

To analyze the difference in survival between patients with mutated K-ras and those with K-ras wild-type status.

METHODS

Thirty-one clinical records were retrospectively analyzed of patients presenting with colorectal cancer that underwent K-ras sequencing through real-time polymerase chain reaction within the time frame of 2009 to 2012 at the Hospital de Alta Especialidad de Veracruz of the Instituto para la Salud y Seguridad Social de los Trabajadores del Estado (HAEV-ISSSTE). Survival analysis for patients with and without K-ras mutation was performed using the Kaplan Meier method. Contrast of covariates was performed using logarithmic transformations.

RESULTS

No statistically significant difference was found in relation to survival in the patients with mutated K-ras vs. those with K-ras wild-type (P=.416), nor were significant differences found when analyzing the covariants and survival in the patients with mutated K-ras: ECOG scale (P=.221); age (less than, equal to or greater than 65years, P=.441); clinical stage according to the AJCC (P=.057), and primary lesion site (P=.614).

CONCLUSIONS

No relation was found between the K-ras oncogene mutation and reduced survival, in contrast to what has been established in the international medical literature. Further studies that include both a larger number of patients and those receiving monoclonal treatment, need to be conducted. There were only 5 patients in the present study that received cetuximab, resulting in a misleading analysis.

Tumour cell invasion: an emerging role for basal epithelial cell extrusion

Metastasis is the leading cause of cancer-related deaths, but it is unclear how cancer cells escape their primary sites in epithelia and disseminate to other sites in the body. One emerging possibility is that transformed epithelial cells could invade the underlying tissue by a process called cell extrusion, which epithelia use to remove cells without disrupting their barrier function. Typically, during normal cell turnover, live cells extrude apically from the epithelium into the lumen and later die by anoikis; however, several oncogenic mutations shift cell extrusion basally, towards the tissue that the epithelium encases. Tumour cells with high levels of survival and motility signals could use basal extrusion to escape from the tissue and migrate to other sites within the body.

CSE1L modulates Ras-induced cancer cell invasion: correlation of K-Ras mutation and CSE1L expression in colorectal cancer progression

BACKGROUND

Ras plays an important role in colorectal cancer progression. CSE1L (chromosome segregation 1-like) gene maps to 20q13, a chromosomal region that correlates with colorectal cancer development. We investigated the association of CSE1L with Ras in colorectal cancer progression.

METHODS

The effect of CSE1L on metastasis-stimulating activity of Ras was studied in an animal model with tumor cells expressing CSE1L-specific shRNA and v-H-Ras. CSE1L expression was evaluated by the immunohistochemical analysis of 127 surgically resected colorectal tumors. K-Ras mutations were analyzed by direct sequencing.

RESULTS

CSE1L knockdown reduced Ras-induced metastasis of B16F10 melanoma cells in C57BL/6 mice. v-H-Ras expression altered the cellular trafficking of CSE1L and increased CSE1L secretion. Most colorectal tumors were positive for CSE1L staining (98.4%, 125 of 127). Colorectal tumors with K-Ras mutation or high cytoplasmic CSE1L expression were correlated with T status (depth of tumor penetration; P = .004), stage (P = .004), and lymph node metastasis (P = .019).

CONCLUSIONS

CSE1L may be a target for treating Ras-associated tumors. Analysis of K-Ras mutation and CSE1L expression may provide valuable clinical and pathological information to aid in the determination of treatment options for colorectal cancer.

The usability of allele-specific PCR and reverse-hybridization assays for KRAS genotyping in Serbian colorectal cancer patients

BACKGROUND

Colorectal cancers (CRCs) with wild-type KRAS respond to EGFR-targeted antibody treatment. Analysis of the hotspot clustered mutations in codons 12 and 13 is compulsory before therapy and no standardized methodology for that purpose has been established so far. Since these mutations may have different biological effects and clinical outcome, reliable frequency and types of KRAS mutations need to be determined for individual therapy.

AIMS

The purpose of this study was to describe the KRAS mutation spectrum in a group of 481 Serbian mCRC patients and to compare the general performances of allele-specific PCR and reverse-hybridization assays.

METHODS

KRAS testing was performed with two diagnostic analyses, DxS TheraScreen K-RAS PCR Kit and KRAS StripAssay™.

RESULTS

KRAS mutations in codons 12 and 13 were present in 37.6 % of analyzed formalin-fixed paraffin-embedded (FFPE) DNA samples. The seven most frequent mutation types were observed with both assays: p.G12D 34.6 %, p.G12V 24.9 %, p.G12A 10.3 %, p.G12C 8.1 %, p.G12S 5.4 %, p.G12R 1.6 %, and p.G13D 15.1 %. Regarding double mutants, 0.8 % of them were present among all tested samples and 2.2 % among KRAS mutated ones.

CONCLUSIONS

Two screening approaches that were used in this study have been shown as suitable tests for detecting KRAS mutations in diagnostic settings. In addition, they appear to be good alternatives to methods presently in use. In our experience, both methods showed capacity to detect and identify double mutations which may be important for potential further subgrouping of CRC patients.

Detection of KRAS mutations and their associations with clinicopathological features and survival in Chinese colorectal cancer patients

OBJECTIVE

Mutation of the KRAS (v-Kiras2 Kirsten rat sarcoma viral oncogene homologue) gene plays an important role in colorectal tumorigenesis. This study examined associations between KRAS gene mutations and clinicopathological and survival data in Chinese patients with colorectal cancer (CRC).

METHODS

CRC patients were recruited for the detection of KRAS gene mutations using polymerase chain reaction and DNA sequencing. Data on clinicopathological features and survival times were collected.

RESULTS

The study included 78 CRC patients. The overall mutation frequency of the KRAS gene at codons 12 and 13 was 33.3% (26/78). KRAS gene mutations were significantly associated with poor tumour differentiation and liver metastasis. Patients with the wild-type KRAS gene had significantly higher median survival times than patients with KRAS gene mutations (35.05 months versus 25.72 months). Those with KRAS gene mutations at codons 12 or 13 did not have significantly different median survival times (25.69 months versus 20.67 months, respectively).

CONCLUSIONS

These findings suggest that a high frequency of KRAS gene mutations exists in Chinese patients with CRC, and that such mutations are associated with poor survival, tumour differentiation and liver metastasis in CRC patients.

Expression of EGFR, HER2, phosphorylated ERK and phosphorylated MEK in colonic neoplasms of familial adenomatous polyposis patients

PURPOSE

The expression of epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2) is associated with poor prognosis in sporadic colorectal carcinoma (CRC). EGFR inhibitors are approved for the treatment of refractory CRC. The aim of this study was to investigate the expression of EGFR and HER2 and downstream extracellular signal regulated kinase (ERK) and mitogen activated protein kinase (MAPK) in non-neoplastic colonic mucosa, adenomas and carcinomas from familial adenomatous polyposis coli (FAP) patients, exploring the expression along the adenoma-carcinoma sequence.

METHODS

The expression of EGFR, HER2, phosphorylated MAPK/ERK kinase (pMEK) and phosphorylated ERK (pERK) proteins was studied by immunohistochemistry in samples of colonic non-neoplastic mucosa (n = 65), adenomas (n = 149) and adenocarcinomas (n = 16) from each of the 16 FAP patients.

RESULTS

For HER2, only weak cytoplasmic expression was seen in 8% of adenomas, 6% of carcinomas and 3% of the non-neoplastic mucosa. EGFR was expressed in non-neoplastic mucosa, adenomas and carcinomas with a statistically significant increase in expression in adenomas compared with non-neoplastic mucosa (p < 0.001). There was also a statistically significant increase in nuclear staining intensity for pERK (p < 0.001) and pMEK (p < 0.001) in adenomas compared to non-neoplastic mucosa.

CONCLUSIONS

This is the first study investigating the expression of these receptors in non-neoplastic mucosa, adenomas and carcinomas from FAP patients. HER2 is not upregulated in the tumours of FAP patients, while EGFR appears to be upregulated in most adenomas and carcinomas, with associated upregulation of pERK and pMEK. We conclude that EGFR and downstream members of its signalling pathway, but not HER2, may be potential therapeutic targets in FAP patients.

Development of a novel, fully-automated genotyping system: principle and applications

Genetic testing prior to treatment, pharmacogenetic analysis, is key to realizing personalized medicine which is a topic that has attracted much attention recently. Through the optimization of therapy selection and dosage, a reduction in side effects is expected. Genetic testing has been conducted as a type of pharmacogenetic analysis in recent years, but it faces challenges in terms of cost effectiveness and its complicated procedures. Here we report on the development of a novel platform for genetic testing, the i-densy^™, with the use of quenching probe system (QP-system) as principle of mutant detection. The i-densy^™ automatically performs pre-treatment, PCR and detection to provide the test result from whole blood and extracted DNA within approximately 90 and 60 min, respectively. Integration of all steps into a single platform greatly reduces test time and complicated procedures. An even higher-precision genetic analysis has been achieved through the development of novel and highly-specific detection methods. The applications of items measured using the i-densy^™ are diverse, from single nucleotide polymorphism (SNP), such as CYP2C19 and UGT1A1, to somatic mutations associated with cancer, such as EGFR, KRAS and JAK2. The i-densy^™ is a useful tool for optimization of anticancer drug therapy and can contribute to personalized medicine.

Proteomics, genomics, and molecular biology in the personalized treatment of colorectal cancer

Colorectal cancer develops and progresses from genetic and genomic changes that occur within and transforms the growth behavior of a normal colonic cell. Molecular tools have advanced enough to allow the scientific community to probe deeper into risk alleles within a population as well as into individual patient genetic data that can ascribe such a risk. Detected genetic and genomic changes from colorectal cancer can help determine a patient's prognosis, predict response to chemotherapy, and determine the approach to care with biological therapies. Utilizing stool, blood/plasma, and tumor tissue to obtain genetic, genomic, and pharmacokinetic information contribute to a person's profile to direct specific cancer care.

BAG-1 interacts with the p50-p50 homodimeric NF-κB complex: implications for colorectal carcinogenesis

Understanding the mechanisms that promote aberrant tumour cell survival is critical for the determination of novel strategies to combat colorectal cancer (CRC). We have recently shown that the anti-apoptotic protein BAG-1, highly expressed in pre-malignant and CRC tissue, can potentiate cell survival through regulating NF-κB transcriptional activity. In this study, we identify a novel complex between BAG-1 and the p50-p50 NF-κB homodimers, implicating BAG-1 as a co-regulator of an atypical NF-κB pathway. Importantly, the BAG-1-p50 complex was detected at gene regulatory sequences including the epidermal growth factor receptor (EGFR) and COX-2 (PTGS2) genes. Suppression of BAG-1 expression using small interfering RNA was shown to increase EGFR and suppress COX-2 expression in CRC cells. Furthermore, mouse embryonic fibroblasts derived from the NF-κB1 (p105/p50) knock-out mouse were used to demonstrate that p50 expression was required for BAG-1 to suppress EGFR expression. This was shown to be functionally relevant as attenuation of BAG-1 expression increased ligand activated phosphorylation of EGFR in CRC cells. In summary, this paper identifies a novel role for BAG-1 in modulating gene expression through interaction with the p50-p50 NF-κB complexes. Data presented led us to propose that BAG-1 can act as a selective regulator of p50-p50 NF-κB responsive genes in colorectal tumour cells, potentially important for the promotion of cell survival in the context of the fluctuating tumour microenvironment. As BAG-1 expression is increased in the developing adenoma through to metastatic lesions, understanding the function of the BAG-1-p50 NF-κB complexes may aid in identifying strategies for both the prevention and treatment of CRC.

Heterogeneous distribution of K-ras mutations in primary colon carcinomas: implications for EGFR-directed therapy

PURPOSE

K-ras mutations predict resistance against epidermal growth factor receptor (EGFR)-directed therapy of metastatic colorectal cancer (CRC). The purpose of this study was to analyze the distribution of K-ras mutations in primary tumors and corresponding sentinel lymph nodes (SLNs) from colon cancer patients.

METHODS

Tumor biopsies and SLNs from 158 patients with non-metastatic colon cancer were analyzed for K-ras mutations in codons 12 and 13 by a sensitive and quantitative peptide nucleic acid clamp PCR assay.

RESULTS

Analyses of single fresh-frozen tumor biopsies revealed K-ras mutations in 67 (42%) of the patients. Apparently low levels of K-ras mutations in 13 of the mutated primary tumors and the presence of K-ras mutations in SLNs from seven patients with a wild-type primary tumor biopsy suggested possible intratumoral heterogeneity for 20 of the patients. To confirm this hypothesis, we analyzed tissue sections from all available formalin-fixed, paraffin-embedded (FFPE) tumor blocks from these 20 patients. Ten of the patients had a mixture of tissue sections positive and tissue sections negative for K-ras mutations, two patients had K-ras mutations in all sections, and eight patients had no detectable K-ras mutations in tumor FFPE tissue blocks. Among these eight patients, five had K-ras mutations detected in SLNs. Thus, evidence supporting a heterogeneous distribution of K-ras mutations was obtained for 15 patients.

CONCLUSIONS

Heterogeneous distribution of K-ras codon 12 and 13 mutations within primary tumor, or between primary tumor and lymph node metastases, was demonstrated for 15 (20%) of 74 colon cancer patients having K-ras mutations. This may have implications for tissue sampling routines with regard to EGFR-directed therapy of CRC, both in adjuvant and metastatic settings.

The liver prometastatic reaction of cancer patients: implications for microenvironment-dependent colon cancer gene regulation

Colon cancer frequently metastasizes to the liver but the genetic and phenotypic properties of specific cancer cells able to implant and grow in this organ have not yet been established. The contribution of the patient's genetic, physiologic and pathologic backgrounds to the incidence and development of hepatic colon cancer metastases is also presently misunderstood. At a transcriptional level, hepatic metastasis development is in part associated with marked changes in gene expression of colon cancer cells that may originate in the primary tumor. Other changes occur in the liver and are regulated by hepatic cells, which represent the new microenvironment for metastatic colon cancer cells. However, hepatic parenchymal and non-parenchymal cell functions are also affected by both tumor-derived factors and systemic host factors, which suggests that the hepatic metastasis microenvironment is a functional linkage between the hepatic pathophysiology of the colon cancer patient and the biology of its cancer cells. Therefore, together with metastasis-related gene profiles suggesting the existence of liver metastasis potential in primary tumors, new biomarkers of the prometastatic microenvironment supported by the liver reaction to colon cancer factors may be helpful for the individual assessment of hepatic metastasis risk in colon cancer patients. In addition, knowledge on hepatic metastasis gene regulation by the hepatic microenvironment may open multiple opportunities for therapeutic intervention during colon cancer metastasis at both subclinical and advanced stages.

The inhibitory effects of 5-hydroxy-3,6,7,8,3',4'-hexamethoxyflavone on human colon cancer cells

SCOPE

Previously, we reported that 5-hydroxy-3,6,7,8,3',4'-hexamethoxyflavone (5HHMF), a polymethoxyflavone found in citrus peels, potently inhibited the growth of multiple human colon cancer cells. Herein, we further investigated the anti-cancer mechanisms of 5HHMF in human colon cancer cells.

METHODS AND RESULTS

Colony formation assay revealed that 5HHMF dose dependently inhibited colony formation of multiple colon cancer cells. Western blot analysis demonstrated 5HHMF decreased nuclear β-catenin levels and increased the E-cadherin level in a dose-dependent manner. 5HHMF also modified plasma membrane-associated proteins, such as K-Ras, EGFR, and their downstream effectors, such as Akt. Moreover, treatments with 5HHMF inhibited nuclear translocation of NF-κB, which may contribute to its anti-cancer effects. Add-back study showed that the inhibitory effect of 5HHMF was not associated with the production of reactive oxygen species (ROS). In addition, 5HHMF treatment inhibited the capillary tube formation of human umbilical vein endothelial cells (HUVECs) on matrigel, suggesting a potential anti-tumor angiogenesis effect.

CONCLUSION

Our results demonstrated that 5HHMF suppressed multiple oncogenic molecular events in colon cancer cells.

Cost-effectiveness analysis of KRAS testing and cetuximab as last-line therapy for colorectal cancer

BACKGROUND

Cetuximab, a monoclonal antibody directed against the epidermal growth factor receptor, improves progression-free survival and overall survival in patients with metastatic colorectal cancer (mCRC). However, patients with a KRAS gene mutation do not benefit from cetuximab therapy.

METHODS

We performed a cost-effectiveness analysis of KRAS testing and cetuximab treatment as last-line therapy for patients with mCRC in Japan. In our analysis, we considered three treatment strategies. In the 'KRAS-testing strategy' (strategy A), KRAS testing was performed to guide treatment: patients with wild-type KRAS received cetuximab, and those with mutant KRAS received best supportive care (BSC). In the 'no-KRAS-testing strategy' (strategy B), genetic testing was not conducted and all patients received cetuximab. In the 'no-cetuximab strategy' (strategy C), genetic testing was not conducted and all patients received BSC. To evaluate the cost effectiveness of KRAS testing, the KRAS-testing strategy was compared with the no-KRAS-testing strategy; to evaluate the cost effectiveness of KRAS testing and cetuximab, the KRAS-testing strategy was compared with the no-cetuximab strategy; and to evaluate the cost effectiveness of cetuximab treatment without KRAS testing, the no-KRAS-testing strategy was compared with the no-cetuximab strategy. A three-state Markov model was used to predict expected costs and outcomes for each group. Outcomes in the model were based on those reported in a retrospective analysis of data from the National Cancer Institute of Canada Clinical Trials Group CO.17 study. We included only direct medical costs from the perspective of the Japanese healthcare payer. A 3% discount rate was used for both costs and outcome. Two outcomes, life-years (LYs) gained and quality-adjusted life-years (QALYs) gained, were used to calculate the incremental cost-effectiveness ratio (ICER).

RESULTS

Our cost-effectiveness analysis revealed that the KRAS-testing strategy was dominant compared with the no-KRAS-testing strategy, with an expected cost reduction of ¥0.5 million per patient and an estimated budget impact of ¥3-5 billion ($US42-59 million; July 2010 values) per year. The ICER of the KRAS-testing strategy compared with the no-cetuximab strategy was ¥11 million ($US120 000) per LY gained and ¥16 million ($US160 000) per QALY gained, whereas the ICER of the KRAS-testing strategy compared with the no-KRAS-testing strategy was ¥14 million ($US180 000) per LY gained and ¥21 million ($US230 000) per QALY gained. These results were supported by the sensitivity analysis.

CONCLUSIONS

KRAS testing is recommended before administering cetuximab as last-line therapy for patients with mCRC. However, our analysis suggests that the ICER of cetuximab treatment (with or without KRAS testing) is too high, even if treatment is limited to patients with wild-type KRAS.

Rapid detection of low-abundance K-ras mutation in stools of colorectal cancer patients using chip-based temperature gradient capillary electrophoresis

Mutant K-ras provides an independent negative predictive marker for epidermal growth factor receptor (EGFR)-targeted therapy in colorectal cancers (CRCs). Rapid, sensitive, and cost-effective screening for K-ras status will overarch rational personalized medicine. Stool-based DNA testing offers unique advantages for CRC screening such as noninvasiveness, high specificity, and patient compliance, whereas complicated procedures and the low sensitivity of the present approaches have hampered its application on a wide scale. In this study, a chip-based temperature gradient capillary electrophoresis (TGCE) technique was applied to detect low-abundance K-ras mutations under a pooled experiment and analyze K-ras mutations in 30 paired stool samples and cancer tissues of CRC patients and 15 stool samples of healthy volunteers. The chip-based TGCE results showed that the successful analysis of K-ras status could be achieved within 6 min with an extremely low sample consumption of 14 nl. Detection is sensitive enough to reliably report 0.2% mutant CRC cells in a wild-type background, and 0.5 ng of template DNA was sufficient for chip-based TGCE. Of the 30 stool samples of CRC patients analyzed, 17 (57%) harbored K-ras mutations, and the lowest percentage of the detectable mutant K-ras in stool samples was 2%. The coincidence rate for K-ras mutations between stools and tissues obtained by the chip-based method reached 97% (29/30). One of the 15 stool samples of normal controls carried K-ras mutations, producing a specificity of 93%. Clone sequencing data entirely confirmed the results obtained by chip-based TGCE. The study demonstrates that chip-based TGCE is capable of rapidly screening low-abundance K-ras mutations with high sensitivity, reproducibility, simplicity, and significant savings of time and sample. Application of this method to genotype the K-ras gene in stools would provide a potential means for predicting the effectiveness of EGFR-targeted therapy in CRC patients using noninvasive approaches.

The American College of Gastroenterology Emily Couric Lecture--the adenoma-carcinoma sequence revisited: has the era of genetic tailoring finally arrived?

Colorectal cancer (CRC) remains a common and often lethal disease. The classic adenoma-carcinoma sequence was defined on histologic grounds but over the last 25 years, the molecular basis of this process has been progressively clarified. There are at least three distinct molecular pathways to CRC: the chromosomal instability (CIN) pathway is thought to be largely driven by mutational events in oncogenes and tumor suppressor genes, the microsatellite instability pathway is responsible for Lynch syndrome CRCs and is driven by mutations in one of the DNA mismatch repair genes, and the epigenetic pathway is thought to be driven in large part by hypermethylation-induced silencing of tumor suppressor-like genes. The molecular understanding of this sequence has had a profound impact on our understanding of the process(s) of colonic carcinogenesis and this understanding has begun to change the clinical care of patients with colonic polyps and cancer including changes in therapy of established CRCs (anti-epidermal growth factor receptor antibody therapy is no longer offered to patients with mutant KRAS CRCs), identification of high-risk groups (diagnosis of Lynch syndrome by molecular analysis of CRCs) and the management of precursor lesions (identification of the serrated polyp pathway to CRC).

Horizontal gene transfers with or without cell fusions in all categories of the living matter

This article reviews the history of widespread exchanges of genetic segments initiated over 3 billion years ago, to be part of their life style, by sphero-protoplastic cells, the ancestors of archaea, prokaryota, and eukaryota. These primordial cells shared a hostile anaerobic and overheated environment and competed for survival. "Coexist with, or subdue and conquer, expropriate its most useful possessions, or symbiose with it, your competitor" remain cellular life's basic rules. This author emphasizes the role of viruses, both in mediating cell fusions, such as the formation of the first eukaryotic cell(s) from a united crenarchaeon and prokaryota, and the transfer of host cell genes integrated into viral (phages) genomes. After rising above the Darwinian threshold, rigid rules of speciation and vertical inheritance in the three domains of life were established, but horizontal gene transfers with or without cell fusions were never abolished. The author proves with extensive, yet highly selective documentation, that not only unicellular microorganisms, but the most complex multicellular entities of the highest ranks resort to, and practice, cell fusions, and donate and accept horizontally (laterally) transferred genes. Cell fusions and horizontally exchanged genetic materials remain the fundamental attributes and inherent characteristics of the living matter, whether occurring accidentally or sought after intentionally. These events occur to cells stagnating for some 3 milliard years at a lower yet amazingly sophisticated level of evolution, and to cells achieving the highest degree of differentiation, and thus functioning in dependence on the support of a most advanced multicellular host, like those of the human brain. No living cell is completely exempt from gene drains or gene insertions.

Clinical impact of K-ras mutation in colorectal cancer patients treated with adjuvant FOLFOX

BACKGROUND

K-ras proto-oncogene is commonly mutated in colorectal cancer (CRC) and has been associated with predictive markers for anti-EGFR (epidermal growth factor receptor) therapy. However, the prognostic role of K-ras status is still unclear. The aim of this study was to evaluate the association between k-ras status and addition of oxaliplatin to fluorouracil plus leucovorin (FOLFOX) chemotherapy in CRC patients with curative surgical resection.

METHODS

Sixty-six patients with stage II or III CRC were treated with FOLFOX or fluorouracil plus leucovorin (FL) followed by curative surgery between January 2004 and October 2007. K-ras status was assessed by direct sequencing.

RESULTS

Fifteen patients (22.7%) had K-ras mutations of codon 12 (11/15) or codon 13 (4/15). There were no significant differences in clinicopathological parameters, such as age, sex, stage, or adjuvant regimen between the wild-type K-ras and mutant K-ras. With a median follow-up of 41.6 months (range 25.1-72.3 months), median disease-free survival (DFS) and overall survival (OS) were not reached. With regard to K-ras status, DFS and OS were not statistically different (P = 0.269 and P = 0.917, respectively). Even in the group treated with FOLFOX only, neither DFS (P = 0.651) nor OS (P = 0.265) was significantly different according to K-ras status. With the exception of tumor location in DFS and OS, no differences in other variables were observed. Proximal colon cancer patients had a longer DFS than distal CRC patients (P = 0.079); this trend was maintained only in the wild-type K-ras group (P = 0.051).

CONCLUSIONS

These results showed that K-ras status was not associated with clinical outcome in patients treated with adjuvant FOLFOX.

A review of the most promising biomarkers in colorectal cancer: one step closer to targeted therapy

Rapidly growing insights into the molecular biology of colorectal cancer (CRC) and recent developments in gene sequencing and molecular diagnostics have led to high expectations for the identification of molecular markers to be used in optimized and tailored treatment regimens. However, many of the published data on molecular biomarkers are contradictory in their findings and the current reality is that no molecular marker, other than the KRAS gene in the case of epidermal growth factor receptor (EGFR)- targeted therapy for metastatic disease, has made it into clinical practice. Many markers investigated suffer from technical shortcomings, resulting from lack of quantitative techniques to capture the impact of the molecular alteration. This understanding has recently led to the more comprehensive approaches of global gene expression profiling or genome-wide analysis to determine prognostic and predictive signatures in tumors. In this review, an update of the most recent data on promising biological prognostic and/or predictive markers, including microsatellite instability, epidermal growth factor receptor, KRAS, BRAF, CpG island methylator phenotype, cytotoxic T lymphocytes, forkhead box P3-positive T cells, receptor for hyaluronic acid-mediated motility, phosphatase and tensin homolog, and T-cell originated protein kinase, in patients with CRC is provided.

K-RAS mutation in the screening, prognosis and treatment of cancer

The potential use of K-RAS mutation as a cancer screening biomarker has been investigated for many years. Numerous associations between K-RAS mutation and various cancers have been established, but these associations have not been translated into effective, cost-efficient cancer screening strategies. This lack of progress may be due to the existence of K-RAS mutation in nontumor tissues and/or using detection, rather than quantitation, of K-RAS mutation as the endpoint for cancer risk categorization. K-RAS mutation appears to be a useful prognostic biomarker for colon cancer. Recent progress toward sensitive and quantitative mutation characterization and the successful use of K-RAS mutation in a personalized medicine approach to targeted biological therapy selection are likely to re-direct and expand the use of K-RAS mutation as a cancer biomarker in the near future.

Lack of evidence for KRAS oncogenic mutations in triple-negative breast cancer

Background

Mutational analysis of the KRAS gene has recently been established as a complementary in vitro diagnostic tool for the identification of patients with colorectal cancer who will not benefit from anti-epidermal growth factor receptor (EGFR) therapies. Assessment of the mutation status of KRAS might also be of potential relevance in other EGFR-overexpressing tumors, such as those occurring in breast cancer. Although KRAS is mutated in only a minor fraction of breast tumors (5%), about 60% of the basal-like subtype express EGFR and, therefore could be targeted by EGFR inhibitors. We aimed to study the mutation frequency of KRAS in that subtype of breast tumors to provide a molecular basis for the evaluation of anti-EGFR therapies.

Methods

Total, genomic DNA was obtained from a group of 35 formalin-fixed paraffin-embedded, triple-negative breast tumor samples. Among these, 77.1% (27/35) were defined as basal-like by immunostaining specific for the established surrogate markers cytokeratin (CK) 5/6 and/or EGFR. KRAS mutational status was determined in the purified DNA samples by Real Time (RT)-PCR using primers specific for the detection of wild-type KRAS or the following seven oncogenic somatic mutations: Gly12Ala, Gly12Asp, Gly12Arg, Gly12Cys, Gly12Ser, Gly12Val and Gly13Asp.

Results

We found no evidence of KRAS oncogenic mutations in all analyzed tumors.

Conclusions

This study indicates that KRAS mutations are very infrequent in triple-negative breast tumors and that EGFR inhibitors may be of potential benefit in the treatment of basal-like breast tumors, which overexpress EGFR in about 60% of all cases.

Inhibition of MLK3 Decreases Proliferation and Increases Antiproliferative Activity of Epidermal Growth Factor Receptor (EGFR) Inhibitor in pancreatic cancer cell Lines

Pancreatic adenocarcinoma is associated with advanced presentation and poor survival. Currently approved therapies have minimal effect on patient survival. Pancreatic adenocarcinomas have a high incidence of activated K-RAS, which may confer resistance to epidermal growth factor receptor (EGFR) inhibitors. Mixed lineage kinase-3 (MLK3) is a MAP3K that activates multiple MAPK pathways. The role of MLK3 in the pathophysiology and resistance to therapy of pancreatic adenocarcinoma has not been investigated. MLK3 is over expressed in pancreatic cancer cell lines compared to an immortalized pancreatic epithelial cell line. The requirement of MLK3 for cell proliferation and survival of pancreatic cancer cell lines, PANC-1 and MiaPaCa-2, was investigated using RNA interference (siRNA) and MLK inhibitor, K252a, alone or in conjunction with the EGFR inhibitor, Compound 56. Ablation of expression of MLK3 via siRNA-mediated gene silencing and pharmacological inhibition of MLK3 by K252a each decreased cell viability in both pancreatic cancer cell lines, with a concurrent decrease in the activation of ERK, JNK and AKT. Concomitant inhibition of EGFR and MLK3 induced apoptosis, as evidenced by increased cleavage of PARP and caspase-3. These results suggest that MLK3 plays an important role in survival and proliferation of pancreatic cancer cell lines and that inhibition of MLK3 may enhance the therapeutic efficacy of EGFR inhibitors in the treatment of pancreatic cancer.

Annual report to the nation on the status of cancer, 1975-2006, featuring colorectal cancer trends and impact of interventions (risk factors, screening, and treatment) to reduce future rates

BACKGROUND

The American Cancer Society, the Centers for Disease Control and Prevention (CDC), the National Cancer Institute (NCI), and the North American Association of Central Cancer Registries (NAACCR) collaborate annually to provide updated information regarding cancer occurrence and trends in the United States. This year's report includes trends in colorectal cancer (CRC) incidence and death rates and highlights the use of microsimulation modeling as a tool for interpreting past trends and projecting future trends to assist in cancer control planning and policy decisions.

METHODS

Information regarding invasive cancers was obtained from the NCI, CDC, and NAACCR; and information on deaths was obtained from the CDC's National Center for Health Statistics. Annual percentage changes in the age-standardized incidence and death rates (based on the year 2000 US population standard) for all cancers combined and for the top 15 cancers were estimated by joinpoint analysis of long-term trends (1975-2006) and for short-term fixed-interval trends (1997-2006). All statistical tests were 2-sided.

RESULTS

Both incidence and death rates from all cancers combined significantly declined (P < .05) in the most recent time period for men and women overall and for most racial and ethnic populations. These decreases were driven largely by declines in both incidence and death rates for the 3 most common cancers in men (ie, lung and prostate cancers and CRC) and for 2 of the 3 leading cancers in women (ie, breast cancer and CRC). The long-term trends for lung cancer mortality in women had smaller and smaller increases until 2003, when there was a change to a nonsignificant decline. Microsimulation modeling demonstrates that declines in CRC death rates are consistent with a relatively large contribution from screening and with a smaller but demonstrable impact of risk factor reductions and improved treatments. These declines are projected to continue if risk factor modification, screening, and treatment remain at current rates, but they could be accelerated further with favorable trends in risk factors and higher utilization of screening and optimal treatment.

CONCLUSIONS

Although the decrease in overall cancer incidence and death rates is encouraging, rising incidence and mortality for some cancers are of concern.

[When only the pathologist may help. Limitation and possibilities of biopsies in Internal Medicine]

Histological evaluation after biopsy remains the gold standard for the diagnosis of numerous diseases in Internal Medicine. The gastrointestinal tract (e. g. esophagus, liver and large intestine), the kidneys or bone marrow are organs, where biopsy-driven diagnosis and evaluation of therapeutic regimens are of major relevance. Improvement in blood analysis, endoscopic techniques and radiology could significantly reduce the number of biopsies. Hence under certain circumstances, the risk of biopsy can be avoided and non-invasive markers can sufficiently substitute the histological evaluation. However, histological evaluation derived from biopsies remains the standard of diagnosis in many cases in Internal Medicine. In the present review the current standards and future developments of pathologic diagnosis through biopsy are illustrated.

The effects of obesity and obesity-related conditions on colorectal cancer prognosis

BACKGROUND

Colorectal cancer is the second-leading cause of cancer death in the United States among men and women combined. Refinements in screening, staging, and treatment strategies have improved survival from this disease, with over 65% of patients diagnosed with colorectal cancer surviving over 5 years after diagnosis. In the prognosis of colorectal cancer, clinicopathological factors are important. However, modifiable prognostic factors are emerging as significant contributors to cancer outcomes, including obesity and obesity-related inflammation and metabolic conditions.

METHODS

This report reviews the literature on obesity and obesity-related inflammation and metabolic disturbances and colorectal cancer outcomes (recurrence, disease-free survival, and/or mortality). A PubMed search was conducted of all English-language papers published between August 2003 and 2009 and cited in MEDLINE.

RESULTS

Primary research papers were reviewed for colorectal cancer outcomes related to obesity, inflammation, or metabolic conditions. An association between body size and colorectal cancer recurrence and possibly survival was found; however, reports have been inconsistent. These inconsistent findings may be due to the complex interaction between adiposity, physical inactivity, and dietary intake. Circulating prognostic markers such as C-reactive protein, insulin-like growth factor, and insulin, alone or in combination, have been associated with prognosis in observational studies and should be evaluated in randomized trials and considered for incorporation into surveillance.

CONCLUSIONS

The literature suggests that obesity and obesity-related inflammation and metabolic conditions contribute to the prognosis of colorectal cancer; however, comprehensive large scale trials are needed. Interventions to reduce weight and control inflammation and metabolic conditions, such as diabetes, need to be evaluated and rapidly translated to behavior guidelines for patients.

Annual report to the nation on the status of cancer, 1975-2006, featuring colorectal cancer trends and impact of interventions (risk factors, screening, and treatment) to reduce future rates

BACKGROUND

The American Cancer Society, the Centers for Disease Control and Prevention (CDC), the National Cancer Institute (NCI), and the North American Association of Central Cancer Registries (NAACCR) collaborate annually to provide updated information regarding cancer occurrence and trends in the United States. This year's report includes trends in colorectal cancer (CRC) incidence and death rates and highlights the use of microsimulation modeling as a tool for interpreting past trends and projecting future trends to assist in cancer control planning and policy decisions.

METHODS

Information regarding invasive cancers was obtained from the NCI, CDC, and NAACCR; and information on deaths was obtained from the CDC's National Center for Health Statistics. Annual percentage changes in the age-standardized incidence and death rates (based on the year 2000 US population standard) for all cancers combined and for the top 15 cancers were estimated by joinpoint analysis of long-term trends (1975-2006) and for short-term fixed-interval trends (1997-2006). All statistical tests were 2-sided.

RESULTS

Both incidence and death rates from all cancers combined significantly declined (P < .05) in the most recent time period for men and women overall and for most racial and ethnic populations. These decreases were driven largely by declines in both incidence and death rates for the 3 most common cancers in men (ie, lung and prostate cancers and CRC) and for 2 of the 3 leading cancers in women (ie, breast cancer and CRC). The long-term trends for lung cancer mortality in women had smaller and smaller increases until 2003, when there was a change to a nonsignificant decline. Microsimulation modeling demonstrates that declines in CRC death rates are consistent with a relatively large contribution from screening and with a smaller but demonstrable impact of risk factor reductions and improved treatments. These declines are projected to continue if risk factor modification, screening, and treatment remain at current rates, but they could be accelerated further with favorable trends in risk factors and higher utilization of screening and optimal treatment.

CONCLUSIONS

Although the decrease in overall cancer incidence and death rates is encouraging, rising incidence and mortality for some cancers are of concern.