DUCK HEPATITIS B VIRUS DNA WITHIN HEPATIC MULTICENTRIC CANCER AND/OR METASTATIC CANCER

Duck hepatitis B vims (DHBV) DNA was detected in different tumorous nodules of ducks with hepatic multicentric cancer or intrahepatic metastasis by Southern blot technique. Among 7 ducks with hepatocellular carcinoma of multiple tumor nodules, the hybridization pattern of Integrated DHBV DNA In different tumorous nodules was identical in 3 cases and different in 2 cases. One case showed a similar hybridization pattern in two tumorous nodules and other one was negative tor DHBV DNA. Integrated DHBV DNA was also identified in a metastatic lung cancer of ducks with hepatocellular carcinoma. The hybridization pattern of metastasis of lungs was as the some as that in primary hepatocellular carcinoma. The same discrete hybridization bands In the different tumorous nodules indicate that these nodules might arise from one transformed cell. The different hybridization patterns In various tumorous nodules show that these tumorous nodules might arise from various transformed cells. The results suggest that the hybridization pattern of different nodules of hepatocellular carcinoma with viral DNA probe could make a cell clone origin marker of tumor nodule to differentiate hepatic multlcentric cancer from Intrahepatic metastatic cancer.

Cohort study on the treatment of BRAF V600E mutant metastatic colorectal cancer with integrated Chinese and western medicine

BACKGROUND Patients with BRAF V600E mutant metastatic colorectal cancer(mCRC)have a low incidence rate,poor biological activity,suboptimal response to conventional treatments,and a poor prognosis.In the previous cohort study on mCRC conducted by our team,it was observed that integrated Chinese and Western medicine treatment could significantly prolong the overall survival(OS)of patients with colorectal cancer.Therefore,we further explored the survival benefits in the population with BRAF V600E mutant mCRC.AIM To evaluate the efficacy of integrated Chinese and Western medicine in the treatment of BRAF V600E mutant metastatic colorectal cancer.METHODS A cohort study was conducted on patients with BRAF V600E mutant metastatic colorectal cancer admitted to Xiyuan Hospital of China Academy of Chinese Medical Sciences and Traditional Chinese Medicine Hospital of Xinjiang Uygur Autonomous Region from January 2016 to December 2022.The patients were divided into two cohorts.RESULTS A total of 34 cases were included,with 23 in Chinese-Western medicine cohort(cohort A)and 11 in Western medicine cohort(cohort B).The median overall survival was 19.9 months in cohort A and 14.2 months in cohort B,with a statistically significant difference(P=0.038,hazard ratio=0.46).The 1-3-year survival rates were 95.65%(22/23),39.13%(9/23),and 26.09%(6/23)in cohort A,and 63.64%(7/11),18.18%(2/11),and 9.09%(1/11)in cohort B,respectively.Subgroup analysis showed statistically significant differences in median OS between the two cohorts in the right colon,liver metastasis,chemotherapy,and first-line treatment subgroups(P<0.05).CONCLUSION Integrated Chinese and Western medicine can prolong the survival and reduce the risk of death in patients with BRAF V600E mutant metastatic colorectal cancer,with more pronounced benefits observed in patients with right colon involvement,liver metastasis,combined chemotherapy,and first-line treatment.

Clear cell sarcoma of the pancreas,an unusual cancer with unusual metastatic site or unusual primary site?

Clear cell sarcoma(CCS)is a type of malignant tumor that can arise from tendons and aponeuroses.This malignant proliferation of cells with melanocytic lineage normally occurs in young patients,and it is normally identified in extremities.However,different sites including gastrointestinal organs are also described.Due difficulties in the molecular and histopathology evaluation,the diagnosis is often confused with malignant melanoma.Most cases are treated with surgical resection,but overall,the prognosis is poor.In this editorial,we will discuss a very interesting case of CCS identified in the pancreas.We will discuss the literature and controversies in the management of this type of cancer.Furthermore,we will address molecular strategies to be incorporated in those cases to better understand the primary location of the tumor.Finally,future perspectives of the field and new strategies of treatment will be described.

Efficacy of chemotherapy containing bevacizumab in patients with metastatic colorectal cancer according to programmed cell death ligand 1

BACKGROUND Bevacizumab,an anti-vascular endothelial growth factor(VEGF)monoclonal antibody,inhibits angiogenesis and reduces tumor growth.Serum VEGF-C,lactate dehydrogenase,and inflammatory markers have been reported as predictive markers related to bevacizumab treatment.Programmed cell death ligand 1(PD-L1)could act upon VEGF receptor 2 to induce cancer cell angiogenesis and metastasis.AIM To investigate the efficacy of bevacizumab-containing chemotherapy in patients with metastatic colorectal cancer(CRC)according to the expression of PD-L1.METHODS This analysis included CRC patients who received bevacizumab plus FOLFOX or FOLFIRI as first-line therapy between June 24,2014 and February 28,2022,at Samsung Medical Center(Seoul,South Korea).Analysis of patient data included evaluation of PD-L1 expression by the combined positive score(CPS).We analyzed the efficacy of bevacizumab according to PD-L1 expression status in patients with CRC.RESULTS A total of 124 patients was included in this analysis.Almost all patients were treated with bevacizumab plus FOLFIRI or FOLFOX as the first-line chemotherapy.While 77%of patients received FOLFOX,23%received FOLFIRI as backbone first-line chemotherapy.The numbers of patients with a PD-L1 CPS of 1 or more,5 or more,or 10 or more were 105(85%),64(52%),and 32(26%),respectively.The results showed no significant difference in progression-free survival(PFS)and overall survival(OS)with bevacizumab treatment between patients with PDL1 CPS less than 1 and those with PD-L1 CPS of 1 or more(PD-L1<1%vs PD-L1≥1%;PFS:P=0.93,OS:P=0.33),between patients with PD-L1 CPS less than 5 and of 5 or more(PD-L1<5%vs PD-L1≥5%;PFS:P=0.409,OS:P=0.746),and between patients with PD-L1 CPS less than 10 and of 10 or more(PD-L1<10%vs PD-L1≥10%;PFS:P=0.529,OS:P=0.568).CONCLUSION Chemotherapy containing bevacizumab can be considered as first-line therapy in metastatic CRC irrespective of PD-L1 expression.

Emerging role of liquid biopsy in rat sarcoma virus mutated metastatic colorectal cancer:A case report

BACKGROUND In patients with metastatic colorectal cancer(mCRC),the treatment options are limited and have been proved to be affected by rat sarcoma virus(RAS)mutational status.In RAS wild-type(wt)patients,the combination of antiepidermal growth factor receptor(EGFR)monoclonal antibodies with chemotherapy(CT)is more effective than CT alone.On the other hand,RAS-mutated patients are not eligible for treatment with anti-EGFR antibodies.CASE SUMMARY Eleven patients with initially RAS-mutated mCRC were followed from diagnosis to May 2022.At the time of cell-free DNA determination,five patients had undergone one CT line,five patients had undergone two CT lines,and one patient had undergone three CT lines(all in combination with bevacizumab).At the second and third treatment lines[second line(2L),third line(3L)],patients with neo-RAS wt received a combination of CT and cetuximab.In neo-RAS wt patients treated with anti-EGFR,our findings indicated an increase in progression-free survival for both 2L and 3L(14.5 mo,P=0.119 and 3.9 mo,P=0.882,respectively).Regarding 2L overall survival,we registered a slight increase in neo-RAS wt patients treated with anti-EGFR(33.6 mo vs 32.4 mo,P=0.385).At data cut-off,two patients were still alive:A RAS-mutated patient undergoing 3L treatment and a neo-RAS wt patient who received 2L treatment with anti-EGFR(ongoing).CONCLUSION Our case series demonstrated that monitoring RAS mutations in mCRC by liquid biopsy may provide an additional treatment line for neo-RAS wt patients.

Anti-PD1 antibody and not anti-LAG-3 antibody improves the antitumor effect of photodynamic therapy for treating metastatic breast cancer

Photodynamic therapy(PDT)has limited effects in treating metastatic breast cancer.Immune checkpoints can deplete the function of immune cells;however,the expression of immune checkpoints after PDT is unclear.This study investigates whether the limited e±cacy of PDT is due to upregulated immune checkpoints and tries to combine the PDT and immune checkpoint inhibitor to observe the e±cacy.A metastatic breast cancer model was treated by PDT mediated by hematoporphyrin derivatives(HpD-PDT).The anti-tumor effect of HpD-PDT was observed,as well as CD4þT,CD8þT and calreticulin(CRT)by immunohistochemistry and immunofluorescence.Immune checkpoints on T cells were analyzed byflow cytometry after HpD-PDT.When combining PDT with immune checkpoint inhibitors,the antitumor effect and immune effect were assessed.For HpD-PDT at 100 mW/cm2 and 40,60 and 80 J/cm2,primary tumors were suppressed and CD4þT,CD8þT and CRT were elevated;however,distant tumors couldn't be inhibited and survival could not be prolonged.Immune checkpoints on T cells,especially PD1 and LAG-3 after HpD-PDT,were upregulated,which may explain the reason for the limited HpD-PDT effect.After PDT combined with anti-PD1 antibody,but not with anti-LAG-3 antibody,both the primary and distant tumors were signi-cantly inhibited and the survival time was prolonged,additionally,CD4þT,CD8þT,IFN-þCD4þT and TNF-þCD4þT cells were signi-cantly increased compared with HpD-PDT.HpD-PDT could not combat metastatic breast cancer.PD1 and LAG-3 were upregulated after HpD-PDT.Anti-PD1 antibody,but not anti-LAG-3 antibody,could augment the antitumor effect of HpD-PDT for treating metastatic breast cancer.

Vascular endothelial growth factor pathway’s influence on bevacizumab efficacy in metastatic colorectal cancer treatment

In this article,an article published in the World Journal of Gastrointestinal Oncology,which focuses on whether the expression of programmed death-ligand 1(PD-L1)affects the effectiveness of chemotherapy regimens,including bevacizumab,in treating patients with colorectal cancer(CRC).Through neutralization of vascular endothelial growth factor(VEGF),bevacizumab inhibits tumor angiogenesis,impairing neovascularization and thereby depriving the tumor of essential nutrients and oxygen.Conversely,PD-L1 binding to VEGF receptor 2 promotes angiogenesis,supporting tumor vasculature.The interplay between these pathways complicates the assessment of bevacizumab’s efficacy in cancer therapy,notably in CRC,where VEGF and PD-L1 significantly affect treatment response.This review examines metastatic CRC treatment strategies,focusing on bevacizumab’s mechanism of action and the role of PD-L1 in this therapeutic context.

Comparative effectiveness of immunotherapy and chemotherapy in patients with metastatic colorectal cancer stratified by microsatellite instability status

BACKGROUND Immunotherapy have demonstrated promising outcomes in patients with high microsatellite instability(MSI)(MSI-H)metastatic colorectal cancer.However,the comparative effectiveness of Immunotherapy and chemotherapy for patients with low MSI(MSI-L),and microsatellite stable(MSS)metastatic colorectal cancer remains unclear.AIM To investigate immunotherapy vs chemotherapy for treatment of MSI-L/MSS metastatic colorectal cancer,and to evaluate the success of immunotherapy against chemotherapy in managing MSI-H metastatic colorectal cancer during a follow-up of 50 months.METHODS We conducted a retrospective cohort study using the National Cancer Database(NCDB)to evaluate the overall survival(OS)of patients with metastatic colorectal cancer treated with immunotherapy or chemotherapy.The study population was stratified by MSI status(MSI-H,MSI-L,and MSS).Multivariable Cox proportional hazard models were used to assess the association between treatment modality and OS,adjusting for potential confounders.RESULTS A total of 21951 patients with metastatic colorectal cancer were included in the analysis,of which 2358 were MSI-H,and 19593 were MSI-L/MSS.In the MSI-H cohort,immunotherapy treatment(n=142)was associated with a significantly improved median OS compared to chemotherapy(n=860).After adjusting for potential confounders,immunotherapy treatment remained significantly associated with better OS in the MSI-H cohort[adjusted hazard ratio(aHR):0.57,95%confidence interval(95%CI):0.43-0.77,P<0.001].In the MSS cohort,no significant difference in median OS was observed between immunotherapy treatment and chemotherapy(aHR:0.94,95%CI:0.69-1.29,P=0.715).CONCLUSION In this population-based study using the NCDB,immunotherapy treatment was associated with significantly improved OS compared to chemotherapy in patients with MSI-H metastatic colorectal cancer,but not in those with MSI-L/MSS metastatic colorectal cancer.Further studies are warranted to determine the optimal therapeutic approach for patients with MSI-L/MSS metastatic colorectal cancer.

Successful cetuximab rechallenge in metastatic colorectal cancer:A case report

BACKGROUND Metastatic colorectal cancer(mCRC)treatment has been evolving and increasingly driven by tumor biology and gene expression analysis.Rechallenge with epidermal growth factor receptor(EGFR)inhibitors(anti-EGFR)represents a promising strategy for patients with RAS wild-type(RAS-wt)mCRC and circulating tumor DNA has emerged as a potential selection strategy.Herein,we report the case of a RAS-wt mCRC patient who had a successful response to cetuximab rechallenge.CASE SUMMARY Our patient was diagnosed with stage IV RAS-wt,microsatellite-stable rectosigmoid junction adenocarcinoma.He was started on first-line treatment with FOLFIRI and cetuximab and achieved partial response,allowing for a left hepatectomy(R0),followed by post-operative chemotherapy and an anterior resection;progression-free survival(PFS)of 16 months was obtained.Due to hepatic and nodal relapse,second-line treatment with FOLFOX and bevacizumab was started with partial response;metastasectomy was performed(R0),achieving a PFS of 11 months.After a 15 months anti-EGFR-free interval,FOLFIRI and cetuximab were reintroduced upon disease progression,again with partial response and a PFS of 16 months.Following extensive hepatic relapse,cetuximab was reintroduced and a marked clinical and analytical improvement was seen,after only one cycle.RASwt status was confirmed on circulating tumor DNA.The patient’s overall survival exceeded 5 years.CONCLUSION Our case provides real-world data to support cetuximab rechallenge in later lines of RAS-wt mCRC treatment.

Therapeutic strategies targeting the epidermal growth factor receptor signaling pathway in metastatic colorectal cancer

More than 1.9 million new colorectal cancer(CRC)cases and 935000 deaths were estimated to occur worldwide in 2020,representing about one in ten cancer cases and deaths.Overall,colorectal ranks third in incidence,but second in mortality.More than half of the patients are in advanced stages at diagnosis.Treatment options are complex because of the heterogeneity of the patient population,including different molecular subtypes.Treatments have included conventional fluorouracil-based chemotherapy,targeted therapy,immunotherapy,etc.In recent years,with the development of genetic testing technology,more and more targeted drugs have been applied to the treatment of CRC,which has further prolonged the survival of metastatic CRC patients.

Survival Rate and Factors Influencing It in Triptorelin-Castrated Metastatic Prostate Cancer Patients

Background: Most newly diagnosed prostate cancers in Benin are metastatic diseases and patients are reluctant to undergo orchiectomy. Still, chemical androgen deprivation therapy is not always available and not every patient can afford it. Thus, it will be interesting to evaluate the results of that therapy in the country. Objective: To analyze the survival rate and factors influencing it in metastatic prostate cancer patients who underwent triptorelin-based androgen deprivation therapy at the former Military Teaching Hospital of Cotonou from January 1, 2012, to December 31, 2022. Patients and Method: Metastatic prostate cancer patients received intragluteal injections of triptorelin 11.25 mg every 3 months. We retrospectively collected follow-up data from the patients’ medical records. By means of the software StataTM version 15, we performed a descriptive analysis of qualitative data. We used Kaplan-Meir method to estimate the overall survival rate in the whole cohort and in specific subgroups of patients. We compared survival rates by using the log-rank test. Results: 68 metastatic prostate cancer patients aged 47-86 years (mean = 69.9) with initial PSA ranging from 24.25 to 6334 ng/mL (mean = 666.1) started triptorelin-based castration. The tumor grade in 21 (33.3%), 14 (22.2%), 15 (23.8), 8 (12.7%), and 5 (7.9%) patients was respectively ISUP grade groups 5, 4, 3, 2, and 1. 15 (22.1%), 4 (5.9%), 2 (2.9%), 1 (1.5%), 11 (16.2%), and 7 (10.3%) patients respectively had hypertension, diabetes mellitus, peptic ulcer, asthma, unilateral or bilateral hydronephrosis, and paralysis. The mean nadir PSA level was 22.5 ng/mL (range: 0.01-220.25). The mean time to nadir PSA level was 8.9 months (range: 3-57). The overall survival rate was 42.6%. There was no significant survival difference between age groups (p = 0.475), relating to the presence of diabetes or hypertension (p = 0.757) or to the presence of paralysis or hydronephrosis (p = 0.090). The initial PSA level exerted no significant impact on patients’ survival (p = 0.461). Neither did the time to PSA nadir (p = 0.263). The PSA nadir less than 4 ng/mL (p = 0.005) and the PSA nadir less than 4 ng/mL achieved in 12 months or less (p = 0.002) were predictive of longer survival rate. The difference in survival rate through the ISUP grade groups was not significant (p = 0.061). Conclusion: The overall survival rate was 42.6% at 5 years. Achieving PSA nadir of less than 4 ng/mL in less than 12 months of castration was predictive of longer survival rate in triptorelin-castrated metastatic prostate cancer patients.

Current and future perspectives in the management and treatment of colorectal cancer

In this editorial,we reviewed the article by Fadlallah et al that was recently published in the World Journal of Clinical Oncology.The article provided a comprehensive and in-depth view of the management and treatment of colorectal cancer(CRC),one of the leading causes of cancer-related morbidity and mortality worldwide.The article analyzed the therapeutic modalities and their sequencing,focusing on total neoadjuvant therapy for locally advanced rectal cancer.It highlighted the role of immunotherapy in tumors with high microsatellite instability or deficient mismatch repair,addressing recent advances that have improved prognosis and therapeutic response in localized and metastatic CRC.Innovations in surgical techniques,advanced radiotherapy,and systemic agents targeting specific mutational profiles are also discussed,reflecting on how they revolutionized clinical management.Circulating tumor DNA has emerged as a promising tool for detecting minimal residual disease,prognosis,and therapeutic monitoring,solidifying its role in precision oncology.This review emphasized the importance of technological and therapeutic advancements in improving clinical outcomes and personalizing CRC treatment.

Discovery of primary lung cancer following resection of rectal cancer lung metastasis:A case report

BACKGROUND Colorectal cancer(CRC)ranks high among the most common types of malignant tumors.The primary cause of cancer-related mortality is metastasis,with lung metastases accounting for 32.9%of all cases of metastatic CRC(MCRC).However,cases of MCRC in the lungs,which present concurrently with primary peripheral lung adenocarcinoma,are exceptionally rare.CASE SUMMARY This report describes the case of a 52-year-old female patient who,following a colonoscopy,was diagnosed with moderately differentiated adenocarcinoma based on rectal mucosal biopsy findings.A preoperative chest computed tomography scan revealed a ground-glass nodule in the right lung and a small nodule(approximately 0.6 cm in diameter)in the extramural basal segment of the left lower lobe,which suggested multiple lung metastases from rectal cancer.Subsequent treatment and follow-up led to a diagnosis of rectal cancer with left lung metastasis and peripheral adenocarcinoma of the lower lobe of the right lung.CONCLUSION This case report describes the therapeutic journey of a patient with lung metastasis from rectal cancer in addition to primary peripheral adenocarcinoma,thus underscoring the critical roles of multidisciplinary collaboration,personalized treatment strategies,and comprehensive patient rehabilitation guidance.

Mitomycin C and capecitabine: An additional option as an advanced line therapy in patients with metastatic colorectal cancer

BACKGROUND In recent years survival of patients with metastatic colorectal cancer(mCRC),though still limited,has improved significantly;clearly,when the disease becomes refractory to standard regimens,additional treatment options are needed.Studies have shown that mitomycin C(MMC),an antitumor antibiotic,and capecitabine,a precursor of 5-fluorouracil,may act synergistically in combination.The efficacy of MMC/capecitabine has been demonstrated in the first-line setting,but only a few small studies have tested it in the advanced-line setting,with contradictory results.received a median of 2 MMC/capecitabine cycles(range 0.5-9.0).Thirty-four patients(28.6%)experienced grade≥3 toxicity,including 2(1.7%)with grade 4;there was no drug-related mortality.The objective response rate was 0.8%,and the disease control rate,24.4%.Median progression-free survival(PFS)was 2.1 mo(range 0.2-20.3),and median overall survival,4.8 mo(range 0.2-27.5).The 6-month overall survival rate was 44%;8.7%of patients remained progression-free.Factors associated with longer PFS were lower gamma-glutamyl transferase level(P=0.030)and primary tumor location in the left colon(P=0.017).Factors associated with longer overall survival were lower gamma-glutamyl transferase level(P=0.022),left-colon tumor location(P=0.044),low-to-moderate histological grade(P=0.012),Eastern Cooperative Oncology Group performance status 0-1(P=0.036),and normal bilirubin level(P=0.047).CONCLUSION MMC/capecitabine is an active,available,and relatively safe regimen for use beyond standard lines of therapy in mCRC.Several clinical and laboratory parameters can identify patients more likely to benefit.

Unplanned hospitalizations for metastatic cancers:The changing patterns of inpatient palliative care,discharge to hospice care,and in-hospital mortality in the United States

Objective:To describe the rates and temporal trends of inpatient end-of-life care among patients hospitalized with metastatic cancer in the United States.Methods:We used data from the Nationwide Inpatient Sample to conduct a cross-sectional analysis of unplanned inpatient hospitalizations of patients aged 18 years or older with metastatic cancer from 2002 to 2011.Multivariable logistic regression was used to assess patient-and hospital-level predictors of discharge to hospice care,palliative care,and in-hospital mortality.Temporal trends in outcomes were characterized with use of joinpoint regression.Results:There were an estimated 350,241 unplanned hospitalizations per year of patients with a diagnosis of metastatic cancer.During their inpatient stay,5.8%of patients received palliative care,and among those discharged alive,12.2%were referred to hospice care.The rate of inpatient palliative care increased from 2.3%to 13.6%,the rate of discharge to hospice care increased from 4.1%to 15.6%,and the in-hospital mortality rate decreased from more than 14.0%to 9.8%.These patterns were consistent across cancer subtypes,and were most pronounced among patients with extreme risk of mortality.Conclusion:Despite increases in the provision of comfort-oriented care to patients with meta-static cancer,few receive such services.We recommend screening protocols in hospitals to identify patients who are good candidates for palliative care consultation and hospice referral.

Withaferin A targeting both cancer stem cells and metastatic cancer stem cells in the UP-LN1 carcinoma cell model

Aim:As our understanding of cancer stem cell(CSC)biology improves,search for inhibitory agents of CSCs and metastatic CSCs(mCSCs)positive for CXCR4 is warranted.Withaferin A(WA),a withanolide extracted from the medicinal plant Withania somnifera,has been shown to exhibit anti-cancer effects through multiple mechanisms.Whether WA could selectively target CSCs,mCSCs,or non CSCs of a gastrointestinal(GI)carcinoma tumor remains unclear.Methods:Side-population(SP)analysis,flow cytometric phenotyping and sorting,non-invasive imaging in conjunction with xenotransplantation,and immunohistology were used in this investigation.Results:Using the lymph node metastatic GI cancer cell line UP-LN1,consisting of CD44^(high)/CD24^(low)floating(F)and CD44^(low)/CD24^(high)adherent(A)cell subsets,this study demonstrated that as compared with parental UP-LN1 cells or A cells,WA preferentially reduced F-cell proliferation,tumor sphere formation,and SP cells in vitro in greater effi ciencies by apoptosis.This action was mechanistically mediated via the down-regulation of CXCR4/CXCL12 and STAT3/interleukin-6 axes,both of which are instrumental in the acquisition of metastatic ability.Attenuation of interferon-γ-induced CXCR4 expression in F cells by knockdown with siRNA or blocking with an anti-CXCR4 antibody,followed by Western blot analysis,showed signifi cantly reduced metastatic potential in vitro.The extent of in vitro anti-invasive effect of WA on the IFN-γ-treated F cells was signifi cantly greater than on the F cells without WA treatment,or F cells treated with control siRNA or with control IgG antibody.The observed in vitro effects of WA on the CSC and mCSC targeting were validated by data obtained with non-invasive imaging in NOD/SCID mouse xenotransplantation.Conclusion:WA could effi ciently block the formation of both CSCs and mCSCs in the UP-LN1 cell line,suggesting that WA may be considered an effective therapeutic agent for this type of GI malignancies.

KRAS mutation testing in metastatic colorectal cancer

The KRAS oncogene is mutated in approximately 35%-45% of colorectal cancers, and KRAS mutational status testing has been highlighted in recent years. The most frequent mutations in this gene, point substitutions in codons 12 and 13, were validated as negative predictors of response to anti-epidermal growth factor receptor antibodies. Therefore, determining the KRAS mutational status of tumor samples has become an essential tool for managing patients with colorectal cancers. Currently, a variety of detection methods have been established to analyze the mutation status in the key regions of the KRAS gene; however, several challenges remain related to standardized and uniform testing, including the selection of tumor samples, tumor sample processing and optimal testing methods. Moreover, new testing strategies, in combination with the mutation analysis of BRAF , PIK3CA and loss of PTEN proposed by many researchers and pathologists, should be promoted. In addition, we recommend that microsatellite instability, a prognostic factor, be added to the abovementioned concomitant analysis. This review provides an overview of KRAS biology and the recent advances in KRAS mutation testing. This review also addresses other aspects of status testing for determining the appropriate treatment and offers insight into the potential drawbacks of mutational testing.

Cetuximab plus FOLFOX6 or FOLFIRI in metastatic colorectal cancer: CECOG trial

AIM: To investigate efficacy and safety of cetuximab combined with two chemotherapy regimens in patients with unresectable metastatic colorectal cancer (mCRC). METHODS: Randomized patients received cetuximab with 5-fluorouracil (5-FU), folinic acid (FA) and oxaliplatin (FOLFOX) 6 (arm A, n = 74) or 5-FU, FA and irinotecan (FOLFIRI) (arm B, n = 77). KRAS mutation status was determined retrospectively in a subset of tumors (n = 117). RESULTS: No significant difference was found between treatment arms A and B in the progression-free survival (PFS) rate at 9 mo, 45% vs 34%; median PFS, 8.6 mo vs 8.3 mo [hazard ratio (HR) = 1.06]; overall response rate (ORR) 43% vs 45% [odds ratio (OR) = 0.93] and median overall survival (OS), 17.4 mo vs 18.9 mo (HR = 0.98). Patients with KRAS wild-type tumors demonstrated improved PFS (HR = 0.55, P = 0.0051), OS, (HR = 0.62, P = 0.0296) and ORR (53% vs 36%) and in arm A, improved PFS (HR = 0.49, P = 0.0196), OS (HR = 0.48, P = 0.0201) and ORR (56%vs 30%), compared with patients with KRAS mutated tumors. In arm B no significant differences were found in efficacy by KRAS mutation status. Treatment in arms A and B was generally well tolerated. CONCLUSION: This study confirms that combinations of cetuximab with FOLFOX6 or FOLFIRI are effective and significantly improve clinical outcome in KRAS wild-type compared with KRAS mutated mCRC.

Systemic treatment for metastatic colorectal cancer

Significant progress has been achieved in the treatment of metastatic colorectal cancer(mCRC)patients during the last 20 years.There are currently numerous treatments available for the first-line treatment of mCRC.Sophisticated molecular technologies have been developed to reveal novel prognostic and predictive biomarkers for CRC.The development of next-generation sequencing and wholeexome sequencing,which are strong new tools for the discovery of predictive molecular biomarkers to facilitate the delivery of customized treatment,has resulted in tremendous breakthroughs in DNA sequencing technology in recent years.The appropriate adjuvant treatments for mCRC patients are determined by the tumor stage,presence of high-risk pathologic characteristics,microsatellite instability status,patient age,and performance status.Chemotherapy,targeted therapy,and immunotherapy are the main systemic treatments for patients with mCRC.Despite the fact that these novel treatment choices have increased overall survival for mCRC,survival remains optimal for individuals with non-metastatic disease.The molecular technologies currently being used to support our ability to practice personalized medicine;the practical aspects of applying molecular biomarkers to regular clinical practice;and the evolution of chemotherapy,targeted therapy,and immunotherapy strategies for the treatment of mCRC in the front-line setting are all reviewed here.

Mechanisms of resistance to anti-epidermal growth factor receptor inhibitors in metastatic colorectal cancer

The prognosis of patients with metastatic colorectal cancer (mCRC) remain poor despite the impressive improvement of treatments observed over the last 20 years that led to an increase in median overall survival from 6 mo, with the only best supportive care, to approximately 30 mo with the introduction of active chemotherapy drugs and targeted agents. The monoclonal antibodies (moAbs) cetuximab and panitumumab, directed against the epidermal growth factor receptor (EGFR), undoubtedly represent a major step forward in the treatment of mCRC, given the relevant efficacy in terms of progression-free survival, overall survival, response rate, and quality of life observed in several phase III clinical trials among different lines of treatment. However, the anti-EGFR moAbs were shown only to be effective in a subset of patients. For instance, KRAS and NRAS mutations have been identified as biomarkers of resistance to these drugs, improving the selection of patients who might derive a benefit from these treatments. Nevertheless, several other alterations might affect the response to these drugs, and unfortunately, even the responders eventually become resistant by developing secondary (or acquired) resistance in approximately 13-18 mo. Several studies highlighted that the landscape of responsible alterations of both primary and acquired resistance to anti-EGFR drugs biochemically converge into MEK-ERK and PIK3CA-AKT pathways. In this review, we describe the currently known mechanisms of primary and acquired resistance to anti-EGFR moAbs together with the various strategies evaluated to prevent, overcame or revert them.