Ribosome biogenesis in cancer: new players and therapeutic avenues

The ribosome is a complex molecular machine composed of numerous distinct proteins and nucleic acids and is responsible for protein synthesis in every living cell. Ribosome biogenesis is one of the most multifaceted and energy- demanding processes in biology, involving a large number of assembly and maturation factors, the functions of which are orchestrated by multiple cellular inputs, including mitogenic signals and nutrient availability. Although causal associations between inherited mutations affecting ribosome biogenesis and elevated cancer risk have been established over the past decade, mechanistic data have emerged suggesting a broader role for dysregulated ribosome biogenesis in the development and progression of most spontaneous cancers. In this Opinion article, we highlight the most recent findings that provide new insights into the molecular basis of ribosome biogenesis in cancer and offer our perspective on how these observations present opportunities for the design of new targeted cancer treatments.

Targeting Colon Cancers with Mutated BRAF and Microsatellite Instability

The subgroup of colon cancer (CRC) characterized by mutation in the BRAF gene and high mutation rate in the genomic DNA sequence, known as the microsatellite instability (MSI) phenotype, accounts for roughly 10% of the patients and derives from polyps with a serrated morphology. In this review, both features are discussed with regard to therapeutic opportunities. The most prevalent cancer-associated BRAF mutation is BRAF V600E that causes constitutive activation of the pro-proliferative MAPK pathway. Unfortunately, the available BRAF-specific inhibitors had little clinical benefit for metastatic CRC patients due to adaptive MAPK reactivation. Recent contributions for the development of new combination therapy approaches to pathway inhibition will be highlighted. In addition, we review the promising role of the recently developed immune checkpoint therapy for the treatment of this CRC subtype. The MSI phenotype of this subgroup results from an inactivated DNA mismatch repair system and leads to frameshift mutations with translation of new amino acid stretches and the generation of neo-antigens. This most likely explains the observed high degree of infiltration by tumour-associated lymphocytes. As cytotoxic lymphocytes are already part of the tumour environment, their activation by immune checkpoint therapy approaches is highly promising.

Dishevelled1-3 contribute to multidrug resistance in colorectal cancer via activating Wnt/β-catenin signaling

Multidrug resistance is a great obstacle in successful chemotherapy of colorectal cancer. However, the molecular mechanism underlying multidrug resistance is not fully understood. Dishevelled, a pivot in Wnt signaling, has been linked to cancer progression, while its role in chemoresistance remains unclear. Here, we found that Dishevelled1-3 was over-expressed in multidrug-resistant colorectal cancer cells (HCT-8/VCR) compared to their parental cells. Silencing Dishevelled1-3 resensitized HCT-8/VCR cells to multiple drugs including vincristine, 5-fluorouracil and oxaliplatin. Moreover, Dishevelled1-3 increased the protein levels of multidrug resistance protein 1 (P-gp/MDR1), multidrug resistance-associated protein 2 (MRP2), and breast cancer resistance protein (BCRP), Survivin and Bcl-2 which are correlated with multidrug resistance. shβ-catenin abolished Dishevelled-mediated these protein expressions. Unexpectedly, none of Dishevelled1-3 controlled β-catenin accumulation and nuclear translocation. Furthermore, the nuclear translocations of Dishevelled1-3 were promoted in HCT-8/VCR cells compared to HCT-8. Dishevelled1-3 bound to β-catenin in nucleus, and promoted nuclear complex formation and transcription activity of β-catenin/TCF. Taken together, Dishevelled1-3 contributed to multidrug resistance in colorectal cancer via activating Wnt/β-catenin signaling and inducing the expressions of P-gp, MRP2, BCRP, Survivin and Bcl-2, independently of β-catenin accumulation and nuclear translocation. Silencing Dishevelled1-3 resensitized multidrug-resistant colorectal cancer cells, providing a novel therapeutic target for successful chemotherapy of colorectal cancer.

Circulating tumor DNA analysis detects minimal residual disease and predicts recurrence in patients with stage II colon cancer

Detection of circulating tumor DNA (ctDNA) after resection of stage II colon cancer may identify patients at the highest risk of recurrence and help inform adjuvant treatment decisions. We used massively parallel sequencing-based assays to evaluate the ability of ctDNA to detect minimal residual disease in 1046 plasma samples from a prospective cohort of 230 patients with resected stage II colon cancer. In patients not treated with adjuvant chemotherapy, ctDNA was detected postoperatively in 14 of 178 (7.9%) patients, 11 (79%) of whom had recurred at a median follow-up of 27 months; recurrence occurred in only 16 (9.8 %) of 164 patients with negative ctDNA [hazard ratio (HR), 18; 95% confidence interval (CI), 7.9 to 40; P < 0.001]. In patients treated with chemotherapy, the presence of ctDNA after completion of chemotherapy was also associated with an inferior recurrence-free survival (HR, 11; 95% CI, 1.8 to 68; P = 0.001). ctDNA detection after stage II colon cancer resection provides direct evidence of residual disease and identifies patients at very high risk of recurrence.

Personalizing Adjuvant Therapy for Stage II/III Colorectal Cancer

This review focuses on three areas of interest with respect to the treatment of stage II and III colon and rectal cancer, including (1) tailoring adjuvant therapy for the geriatric population, (2) the controversy as to the optimal adjuvant therapy strategy for patients with locoregional rectal cancer and for patients with colorectal resectable metastatic disease, and (3) discussion of the microenvironment, molecular profiling, and the future of adjuvant therapy. It has become evident that age is the strongest predictive factor for receipt of adjuvant chemotherapy, duration of treatment, and risk of treatment-related toxicity. Although incorporating adjuvant chemotherapy for patients who have received neoadjuvant chemoradiation and surgery would appear to be a reasonable strategy to improve survivorship as an extrapolation from stage III colon cancer adjuvant trials, attempts at defining the optimal rectal cancer population that would benefit from adjuvant therapy remain elusive. Similarly, the role of adjuvant chemotherapy for patients after resection of metastatic colorectal cancer has not been clearly defined because of very limited data to provide guidance. An understanding of the biologic hallmarks and drivers of metastatic spread as well as the micrometastatic environment is expected to translate into therapeutic strategies tailored to select patients. The identification of actionable targets in mesenchymal tumors is of major interest.

Molecular Landscape and Treatment Options for Patients with Metastatic Colorectal Cancer

Over the last 20 years, median survival for patients with metastatic colorectal cancer (CRC) has remarkably improved from about 12 to over 30 months, mainly because of the development of new agents and patient selection using predictive biomarkers. However, the identification of the most effective treatment for an individual patient is still a challenge. Molecular profiling of CRC has made great progress, but it is limited by tumor heterogeneity and absence of driver mutation. However, RAS, BRAF, and microsatellite instability are validated biomarker recommended by NCCN and ESMO. In this review, we discuss recent advances and future developments.

Combination adjuvant chemotherapy with targeted drugs for treatment of colorectal cancer: A network meta-analysis

Colorectal cancer (CRC) is one of the most fatal diseases in the world. The efficacy of present chemotherapy treatments are limited and the addition of targeted drugs have been put into practice. However, the preferred treatments among adjuvant chemotherapies still remain controversial and uncertain. To evaluate the efficacy of different adjuvant chemotherapies combined with or without targeted drugs to determine the optimal treatment for patients with CRC in clinical practice. PubMed and Embase were searched for eligible articles and only randomized controlled trials (RCTs) were included. R (Version 3.2.5) software was utilized to conduct the Bayesian network meta-analysis (NMA). Outcomes including overall survival (OS) and progression-free survival (PFS) were displayed using hazard ratios. And the rank probabilities of each treatment were evaluated using the surface under cumulative ranking curve. A total of 75 RCTs published after 1997 were included in the data analysis. Overall, FOLFIRI+ cetuximab was found to be the most effective treatment in terms of long-term survival and FOLFOX was the most effective pure chemotherapy treatment. The addition of targeted drugs will greatly improve the efficacy of chemotherapy. Targeted drug cetuximab combined with the chemotherapy regiment FOLFIRI is the preferable treatment for patients with CRC in clinical practice.

Combination of primary tumor location and mismatch repair status guides adjuvant chemotherapy in stage II colon cancer

Background

Current opinions on the benefits of adjuvant chemotherapy for stage II colon cancer are divided and reformative election of these patients is required. We examined whether the primary tumor location based on mismatch repair status and other risk factors could better inform the current guideline.

Materials and Methods

A total of 673 consecutive patients with stage II colon cancer were included in the analysis. Differences in the common clinicopathological factors between left-sided colon cancer and right-sided colon cancer were analyzed using Fisher's exact analysis. Kaplan-Meier analysis was used to distinguish the survival difference by primary tumor location and/or MMR status.

Results

RCC had a shorter overall survival (P = 0.001) and Disease-free survival (P = 0.050) than LCC but was associated with survival benefit from adjuvant chemotherapy (P = 0.001 and P = 0.011 for OS and DFS, respectively). Mismatch repair-proficient had a shorter OS (P = 0.036) and disease free survival (P = 0.034) than mismatch-repair deficient but chemotherapy improved the OS (P = 0.007). When the primary tumor location and MMR status were combined, the PMMR/RCC was the only subgroup that could benefit from adjuvant chemotherapy (P < 0.001 and P = 0.002 for OS and DFS, respectively). Other tumors such as DMMR/RCC, DMMR/LCC, and PMMR/LCC did not benefit.

Conclusions

The observed survival benefits in PMMR/RCC patients treated with adjuvant chemotherapy will allow better selection of patients for chemotherapy who are in stage II.

Comparative Analysis of Tumor Cell Dissemination to the Sentinel Lymph Nodes and to the Bone Marrow in Patients With Nonmetastasized Colon Cancer: A Prospective Multicenter Study

Importance

Small nodal tumor infiltrates (SNTI; isolated tumor cells and micrometastases) in sentinel lymph nodes and bone marrow micrometastases (BMM) were independently described as prognostic factors in patients with colon cancer.

Objective

To examine the association between the occurrence of SNTI and BMM as well as their prognostic relevance.

Design, Setting, and Participants

This prospective study was conducted at 3 university-affiliated institutions in Switzerland between May 2000 and December 2006. Statistical analyses were performed in October 2016. A total of 122 patients with stage I to III colon cancer were included. Follow-up time exceeded 6 years, with no patients lost to follow-up.

Interventions

Bone marrow aspiration from the iliac crests and in vivo sentinel lymph node mapping were performed during open standard oncological resection. Bone marrow aspirates were stained with the pancytokeratin marker A45-B/B3. All sentinel lymph nodes underwent multilevel sectioning and were stained with hematoxylin-eosin and the pancytokeratin marker AE1/AE3.

Main Outcomes and Measures

Association of SNTI in sentinel lymph nodes and BMM in patients with stage I to III colon cancer and the prognostic effect on disease-free survival (DFS) and overall survival (OS).

Results

Of the 122 patients, 63 (51.6%) were female, with a mean (SD) age of 71.2 (11.7) years. Small nodal tumor infiltrates and BMM were found in a total of 21 patients (17.2%) and 46 patients (37.7%), respectively. The occurrence of BMM was not associated with the presence of SNTI by standard correlation (κ, -0.07; 95% CI, -0.29 to 0.14; P = .49) nor by univariate logistic regression analysis (odds ratio, 0.64; 95% CI, 0.22-1.67; P = .37) or multivariate logistic regression analysis (odds ratio, 1.09; 95% CI, 0.34-3.28; P = .88). The presence of SNTI was an independent negative prognostic factor for DFS (hazard ratio [HR], 2.93; 95% CI, 1.24-6.93; P = .02) and OS (HR, 4.04; 95% CI, 1.56-10.45; P = .005), as was BMM (HR, 2.07; 95% CI, 1.06-4.06; P = .04; and HR, 2.68; 95% CI, 1.26-5.70; P = .01; respectively). The combined detection of BMM and SNTI demonstrated the poorest DFS (HR, 6.73; 95% CI, 2.29-19.76; P = .006) and OS (HR, 5.96; 95% CI, 1.66-21.49; P = .03).

Conclusions and Relevance

This study demonstrates no association between the occurrence of SNTI and BMM in patients with stage I to III colon cancer. However, both SNTI and BMM are independent negative prognostic factors regarding DFS and OS, and the occurrence of both is associated with significantly worse prognosis compared with either one of them.

Trial Registration

clinicaltrials.gov Identifier: NCT00826579.

Clinical and molecular characterisation of hereditary and sporadic metastatic colorectal cancers harbouring microsatellite instability/DNA mismatch repair deficiency

BACKGROUND

Patients treated with chemotherapy for microsatellite unstable (MSI) and/or mismatch repair deficient (dMMR) cancer metastatic colorectal cancer (mCRC) exhibit poor prognosis. We aimed to evaluate the relevance of distinguishing sporadic from Lynch syndrome (LS)-like mCRCs.

PATIENTS AND METHODS

MSI/dMMR mCRC patients were retrospectively identified in six French hospitals. Tumour samples were screened for MSI, dMMR, RAS/RAF mutations and MLH1 methylation. Sporadic cases were molecularly defined as those displaying MLH1/PMS2 loss of expression with BRAFV600E and/or MLH1 hypermethylation and no MMR germline mutation.

RESULTS

Among 129 MSI/dMMR mCRC patients, 81 (63%) were LS-like and 48 (37%) had sporadic tumours; 22% of MLH1/PMS2-negative mCRCs would have been misclassified using an algorithm based on local medical records (age, Amsterdam II criteria, BRAF and MMR statuses when locally tested), compared to a systematical assessment of MMR, BRAF and MLH1 methylation statuses. In univariate analysis, parameters associated with better overall survival were age (P < 0.0001), metastatic resection (P = 0.001) and LS-like mCRC (P = 0.01), but not BRAFV600E. In multivariate analysis, age (hazard ratio (HR) = 3.19, P = 0.01) and metastatic resection (HR = 4.2, P = 0.001) were associated with overall survival, but not LS. LS-like patients were associated with more frequent liver involvement, metastatic resection and better disease-free survival after metastasectomy (HR = 0.28, P = 0.01). Median progression-free survival of first-line chemotherapy was similar between the two groups (4.2 and 4.2 months; P = 0.44).

CONCLUSIONS

LS-like and sporadic MSI/dMMR mCRCs display distinct natural histories. MMR, BRAF mutation and MLH1 methylation testing should be mandatory to differentiate LS-like and sporadic MSI/dMMR mCRC, to determine in particular whether immune checkpoint inhibitors efficacy differs in these two populations.

The Balance Between Cytotoxic T-cell Lymphocytes and Immune Checkpoint Expression in the Prognosis of Colon Tumors

Background

Immune checkpoint (ICK) expression might represent a surrogate measure of tumor-infiltrating T cell (CTL) exhaustion and therefore be a more accurate prognostic biomarker for colorectal cancer (CRC) patients than CTL enumeration as measured by the Immunoscore.

Methods

The expression of ICKs, Th1, CTLs, cytotoxicity-related genes, and metagenes, including Immunoscore-like metagenes, were evaluated in three independent cohorts of CRC samples (260 microsatellite instable [MSI], 971 non-MSI). Their associations with patient survival were analyzed by Cox models, taking into account the microsatellite instability (MSI) status and affiliation with various Consensus Molecular Subgroups (CMS). PD-L1 and CD8 expression were examined on a subset of tumors with immunohistochemistry. All statistical tests were two-sided.

Results

The expression of Immunoscore-like metagenes was statistically significantly associated with improved outcome in non-MSI tumors displaying low levels of both CTLs and immune checkpoints (ICKs; CMS2 and CMS3; hazard ratio [HR] = 0.63, 95% confidence interval [CI] = 0.43 to 0.92, P = .02; and HR = 0.55, 95% CI = 0.34 to 0.90, P = .02, respectively), but clearly had no prognostic relevance in CRCs displaying higher levels of CTLs and ICKs (CMS1 and CMS4; HR = 0.46, 95% CI = 0.10 to 2.10, P = .32; and HR = 1.13, 95% CI = 0.79 to 1.63, P = .50, respectively), including MSI tumors. ICK metagene expression was statistically significantly associated with worse prognosis independent of tumor staging in MSI tumors (HR = 3.46, 95% CI = 1.41 to 8.49, P = .007). ICK expression had a negative impact on the proliferation of infiltrating CD8 T cells in MSI neoplasms (median = 0.56 in ICK low vs median = 0.34 in ICK high, P = .004).

Conclusions

ICK expression cancels the prognostic relevance of CTLs in highly immunogenic colon tumors and predicts a poor outcome in MSI CRC patients.

Oxaliplatin-induced increase in splenic volume; irreversible change after adjuvant FOLFOX

BACKGROUND AND OBJECTIVES

Oxaliplatin can cause hepatic sinusoidal obstruction syndrome (SOS). SOS can cause chemotherapy-related adverse effects or morbidity after liver resection. Conventionally, SOS is diagnosed using liver biopsy. Recently, it was reported that increased splenic volume (SV) can be used to detect SOS. In this study, we evaluated the changes in SV during adjuvant chemotherapy.

METHODS

We enrolled 103 consecutive patients with stage III and high-risk stage II colorectal cancer treated with mFOLFOX6 (n = 37) or oral fluorouracil and leucovorin (n = 66) after curative surgery. SV was measured three times; pre-operatively, after chemotherapy, and 1 year after chemotherapy.

RESULTS

SV was higher after mFOLFOX6 (median 135.89 mL) than pre-operatively (105.75 mL) (P < 0.001); SV at 1-year after finishing mFOLFOX6 (114.16 mL) returned to the same level as before surgery (P = 0.0015). SV increased in 28 patients (75.7%) treated with mFOLFOX6 (95%CI, 61.8-89.5), but had not recovered in 12 of these cases (42.9%) 1 year after finishing treatment (95%CI, 17.3-47.5). In contrast, oral fluorouracil and leucovorin did not change SV.

CONCLUSIONS

SV increased after adjuvant mFOLFOX6, and had not recovered in almost half of cases 1-year after finishing chemotherapy. This increase may indicate continuous SOS, which can adversely affect treatment after recurrence.

Hypermutated tumours in the era of immunotherapy: The paradigm of personalised medicine

Immune checkpoint inhibitors have demonstrated unprecedented clinical activity in a wide range of cancers. Significant therapeutic responses have recently been observed in patients presenting mismatch repair-deficient (MMRD) tumours. MMRD cancers exhibit a remarkably high rate of mutations, which can result in the formation of neoantigens, hypothesised to enhance the antitumour immune response. In addition to MMRD tumours, cancers mutated in the exonuclease domain of the catalytic subunit of the DNA polymerase epsilon (POLE) also exhibit an ultramutated genome and are thus likely to benefit from immunotherapy. In this review, we provide an overview of recent data on hypermutated tumours, including MMRD and POLE-mutated cancers, with a focus on their distinctive clinicopathological and molecular characteristics as well as their immune environment. We also discuss the emergence of immune therapy to treat these hypermutated cancers, and we comment on the recent Food and Drug Administration approval of an immune checkpoint inhibitor, the programmed cell death 1 antibody (pembrolizumab, Keytruda), for the treatment of patients with metastatic MMRD cancers regardless of the tumour type. This breakthrough represents a turning point in the management of these hypermutated tumours and paves the way for broader strategies in immunoprecision medicine.

BRAF-Mutated Colorectal Cancer: What Is the Optimal Strategy for Treatment?

OPINION STATEMENT

The BRAF activating mutation, harbored by approximately 10% of colorectal cancers (CRC), confers dramatic prognosis to advanced diseases. In early-stage setting, the identification of the BRAF mutation does not impact the therapeutic decision. Yet, the BRAF mutation could be considered as a stratification factor in adjuvant trials, because of its prognostic impact after relapse. Moreover, both BRAF mutation and mismatch repair (MMR) statuses should be determined in all CRC to help identify sporadic tumors versus Lynch syndrome-related tumors. Indeed, in patients with MMR-deficient (dMMR) tumors and MLH1 loss of expression, the BRAFV600E mutation indicates a sporadic origin. In advanced BRAF-mutated CRC, the standard of care remains fluoropyrimidine-based cytotoxic regimen in combination with bevacizumab. Although a recent meta-analysis showed that there was insufficient data to justify the exclusion of anti-EGFR monoclonal antibodies, antiangiogenic agents should be preferred in the first-line setting. Despite the lack of a randomized phase 3 study dedicated to BRAF-mutated CRC, chemotherapy intensification combining a quadruple association of 5-fluorouracil, oxaliplatin, irinotecan (FOLFOXIRI), and bevacizumab seems like a valid option. Although first results with BRAF inhibitors as single agents in BRAF-mutated CRC were disappointing, their association with therapies targeting the MAPK pathway seems to overcome the primary resistance to BRAF inhibition. In the field of sporadic CRC, the BRAF mutation is strongly associated with MMR deficiency. Considering breakthrough results of immune checkpoint inhibitors in dMMR repair tumors, determination of the MMR status appears to be mandatory. Given the dramatic prognosis conferred by the BRAF mutation, patients with BRAF-mutated advanced CRC need to be systematically identified and proposed for clinical trial enrolment in order to benefit from innovative therapies.

Time-dependent and nonlinear effects of prognostic factors in nonmetastatic colorectal cancer

The survival risk following curative surgery for nonmetastatic colorectal cancer (CRC) may be over- or underestimated due to a lack of attention to nonlinear effects and violation of the proportional hazards assumption. In this paper, we aimed to detect and interpret the shape of time-dependent and nonlinear effects to improve the predictive performance of models of prognoses in nonmetastatic CRC patients. Data for nonmetastatic CRC patients diagnosed between 2004 and 2012 were obtained from the Surveillance Epidemiology End Results registry. Time-dependent and nonlinear effects were tested and plotted. A nonlinear model that used random survival forests was implemented. The estimated 5-year cancer-specific death rate was 17.95% (95% CI, 17.70-18.20%). Tumor invasion depth, lymph node status, age at diagnosis, tumor grade, histology and tumor site were significantly associated with cancer-specific death. Nonlinear and time-dependent effects on survival were detected. Positive lymph node number had a larger effect per unit of measurement at low values than at high values, whereas age at diagnosis showed the opposite pattern. Moreover, nonproportional hazards were detected for all covariates, indicating that the contributions of these risks to survival outcomes decreased over time. The nonlinear model predicted prognoses more accurately (C-index: 0.7934, 0.7933-0.7934) than did the Fine and Gray model (C-index: 0.7550, 0.7510-0.7583). The three-dimensional cumulative incidence curves derived from nonlinear model were used to identify the change points of the risk trends. It would be useful to implement these findings in treatment plans and follow-up surveillance in nonmetastatic CRC patients.

Molecular Markers for Colorectal Cancer

Colorectal cancers develop through at least 3 major pathways, including chromosomal instability, mismatch repair, and methylator phenotype. These pathways can coexist in a single individual and occur in both sporadic and inherited colorectal cancers. In spite of the unique molecular and genetic signatures of colorectal cancers, nonspecific chemotherapy based on the antineoplastic effects of 5-fluorouracil is the cornerstone of therapy for stage III and some stage II disease. Techniques to recognize colorectal cancer at the molecular level have facilitated development of new signature drugs designed to inhibit the unique pathways of colorectal cancer growth and immunity.

Present and future of metastatic colorectal cancer treatment: A review of new candidate targets

In the last two decades, great efforts have been made in the treatment of metastatic colorectal cancer (mCRC) due to the approval of new target agents for cytotoxic drugs. Unfortunately, a large percentage of patients present with metastasis at the time of diagnosis or relapse after a few months. The complex molecular heterogeneity of this disease is not completely understood; to date, there is a lack of predictive biomarkers that can be used to select subsets of patients who may respond to target drugs. Only the RAS-mutation status is used to predict resistance to anti-epidermal growth factor receptor agents in patients with mCRC. In this review, we describe approved targeted therapies for the management of metastatic mCRC and discuss new candidate targets on the horizon.

Tumor location as a novel high risk parameter for stage II colorectal cancers

Current studies do not accurately evaluate the influence of tumor location on survival of colorectal cancer patients. This study aimed to explore whether tumor location could be identified as another high-risk factor in stage II colorectal cancer by using data identified from the Surveillance, Epidemiology, and End Results database. All colorectal cancer patients between 2004 and 2008 were grouped into three according to tumor location. Of 33,789 patients diagnosed with stage II colorectal cancer, 46.8% were right colon cancer, 37.5% were left colon cancer and 15.7% were rectal cancer. The 5-year cancer specific survivals were examined. Right colon cancer was associated with the female sex, older age (> 50), and having over 12 lymph nodes resected. Conversely, rectal cancer was associated with the male sex, patients younger than 50 years of age and insufficient lymph node resection. The characteristics of left colon cancer were between them and associated with Asian or Pacific Islander populations, T4 stage, and Grade II patients. The prognostic differences between three groups were significant and retained after stratification by T stage, histological grade, number of regional nodes dissected, age at diagnose, race and sex. Furthermore, the significant difference of location was retained as an independent high-risk parameter. Thus, stage II colorectal cancers of different locations have different clinic-pathological features and cancer-specific survivals, and tumor location should be recognized as another high-risk parameter in stage II colorectal cancer.

What We Know About Stage II and III Colon Cancer: It's Still Not Enough

The introduction of oxaliplatin as adjuvant treatment for stage III colon cancer in 2004 has been the last practice changing progress in adjuvant treatment for patients with early colon cancer. Since then, many prognostic and predictive biomarkers have been studied, but only DNA mismatch repair status has been validated as having an important prognostic value. Accordingly, TNM and clinical-pathological patterns, such as pT4 lesions and lymph node sampling <12 nodes, are the main factors that guide physicians' choice regarding adjuvant treatment. More recently, many biomarkers showed promising results: POLE, ErbB2, CDX2, SMAD4, BRAF and KRAS. In addition to these, immune-contexture, molecular classification, and gene signatures could become new ways to better classify colon cancer patients with more discriminatory power than TNM. The aim of this review is to report the state-of-the-art of prognostic and predictive factors in the adjuvant setting and which of these could modify clinical practice and maybe replace TNM classification.

The G2 checkpoint inhibitor CBP-93872 increases the sensitivity of colorectal and pancreatic cancer cells to chemotherapy

CBP-93872 suppresses maintenance of DNA double-stranded break-induced G2 checkpoint, by inhibiting the pathway between ataxia-telangiectasia mutated (ATM) and ATM- and Rad3-related (ATR) activation. To examine the potential use of CBP-93872 for clinical applications, we analyzed the synergistic effects of platinum-containing drugs, oxaliplatin and cisplatin, pyrimidine antimetabolites, gemcitabine and 5-fluorouracil (5-FU), in combination with CBP-93872, on cell lethality in colorectal and pancreatic cancer cell lines. Treatment with CBP-93872 significantly increased cancer cell sensitivities to various chemotherapeutic agents tested through suppression of checkpoint activation. Our results thus reveal that combination treatment of CBP-93872 with known chemotherapeutic agents inhibits phosphorylation of ATR and Chk1, and induces cell death.

Dissecting microsatellite instability in colorectal cancer: one size does not fit all

Microsatellite instability (MSI) marks distinct subsets of tumors in many cancer types and is caused by mutations in genes required for mismatch repair. A recent report analyses the molecular foundations of MSI-positive colorectal cancers and reveals substantial molecular heterogeneity, which might have consequences for the potential use of immunotherapy in MSI-positive cancers.See related research by Sveen et al. 10.1186/s13073-017-0434-0.

The current value of determining the mismatch repair status of colorectal cancer: A rationale for routine testing

Colorectal Cancer (CRC) is the third most prevalent cancer in men and women. Up to 15% of CRCs display microsatellite instability (MSI). MSI is reflective of a deficient mismatch repair (MMR) system and is most commonly caused by hypermethylation of the MLH1 promoter. However, it may also be due to autosomal dominant constitutional mutations in DNA MMR, termed Lynch Syndrome. MSI may be diagnosed via polymerase chain reaction (PCR) or alternatively, immunohistochemistry (IHC) can identify MMR deficiency (dMMR). Many institutions now advocate universal tumor screening of CRC via either PCR for MSI or IHC for dMMR to guide Lynch Syndrome testing. The association of sporadic MSI with methylation of the MLH1 promoter and an activating BRAF mutation may offer further exclusion criteria for genetic testing. Aside from screening for Lynch syndrome, MMR testing is important because of its prognostic and therapeutic implications. Several studies have shown MSI CRCs exhibit different clinicopathological features and prognosis compared to microsatellite-stable (MSS) CRCs. For example, response to conventional chemotherapy has been reported to be less in MSI tumours. More recently, MSI tumours have been shown to be responsive to immune-checkpoint inhibition providing a novel therapeutic strategy. This provides a rationale for routine testing for MSI or dMMR in CRC.

Association between mutations of critical pathway genes and survival outcomes according to the tumor location in colorectal cancer

BACKGROUND

Colorectal cancer (CRC) develops through the alteration of several critical pathways. This study was aimed at evaluating the influence of critical pathways on survival outcomes for patients with CRC.

METHODS

Targeted next-generation sequencing of 40 genes included in the 5 critical pathways of CRC (WNT, P53, RTK-RAS, phosphatidylinositol-4,5-bisphosphate 3-kinase [PI3K], and transforming growth factor β [TGF-β]) was performed for 516 patients with stage III or high-risk stage II CRC treated with surgery followed by adjuvant fluoropyrimidine and oxaliplatin chemotherapy. The associations between critical pathway mutations and relapse-free survival (RFS) and overall survival were analyzed. The associations were further analyzed according to the tumor location.

RESULTS

The mutation rates for the WNT, P53, RTK-RAS, PI3K, and TGF-β pathways were 84.5%, 69.0%, 60.7%, 30.0%, and 28.9%, respectively. A mutation in the PI3K pathway was associated with longer RFS (adjusted hazard ratio [HR], 0.59; 95% confidence interval [CI], 0.36-0.99), whereas a mutation in the RTK-RAS pathway was associated with shorter RFS (adjusted HR, 1.60; 95% CI, 1.01-2.52). Proximal tumors showed a higher mutation rate than distal tumors, and the mutation profile was different according to the tumor location. The mutation rates of Kirsten rat sarcoma viral oncogene homolog (KRAS), phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit α (PIK3CA), and B-Raf proto-oncogene serine/threonine kinase (BRAF) were higher in proximal tumors, and the mutation rates of adenomatous polyposis coli (APC), tumor protein 53 (TP53), and neuroblastoma RAS viral oncogene homolog (NRAS) were higher in distal tumors. The better RFS with the PI3K pathway mutation was significant only for proximal tumors, and the worse RFS with the RTK-RAS pathway mutation was significant only for distal tumors.

CONCLUSIONS

A PI3K pathway mutation was associated with better RFS for CRC patients treated with adjuvant chemotherapy, and an RTK-RAS pathway mutation was associated with worse RFS. The significance of the prognostic impact differed according to the tumor location. Cancer 2017;123:3513-23. © 2017 American Cancer Society.

Association of DNA Mismatch Repair and Mutations in BRAF and KRAS With Survival After Recurrence in Stage III Colon Cancers : A Secondary Analysis of 2 Randomized Clinical Trials

Importance

The association of biomarkers with patient survival after recurrence (SAR) of cancer is poorly understood but may guide management and treatment.

Objective

To determine the association of DNA mismatch repair (MMR) status and somatic mutation in the B-Raf proto-oncogene (c.1799T>A [V600E]; BRAFV600E) or exon 2 of the KRAS proto-oncogene (KRAS) in the primary tumor with SAR in patients with stage III colon carcinomas treated with adjuvant chemotherapy.

Design, Setting, and Participants

Patients with resected stage III colon cancers were randomized to adjuvant FOLFOX (folinic acid [leucovorin calcium], fluorouracil, and oxaliplatin) chemotherapy with or without cetuximab (North Central Cancer Treatment Group N0147 trial) or adjuvant FOLFOX chemotherapy with or without bevacizumab (National Surgical Adjuvant Breast and Bowel Project C-08 trial). Associations of biomarkers with SAR were analyzed using Cox proportional hazards models adjusted for clinicopathologic features and time to recurrence (data collected February 10, 2004, to August 7, 2015).

Main Outcomes and Measures

The primary study outcome was survival after recurrence of cancer. A secondary outcome measure was the effect of the site of the primary tumor on the association of biomarkers with SAR.

Results

Among 871 patients with cancer recurrence in the N0147 trial (472 men [54.2%] and 399 women [45.8%]; mean [SD] age, 57.8 [11.2] years) and 524 in the C-08 trial (269 men [51.3%] and 255 women [48.7%]; mean [SD] age, 57.0 [11.7] years), multivariable analysis revealed that patients whose tumors had deficient vs proficient MMR had significantly better SAR (adjusted hazard ratio [AHR], 0.70; 95% CI, 0.52-0.96; P = .03). Patients whose tumors harbored mutant BRAFV600E (AHR, 2.45; 95% CI, 1.85-3.25; P < .001) or mutant KRAS (AHR, 1.21; 95% CI, 1.00-1.47; P = .052) had worse SAR compared with those whose tumors had wild-type copies of both genes, although only results for BRAFV600E achieved statistical significance. Significant interactions were found for MMR (P = .03) and KRAS (P = .02) by primary tumor site for SAR. Improved SAR was observed for patients with deficient MMR tumors of the proximal vs distal colon (AHR, 0.57; 95% CI, 0.40-0.83; P = .003), and worse SAR was observed for tumors of the distal colon with mutant KRAS in codon 12 (AHR, 1.76; 95% CI, 1.30-2.38; P < .001) and codon 13 (AHR, 1.76; 95% CI, 1.08-2.86; P = .02).

Conclusions and Relevance

In patients with recurrence of stage III colon cancer, deficient MMR was significantly associated with better SAR, and this benefit was limited to primary tumors of the proximal colon. Mutations in BRAFV600E were significantly associated with worse SAR, and worse SAR for BRAFV600E or KRAS mutant tumors was more strongly associated with distal cancers. These biomarkers have implications for patient management at recurrence.

Trial Registration

clinicaltrials.gov Identifiers: NCT00079274 and NCT00096278.

Sidedness is prognostic in locoregional colon cancer: an analysis of 9509 Australian patients

BACKGROUND/AIM

Right sided colon cancer (RsCC) is proposed to be a distinct disease entity to left sided colon cancer (LsCC). We seek to confirm primary tumour location as an independent prognostic factor in locoregional colorectal cancer.

METHODS

All patients with stage I - III primary adenocarcinoma of colon were identified from the New South Wales (NSW) clinical cancer registry (2006-2013). Primary tumour location (RsCC vs LsCC) survival analyses were conducted using the Kaplan-Meier method, and adjusted hazard ratios for 5-year all-cause mortality (OS) and 5-year cancer specific mortality (CSS) were obtained using Cox proportional hazards regression.

RESULTS

We identified 9509 patients including 5051 patients with RsCC and 4458 with LsCC. Patients with RsCC were more likely to be older, female, have a higher Charlson comorbidity index, and have worse tumour prognostic factors. In univariate analysis of all stages combined, those patients with RsCC had a worse overall survival (OS, HR 1.20 95% CI 1.11-1.29, p < 0.0001), although this was not significant in the multivariate analysis (HR 0.96 95% CI 0.89-1.04, p = 0.35). Stage I patients with RsCC had a trend to improved OS (multivariate HR 0.84 95% CI 0.69-1.01, p = 0.07) and a significantly improved CSS (multivariate HR 0.51 95% CI 0.35-0.75, p = 0.0006). In stage II patients with RsCC there was a significantly improved OS (multivariate HR 0.85 95% CI 0.75-0.98, p = 0.02) and CSS (multivariate HR 0.59 95% CI 0.45-0.78, p = 0.0002) compared to LsCC. In stage III patients, those with RsCC had a worse OS (multivariate HR 1.13 95% CI 1.01-1.26, p = 0.032) and a trend to worse CSS (multivariate HR 1.12 95% CI 0.94-1.33, p = 0.22).

CONCLUSIONS

Primary tumour location is an important prognostic factor in locoregional colon cancer with an effect that varies by stage. RsCC is associated with lower all-cause mortality in stage II, and higher all-cause mortality in stage III.

Current and future biomarkers in the treatment of colorectal cancer

Colorectal cancer (CRC) is a leading cause of cancer deaths worldwide. CRC develops as a consequence of genomic instability, characterized by various genetic and epigenetic alterations. Its molecular heterogeneity explains the large variability in patient prognosis and treatment response, emphasizing the need for development of accurate prognostic and predictive biomarkers. This article delineates the different pathways of colorectal carcinogenesis and its molecular subtype classification. With this review, we aim to provide a comprehensive overview of the current and future biomarkers guiding clinical decision-making and CRC treatment.

Comparative Effectiveness Research: The Impact of Biologic Agents in Ethnic Minorities With Metastatic Colorectal Cancer

BACKGROUND

Biologic agents have improved the outcomes of patients with metastatic colorectal cancer (mCRC). However, the clinical trials included a predominately white population (85%), with Hispanic and black patients underrepresented. Thus, the real world benefit for the latter remains unknown. Comparative effectiveness research is a tool allowing for this exploration.

PATIENTS AND METHODS

The demographic and clinical characteristics of patients treated for mCRC from 2000 to 2011 were extracted from the medical records of Montefiore Medical Center. A semiparametric accelerated failure time model was used to assess the survival differences between patients receiving chemotherapy (CT) alone versus CT plus biologic agents (CBT).

RESULTS

Of the 290 patients (black, 45.9%; Hispanic, 26.2%; and white, 27.9%), 53.8% received biologic agents. The median overall survival was 15.2 months in the CT-alone group and 25.6 months in CBT group (P = .004). On univariate analysis, a lower number of metastatic sites, carcinoembryonic antigen < 41 ng/mL, and more lines of CT were associated with improved overall survival. In a propensity score-based analysis of the entire cohort, CBT offered a survival benefit compared with CT alone (increased median survival, 1.44-fold; 95% confidence interval [CI], 1.11-1.86; P = .038). The results of the subgroup analysis suggested a survival benefit for white patients (2.01; 95% CI, 1.26-3.23; P = .031) but not for Hispanic (1.42; 95% CI, 0.91-2.20; P = .370) or black (1.12; 95% CI, 0.76-1.66; P = .596) patients.

CONCLUSION

In the present cohort, CBT was associated with longer survival, with the effect mainly driven by the outcomes for white patients, with black patients not appearing to benefit. These data are provocative and warrant further confirmation. Efforts to increase ethnic minority patients' enrollment in clinical trials is required to prospectively define the benefit from novel therapies.

Distinct clinical outcomes of two CIMP-positive colorectal cancer subtypes based on a revised CIMP classification system

Background:

Colorectal cancer (CRC) is a heterogeneous disease in terms of molecular carcinogenic pathways. Based on recent findings regarding the multiple serrated neoplasia pathway, we revised an eight-marker panel for a new CIMP classification system.

Methods:

1370 patients who received surgical resection for CRCs were classified into three CIMP subtypes (CIMP-N: 0–4 methylated markers, CIMP-P1: 5–6 methylated markers and CIMP-P2: 7–8 methylated markers). Our findings were validated in a separate set of high-risk stage II or stage III CRCs receiving adjuvant fluoropyrimidine plus oxaliplatin (n=950).

Results:

A total of 1287/62/21 CRCs cases were classified as CIMP-N/CIMP-P1/CIMP-P2, respectively. CIMP-N showed male predominance, distal location, lower T, N category and devoid of BRAF mutation, microsatellite instability (MSI) and MLH1 methylation. CIMP-P1 showed female predominance, proximal location, advanced TNM stage, mild decrease of CK20 and CDX2 expression, mild increase of CK7 expression, BRAF mutation, MSI and MLH1 methylation. CIMP-P2 showed older age, female predominance, proximal location, advanced T category, markedly reduced CK20 and CDX2 expression, rare KRAS mutation, high frequency of CK7 expression, BRAF mutation, MSI and MLH1 methylation. CIMP-N showed better 5-year cancer-specific survival (CSS; HR=0.47; 95% CI: 0.28–0.78) in discovery set and better 5-year relapse-free survival (RFS; HR=0.50; 95% CI: 0.29–0.88) in validation set compared with CIMP-P1. CIMP-P2 showed marginally better 5-year CSS (HR=0.28, 95% CI: 0.07–1.22) in discovery set and marginally better 5-year RFS (HR=0.21, 95% CI: 0.05–0.92) in validation set compared with CIMP-P1.

Conclusions:

CIMP subtypes classified using our revised system showed different clinical outcomes, demonstrating the heterogeneity of multiple serrated precursors of CIMP-positive CRCs.

Prognostic Value of E-cadherin-, CD44-, and MSH2-associated Nomograms in Patients With Stage II and III Colorectal Cancer

BACKGROUND: To evaluate the prognostic value of E-cadherin, CD44, and MSH2 expression for colorectal cancer (CRC) and construct nomograms that can predict prognosis. METHODS: We retrospectively analyzed the expression of E-cadherin, CD44, and MSH2 in 223 paraffin-embedded stage II and III CRC specimens using immunohistochemistry in the training cohort. Their prognostic values were assessed using Kaplan–Meier curves and univariate and multivariate COX regression models. Moreover, a number of risk factors were used to form nomograms to evaluate survival, and Harrell's concordance index (C-index) was used to evaluate the predictive accuracy. Further validation of the nomograms was performed in an independent cohort of 115 cases. RESULTS: Low E-cadherin expression and low CD44 expression were significantly associated with diminished overall survival (OS) and disease-free survival (DFS) in stage II and III CRC patients and patients with negative MSH2 expression had better clinical outcomes. Moreover, the multivariate COX analysis identified E-cadherin, CD44 and MSH2 expression as independent prognostic factors for DFS and OS. Using these three markers and three clinicopathological risk variables, two nomograms were constructed and externally validated for predicting OS and DFS (C-index: training cohort, 0.779 (95% CI 0.722–0.835) and 0.771 (0.720–0.822), respectively; validation cohort, 0.773 (0.709–0.837) and 0.670 (0.594–0.747), respectively). CONCLUSION: The expression levels of E-cadherin, CD44 and MSH2 were independent prognostic factors for stage II and III CRC patients. By incorporating clinicopathological features and these biomarkers, we have established two nomograms that could be used to make individualized predictions for OS and DFS.

Colorectal Cancer Liver Metastasis: Evolving Paradigms and Future Directions

In patients with colorectal cancer (CRC) that metastasizes to the liver, there are several key goals for improving outcomes including early detection, effective prognostic indicators of treatment response, and accurate identification of patients at high risk for recurrence. Although new therapeutic regimens developed over the past decade have increased survival, there is substantial room for improvement in selecting targeted treatment regimens for the patients who will derive the most benefit. Recently, there have been exciting developments in identifying high-risk patient cohorts, refinements in the understanding of systemic vs localized drug delivery to metastatic niches, liquid biomarker development, and dramatic advances in tumor immune therapy, all of which promise new and innovative approaches to tackling the problem of detecting and treating the metastatic spread of CRC to the liver. Our multidisciplinary group held a state-of-the-science symposium this past year to review advances in this rapidly evolving field. Herein, we present a discussion around the issues facing treatment of patients with CRC liver metastases, including the relationship of discrete gene signatures with prognosis. We also discuss the latest advances to maximize regional and systemic therapies aimed at decreasing intrahepatic recurrence, review recent insights into the tumor microenvironment, and summarize advances in noninvasive multimodal biomarkers for early detection of primary and recurrent disease. As we continue to advance clinically and technologically in the field of colorectal tumor biology, our goal should be continued refinement of predictive and prognostic studies to decrease recurrence after curative resection and minimize treatment toxicity to patients through a tailored multidisciplinary approach to cancer care.

Role of circulating free DNA in colorectal cancer

The gradual elucidation of the underlying biology of colorectal cancer has provided new insights and therapeutic options for patients with metastatic disease which are selected according to predictive biomarkers. This precision medicine paradigm, however, is incomplete since not all eligible patients respond to these agents and prognostic stratification is largely based on clinicopathologic variants. Importantly, no robust data exist to help properly select patients with localized disease at high risk for recurrence and most likely to benefit from adjuvant chemotherapy. There is a rapidly expanding body of literature regarding the role of the qualitative and quantitative analysis of circulating free DNA in various neoplasms, which consistently outperforms traditional tumor markers both as a predictive and as a prognostic marker. Several lines of evidence suggest that circulating free DNA may exhibit a complementary role to existing modalities for the early diagnosis of colorectal cancer, the selection of patients for adjuvant chemotherapy, for the follow-up of treated patients, for the selection of treatment for advanced disease and the assessment of response and for determining the prognosis of patients. These data, which are reviewed here, illustrate the important role that circulating biomarkers may soon have at the daily clinical practice.

Immunotherapy and patients treated for cancer with microsatellite instability

Microsatellite instability (MSI) is a tumor phenotype linked to somatic or germline (Lynch syndrome) inactivating alterations of DNA mismatch repair genes. A broad spectrum of neoplasms exhibits MSI phenotype, mainly colorectal cancer, endometrial cancer, and gastric cancer. MSI tumors are characterized by dense immune infiltration and high load of tumor neo-antigens. Growing evidence is accumulating on the efficacy of immune checkpoint inhibition for patients treated for MSI solid tumors. We present a comprehensive overview of MSI phenotype, its biological landscape and current diagnostic methods. Then we focus on MSI as a predictive biomarker of response to immune checkpoint inhibition in the context of colorectal cancer and non-colorectal tumors.

From tumour heterogeneity to advances in precision treatment of colorectal cancer

In recent years, the high heterogeneity of colorectal cancer (CRC) has become evident. Hence, biomarkers need to be developed that enable the stratification of patients with CRC into different prognostic subgroups and in relation to response to therapies, according to the distinctive tumour biology. Currently, only RAS-mutation status is used routinely as a negative predictive marker to avoid treatment with anti-EGFR agents in patients with metastatic CRC, and mismatch-repair status can guide the use of adjuvant chemotherapy in patients with early stage colon cancer. Advances in molecular biology over the past decade have enabled a better understanding of the development of CRC, as well as the more-precise use of innovative targeted therapies for this disease, and include three fundamental achievements. First, the availability of large databases to capture and store the genomic landscape of patients with CRC, providing information on the genes that are frequently deregulated in CRC. Second, the possibility of using gene-expression profiling to differentiate the subtypes of CRC into prognostic groups. Third, results from highly sensitive next-generation sequencing analyses have led to an appreciation of the extensive intratumoural heterogeneity of CRC. Herein, we discuss these advances and place them into the clinical context, and present the novel targets and therapeutic opportunities that are on the horizon.

Hospital Variability in Use of Adjuvant Chemotherapy for Patients with Stage 2 and 3 Colon Cancer

BACKGROUND

Following oncologic resection, adjuvant chemotherapy is associated with decreased recurrence and improved survival in stage 3 colon cancer. However, there is controversy regarding its use in stage 2 colon cancer with high-risk features (tumor depth T4, poorly differentiated, positive margin, and/or inadequate lymph node retrieval). Consensus guidelines recommend no adjuvant chemotherapy in the absence of these high-risk features (low-risk stage 2).

OBJECTIVE

This study aimed to examine hospital characteristics associated with poor risk-adjusted, stage-specific guideline compliance for the use of adjuvant chemotherapy in stage 3 and low-risk stage 2 colon cancer.

DESIGN

This was a retrospective study. Stepwise logistic regression was used to identify patient and hospital factors associated with administration of adjuvant chemotherapy. Hierarchical regression models were used to calculate risk- and reliability-adjusted rates of chemotherapy use and observed-to-expected ratios in each hospital's stage 2 low-risk and stage 3 patients.

SETTINGS

Data were retrieved from the National Cancer Database.

PATIENTS

Patients selected were adults treated with oncologic resection for stage 2 to 3 colon cancer between 2004 and 2010.

MAIN OUTCOME MEASURES

The primary outcome measured was receipt of adjuvant chemotherapy.

RESULTS

A total of 167,345 patients were identified at 1395 hospitals. The mean overall risk-adjusted adjuvant chemotherapy rate was 65.3% for stage 3 and 15.2% for low-risk stage 2. Analysis of low outlier hospitals for stage 3 colon cancer, where adjuvant chemotherapy was underutilized, demonstrated that 62.8% were low-volume centers and 51.4% were community centers. Of high outlier hospitals for stage 2 low-risk disease, where adjuvant chemotherapy was overutilized, 87.2% were low-volume hospitals and 67.2% were community centers.

LIMITATIONS

Selection bias and the inability to compare specific chemotherapy regimens were limitations of this study.

CONCLUSIONS

Following oncologic resection, administration of adjuvant chemotherapy for low-risk stage 2 and stage 3 disease varies substantially among hospitals in the United States. Outlier hospitals were most likely to be low-volume community centers.

The evolving role of microsatellite instability in colorectal cancer: A review

Microsatellite instability (MSI) is a molecular marker of a deficient mismatch repair (MMR) system and occurs in approximately 15% of colorectal cancers (CRCs), more frequently in early than late-stage of disease. While in sporadic cases (about two-thirds of MSI-H CRCs) MMR deficiency is caused by an epigenetic inactivation of MLH1 gene, the remainder are associated with Lynch syndrome, that is linked to a germ-line mutation of one of the MMR genes (MLH1, MSH2, MSH6, PMS2). MSI-H colorectal cancers have distinct clinical and pathological features such as proximal location, early-stage (predominantly stage II), poor differentiation, mucinous histology and association with BRAF mutations. In early-stage CRC, MSI can select a group of tumors with a better prognosis, while in metastatic disease it seems to confer a negative prognosis. Although with conflicting results, a large amount of preclinical and clinical evidence suggests a possible resistance to 5-FU in these tumors. The higher mutational load in MSI-H CRC can elicit an endogenous immune anti-tumor response, counterbalanced by the expression of immune inhibitory signals, such as PD-1 or PD-L1, that resist tumor elimination. Based on these considerations, MSI-H CRCs seem to be particularly responsive to immunotherapy, such as anti-PD-1, opening a new era in the treatment landscape for patients with metastatic CRC.

The Clinical Significance of MiR-429 as a Predictive Biomarker in Colorectal Cancer Patients Receiving 5-Fluorouracil Treatment

Background

5-Fluorouracil (5-FU) based treatment is the standard therapy for metastatic colorectal cancer (CRC), but the development of chemoresistance is inevitable. Increasing evidence shows that dysregulation of microRNAs (miRNAs) is involved in malignant transformation. Thus, it is imperative that we find new diagnostic and prognostic marker for chemotherapy in CRC.

Material/Methods

For clinical parameter analysis, 78 CRC tissues and adjacent normal tissues and 45 serum specimens from CRC patients were included in this study. For chemo-response analysis, 116 primary tissues were collected from the patients receiving first-line 5-FU treatment. Quantitative Real-Time PCR (qRT-PCR) was used to detect microRNAs expression.

Results

The expression of miR-429 was significantly increased in both serum and primary tissues from CRC patients, and enhanced miR-429 level was associated with tumor size, lymph node metastasis, and TNM stage. The diagnostic and prognostic values were also confirmed in CRC by using primary tissues. For patients receiving 5-FU-based treatment, miR-429 levels were significantly lower in responding group. The proportions of patients that did not experience response to therapy were higher in primary tumors with high miR-429 expression levels as compared with primary tumors with low miR-429 expression levels. Finally, Kaplan-Meier survival analysis showed that miR-429 is an independent prognostic indicator for chemo-response to 5-FU therapy among CRC patients.

Conclusions

High level of miR-429 expression was correlated with enhanced malignant potential and poor prognosis of CRC patients. Furthermore, miR-429 could affect the chemo-sensitivity of CRC patients to 5-FU therapy and was associated with poor response to 5-FU-based chemotherapy in patients with CRC.

Single Nucleotide Polymorphisms in Genes MACC1, RAD18, MMP7 and SDF-1a As Prognostic Factors in Resectable Colorectal Cancer

BACKGROUND

Colorectal cancer (CRC) represents one of the most common malignancies worldwide. Research has indicated that functional gene changes such as single nucleotide polymorphism (SNP) influence carcinogenesis and metastasis and might have an influence on disease relapse. The aim of our study was to evaluate the role of SNPs in selected genes as prognostic markers in resectable CRC.

PATIENTS AND METHODS

In total, 163 consecutive patients treated surgically for CRC of stages I, II and III at the University Medical Centre in Maribor in 2007 and 2008 were investigated. DNA was isolated from formalin-fixed paraffin-embedded CRC tissue from the Department of Pathology and SNPs in genes SDF-1a, MMP7, RAD18 and MACC1 were genotyped using polymerase chain reaction followed by high resolution melting curve analysis or restriction fragment length polymorphism.

RESULTS

We found worse disease-free survival (DFS) for patients with TT genotype of SNP rs1990172 in gene MACC1 (p = 0.029). Next, we found worse DFS for patients with GG genotype for SNP rs373572 in gene RAD18 (p = 0.020). Higher frequency of genotype GG of MMP7 SNP rs11568818 was found in patients with T3/T4 stage (p = 0.014), N1/N2 stage (p = 0.041) and with lymphovascular invasion (p = 0.018). For MACC1 rs1990172 SNP we found higher frequency of genotype TT in patients with T3/T4 staging (p = 0.024). Higher frequency of genotype GG of RAD18 rs373572 was also found in patients with T1/T2 stage with disease relapse (p = 0.041).

CONCLUSIONS

Our results indicate the role of SNPs as prognostic factors in resectable CRC.

Oxaliplatin added to fluoropyrimidine for adjuvant treatment of colorectal cancer is associated with long-term impairment of peripheral nerve sensory function and quality of life

BACKGROUND

Oxaliplatin-induced peripheral neuropathy (OIPN) of acute and chronic type is well known, but long-term chronic type OIPN and its impact on quality of life (QoL) has not been extensively studied. Clinical experience indicates that oxaliplatin tolerance might vary with climate.

MATERIAL AND METHODS

Patient-reported chronic type OIPN and QoL among patients treated with oxaliplatin added to a fluoropyrimidine (Folfox or Capox) in the adjuvant setting of colorectal cancer (CRC) were assessed in a single center cross-sectional study by using the EORTC QLQ-CIPN20 and QLQ-C30 questionnaires. Comparison was made to patients treated with a fluoropyrimidine (5-FU or capecitabine) alone during the same time period.

RESULTS

Of 161 patients being disease-free 1-8 years after stop of treatment and invited, 84% participated; 65 treated with oxaliplatin and 71 with a fluoropyrimidine alone. Mean cumulative oxaliplatin dose was 567 mg/m² (55% of planned dose). Oxaliplatin-treated patients reported statistically and clinically significant worse sensory as well as motor scale scores, dominated by symptoms from the feet. Severe tingling and numbness in toes/feet was reported by 38% and 37%, respectively, by oxaliplatin-treated patients compared with 8% for both by fluoropyrimidine alone patients (p < 0.001). Subgroup analyses indicated no impact of gender, age, regimen, time since stop of treatment or cumulated oxaliplatin dose for severity of the chronic type OIPN. The oxaliplatin compared with the fluoropyrimidine group reported worse QoL scores throughout all domains, with statistically and clinically significant differences for role and social function, nausea/loss of appetite and financial problems.

CONCLUSIONS

Oxaliplatin added to a fluoropyrimidine for adjuvant treatment of CRC in a country with subarctic climate is associated with long-term, seemingly chronic, sensory neuropathy and impairment of QoL. This should be taken into account in clinical decision making on oxaliplatin treatment in the adjuvant setting.

Optimizing adjuvant therapy and survivorship care of stage III colon cancer

The MOSAIC trial demonstrated nearly a decade ago that the addition of oxaliplatin to 5-fluorouracil improves outcomes in the adjuvant treatment of colon cancer, but no new agents have been shown to be superior to standard FOLFOX therapy. Oncologists have refined the use of oxaliplatin containing regimens to optimize outcomes, improved patient selection for multi-agent chemotherapy and expanded survivorship care to meet the needs of the growing number of survivors. In this article, we review the historical contexts of current therapy, appropriate staging investigations, the importance of timely initiation of therapy and key survivorship issues. We also discuss exciting opportunities for change, including reduced duration of adjuvant chemotherapy and the use of circulating tumor cells and DNA in surveillance.

Cancer vaccines in colon and rectal cancer over the last decade: lessons learned and future directions

INTRODUCTION

Great advances have been made in screening for and treatment of colorectal cancer (CRC), but recurrence rates remain high and additional therapies are needed. There is great excitement around the field of immunotherapy and many attempts have been made to bring immunotherapy to CRC through a cancer vaccine. Areas covered: This is a detailed review of the last decade's significant CRC vaccine trials. Expert commentary: Monotherapy with a CRC vaccine is likely best suited for adjuvant therapy in disease free patients. Vaccine therapy elicits crucial tumor infiltrating lymphocytes, which are lacking in microsatellite-stable tumors, and therefore may be better suited for these patients. The combination of CRC vaccines with checkpoint inhibitors may unlock the potential of immunotherapy for a much broader range of patients. Future studies should focus on vaccine monotherapy in correctly selected patients and combination therapy in more advanced disease.