Prognostic variables in low and high risk stage III colon cancers treated in two adjuvant chemotherapy trials

Standardizing data collection in adjuvant colon cancer trials: A consensus project from the IDEA and ACCENT international consortia and national experts

BACKGROUND

Despite contributions provided by the recent clinical trials, several issues and challenges still remain unsolved in adjuvant colon cancer (CC). Hence, further studies should be planned to better refine risk assessment as well as to establish the optimal treatment strategy in the adjuvant setting. However, it is necessary to request adequate, contemporary and relevant variables and report them homogeneously in order to bring maximal information when analyzing their prognostic value.

MATERIAL AND METHODS

The project was devised to gain a consensus from experts engaged in the planning, accrual and analyses of stage II and III CC clinical trials, to identify mandatory and recommended baseline variables in order to i) harmonize future data collection worldwide in clinical trials dedicated to adjuvant treatment of CC; ii) propose guidance for Case Report Forms to be used for clinical trials in this setting. A total of 72 questions related to variables that should be reported and how to report them in adjuvant clinical trials were approved and then voted to reach a final consensus from panelists.

RESULTS

Data items on patient-related factors, histopathological features, molecular profile, circulating biomarkers and blood analyses were analyzed and discussed by the whole expert panel. For each item, we report data supporting the acquired consensus and the relevant issues that were discussed. Nineteen items were deemed to be mandatory for resected stage III patients and 24 for resected stage II disease. In addition, 9 and 4 items were judged as recommended for stage III and II, respectively.

CONCLUSION

In our opinion, these 28 variables should be used and uniformly reported in more comprehensive CRFs as research groups design future clinical trials in the field of adjuvant colon cancer.

Efficacy and Safety of Neoadjuvant Subcutaneous Envafolimab in dMMR/MSI-H Locally Advanced Colon Cancer

BACKGROUND

Neoadjuvant immunotherapy with programmed death-ligand 1 blockade for colon cancer, especially for mismatch repair-deficient (dMMR)/high microsatellite instability (MSI-H) colon cancer, has gained considerable attention recently.

OBJECTIVE

This study aimed to assess the safety and efficacy of neoadjuvant subcutaneous envafolimab in patients with dMMR/MSI-H locally advanced colon cancer.

METHODS

Patients with dMMR/MSI-H locally advanced colon cancer treated with envafolimab at Sun Yat-sen University Cancer Center and Yunnan Cancer Hospital from October 2021 to July 2023 were retrospectively reviewed and analyzed. The primary endpoint was the pathological complete response (CR) rate, and secondary endpoints were treatment-related adverse events and complete clinical response rate.

RESULTS

Overall, 15 patients were analyzed. After neoadjuvant immunotherapy with envafolimab, six patients achieved a CR, with five partial responses, and four stable disease. Three patients achieving a complete clinical response chose to accept a "watch and wait" strategy, and surgery was performed in 12 patients. Postoperative pathology results revealed seven patients achieved pathological CRs, and five patients achieved tumor regression grade 2, with 66.7% of the total CR rate. The most common treatment-related adverse events were pruritus and rash (40%), with no severe cases. No recurrences occurred over a 7.9-month follow-up.

CONCLUSIONS

Envafolimab yielded promising surgical outcomes and safety in dMMR/MSI-H locally advanced colon cancer, representing a promising treatment modality for this population.

Sidedness is not a prognostic factor in an unselected cohort of patients with colon cancer but prognosis for caecal carcinoma is worse - A multivariate analysis of a large single institution database

PURPOSE

Sidedness has emerged as a prognostic factor for metastatic colorectal cancer treated with modern systemic therapies. This study investigates whether it is also relevant for an unselected patient cohort including all stages.

METHODS

All consecutive patients admitted with colon cancer between 1995 and 2018 were retrieved from an institution-held database. Patients were divided into two cohorts. The first cohort included patients without distant metastases who were able to undergo curative resection. The second cohort presented with distant metastases (stage IV). Potentially prognostic factors were subjected to multivariate Cox Regression analysis.

RESULTS

Overall, 1,606 patients met the inclusion and exclusion criteria. An R0-resection was achieved in 1,222 patients without distant metastases. Five-year cause-specific survival rate was 89.3% for this group. There was no difference between right- and left-sided cancers (88.2% vs. 90.1%, p = 0.220). However, prognosis of caecal carcinoma was significantly worse than that of all other sites combined (83.5% vs. 90.2%, p = 0.007). In multivariate analysis, pT-category, pN-category, grading, vascular invasion, emergency operation, adjuvant chemotherapy, and caecal carcinoma remained as independent prognostic factors. In the 384 patients with stage IV-disease, 3-year overall survival for right- vs. left-sided cancers differed only in univariate analysis (17.7% vs. 28.6%, p = 0.013).

CONCLUSION

In non-metastatic colon cancer, location in the caecum is an independent prognostic factor. In unselected patients with stage IV colon cancer, sidedness was not found to be a prognostic factor. Differentiation into right- and left-sided tumors may be simplistic, and further studies on the biological behavior of different colonic sites are warranted.

Assessment of the DNA Mismatch Repair System Is Crucial in Colorectal Cancers Necessitating Adjuvant Treatment: A Propensity Score-Matched and Win Ratio Analysis

A deficient DNA mismatch repair (MMR) system is identified in a non-negligible part of sporadic colorectal cancers (CRCs), and its prognostic value remains controversial. High tumor mutational burden, along with a poor response to conventional chemotherapy and excellent results from immunotherapy, are the main features of this subset. The aim of this study was to evaluate the predictive value of DNA MMR system status for its best treatment. Four hundred and three CRC patients, operated on from 2014 to 2021 and not treated with immunotherapy, entered this study. Immunohistochemistry and polymerase chain reaction, as appropriate, were used to unequivocally group specimens into microsatellite stable (MSS) and instable (MSI) tumors. The win-ratio approach was utilized to compare composite outcomes. MSI tumors accounted for 12.9% of all series. The right tumor location represented the most important factor related to MSI. The status of the DNA MMR system did not appear to correlate with outcome in early-stage CRCs not requiring adjuvant treatment; in advanced stages undergoing conventional chemotherapy, MSI tumors showed significantly poorer overall and disease-free survival rates and the highest win ratio instead. The determination of DNA MMR status is crucial to recommending correct management. There is clear evidence that instable CRCs needing adjuvant therapy should undergo appropriate treatments.

Short- and long-term outcomes of transanal decompression tube and self-expandable metallic stent for obstructive colorectal cancer based on a multicenter database (KYCC2110)

AIM

There are well-known methods for decompressing the colorectal tract before surgery, including transanal decompression tubes (TDT) and self-expanding metallic stents (SEMS). This study aimed to compare the short and long-term results in patients with malignant large bowel obstruction in whom TDT or SEMS were placed before surgery.

METHODS

This retrospective observational study enrolled 225 patients with malignant large bowel obstruction in whom TDT or SEMS were placed preoperatively and underwent R0 resection between 2008 and 2020. One-to-two propensity score matching was performed according to patient characteristics. Short- and long-term outcomes were compared. The primary endpoint was relapse-free survival (RFS). The secondary endpoints were the overall survival (OS) and postoperative complication rate.

RESULTS

Fifty-seven patients in the TDT group and 114 in the SEMS group were matched. The 3-year RFS rates were 66.7% in the TDT group and 69.9% in the SEMS group (p = 0.54), and the 3-year OS rates were 90.5% in the TDT group and 87.1% in the SEMS group (p = 0.52). No significant differences in the long-term results were observed between the two groups. Regarding short-term results, the SEMS group had significantly fewer stoma construction (p = 0.007) and shorter postoperative hospitalization (p < 0.001). The incidence of postoperative complications (grade ≥ 2) was significantly lower in the SEMS group (p = 0.04).

CONCLUSION

No significant differences in the long-term results were observed between the TDT and SEMS group. The SEMS showed significant usefulness in terms of improving short-term outcomes.

The effect of adjuvant chemotherapy on survival in node negative colorectal cancer with or without perineural invasion: a systematic review and meta-analysis

Purpose

It was aimed at assessing the benefits of adjuvant chemotherapy (ACT) for patients with node-negative colorectal cancer (CRC) either with or without perineural invasion (PNI).

Methods

We systematically searched PubMed, Cochrane Library, Embase, and Web of Science from database inception through October 1, 2023. Survival outcomes were analyzed using hazard ratios (HRs) and corresponding 95% confidence intervals (CIs). The methodological quality of included studies was assessed using the Newcastle-Ottawa Scale (NOS). Heterogeneity for the descriptive meta-analyses was quantified using the I2 statistic.

Results

Ten studies included in this review. ACT improved overall survival (OS) (HR 0.52, 95% CI 0.40-0.69) and disease-free survival (DFS) (HR 0.53, 95% CI 0.35-0.82) in PNI + patients but did not affect DFS (HR 1.13, 95% CI 0.72-1.77) in PNI- patients. A disease-specific survival (DSS) benefit with chemotherapy was observed in PNI + (HR 0.76, 95% CI 0.58-0.99) and PNI- patients (HR 0.76, 95% CI 0.57-1.00). And PNI decreased DFS (HR 1.94, 95% CI 1.52-2.47) and OS (HR 1.75, 95% CI 0.96-3.17) in node-negative CRC.

Conclusions

In conclusion, chemotherapy appears most beneficial for survival outcomes in node-negative patients with PNI, but may also confer some advantage in those without PNI.

Systematic Review Registration

Identifier INPLASY2021120103.

Synchronous and metachronous primary colorectal cancers with concordant and discordant mismatch repair status

Multiple primary colorectal carcinomas (CRCs) synchronous, when detected approximately at the same time, or metachronous, when a significant amount of time has elapsed between diagnoses can show both mismatch repair (MMR) status concordance and discordance between primary tumors. The aim was to evaluate the MMR status of a monoinstitutional, retrospective cohort of synchronous and metachronous CRCs, with a focus on the frequency of cases with discordant MMR status, and explore the MMR status of metastatic nodal deposits. All synchronous and metachronous CRCs diagnosed in our institution between 2011 and 2023 were collected. Clinicopathologic characteristics were evaluated, including MMR status of all CRCs, BRAF mutation, and MLH1 promoter methylation analyses. MMR status discordant cases were further analyzed, and MMR testing was performed on nodal metastases. Of 3671 patients, 107 (2.9%) had multiple CRCs (94 synchronous and 13 metachronous; total number of CRCs 220). Sixty CRCs were MMR deficient (dMMR) (27.3%), and most were right-sided and high-grade and showed special histologic features (P < .00001). Ninety-three patients showed intertumoral MMR concordance: 70 (65.4%) with MMR-proficient (pMMR) CRCs, and 23 (21.5%) were dMMR. Fourteen patients (13.1%) showed intertumoral MMR discordance (at least one dMMR and one pMMR), and in 5 patients, nodal metastases were present: 2 patients harbored metastases only from their pMMR cancer, 2 only from their dMMR cancer, and in 1 patient both pMMR and dMMR metastases were present. In conclusion, all multiple primary CRCs should be analyzed for MMR status as discordant MMR is possible as well as discordant metastatic nodal deposits, and this may be important for patient management.

Outcome of Patients With Early-Stage Mismatch Repair Deficient Colorectal Cancer Receiving Neoadjuvant Immunotherapy: A Systematic Review

PURPOSE

We conducted a systematic review to evaluate the outcome of patients with early-stage (stages I-III) mismatch repair deficient (dMMR) colorectal cancer (CRC) receiving neoadjuvant immunotherapy (NIT) with immune checkpoint inhibitor (ICI)-based regimens.

METHODS

MEDLINE, Scopus, Embase, Web of Science, and Cochrane Central Register of Controlled Trials were searched for publications reporting the outcome of patients with early-stage dMMR CRC receiving NIT. The primary outcome measures were the complete response (CR) rate (clinical CR [cCR] or pathologic CR [pCR]) and the incidence of grade 3 or higher toxicities.

RESULTS

The search identified 37 publications that included 423 patients with colon (n = 326, 77%) and rectal (n = 97,23%) cancers aged 19-82 years; most patients had stage III CRC (88%). Approximately 67% of patients received monotherapy with anti-PD-1 agents; the rest received dual ICIs (ipilimumab plus nivolumab). The CR rate (pCR + cCR) in the overall population was 72% (305 of 423). The R0 resection and pCR rates were 99.3% and 70% among the patients undergoing surgery, respectively. Only four (0.9%) patients had primary resistance to NIT. After median follow-up periods ranging from 4 to 27 months, 3 (0.7%) patients progressed after an initial response. Grade 3 or higher toxicities were uncommon (6.3%), rarely delaying planned surgery.

CONCLUSION

NIT in patients with early-stage dMMR CRC is associated with a high response rate, low primary resistance to immunotherapy and cancer recurrence rate, and an excellent safety profile. The findings of the present systematic review support further investigation of NIT in patients with early-stage dMMR CRC, with a particular emphasis on the organ-preserving potential of this strategy.

Evaluating mismatch repair deficiency in colorectal cancer biopsy specimens

Mismatch repair (MMR) testing on all new cases of colorectal cancer (CRC) has customarily been preferably performed on surgical specimens, as more tissue is available; however, new clinical trials for the use of immune checkpoint inhibitors in the neoadjuvant setting require MMR testing on biopsy samples. This study aims at identifying advantages, disadvantages and any potential pitfalls in MMR evaluation on biopsy tissue and how to cope with them. The study is prospective-retrospective, recruiting 141 biopsies (86 proficient (p)MMR and 55 deficient (d)MMR) and 97 paired surgical specimens (48 pMMR; 49 dMMR). In biopsy specimens, a high number of indeterminate stains was observed, in particular for MLH1 (31 cases, 56.4%). The main reasons were a punctate nuclear expression of MLH1, relatively weak MLH1 nuclear expression compared to internal controls, or both (making MLH1 loss difficult to interpret), which was solved by reducing primary incubation times for MLH1. A mean of  ≥ 5 biopsies had adequate immunostains, compared to ≤ 3 biopsies in inadequate cases. Conversely, surgical specimens rarely suffered from indeterminate reactions, while weaker staining intensity (p < 0.007) for MLH1 and PMS2 and increased patchiness grade (p < 0.0001) were seen. Central artefacts were almost exclusive to surgical specimens. MMR status classification was possible in 92/97 matched biopsy/resection specimen cases, and all of these were concordant (47 pMMR and 45 dMMR). Evaluation of MMR status on CRC biopsy samples is feasible, if pitfalls in interpretation are known, making laboratory-specific appropriate staining protocols fundamental for high-quality diagnoses.

Microsatellite Instability: A Review of Molecular Epidemiology and Implications for Immune Checkpoint Inhibitor Therapy

Microsatellite instability (MSI) is one of the most important molecular characteristics of a tumor, which occurs among various tumor types. In this review article, we examine the molecular characteristics of MSI tumors, both sporadic and Lynch-associated. We also overview the risks of developing hereditary forms of cancer and potential mechanisms of tumor development in patients with Lynch syndrome. Additionally, we summarize the results of major clinical studies on the efficacy of immune checkpoint inhibitors for MSI tumors and discuss the predictive role of MSI in the context of chemotherapy and checkpoint inhibitors. Finally, we briefly discuss some of the underlying mechanisms causing therapy resistance in patients treated with immune checkpoint inhibitors.

MSI colorectal cancer, all you need to know

Colorectal cancer management has been dramatically impacted by molecular profiling these last years. Among these molecular subgroups, patients with microsatellite instability (MSI) are of particular interest, owing to the prognostic and predictive value of this tumor biomarker. This review article explains the molecular abnormalities underlying MSI phenotype and the consequences of such molecular abnormalities on carcinogenesis, genetic instability and immune infiltration. It details the diagnostic methods for identifying MSI colorectal cancer patients and describes how the prognostic and theranostic values of this marker are impacting treatment decision-making for these patients in 2022.

Deficient mismatch repair/microsatellite unstable colorectal cancer: Diagnosis, prognosis and treatment

Microsatellite unstable (MSI) colorectal cancers (CRCs) are due to DNA mismatch repair (MMR) deficiency and occurs in15% of non-metastatic diseases and 5% in the metastatic setting. Nearly 30% of MSI CRCs occur in a context of constitutional mutation of the MMR system (Lynch syndrome). Others are sporadic cancers linked to a hypermethylation of the MLH-1 promoter. The pathogenic alterations of MMR genes lead to the accumulation of frequent somatic mutational events and these tumours arbour a high antigen burden and are highly infiltrated with cytotoxic T-cell lymphocytes. Microsatellite instability/DNA mismatch repair deficiency (MSI/dMMR) status has prognostic and predictive implications in non-metastatic and metastatic CRCs. The prognostic value of MSI status in non-metastatic CRCs has been studied extensively, yet the data are more limited for its predictive value in terms of adjuvant chemotherapy efficacy. In both cases (metastatic and non-metastatic settings) treatment with immune check-point inhibitors (ICIs) have shown a remarkable effectiveness in the context of MSI/dMMR status. Indeed, recent data from prospective cohorts and randomised trials have shown a dramatical improvement of survival with immunotherapy (programmed death-ligand 1 [PD-(L)1]   cytotoxic T-lymphocyte-associated antigen 4 [CTLA-4] blockage) in metastatic or non-metastatic MSI/dMMR CRC. In this review we report and discuss how and for whom to test for the MSI/dMMR phenotype, as well as the prognostic value of this phenotype and the new treatment recommendations options for this unique CRC population. Despite their efficacy, primary and secondary resistance to immune checkpoint inhibitors (ICIs) are observed in more than 50% MSI-H/dMMR CRC patients and in the future how to identify these patients and to overcome resistance will be an important challenge.

Mismatch Repair-Deficient Colorectal Cancer: Building on Checkpoint Blockade

Colorectal cancer (CRC) with deficient DNA mismatch repair (dMMR) is characterized by hypermutation leading to abundant neoantigens that activate an antitumor immune response in the tumor microenvironment. Immune checkpoint inhibitors (ICIs) have transformed the treatment of this subset of CRC and other solid tumors with dMMR, by producing frequent and durable responses that extend patient survival. Recently, the anti-programmed death-1 (PD-1) antibody pembrolizumab was shown to produce significantly longer progression-free survival with fewer adverse events compared with chemotherapy as first-line treatment of metastatic CRC (mCRC) with dMMR. Accordingly, single-agent pembrolizumab represents a new standard of care for dMMR mCRCs including patients with Lynch syndrome and the more common sporadic cases. Furthermore, data indicate that the combination of PD-1 and cytotoxic T-cell lymphocyte-4 inhibitors was more effective than single-agent PD-1 inhibition in patients with dMMR mCRCs, suggesting nonredundant mechanisms of action. Although the benefit of ICIs is currently limited to metastatic disease, studies evaluating ICIs as neoadjuvant and adjuvant therapy in earlier-stage dMMR CRC are ongoing. Despite success of ICIs in the treatment of metastatic dMMR cancers, an appreciable proportion of these tumors demonstrate intrinsic or acquired resistance, and biomarkers to identify these patients are needed. Advances in the understanding of immunotherapy resistance mechanisms hold promise for both biomarker identification and development of novel strategies to circumvent treatment resistance. In this review, we present a comprehensive overview of the evidence for the role of immunotherapy in the treatment of dMMR CRC, discuss resistance mechanisms, and outline potential strategies to circumvent primary and secondary resistance with the goal of broadening the benefit of ICIs.

The relation of blood cell division control protein 42 level with disease risk, comorbidity, tumor features/markers, and prognosis in colorectal cancer patients

BACKGROUND

Cell division control protein 42 (CDC42) is involved in colorectal cancer (CRC) progression by modulating CD8⁺ T cell activation, immune escape, and direct oncogenetic biological processes. This study aimed to explore the correlation of blood CDC42 with disease risk, comorbidities, disease features, tumor markers, and prognosis among CRC patients.

METHODS

CDC42 in peripheral blood mononuclear cells was detected by reverse transcription-quantitative polymerase chain reaction from 250 resectable CRC patients and 50 healthy controls (HCs). CDC42 was divided by quartiles, as well as high and low expressions in CRC patients for correlation and survival analysis.

RESULTS

CDC42 was elevated in CRC patients vs. HCs (p < 0.001), which had a good ability to distinguish CRC patients from HCs with the area under the curve (95% confidence interval) of 0.889 (0.841-0.937). In CRC patients, CDC42 was not associated with demographics or comorbidities (all p > 0.05), while its higher quartile was linked to increased T stage (p < 0.001), N stage (p = 0.009), TNM stage (p < 0.001), abnormal carcinoembryonic antigen (p = 0.043), and adjuvant chemotherapy administration (p = 0.002). Higher CDC42 quartile (p = 0.002) and CDC42 high (vs. low) (p < 0.001) were related to worse disease-free survival (DFS); meanwhile, elevated CDC42 quartile (p = 0.002) and CDC42 high (vs. low) (p = 0.001) were also linked to poor overall survival (OS). Multivariate Cox's regression analysis presented that CDC42 quartile 3 and 4 (vs. quartile 1) independently predicted declined DFS and OS (all p < 0.05).

CONCLUSION

Circulating CDC42 relates to higher disease risk, T, N, and TNM stage, abnormal tumor marker, and poor prognosis among CRC patients.

Salivary Fusobacterium nucleatum serves as a potential biomarker for colorectal cancer

Fusobacterium nucleatum (Fn) is primarily colonized in the oral cavity. Recently, Fn has been closely associated with the tumorigenesis of colorectal cancer (CRC). Here, we showed that the relative level of Fn DNA was increased in the saliva of the CRC group compared with the normal colonoscopy, hyperplastic polyp, and adenoma groups. Receiver operating characteristic curve analysis illustrated that Fn DNA was superior to carcinoembryonic antigen and carbohydrate antigen 19-9 in CRC diagnosis. Moreover, levels of Fn DNA were associated with the overall survival and disease-free survival of CRC patients, which was an independent factor for prognostic prediction. Transcriptome sequencing identified 1,287 differentially expressed mRNAs in tumor tissues between CRC patients with high-Fn and low-Fn infection. Kyoto encyclopedia of genes and genomes analysis showed that ECM-receptor interaction and focal adhesion were the top two significant pathways. Overall, salivary Fn DNA may be a noninvasive diagnostic and prognostic biomarker for CRC patients.

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Fusobacterium nucleatum DNA level is increased in saliva of colorectal cancer patients

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Salivary F. nucleatum DNA is a biomarker for colorectal cancer diagnosis

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Salivary F. nucleatum DNA is an independent prognostic factor

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KEGG identified relationships to ECM-receptor interaction and focal adhesion pathways

PNN and KCNQ1OT1 Can Predict the Efficacy of Adjuvant Fluoropyrimidine-Based Chemotherapy in Colorectal Cancer Patients

The benefit of adjuvant chemotherapy in the early stages of colorectal cancer (CRC) is still disappointing and the prediction of treatment outcome quite difficult. Recently, through a transcriptomic approach, we evidenced a role of PNN and KCNQ1OT1 gene expression in predicting response to fluoropyrimidine-based adjuvant chemotherapy in stage III CRC patients. Thus, the aim of this study was to validate in an independent cohort of stages II–III CRC patients our previous findings. PNN and KCNQ1OT1 mRNA expression levels were evaluated in 74 formalin-fixed paraffin-embedded tumor and matched normal mucosa samples obtained by stages II–III CRC patients treated with fluoropyrimidine-based adjuvant chemotherapy. PININ, the protein encoded by PNN, was immunohistochemically evaluated in 15 tumor and corresponding normal mucosa samples, selected on the basis of a low, medium, or high mRNA expression tumor/mucosa ratio. PNN and KCNQ1OT1 mRNA mean expression levels were significantly higher in tumor compared with normal tissues. Patients with high PNN or KCNQ1OT1 tumor mRNA levels according to ROC-based cutoffs showed a shorter disease-free survival (DFS) compared with patients with low tumor mRNA gene expression. Also, patients with tumor mRNA expression values of both genes below the identified cutoffs had a significantly longer DFS compared with patients with the expression of one or both genes above the cutoffs. In a representative large cohort of stages II–III CRC untreated patients retrieved from GEO datasets, no difference in DFS was observed between patients with high and low PNN or KCNQ1OT1 gene expression levels. These data confirm our previous findings and underscore the relevance of PNN and KCNQ1OT1 expression in predicting DFS in early stages of CRC treated with fluoropyrimidine-based adjuvant chemotherapy. If further validated in a prospective case series, both biomarkers could be used to identify patients who benefit from this treatment and to offer alternative chemotherapy regimens to potential unresponsive patients. In relation to the suggested biological role of PNN and KCNQ1OT1 in CRC, they might also be exploited as potential therapeutic targets.