Utilization and impact of adjuvant chemotherapy among patients with resected stage II colon cancer: a multi-institutional analysis

The Role of Radiomics in Rectal Cancer

PURPOSE

Radiomics is a promising method for advancing imaging assessment in rectal cancer. This review aims to describe the emerging role of radiomics in the imaging assessment of rectal cancer, including various applications of radiomics based on CT, MRI, or PET/CT.

METHODS

We conducted a literature review to highlight the progress of radiomic research to date and the challenges that need to be addressed before radiomics can be implemented clinically.

RESULTS

The results suggest that radiomics has the potential to provide valuable information for clinical decision-making in rectal cancer. However, there are still challenges in terms of standardization of imaging protocols, feature extraction, and validation of radiomic models. Despite these challenges, radiomics holds great promise for personalized medicine in rectal cancer, with the potential to improve diagnosis, prognosis, and treatment planning. Further research is needed to validate the clinical utility of radiomics and to establish its role in routine clinical practice.

CONCLUSION

Overall, radiomics has emerged as a powerful tool for improving the imaging assessment of rectal cancer, and its potential benefits should not be underestimated.

Impact on inadequate lymph node harvest on survival in T4N0 colorectal cancer: A would-be medical center experience in Taiwan

Insufficient lymph node harvest (< 12) may lead to incorrect classification of stage I and II disease. Many studies have indicated a poor prognosis with inadequate lymph node harvest in stages I to III, but few studies have demonstrated the relationship between low lymph node harvest and T4 disease. This study aimed to identify the influence of insufficient number of lymph nodes harvested on survival in T4N0 colorectal cancer. We enrolled patients with T4N0 colorectal cancer who underwent radical resection between 2010 and 2016. A total of 155 patients were divided into 2 groups; 142 patients had ≥ 12 harvested lymph nodes, and the other 13 had < 12 lymph nodes. All patients were followed up for at least 5 years. The primary outcome was the impact of the number of lymph nodes harvested on disease-free survival and overall survival, which were investigated using Kaplan-Meier survival techniques. There were no significant differences in recurrence rate, emergent or elective surgery, laparoscopic or open surgery, or chemotherapy between the 2 groups. Kaplan-Meier analyses showed no statistical differences in 5-year disease-free survival (P = .886) and 5-year overall survival (P = .832) between the groups. There were no significant differences in disease-free survival and overall survival between patients with adequate (≥ 12) and inadequate (< 12) lymph node harvest in T4N0 colorectal cancers.

Cost-effectiveness of precision molecular diagnostic tests for stage II colorectal cancer

Background

In colorectal cancer, inappropriate use of adjuvant chemotherapies may lead to significant increases in healthcare costs and harms to patients. Genome-based interventions are being increasingly used in the stratification of patients according to their risk profiles. However, earlier cost-effectiveness analyses of precision molecular diagnostics have indicated a paucity of data on comparative health economic outcomes. Our aim was to compare the cost-effectiveness of marketed genomic tests used in the prognosis of stage II colorectal cancer patients.

Methods

A Markov model was developed to compare the cost-effectiveness of treatment guided by any one of the following genomic tests: 12-gene assay or the 18-gene expression assay or the 482-gene signature or the Immunoscore assay in a hypothetical cohort of patients (n=1,000) with stage II colorectal cancer. Our study investigated outcomes in three health states: no recurrence, recurrence and death. This study was conducted from a societal perspective, and a 3% discount was applied to the costs and health outcomes. Sensitivity analyses were performed to assess the uncertainty of model parameters on the results.

Results

The cost of the Immunoscore assay strategy in stage II colorectal cancer patients was estimated to be US $23,564 with a gain of 3.903 quality-adjusted life years (QALYs) as compared with the 12-gene assay strategy at US $24,545 and 3.903 QALYs; the 18-gene assay strategy at US $28,374 and 3.623 QALYs; and the 482-gene signature treatment strategy at US $33,315 with 3.704 QALYs. Sensitivity analyses indicated that incremental cost-effectiveness ratio (ICER) values were sensitive to costs of genomic tests and adjuvant chemotherapies; and utilities related to patients in the no-recurrence health state.

Conclusions

Overall, the Immunoscore assay seems to be a dominant strategy at a threshold willingness-to-pay of $50,000 per QALY, but in the US other tests have been used for longer. Thus, the 12-gene assay may generate cost savings compared to the 18-gene expression assay. The findings of our study may provide useful information to policymakers regarding selection of the most appropriate genomic test, and resource allocation decisions.

A national evaluation of the predictors of compliance and survival from adjuvant chemotherapy in high-risk stage II colon cancer: A National Cancer Database (NCDB) analysis

BACKGROUND

Guidelines recommend adjuvant chemotherapy for stage II colon cancer with high-risk features, but there has been little study on compliance with guidelines. This work sought to evaluate compliance with adjuvant chemotherapy and factors associated with compliance in high-risk stage II colon cancer. This work's hypothesis was that compliance with adjuvant chemotherapy recommendations is low, but improves overall survival when used.

METHODS

The National Cancer Database was reviewed for stage II high-risk colon cancers that underwent curative resection from 2010 to 2017. The cases were stratified into adjuvant chemotherapy and no adjuvant chemotherapy cohorts. A multivariate logistic regression identified factors associated with adjuvant chemotherapy compliance. Propensity-score matching was performed to balance the cohorts and Kaplan-Meier analysis assessed overall survival. The main outcome measures were adjuvant chemotherapy compliance, factors associated with compliance, and overall survival in high-risk stage II colon cancer.

RESULTS

A total of 52,609 patients were evaluated, and 23.2% received adjuvant chemotherapy. The factors associated with noncompliance included older age (odds ratio 0.919; 95% confidence interval 0.915-0.922; P < .001), Medicaid (odds ratio 0.720; 95% confidence interval 0.623-0.832; P < .001) payor, greater comorbidities (odds ratio 0.423; 95% confidence interval 0.334-0.530; P < .001), and residing in the Midwest (odds ratio 0.898; 95% confidence interval 0.812-0.994; P = .037). All of the known high-risk features were significantly independently associated with compliance. In a matched cohort, adjuvant chemotherapy significantly improved the 5-year overall survival (78.1% vs 66.6%; P < .001).

CONCLUSION

Nationally, there is low compliance with adjuvant chemotherapy in high-risk stage II colon cancer. Despite the low compliance, adjuvant chemotherapy was associated with improved overall survival. Demographic variables were associated with poor compliance, whereas tumor factors were associated with increased compliance. These results highlighted the disparities in care and opportunities to improve outcomes in high-risk stage II colon cancer.

The Prognostic Reliability of Lymphovascular Invasion for Patients with T3N0 Colorectal Cancer in Adjuvant Chemotherapy Decision Making

Simple Summary

This retrospective analysis evaluated the prognostic implications of lymphovascular invasion (LVI) associated with adjuvant chemotherapy in 1634 patients with pT3N0 colorectal cancer. Extensive pathologic review and dual immunohistochemical (IHC) staining with CD31 and D2-40 were undertaken in a subset of 242 patients to determine the reliability of LVI as a prognostic factor. The diagnosis of LVI and PNI changed in 82 (33.9%) and 61 (25.2%) patients, respectively, after central pathologic review (mean follow up duration, 50 (1–114) months). Five-year recurrence-free survival (RFS) and overall survival (OS) rates were 92% and 94.8%, respectively. Before and after pathologic review, LVI was not associated with OS but was associated with RFS after reviewing patients with pT3N0 colorectal cancer. In this patient cohort, the prognostic implications of LVI may have been underrecognized when using hematoxylin and eosin staining slides only for pathologic diagnoses, possibly leading to low recurrence prediction rates.

Abstract

Lymphovascular invasion (LVI) is a high-risk feature guiding decision making for adjuvant chemotherapy. We evaluated the prognostic importance and reliability of LVI as an adjuvant chemotherapy indicator in 1634 patients with pT3N0 colorectal cancer treated with curative radical resection between 2012 and 2016. LVI and perineural invasion (PNI) were identified in 382 (23.5%) and 269 (16.5%) patients, respectively. In total, 772 patients received adjuvant chemotherapy. The five-year recurrence-free survival (RFS) and OS rates were 92% and 94.8%, respectively. Preoperative obstruction, PNI, and positive margins were significantly associated with RFS and OS; however, adjuvant chemotherapy and LVI were not. Pathologic slide central reviews of 242 patients using dual D2-40 and CD31 immunohistochemical staining was performed. In the review cohort, the diagnosis of LVI and PNI was changed in 82 (33.9%) and 61 (25.2%) patients, respectively. Reviewed LVI, encompassing small vessel invasion, lymphatic invasion, and large vessel invasion, was not an independent risk factor associated with OS but was related to RFS. The prognostic importance of LVI and adjuvant chemotherapy was not defined because LVI may be underrecognized in pathologic diagnoses using hematoxylin and eosin staining slides only, leading to low recurrence rate predictions. Using LVI as a guiding factor for adjuvant chemotherapy requires further consideration.

Predictive and Prognostic Effects of Primary Tumor Size on Colorectal Cancer Survival

Background

Pathologic staging is crucial in colorectal cancer (CRC). Unlike the majority of solid tumors, the current staging model does not use tumor size as a criterion. We evaluated the predictive and prognostic impact of primary tumor size on all stages of CRC.

Methods

Using the National Cancer Database (NCDB), we conducted an analysis of CRC patients diagnosed between 2010 and 2015 who underwent resection of their primary cancer. Univariate and multivariate analyses were used to identify predictive and prognostic factors, Kaplan-Meier analysis and Cox proportional hazards models for association between tumor size and survival.

Results

About 61,000 patients met the inclusion criteria. Median age was 63 years and majority of the tumors were colon primary (82.7%). AJCC stage distribution was: I - 20.1%; II - 32.1%; III - 34.7% and IV - 13.1%. The prognostic impact of tumor size was strongly associated with survival in stage III disease. Compared to patients with tumors <2cm; those with 2-5cm (HR 1.33; 1.19-1.49; p<0.001), 5-10cm (HR 1.51 (1.34-1.70; p<0.001) and >10cm (HR 1.95 (1.65-2.31; p<0.001) had worse survival independent of other variables. Stage II treated without adjuvant chemotherapy had comparable survival outcomes (HR 1.09; 0.97-1.523; p=0.148) with stage III patients who did, while Stage II patients who received adjuvant chemotherapy did much better than both groups (HR 0.76; 0.67-0.86; p<0.001). Stage III patients who did not receive adjuvant chemotherapy had the worst outcomes among the non-metastatic disease subgroups (HR 2.66; 2.48-2.86; p<0.001). Larger tumors were associated with advanced stage, MSI high, non-rectal primary and positive resection margins.

Conclusions

Further studies are needed to clarify the role of tumor size in prognostic staging models, and how to incorporate it into therapy decisions.

Pretreatment MR-based radiomics nomogram as potential imaging biomarker for individualized assessment of perineural invasion status in rectal cancer

PURPOSE

To investigate whether pretreatment magnetic resonance (MR)-based radiomics nomogram can individualize prediction of perineural invasion (PNI) status in rectal cancer (RC).

MATERIAL AND METHODS

A total of 122 RC patients with pathologically confirmed were classified as training cohort (n = 87) and test cohort (n = 35). 180 radiomics features were extracted from all lesions based on oblique axial T₂WI TSE images. The dimensionality reduction and feature selection in training cohort were realized by the maximum relevance minimum redundancy (mRMR) algorithm and the least absolute shrinkage and selection operator (LASSO) regression model. A predictive model combining radiomics features and clinical risk factors (pathological N stage, pathological LVI status) was established by multivariate logistic regression analysis. The performance of the model was assessed based on its receiver operating characteristic (ROC) curve, nomogram, and calibration.

RESULTS

The developed radiomics nomogram that integrated the radiomics signature and clinical risk factors could provide discrimination in the training and test cohorts. The accuracy and the area under the curve (AUC) for assessing PNI status were 0.82, 0.86, respectively, in the training cohort, while they were 0.71 and 0.85 in the test cohort. The goodness-of-fit of the nomogram was evaluated using the Hosmer-Lemeshow test (p = 0.52 in training cohort and p = 0.24 in test cohort). Decision curve analysis (DCA) showed that the radiomics nomogram was clinically useful.

CONCLUSION

The developed radiomics nomogram might be helpful in the individualized assessment PNI status in patients with RC. This stratification of RC patients according to their PNI status may provide the basis for individualized adjuvant therapy, especially for stage II patients.

Combination Immunotherapy With LIGHT and Interleukin-2 Increases CD8 Central Memory T-Cells In Vivo

BACKGROUND

The generation of long-term durable tumor immunity and prolonged disease-free survival depends on the ability to generate and support CD8+ central memory T-cells. Microsatellite-stable colon cancer is resistant to currently available immunotherapies; thus, development of novel mechanisms to increase both lymphocyte infiltration and central memory formation are needed to improve outcomes in these patients. We have previously demonstrated that both interleukin-2 (IL-2) and LIGHT (TNFSF14) independently enhance antitumor immune responses and hypothesize that combination immunotherapy may increase the CD8+ central memory T-cell response.

METHODS

Murine colorectal cancer tumors were established in syngeneic mice. Tumors were treated with control, soluble, or liposomal IL-2 at established intervals. A subset of animal tumors overexpressed tumor necrosis superfamily factor LIGHT (TNFSF14). Peripheral blood, splenic, and tumor-infiltrating lymphocytes were isolated for phenotypic studies and flow cytometry.

RESULTS

Tumors exposed to a combination of LIGHT and IL-2 experienced a decrease in tumor size compared with IL-2 alone that was not demonstrated in wild-type tumors or between other treatment groups. Combination exposure also increased splenic central memory CD8+ cells compared with IL-2 administration alone, while not increasing tumor-infiltrating lymphocytes. In the periphery, the combination enhanced levels of circulating CD8 T-cells and central memory T-cells, while also increasing circulating T-regulatory cells.

CONCLUSIONS

Combination of IL-2, whether soluble or liposomal, with exposure to LIGHT results in increased CD8+ central memory cells in the spleen and periphery. New combination immunotherapy strategies that support both effector and memory T-cell functions are critical to enhancing durable antitumor responses and warrant further investigation.

Postoperative chemotherapy improves survival in patients with resected high-risk Stage II colorectal cancer: results of a systematic review and meta-analysis

AIM

The aim was to assess the benefit of adjuvant chemotherapy in high-risk Stage II colorectal cancer.

METHOD

A systematic literature review and meta-analysis was performed comparing survival in patients with resected Stage II colorectal cancer and high-risk features having postoperative chemotherapy vs no chemotherapy.

RESULTS

Of 1031 articles screened, 29 were included, reporting on 183 749 participants. Adjuvant chemotherapy significantly improved overall survival [hazard ratio (HR) 0.61, P < 0.0001], disease-specific survival (HR = 0.73, P = 0.05) and disease-free survival (HR = 0.59, P < 0.0001) compared to no chemotherapy. Adjuvant chemotherapy significantly increased 5-year overall survival (OR = 0.53, P = 0.0008) and 5-year disease-free survival (OR = 0.50, P = 0.001). Overall survival and disease-free survival remained significantly prolonged during subgroup analysis of studies published from 2015 onwards (HR = 0.60, P < 0.0001; HR = 0.65, P = 0.0001; respectively), in patients with two or more high-risk features (HR = 0.59, P = 0.0001; HR = 0.70, P = 0.03; respectively) and in colon cancer (HR = 0.61, P < 0.0001; HR = 0.51, P = 0.0001; respectively). Overall survival, disease-specific survival and disease-free survival during subgroup analysis of individual high-risk features were T4 tumour (HR = 0.58, P < 0.0001; HR = 0.50, P = 0.003; HR = 0.75, P = 0.05), < 12 lymph nodes harvested (HR = 0.67, P = 0.0002; HR = 0.80, P = 0.17; HR = 0.72, P = 0.02), poor differentiation (HR = 0.84, P = 0.35; HR = 0.85, P = 0.23; HR = 0.61, P = 0.41), lymphovascular or perineural invasion (HR = 0.55, P = 0.05; HR = 0.59, P = 0.11; HR = 0.76, P = 0.05) and emergency surgery (HR = 0.60, P = 0.02; HR = 0.68, P = 0.19).

CONCLUSION

Adjuvant chemotherapy in high-risk Stage II colorectal cancer results in a modest survival improvement and should be considered on an individual patient basis. Due to potential heterogeneity and selection bias of the included studies, and lack of separate rectal cancer data, further large randomized trials with predefined inclusion criteria and standardized chemotherapy regimens are required.

Patient Selection for Adjuvant Chemotherapy in High-Risk Stage II Colon Cancer: A Systematic Review and Meta-Analysis

OBJECTIVES

Patients with high-risk stage II colon cancer (CC) are recommended to undergo adjuvant chemotherapy (ACT). However, whether such patients can benefit from ACT remains unclear. This meta-analysis aimed to investigate the clinicopathologic parameters that are important for selecting patients for ACT in high-risk stage II CC.

METHODS

We systematically retrieved articles from PubMed, the Cochrane Library, and Embase that were published up to September 13, 2018. We analyzed overall survival (OS) and disease-free survival (DFS) based on hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

A total of 23 cohort studies and 1 randomized controlled trial were included in our study. Overall analyses showed that ACT improved OS (HR=0.64, 95% CI=0.51-0.80, P<0.001) and DFS (HR=0.46, 95% CI=0.28-0.76, P=0.002) in patients with high-risk stage II CC. Subgroup analyses showed that ACT improved OS in patients with localized intestinal perforation and obstruction and pT4 lesions and improved OS and DFS in patients with <12 sampled lymph nodes. However, ACT had no significant effect on OS in patients with lymphovascular invasion, perineural invasion, or poorly differentiated histology.

CONCLUSIONS

Our study suggests that not all high-risk factors (lymphovascular invasion, perineural invasion, poorly differentiated histology) show a benefit from ACT. Randomized controlled trials selectively targeting high-risk patients will need to be conducted in the future.

Recurrence Rate in a Patient Treated with Colon Resection Followed by Chemotherapy in Comparison to a Patient Treated with Colon Resection without Chemotherapy

Given that colon cancer is one of the most prevalent cancers worldwide, it is essential to employ strategies to try to reduce its incidence and recurrence rate. Though colon cancer is a sporadic disease in the vast majority of cases, multiple risk factors are linked to this disease, namely, obesity and cigarette smoking. Additionally, not many studies have been done in Saudi Arabia studying the recurrence rate of colon cancer. Therefore, we conducted a retrospective cohort study at King Khalid Hospital, King Abdulaziz Medical City, National Guard Health Affairs (NGHA), Jeddah, Saudi Arabia to investigate the recurrence rate of colon cancer in patients treated with complete colon resection followed by chemotherapy versus patients treated with colon resection alone via electronic and paper medical records. A total of 120 patients were included in this study; 61 were males (50.8%) and 59 were females (49.2%). According to our findings, the recurrence rate in patients who underwent surgical resection with adjuvant chemotherapy was 15.6% (n = 10), while the recurrence rate in patients with surgery alone was 21.4% (n = 12). Cancer recurrence is associated with significant morbidity and mortality. Therefore, further studies should be done to investigate the recurrence rate in patients with risk factors to identify and deal with the causes of recurrence.

A Hallmark-Based Six-Gene Expression Signature to Assess Colorectal Cancer and Its Recurrence Risk

Purpose: As part of the effort to establish a general profile for solid tumors, the aim of this study was to develop a real-time polymerase chain reaction (RT-PCR)-based assay to assess colorectal cancer (CRC) and its recurrence risk utilizing the limited amounts of tissues available from biopsies through colonoscopy. Materials and Methods: Six candidate genes, reflecting the hallmarks of cancer cells, were identified by analyzing the gene expression profiles of primary invasive tumors in the public database. The expression of these genes in CRC and noncancerous colon tissues was quantified by RT-quantitative PCR. Classifiers were then generated to distinguish the tumors from the normal colon tissues, and to assess the risk of CRC recurrence based on the disease-free survival time, overall survival time, and metastatic status of the patients. Results: The expression profile of a five-gene panel was utilized to build a model that is capable of distinguishing CRC cancer tissues from noncancerous colorectal tissues (p < 0.0001). A classifier based on the expression signature of four genes, three of which were included in the five-gene panel, was then developed for assessing the tumor recurrence risk. This classifier could correctly identify those with a poor likelihood of survival (high risk of recurrence) >80% of time. There was a significant difference in disease-free survival time between patients in the low recurrence group and those in the high-risk group. Conclusion: The expression signatures of the six genes that reflect the genetic hallmarks of cancer cells could serve as a biomarker for identifying CRC and assessing the risk of recurrence with high sensitivity and specificity.

Overuse and Limited Benefit of Chemotherapy for Stage II Colon Cancer in Young Patients

BACKGROUND

Few studies have confirmed a benefit for adjuvant chemotherapy (aCTX) in stage II colon cancer. We used the National Cancer Database to explore the use and efficacy of aCTX in patients with both normal-risk (NR) and high-risk (HR) young stage II colon cancer.

PATIENTS AND METHODS

We identified patients with stage II colon cancer who underwent colectomy between 2010 and 2015. HR patients included at least: lymphovascular or perineural invasion, < 12 lymph nodes, poor/un-differentiation, T4, or positive margins. Rates of aCTX by age and risk were calculated, and adjusted factors associated with aCTX were identified. Overall survival was estimated using the Kaplan-Meier method and Cox multivariable analyses for patients < 50 years.

RESULTS

Among the 81,066 stage II patients who underwent colectomy, 6093 (7.5%) were < 50 years old. Of these, 2669 patients were HR. Thirty percent of NR and almost 60% of HR patients < 50 years received aCTX, compared with 8% and 23% of patients > 50 years (P < .001). In NR patients < 50 years, 35.3% with microsatellite-stable tumors and 18% with microsatellite unstable tumors received aCTX (P < .001), whereas 63.6% and 43.2%, respectively, of HR patients did (P < .001). The most significant multivariable predictors of aCTX were risk status and age. On univariate analysis, there was no survival benefit associated with aCTX in patients < 50 years. Multivariate analysis failed to demonstrate a survival benefit for aCTX for either group (HR, 0.97; P = .84; NR, 0.1.03; P = .90).

CONCLUSION

Young patients with HR and NR colon cancer received aCXT more frequently than older patients with no demonstrable survival benefit. This bears further evaluation to avoid the real risks of over-treatment in this increasing population.

Construction and validation of a simple scoring system for stage III colorectal cancer recurrence (SiS-SCORE). A case control study

BACKGROUND

Stage III colorectal cancer is an indication for adjuvant chemotherapy; however, there is no definite view on the selection of regimen. If the recurrence can be predicted, it can serve as the indicator of regimen selection. The present study aimed to predict the recurrence of stage III colorectal cancer by constructing a simple scoring system.

METHODS

The information of stage III cases that underwent curative surgery was obtained from two facilities and analyzed. A scoring system was constructed from the analysis results and evaluated based on the cases from a different facility.

RESULTS

Five factors were extracted by multivariate analysis: age > 65, male, rectum, ≥pN2 and CA19-9 > 37. When these parameters were scored as 1 point each, the score was correlated with the cumulative recurrence rate. Additionally, when cases were divided into three groups (≤1 point, 2 points, ≥3 points), the 5-year recurrence rate was as follows:, ≤1 point: 33.3%, 2 points: 42.1%, ≥3 points: 78.6%. The cumulative recurrence rate of ≥3 points was significantly higher than that of ≤1 point (P < 0.001). Similar results were obtained by evaluating that cases at a different facility (P = 0.032). Both cases with 2 points were located between ≤1 point and ≥3 points, reflecting the average recurrence rate of each institution.

CONCLUSION

As the SiS-SCORE presented the same result in the facility that was different from the base facility, it can be used widely. However, a prospective study is required to prove the usefulness of the SiS-SCORE.

Lymphovascular Invasion and Perineural Invasion Negatively Impact Overall Survival for Stage II Adenocarcinoma of the Colon

BACKGROUND

Lymphovascular invasion and perineural invasion are histopathological features associated with higher-risk colon cancer.

OBJECTIVE

The purpose of this study was to quantify the impact of lymphovascular and perineural invasion on overall survival after diagnosis and to determine the protective effect of adjuvant chemotherapy for early adenocarcinoma with high-risk factors.

DESIGN

This was a retrospective database review of the 2010-2014 National Cancer Database for colon cancer.

SETTINGS

Individuals diagnosed with invasive adenocarcinoma of the colon (histology code 8140) with primary surgical resection with >12 nodes harvested and no positive nodes on pathological examination were included.

PATIENTS

A total of 32,493 patients underwent surgical resection for stage II adenocarcinoma of the colon.

INTERVENTIONS

The study involved multivariate Cox regression analysis of the impact of lymphovascular and perineural invasion and adjuvant chemotherapy on overall survival after a diagnosis of stage II adenocarcinoma of the colon.

MAIN OUTCOME MEASURES

Survival after a diagnosis of stage II adenocarcinoma of the colon was measured.

RESULTS

Five-year survival after diagnosis and surgical resection without adjuvant chemotherapy was lower for patients with lymphovascular (60.0%), perineural (56.9%), and lymphovascular and perineural invasion (55.8%) compared with double-negative disease (66.1%). Log-rank testing confirmed that adjuvant chemotherapy improved 5-year survival after diagnosis for lymphovascular (85.5%), perineural (83.6%), and lymphovascular and perineural invasion (74.3%). After controlling for differences in cohorts, Cox regression analysis showed an increased HR for mortality of 14.0% for lymphovascular (HR = 1.141 (95% CI, 1.060-1.228)), 32.1% for perineural (HR = 1.321 (95% CI, 1.176-1.483)), and 41.0% for lymphovascular and perineural invasion (HR = 1.409 (95% CI, 1.231-1.612)) compared with having neither. Chemotherapy showed a 43% reduction in hazard for mortality (HR = 0.570 (95% CI, 0.513-0.633)).

LIMITATIONS

The study was limited by its retrospective review and observational bias.

CONCLUSIONS

Lymphovascular and perineural invasion have a detrimental effect on survival after diagnosis of stage II adenocarcinoma of the colon. Chemotherapy may be protective specifically when lymphovascular and perineural invasion are present. See Video Abstract at http://links.lww.com/DCR/A786.

High expression of Ras-related protein 1A promotes an aggressive phenotype in colorectal cancer via PTEN/FOXO3/CCND1 pathway

Background

Colorectal cancer (CRC) is a commonly diagnosed digestive malignancy worldwide. Ras-related protein 1A (RAP1A) is a member of the Ras superfamily of small GTPases and has been recently identified as a novel oncoprotein in several human malignancies. However, its specific role in CRC remains unclear.

Method

In this study, we firstly analyzed its expression and clinical significance in a retrospective cohort of 144 CRC patients. Then, cellular assays in vitro and in vivo were performed to clarify its biological role in CRC cells. Finally, microarray analysis was utilized to investigate the molecular mechanisms regulated by RAP1A in CRC progression.

Results

Firstly, RAP1A expression was abnormally higher in CRC tissues as compared with adjacent normal tissues, and significantly correlated tumor invasion. High RAP1A expression was an independent unfavourable prognostic factor for CRC patients. Combining RAP1A expression and preoperative CEA level contributed to a more accurate prognostic stratification in CRC patients. Secondly, knockdown of RAP1A dramatically inhibited the growth of CRC cells, while it was opposite for RAP1A overexpression. Finally, the microarray analysis revealed RAP1A promoted CRC growth partly through phosphatase and tensin homolog (PTEN)/forkhead box O3(FOXO3)/cyclin D1(CCND1) signaling pathway. FOXO3 overexpression could partly mimic the inhibitory effect of RAP1A knockdown in CRC growth. Moreover, FOXO3 overexpression inhibited CCND1 expression, but had no impact on RAP1A and PTEN expression.

Conclusion

RAP1A promotes CRC development partly through PTEN/FOXO3 /CCND1 signaling pathway. It has a great potential to be an effective clinical biomarker and therapeutic target for CRC patients.

Electronic supplementary material

The online version of this article (10.1186/s13046-018-0827-y) contains supplementary material, which is available to authorized users.

Combined use of preoperative lymphocyte counts and the post/preoperative lymphocyte count ratio as a prognostic marker of recurrence after curative resection of stage II colon cancer

Purpose

Diagnostic markers for recurrence of colorectal cancer have not been established. The aim of the present study was to identify new diagnostic markers for recurrence after curative surgery of stage II colon cancer.

Materials and Methods

In this study, the prognostic values of the preoperative lymphocyte count and the post/preoperative lymphocyte count ratio (PPLR) were evaluated in 142 patients with localized colon cancer treated with surgery at a single medical center. The associations of patient demographics, blood chemistry, and serum biochemical indices with recurrence-free survival (RFS) and cancer-specific survival (CSS) were examined by univariate and multivariate analyses.

Results

Receiver operating characteristic (ROC) curve analysis showed that the optimal cut-off values of the lymphocyte count and PPLR were, respectively, 1555.2/μl and 1.151 for RFS. On univariate analysis, tumor depth of invasion, carbohydrate antigen 19-9 (CA19-9), and preoperative low lymphocyte count (≤1555.2/μl) were all correlated with poorer RFS (p < 0.05). On multivariate analysis, T4, low lymphocyte count, and low PPLR were independent predictors of poor RFS. Furthermore, the patients were categorized into four categories based on preoperative lymphocyte count high/low and PPLR high/low. Patients with a low preoperative lymphocyte count and low PPLR had the poorest RFS and CSS compared to the other patients.

Conclusion

The combination of the preoperative lymphocyte count and the PPLR appears to be a potential marker for predicting recurrence of stage II colon cancer.