Clinical and pathological evaluation of patients with early and late recurrence of colorectal cancer

Post recurrence survival in early versus late period and its prognostic factors in rectal cancer patients

To identify factors associated with post-recurrence survival (PRS), we examined our institutional recurrence patterns following definitive resection for rectal cancer. We reviewed all patients with rectal cancer diagnosed at three hospitals in the east of Iran from 2011 to 2020. The optimal cut-off value was determined by receiver operating characteristic (ROC) analysis to determine early recurrence. The effect of recurrence time was evaluated on PRS. 326 eligible patients with a mean ± SD age of 56 ± 12.8 years were included in this study. In a median (IQR: Inter-quartile range) follow-up time of 76 (62.2) months, 106 (32.5%) patients experienced at least any recurrence (locoregional or distant metastasis) following primary resection. The median (IQR) time from initial surgery to recurrence was 29.5 (31.2) months. Based on ROC analysis, early recurrence was specified at ≤ 29 months. However, for the patients who experienced only locoregional recurrence, 33 months was the cut-off to define early recurrence. Recurrence time and recurrence management were both significant variables on PRS. Moreover, TNM staging was significantly associated with early recurrence (P = 0.003). In this research, recurrence time, recurrence management and TNM staging were found to be correlated with PRS.

Pretreatment MRI-detected extramural venous invasion as a prognostic and predictive biomarker for neoadjuvant chemoradiotherapy in non-metastatic rectal cancer: a propensity score matched analysis

OBJECTIVES

This study evaluated pretreatment magnetic resonance imaging (MRI)-detected extramural venous invasion (pmrEMVI) as a predictor of survival after neoadjuvant chemoradiotherapy (nCRT) in patients with locally advanced rectal cancer (LARC).

MATERIALS AND METHODS

Medical records of 1184 patients with rectal adenocarcinoma who underwent TME between January 2011 and December 2016 were reviewed. MRI data were collected from a computerized radiologic database. Cox proportional hazards analysis was used to assess local, systemic recurrence, and disease-free survival risk based on pretreatment MRI-assessed tumor characteristics. After propensity score matching (PSM) for pretreatment MRI features, nCRT therapeutic outcomes according to pmrEMVI status were evaluated. Cox proportional hazards analysis was used to identify risk factors for early recurrence in patients receiving nCRT.

RESULTS

Median follow-up was 62.8 months. Among all patients, the presence of pmrEMVI was significantly associated with worse disease-free survival (DFS; HR 1.827, 95% CI 1.285-2.597, p = 0.001) and systemic recurrence (HR 2.080, 95% CI 1.400-3.090, p < 0.001) but not local recurrence. Among patients with pmrEMVI, nCRT provided no benefit for oncological outcomes before or after PSM. Furthermore, pmrEMVI( +) was the only factor associated with early recurrence on multivariate analysis in patients receiving nCRT.

CONCLUSIONS

pmrEMVI is a poor prognostic factor for DFS and SR in patients with non-metastatic rectal cancer and also serves as a predictive biomarker of poor DFS and SR following nCRT in LARC. Therefore, for patients who are positive for pmrEMVI, consideration of alternative treatment strategies may be warranted.

CLINICAL RELEVANCE STATEMENT

This study demonstrated the usefulness of pmrEMVI as a predictive biomarker for nCRT, which may assist in initial treatment decision-making in patients with non-metastatic rectal cancer.

KEY POINTS

• Pretreatment MRI-detected extramural venous invasion (pmrEMVI) was significantly associated with worse disease-free survival and systemic recurrence in patients with non-metastatic rectal cancer. • pmrEMVI is a predictive biomarker of poor DFS following nCRT in patients with LARC. • The presence of pmrEMVI was the only factor associated with early recurrence on multivariate analysis in patients receiving nCRT.

Prognostic models for colorectal cancer recurrence using carcinoembryonic antigen measurements

Objective

Colorectal cancer (CRC) is one of the most prevalent cancers worldwide. A considerable percentage of patients who undergo surgery with curative intent will experience cancer recurrence. Early identification of individuals with a higher risk of recurrence is crucial for healthcare professionals to intervene promptly and devise appropriate treatment strategies. In this study, we developed prognostic models for CRC recurrence using machine learning models on a limited number of CEA measurements.

Method

A dataset of 1927 patients diagnosed with Stage I-III CRC and referred to Zuyderland Hospital for surgery between 2008 and 2016 was utilized. Machine learning models were trained using this comprehensive dataset, which included demographic details, clinicopathological factors, and serial measurements of Carcinoembryonic Antigen (CEA). In this study, the predictive performance of these models was assessed, and the key prognostic factors influencing colorectal cancer (CRC) recurrence were pinpointed.

Result

Among the evaluated models, the gradient boosting classifier demonstrated superior performance, achieving an Area Under the Curve (AUC) score of 0.81 and a balanced accuracy rate of 0.73. Recurrence prediction was shown to be feasible with an AUC of 0.71 when using only five post-operative CEA measurements. Furthermore, key factors influencing recurrence were identified and elucidated.

Conclusion

This study shows the transformative role of machine learning in recurrence prediction for CRC, particularly by investigating the minimum number of CEA measurements required for effective recurrence prediction. This approach not only contributes to the optimization of clinical workflows but also facilitates the development of more effective, individualized treatment plans, thereby laying the groundwork for future advancements in this area. Future directions involve validating these models in larger and more diverse cohorts. Building on these efforts, our ultimate goal is to develop a risk-based follow-up strategy that can improve patient outcomes and enhance healthcare efficiency.

LAMP2A overexpression in colorectal cancer promotes cell growth and glycolysis via chaperone‑mediated autophagy

Lysosome-associated membrane protein type 2A (LAMP2A) is a key protein in the chaperone-mediated autophagy (CMA) pathway and has been demonstrated to be involved in the pathogenesis of a number of tumors. However, the role of CMA in colorectal cancer cell proliferation, metastasis and cell survival during oxidative stress and oxaliplatin resistance remains to be elucidated. In the present study, elevated expression of LAMP2A was observed in colon cancer tissues. Then, CMA activity was increased in SW480 and HT29 colorectal cancer cells with a LAMP2A overexpression vector and CMA activity was decreased using a LAMP2A short interfering RNA vector. MTT and colony formation assays showed that the colorectal cancer cell proliferation ability and cell viability following treatment with H2O2 or oxaliplatin were decreased significantly after LAMP2A knockdown and increased significantly after LAMP2A overexpression. Wound healing assays and Transwell invasion assays demonstrated that downregulation of LAMP2A expression inhibited the cell migration and invasion abilities of colorectal cancer and that upregulation of LAMP2A expression promoted cell migration and invasion. Extracellular acidification rate (ECAR) assay and lactate determination assay showed that glycolysis in colorectal cancer cells was significantly downregulated after LAMP2A knockdown and significantly upregulated after LAMP2A overexpression. Inhibition of glycolysis by 2-DG markedly attenuated LAMP2A-induced chemoresistance in colorectal cancer cells. Collectively, these data indicated that CMA can promote colorectal cancer cell proliferation, metastasis and cell survival during oxidative stress and oxaliplatin resistance and that the mechanism is related to the glycolytic pathway, which may provide a new therapeutic target for colorectal cancer patients.

Early recurrence after complete mesocolic excision for right-sided colon cancer with D3 lymphadenectomy: pattern, risk factors, prognostic impact, and individualized follow-up

The definition of early recurrence (ER) for right-sided colon cancer patients after complete mesocolic excision (CME) with D3 lymphadenectomy remains unclear. This study aimed to define the optimal time for ER and clarify risk factors for ER and post-recurrence survival (PRS). A total of 578 right-sided colon cancer patients who underwent CME with D3 lymphadenectomy were included. The minimum p value method was used to evaluate theme optimal time of recurrence-free survival to discriminate between ER and late recurrence (LR). Risk factors for ER were determined by a logistics regression model. The PRS was compared between ER and LR. The optimal time to define ER was 15 months (P = 1.8697E-7). 93 patients developed tumor recurrence, 46 patients had ER (≤15 months) and 47 patients had LR (>15 months). Preoperative serum CA19-9 > 37 U/mL (OR = 3.185, P = 0.001), pathological N+ stage (OR = 3.042, P = 0.027), and lymphovascular invasion (OR = 2.182, P = 0.027) were identified as independent risk factors associated with ER. Age > 75 years (HR = 1.828, P = 0.040), pathological N2 stage (HR = 1.850, P = 0.009), multiple sites of recurrence (HR = 1.680, P = 0.024), and time to recurrence ≤15 months (HR = 2.018, P = 0.043) were significantly associated with worse PRS in patients with recurrence. 15 months was the optimal time to distinguish ER and LR. ER was associated with a poor PRS. Elevated preoperative serum CA19-9 level, pathological N+ stage, and lymphovascular invasion were significantly predictive of ER.

Development and validation of a novel radiomics nomogram for prediction of early recurrence in colorectal cancer

BACKGROUND

Early recurrence (ER) is a significant concern following curative resection of advanced colorectal cancer (CRC) and is linked to poor long-term survival. Reliable prediction of ER is challenging, necessitating the development of a novel radiomics-based nomogram for CRC patients.

METHODS

We enrolled 405 patients, with 298 in the training set and 107 in the external test set. Radiomic features were extracted from preoperative venous-phase computed tomography (CT) images. A radiomics signature was created using univariate logistic regression analyses and the least absolute shrinkage and selection operator algorithm. Clinical factors were integrated into the analyses to develop a comprehensive predictive tool in a multivariate logistic regression model, resulting in a radiomics nomogram. Subsequently, the calibration, discrimination, and clinical usefulness of the nomogram were evaluated.

RESULTS

The radiomics signature, consisting of four selected CT features, was significantly associated with ER in both the training and test datasets (P < 0.05). Independent predictors of ER included TNM stage, carcinoembryonic antigen level and differentiation grade were identified. The radiomics nomogram, incorporating all these predictors, exhibited good predictive ability in both the training set with an area under the curve (AUC) of 0.82 (95 % confidence interval (CI), 0.74-0.90) and the test set with an AUC of 0.85 (95 % CI, 0.72-0.99), surpassing the performance of any single candidate factor alone. Furthermore, additional analysis demonstrated that the nomogram was clinically useful.

CONCLUSIONS

We have developed a radiomics-based nomogram that effectively predicts early recurrence in CRC patients, enhancing the potential for timely intervention and improved outcomes.

MiR-509-3p is oncogenic, targets the tumor suppressor PHLPP2, and functions as a novel tumor adjacent normal tissue based prognostic biomarker in colorectal cancer

Background

Recently the role of microRNAs has been explored immensely as novel regulators and potential biomarkers in several cancers. MiR-509-3p is one such miRNA that has been observed to show a mixed expression in different cancers, while it’s expression and clinical relevance in colorectal cancer (CRC) has not yet been characterized.

Methods

We used quantitative PCR to evaluate the expression of miR-509-3p in fresh-frozen CRC tumor tissues and the corresponding tumor-adjacent normal (NAT) tissues from 103 patients. Subsequently, functional studies were performed to further interpret the role of the miRNA in CRC.

Results

MiR-509-3p was found to be overexpressed in CRC tissues in nearly 80% of cases and was associated with an aggressive disease presentation. Notably, a higher expression of the miRNA promoted cell proliferation, migration, and invasion of CRC cells in in vitro and in vivo models. Mechanistically, we confirmed that miR-509-3p directly binds the 3’UTR of the tumor suppressor PHLPP2 and inhibits its expression. Furthermore, within the previous 103 clinical tissue specimens, we observed an overexpression of miR-509-3p within the NAT tissue of patients associated with a poor disease prognosis. Using multivariate analysis, it was observed that the expression of miR-509-3p within the NAT tissue was an independent predictor of prognosis in CRC. At the cellular level, through indirect coculture experiments, miR-509-3p was observed to regulate the proliferative, migratory, and invasive behavior of normal colon cells.

Conclusion

MiR-509-3p strongly contributes to the development and progression of CRC and can potentially function as a prognostic biomarker in the disease.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-09075-x.

Isolated synchronous Virchow lymph node metastasis of sigmoid cancer: A case report

BACKGROUND

Colorectal cancer (CRC) is one of the most common malignant tumors of the digestive tract. Lymphatic metastases of this tumor are mostly confined to the regional lymph nodes, and distant supraclavicular lymph node metastases are very rare.

CASE SUMMARY

In this report, we describe a patient with sigmoid carcinoma and isolated synchronous supraclavicular lymph node metastases. A 56-year-old male presented with a left cervical mass that was confirmed as a lymph node metastasis from sigmoid cancer by several auxiliary examinations. After 6 cycles of chemotherapy with the 5-fluorouracil, leucovorin and oxaliplatin + cetuximab regimen, the sigmoid colon tumor and Virchow’s lymph node metastasis were significantly smaller than before treatment, and no new metastatic sites were observed. Considering the effects of chemotherapy on quality of life, resection of the primary tumor was performed followed by 4 cycles of chemotherapy with the original chemotherapy regimen. Virchow’s lymph node dissection was selected by mutual consultation between the patient and us. After the second surgery, the patient received capecitabine and cetuximab chemotherapy and did not experience recurrence or metastasis during follow-up.

CONCLUSION

In conclusion, supraclavicular lymph node metastasis without any other solid organ metastasis is a potential metastatic pathway for CRC. In addition, after resection of the primary lesion, postoperative chemotherapy combined with supraclavicular lymph node dissection is feasible for the treatment of patients with CRC and isolated synchronous Virchow’s lymph node metastases.

Clinicopathological and Molecular Features of Patients with Early and Late Recurrence after Curative Surgery for Colorectal Cancer

Simple Summary

Colorectal cancer patients with early recurrence had advanced pathological node categories, pathological tumor, node, metastasis stages, adjuvant chemotherapy treatment, a worse overall survival rate, more liver metastases and more APC mutations than those with late recurrence. Patients with right-sided colon cancer tended to have early recurrence than those with left-sided colon cancer or rectal cancer. The postrecurrence survival rates were not significantly different between patients with early and late recurrence, which was observed in right-sided colon, left-sided colon and rectum. Multivariate analysis showed that old age, early recurrence, multiple-site recurrence and BRAF and NRAS mutations were independent prognostic factors.

Abstract

Background: Few reports have investigated genetic alterations between patients with early and late recurrence following curative surgery for colorectal cancer (CRC). Methods: A total of 1227 stage I–III CRC patients who underwent curative resection were included retrospectively. Among them, 236 patients had tumor recurrence: 139 had early (<2 years after surgery) and 97 had late (≥2 years after surgery) recurrence. Clinicopathological features and genetic alterations were compared between the two groups. Results: Compared to those with late recurrence, patients with early recurrence were more likely to have advanced pathological node (N) categories; tumor, node, metastasis (TNM) stages; adjuvant chemotherapy treatment; liver metastases; APC mutations; and worse five-year overall survival rates. Patients with right-sided colon cancer were more likely to develop early recurrence than were those with left-sided colon cancer or rectal cancer. Regarding rectal cancer, patients with early recurrence were more likely to be at advanced pathological N categories and TNM stages than those with late recurrence. Multivariate analysis revealed old age, early recurrence, multiple-site recurrence, and BRAF and NRAS mutations to be independent prognostic factors. Conclusion: CRC patients with early recurrence have a worse OS rate and more APC mutations than those with late recurrence.

Identification of Hub Genes Associated With Sensitivity of 5-Fluorouracil Based Chemotherapy for Colorectal Cancer by Integrated Bioinformatics Analysis

Colorectal cancer (CRC) is one of the most common malignant tumors. 5-fluorouracil (5-FU) has been used for the standard first-line treatment for CRC patients for several decades. Although 5-FU based chemotherapy has increased overall survival (OS) of CRC patients, the resistance of CRC to 5-FU based chemotherapy is the principal cause for treatment failure. Thus, identifying novel biomarkers to predict response to 5-FU based chemotherapy is urgently needed. In the present study, the gene expression profile of GSE3964 from the Gene Expression Omnibus database was used to explore the potential genes related to intrinsic resistance to 5-FU. A gene module containing 81 genes was found to have the highest correlation with chemotherapy response using Weighted Gene Co-expression Network Analysis (WGCNA). Then a protein-protein interaction (PPI) network was constructed and ten hub genes (TGFBI, NID, LEPREL2, COL11A1, CYR61, PCOLCE, IGFBP7, COL4A2, CSPG2, and VTN) were identified using the CytoHubba plugin of Cytoscape. Seven of these hub genes showed significant differences in expression between chemotherapy-sensitive and chemotherapy-resistant samples. The prognostic value of these seven genes was evaluated using TCGA COAD (Colorectal Adenocarcinoma) data. The results showed that TGFBI was highly expressed in chemotherapy-sensitive patients, and patients with high TGFBI expression have better survival.

Evaluation of prognostic factors and clinicopathological patterns of recurrence after curative surgery for colorectal cancer

BACKGROUND

Colorectal cancer is a common tumor with a quite high-related mortality. Despite the used curative treatments, patients will develop cancer recurrence in up to 50% of the cases and/or other primary neoplasms. Although most of the recurrences are discovered within 3 years from the first treatment, a small percentage is found after 5 years. The early detection of recurrence is crucial to allow further therapies improving patients’ survival. Several follow-up programs have been developed but the optimal one is far from being established.

AIM

To evaluation of potential prognostic factors for timing and patterns of recurrence in order to plan tailored follow-up programs.

METHODS

Perioperative and long-term data of all consecutive patients surgically treated with curative intent, from January 2006 to June 2009, for colorectal adenocar-cinoma, were retrospectively reviewed to find potential prognostic factors associated with: (1) Recurrence incidence; (2) Incidence of an early (within 3 years from surgery) or late recurrence; and (3) Different sites of recurrence. In addition, the incidence of other primary neoplasms has been evaluated in a cohort of patients with a minimum potential follow-up of 10 years.

RESULTS

Our study included 234 patients. The median follow-up period has been 119 ± 46.2 mo. The recurrence rate has been 25.6%. Patients with a higher chance to develop recurrence had also the following characteristics: Higher levels of preoperative glycemia and carcinoembryonic antigen, highest anaesthesiologists Score score, occlusion, received a complex operation performed with an open technique, after a longer hospital stay, and showed advanced tumors. The independent prognostic factors for recurrence were the hospital stay, N stage 2, and M stage 1 (multivariate analysis). Younger ages were significantly associated with an early recurrence onset. Patients that received intermediate colectomies or segmental resections, having an N stage 2 or American Joint Committee on Cancer stage 3 tumors were also associated with a higher risk of liver recurrence, while metastatic diseases at diagnosis were linked with local recurrence. Neoadjuvant treatments showed lung recurrence. Finally, bigger tumors and higher lymph node ratio were associated with peritoneal recurrence (marginally significant). Thirty patients developed a second malignancy during the follow-up time.

CONCLUSION

Several prognostic factors should be considered for tailored follow-up programs, eventually, beyond 5 years from the first treatment.

Defining early recurrence in patients with resected primary colorectal carcinoma and its respective risk factors

PURPOSE

There is no evidence-based definition of early recurrence following resection of colorectal cancer. The purpose of this study is to define a point that discriminates between early and late recurrence in patients who have undergone colorectal cancer resection with curative intent and to analyze associated risk factors.

METHODS

A retrospective single-center cohort study was performed at a university hospital recognized as a comprehensive cancer center, specializing in colorectal cancer surgery. Patient data were retrieved from a prospectively maintained institutional database. Included patients underwent resection for primary, non-metastatic colorectal carcinomas with curative intent between 1995 and 2010. Aims of the study were (1) to define the optimal cut-off point of recurrence-free survival based on overall survival using a minimum p value approach and (2) to identify patterns of initial recurrence and putative risk factors for early recurrence using regression models.

RESULTS

Recurrence was diagnosed in 412 of 1893 patients. Statistical analysis suggested that a recurrence-free survival of 16 months could be used to distinguish between early and late recurrence based on overall survival (p < 0.001). Independent risk factors for early recurrence included advanced pT categories (pT3,4/ypT3,4) and positive lymph node status (pN+/ypN+). Early recurrence was independent of site of recurrence and was associated with worse prognosis.

CONCLUSIONS

Recurrence of colorectal carcinoma within 16 months after primary treatment should be labeled as "early." Tumor categories pT3,4/ypT3,4 and positive lymph node status pN+/ypN+ are predictive of early recurrence.

Integrated Analysis of the Functions and Prognostic Values of RNA-Binding Proteins in Colorectal Cancer

Colorectal cancer (CRC) is one of the most common malignant tumors. Selecting effective treatment for CRC patients, especially in the early stages, remains a challenge because of the lack of adequate biomarkers. Recent evidence suggests that RNA-binding proteins (RBPs) play a vital role in development and progression of carcinogenesis. However, their mechanisms in cancer progression are still limited. The role of RBPs in CRC has been poorly understood. There were 1,542 reported RBPs analyzed between CRC tissues and normal tissues using the Wilcoxon test to identify differentially expressed RBPs (DE RBPs). Then, the potential functions and the prognostic value of these DE RBPs were explored through systematic bioinformatics analysis. There were 177 DE RBPs identified between CRC tissues and normal tissues. A protein–protein interaction network was constructed based on DE RBPs, and critical modules were screened. A regulatory network between prognostic DE RBPs and differentially expressed transcription factors was constructed. Besides, a risk signature was built based on prognostic DE RBPs, which is able to predict overall survival of CRC patients with high accuracy. In conclusion, the results provided a comprehensive understanding of the functions of RBPs in CRC, as well as an RBP-related prognostic signature.

Defining and predicting early recurrence in patients with locally advanced rectal cancer treated with neoadjuvant chemoradiotherapy

BACKGROUND

The definition of "early recurrence (ER)" after rectal cancer surgery is currently unclear.

OBJECTIVE

To determine an evidence-based cut-off to distinguish early and late recurrence (LR) for patients with rectal cancer and compare the clinicopathological factors between the two groups.

METHODS

Patients who underwent neoadjuvant chemoradiotherapy (nCRT) and radical resection for locally advanced rectal cancer were included. A minimum p-value approach was used to evaluate the optimal cut-off value of recurrence-free survival to divide the patients into ER and LR groups based on overall survival. A logistic regression model was used to assess risk factors for ER.

RESULTS

A total of 763 patients were included, of which 167 (21.9%) experienced recurrence. The optimal cut-off value of recurrence-free survival to differentiate between ER (n = 125, 74.9%) and LR (n = 42, 25.1%) was 24 months (P = 0.000001). The median postrecurrence survival of ER and LR was 12 months and 22 months, respectively (p = 0.028). The most common recurrent sites in patients with ER and LR were lung metastases, the incidence of liver metastases, however, differed considerably in ER and LR (27.2% vs 9.5%, P = 0.019). Risk factors including elevated preoperative carcinoembryonic antigen (CEA), higher ypTNM stage, positive circumferential resection margin (CRM), and perineural invasion were significantly associated with ER.

CONCLUSION

A recurrence-free interval of 24 months is the optimal cut-off value for defining ER versus LR. Elevated preoperative CEA, higher ypTNM staging, positive CRM, and perineural invasion were associated with ER of locally advanced rectal cancer.

Early postoperative recurrences for colon cancer: Results from a Pakistani rural cohort

Objectives

We conducted this study to determine the factors associated with early postoperative recurrence in colon cancer patients treated with curative intent.

Methods

All consecutive patients who underwent curative resection for colon cancer between January 2014 and December 2016 were reviewed. All patients received either adjuvant chemotherapy or follow-up at the Bannu Institute of Nuclear Medicine Oncology and Radiotherapy (BINOR). The patients lived in rural areas of southern Khyber Pakhtunkhwa province.

Results

We enrolled 72 patients, 28 of whom experienced a postoperative recurrence within 2 years (early recurrence). In univariate analysis, postoperative early relapse was significantly correlated with advanced age (>60 years, p = 0.030), nodal status (p = 0.012), pathological stage (p = 0.013), number of nodes removed (p < 0.001), and perineural invasion (p = 0.044). In multivariate analysis, age more than 60 years (p = 0.031) and fewer than 12 lymph nodes removed (p = 0.003) were independent predictors for early recurrence. The liver was the most common site of recurrence (42.8%) in this study.

Conclusion

Our results showed that advanced age and the removal of fewer than 12 lymph nodes during surgery were significant predictors for early postoperative recurrence. Identification of high-risk patients during follow-up with enhanced therapeutic modalities can improve disease-free survival.

Efficacy and toxicity of adjuvant chemotherapy on colorectal cancer patients: how much influence from the genetics?

We studied the predictive value for response and toxicity of functional polymorphisms in genes involved in the oxaliplatin/fluorouracil pathway in colorectal cancer patients. One hundred and twenty-seven (127) patients were treated with curative intended surgery followed by adjuvant chemotherapy with FOLFOX (fluorouracil, leucovorin and oxaliplatin) regimen. The median age was 65.53 (27-80) years (66.9% male, 59.1% rectum). The median follow-up was 8.5 years (IQR, 4.1-9.4). At the end of follow-up, 59 patients (46.5%) had relapsed or died in the whole study population. We did find that XRCC1GG genotype is associated with a higher risk of developing haematologic toxicity. Furthermore, we report a significant association of the TS 3'UTR 6 bp/6 bp polymorphism and the XRCC1 rs25487 with a higher risk of developing anaemia and diarrhoea, respectively. On the other hand, none of the studied polymorphisms showed clinically relevant association with disease-free survival and overall survival or early failure to adjuvant FOLFOX therapy.

Monoamine Oxidase B Expression Correlates with a Poor Prognosis in Colorectal Cancer Patients and Is Significantly Associated with Epithelial-to-Mesenchymal Transition-Related Gene Signatures

Monoamine oxidases (MAOs) including MAOA and MAOB are enzymes located on the outer membranes of mitochondria, which are responsible for catalyzing monoamine oxidation. Recently, increased level of MAOs were shown in several cancer types. However, possible roles of MAOs have not yet been elucidated in the progression and prognosis of colorectal carcinoma (CRC). We therefore analyzed the importance of MAOs in CRC by an in silico analysis and tissue microarrays. Several independent cohorts indicated that high expression of MAOB, but not MAOA, was correlated with a worse disease stage and poorer survival. In total, 203 colorectal adenocarcinoma cases underwent immunohistochemical staining of MAOs, and associations with clinicopathological parameters and patient outcomes were evaluated. We found that MAOB is highly expressed in CRC tissues compared to normal colorectal tissues, and its expression was significantly correlated with a higher recurrence rate and a poor prognosis. Moreover, according to the univariate and multivariate analyses, we found that MAOB could be an independent prognostic factor for overall survival and disease-free survival, and its prognostic value was better than T and N stage. Furthermore, significant positive and negative correlations of MAOB with mesenchymal-type and epithelial-type gene expressions were observed in CRC tissues. According to the highlighted characteristics of MAOB in CRC, MAOB can be used as a novel indicator to predict the progression and prognosis of CRC patients.

Do clinicopathologic features of rectal and colon cancer guide us towards distinct malignancies?

Background

Unlike developed countries where studies on all aspects of colorectal cancers are widely numerous, Iran as a Middle Eastern country show very few studies especially ones comparing the differences between colon and rectal cancer. In this study, firstly we report demographic, clinical and pathologic characteristics of patients with rectum and colon cancer and secondly compare these findings in order to investigate probable differences.

Methods

In this cross-sectional study, 238 patients were divided into two groups: the rectal cancer group and the colonic cancer group. Demographic, clinical and pathologic information of patients were statistically compared using Stata version 12.

Results

There were no statistical differences between the two groups regarding age and gender and BMI. Regarding clinical presentation, the proportion of rectal bleeding was significantly higher in colon cancer group (P<0.001). Moreover, abdominal pain was significantly more frequent in colon cancer group (P<0.001). Tumor stage showed statistically difference between the two groups (P=0.02).

Conclusions

We did not find enough evidences to conclude that rectal cancer and colon cancer should be investigated as two distinct malignancies but findings showed significant differences such as stage at diagnosis encouraged us in order to conduct other appropriate studies for better evaluation of this issue.

Pattern, Stage, and Time of Recurrent Colorectal Cancer After Curative Surgery

Surgery remains the mainstay of curative treatment for colorectal cancer (CRC). Despite curative surgery, some patients experience cancer recurrence. However, the pattern, stage, and time of recurrent disease (RD) remain unknown. We aimed to determine the pattern and stage of RD after curative open and laparoscopic surgery for CRC. Databases were searched using selected keywords for clinical studies that analyzed the pattern, stage, and time of RD from CRC. A systematic protocol was used for data extraction, data synthesis, and interpretation of results. Of 455 publications retrieved from databases, 9 clinical studies were selected for this systematic review. There is substantial evidence that pulmonary recurrence is most commonly associated with rectal tumors, and multisite RD appears more frequently with right-sided CRC. RD from colon cancers predominantly appears early in liver, while recurrences from rectal cancer appear late in lungs. Approximately 30% to 50% of RD after curative resection of CRC occurs within the first 2 years; however, median time to recurrence is gradually increasing, particularly for patients with rectal cancers. Advanced primary CRC is significantly correlated with more locoregional and distant RD, with worse disease-free survival. There is a decrease in the 5-year incidence of RD that is associated with prolongation of time of RD for both locoregional and metastatic disease. The duration and design of postoperative follow-up protocols for recurrences from CRC should be tailored to site and stage of primary tumor, as rectal cancers demand longer surveillance times than colon cancer.

Prognostic significance of circulating tumor cells (CTCs) in Egyptian non-metastatic colorectal cancer patients: A comparative study for four different techniques of detection (Flowcytometry, CellSearch, Quantitative Real-time PCR and Cytomorphology)

PURPOSE

We assessed CTCs counts in NMCRC patients using four different techniques.

METHODS

CTCs were detected in 63 NMCRC patients, 40 benign bowel diseases (BBD) and 40 normal controls (NC) using, flow-cytometry (FCM), CellSearch (CS), cytomorphology and quantitative real time (qPCR) for CK19, MUC1, CD44, CD133, ALDH1 expression. Results were correlated to progression free (PFS) and overall (OS).

RESULTS

Positive CTCs (≥4 cells /7.5 mL blood) were detected in 50.8% (32/63) NMCRC by FCM and 7.5% (3/40) BBD (p < .001). CTCs were detected in 34/63 (54%) NMCRC, 4/40 (10%) BBD (p < .001) by CS. CK19, MUC1, CD44, CD133 and ALDH1 were expressed in 35 (55.6%), 29 (46.0%), 28 (44.4%), 26 (41.3%) and 25 (41.3%) cases of NMCRC. In BBD 4/40 (10%) cases expressed CK19, MUC1 and CD44, while 2/40 (5%) expressed CD133. Cytomorphology showed the lowest sensitivity (47.6%) and specificity (90%) for CTCs detection. The combined use of FCM or CS with CTCs-mRNA markers improved the sensitivity and specificity to 68.3%, and 95.0%; respectively. Positive CTCs and mRNA markers expression were significantly associated with shorter 5-yr PFS and OS. In multivariate analysis, CTCs mRNA markers were independent prognostic factors for PFS and OS.

CONCLUSIONS

Enumeration of CTCs by FCM and RNA expression for specific colon cancer markers are comparable to CS regarding sensitivity and specificity. CTCs also represent novel therapeutic targets for NMCRC cases.

Risk Factors Predicting Colorectal Cancer Recurrence Following Initial Treatment: A 5-year Cohort Study

Purpose:

Recurrence is one of the most important factors influencing survival of colorectal cancer patients.

Subjects and Methods:

In this cohort study, clinical and demographic characteristics of 561 patients with colorectal cancer were collected from 2010 to 2015. Medical records and telephone interviews were used to define the patient’s clinical status including the date of any recurrence during the study period. The multivariate Cox model was used as the main strategy for analyzing data.

Results:

Some 239 (42.6%) patients experienced cancer recurrence during the 5-year follow-up period. Those with an older age at diagnosis had a higher risk of cancer recurrence than their younger counterparts [Hazard Ratio (HR) >70 y /<50 y= 1.65, P=0.01]. Rectal cancer had a greater risk of disease recurrence compared with other tumor sites [HR colon/ rectum=1.53, P=0.02]. Stage 3 cancer had a higher risk than stage 1 cancer [HR stage 3/ stage 1=4.30, P<0.001], and positive lympho-vascular invasion was also a risk factor [HR yes/ no=2.03, P<0.001]. Finally, tumor size, number of dissected lymph nodes, proportion of positive lymph nodes, perineural invasion and type of treatment did not significantly predict recurrence.

Conclusion:

Access to enhanced medical services including cancer diagnosis at an early stage and optimal treatment is needed to improve the survival and quality of life of CRC patients.

Descriptive characteristics of colon and rectal cancer recurrence in a Danish population-based study

BACKGROUND

Recurrence is a common outcome among patients that have undergone an intended curative resection for colorectal cancer. However, data on factors that influence colorectal cancer recurrence are sparse. We report descriptive characteristics of both colon and rectal cancer recurrence in an unselected population.

MATERIAL AND METHODS

We identified 21,152 patients with colorectal cancer diagnosed between May 2001 and December 2011 and registered with the Danish Colorectal Cancer Group. Recurrences were identified in 3198 colon and 1838 rectal cancer patients during follow-up. We calculated the frequency, proportion, and incidence rates of colon and rectal cancer recurrence within descriptive categories, and the cumulative five- and ten-year incidences of recurrence, treating death as a competing risk. We used a Cox proportional hazard model to calculate hazard ratios (HR) and 95% confidence intervals (CI).

RESULTS

Recurrence risk was highest in the first three years of follow-up. Patients <55 years old at initial diagnosis (incidence rate for colon: 7.2 per 100 person-years; 95% CI: 6.5-7.9; rectum: 8.1 per 100 person-years; 95% CI: 7.2-9.0) and patients diagnosed with stage III cancer (colon HR: 5.70; 95% CI: 4.61-7.06; rectal HR: 7.02; 95% CI: 5.58-8.82) had increased risk of recurrence. Patients diagnosed with stage III cancer from 2009 to 2011 had a lower incidence of recurrence than those diagnosed with stage III cancer in the years before. Cumulative incidences of colon and rectal cancer recurrence were similar for both cancer types among each descriptive category.

CONCLUSIONS

In this population, increases in colorectal cancer recurrence risk were associated with younger age and increasing stage at diagnosis. Cumulative incidence of recurrence did not differ by cancer type. Descriptive characteristics of colon and rectal cancer recurrence may help to inform patient-physician decision-making, and could be used to determine adjuvant therapies or tailor surveillance strategies so that recurrence may be identified early, particularly within the first 3 years of follow-up.

Germline INDELs and CNVs in a cohort of colorectal cancer patients: their characteristics, associations with relapse-free survival time, and potential time-varying effects on the risk of relapse

INDELs and CNVs are structural variations that may play roles in cancer susceptibility and patient outcomes. Our objectives were a) to computationally detect and examine the genome‐wide INDEL/CNV profiles in a cohort of colorectal cancer patients, and b) to examine the associations of frequent INDELs/CNVs with relapse‐free survival time. We also identified unique variants in 13 Familial Colorectal Cancer Type X (FCCX) cases. The study cohort consisted of 495 colorectal cancer patients. QuantiSNP and PennCNV algorithms were utilized to predict the INDELs/CNVs using genome‐wide signal intensity data. Duplex PCR was used to validate predictions for 10 variants. Multivariable Cox regression models were used to test the associations of 106 common variants with relapse‐free survival time. Score test and the multivariable Cox proportional hazards models with time‐varying coefficients were applied to identify the variants with time‐varying effects on the relapse‐free survival time. A total of 3486 distinct INDELs/CNVs were identified in the patient cohort. The majority of these variants were rare (83%) and deletion variants (81%). The results of the computational predictions and duplex PCR results were highly concordant (93–100%). We identified four promising variants significantly associated with relapse‐free survival time (P < 0.05) in the multivariable Cox proportional hazards regression models after adjustment for clinical factors. More importantly, two additional variants were identified to have time‐varying effects on the risk of relapse. Finally, 58 rare variants were identified unique to the FCCX cases; none of them were detected in more than one patient. This is one of the first genome‐wide analyses that identified the germline INDEL/CNV profiles in colorectal cancer patients. Our analyses identified novel variants and genes that can biologically affect the risk of relapse in colorectal cancer patients. Additionally, for the first time, we identified germline variants that can potentially be early‐relapse markers in colorectal cancer.

Identification of Predictive DNA Methylation Biomarkers for Chemotherapy Response in Colorectal Cancer

Resistance to 5-Fluorouracil (5-FU) is a major obstacle to the successful treatment of colorectal cancer (CRC) and posed an increased risk of recurrence. DNA methylation has been suggested as one of the underlying mechanisms for recurrent disease and its contribution to the development of drug resistance remains to be clarified. This study aimed to determine the methylation phenotype in CRC for identification of predictive markers for chemotherapy response. We performed DNA methylation profiling on 43 non-recurrent and five recurrent CRC patients using the Illumina Infinium HumanMethylation450 Beadchip assay. In addition, CRC cells with different genetic backgrounds, response to 5-FU and global methylation levels (HT29 and SW48) were treated with 5-FU and DNA methylation inhibitor 5-aza-2′-deoxycytidine (5-azadC). The singular and combined effects of these two drug classes on cell viability and global methylation profiles were investigated. Our genome-wide methylation study on the clinical specimens showed that recurrent CRCs exhibited higher methylation levels compared to non-recurrent CRCs. We identified 4787 significantly differentially methylated genes (P < 0.05); 3112 genes were hyper- while 1675 genes were hypomethylated in the recurrent group compared to the non-recurrent. Fifty eight and 47 of the significantly hypermethylated and hypomethylated genes have an absolute recurrent/non-recurrent methylation difference of ≥20%. Most of the hypermethylated genes were involved in the MAPK signaling pathway which is a key regulator for apoptosis while the hypomethylated genes were involved in the PI3K-AKT signaling pathway and proliferation process. We also demonstrate that 5-azadC treatment enhanced response to 5-FU which resulted in significant growth inhibition compared to 5-FU alone in hypermethylated cell lines SW48. In conclusion, we found the evidence of five potentially biologically important genes in recurrent CRCs that could possibly serve as a new potential therapeutic targets for patients with chemoresistance. We postulate that aberrant methylation of CCNEI, CCNDBP1, PON3, DDX43, and CHL1 in CRC might be associated with the recurrence of CRC and 5-azadC-mediated restoration of 5-FU sensitivity is mediated at least in part by MAPK signaling pathway.

Base excision repair imbalance in colorectal cancer has prognostic value and modulates response to chemotherapy

Colorectal cancer (CRC) is prevalent worldwide, and treatment often involves surgery and genotoxic chemotherapy. DNA repair mechanisms, such as base excision repair (BER) and mismatch repair (MMR), may not only influence tumour characteristics and prognosis but also dictate chemotherapy response. Defective MMR contributes to chemoresistance in colorectal cancer. Moreover, BER affects cellular survival by repairing genotoxic base damage in a process that itself can disrupt metabolism. In this study, we characterized BER and MMR gene expression in colorectal tumours and the association between this repair profile with patients’ clinical and pathological features. In addition, we exploited the possible mechanisms underlying the association between altered DNA repair, metabolism and response to chemotherapy. Seventy pairs of sporadic colorectal tumour samples and adjacent non-tumour mucosal specimens were assessed for BER and MMR gene and protein expression and their association with pathological and clinical features. MMR-deficient colon cancer cells (HCT116) transiently overexpressing MPG or XRCC1 were treated with 5-FU or TMZ and evaluated for viability and metabolic intermediate levels. Increase in BER gene and protein expression is associated with more aggressive tumour features and poor pathological outcomes in CRC. However, tumours with reduced MMR gene expression also displayed low MPG, OGG1 and PARP1 expression. Imbalancing BER by overexpression of MPG, but not XRCC1, sensitises MMR-deficient colon cancer cells to 5-FU and TMZ and leads to ATP depletion and lactate accumulation. MPG overexpression alters DNA repair and metabolism and is a potential strategy to overcome 5-FU chemotherapeutic resistance in MMR-deficient CRC.

Racial disparity in colorectal cancer: Gut microbiome and cancer stem cells

Over the past two decades there has been remarkable progress in cancer diagnosis, treatment and screening. The basic mechanisms leading to pathogenesis of various types of cancers are also understood better and some patients, if diagnosed at a particular stage go on to lead a normal pre-diagnosis life. Despite these achievements, racial disparity in some cancers remains a mystery. The higher incidence, aggressiveness and mortality of breast, prostate and colorectal cancers (CRCs) in African-Americans as compared to Caucasian-Americans are now well documented. The polyp-carcinoma sequence in CRC and easy access to colonic epithelia or colonic epithelial cells through colonoscopy/colonic effluent provides the opportunity to study colonic stem cells early in course of natural history of the disease. With the advent of metagenomic sequencing, uncultivable organisms can now be identified in stool and their numbers correlated with the effects on colonic epithelia. It would be expected that these techniques would revolutionize our understanding of the racial disparity in CRC and pave a way for the same in other cancers as well. Unfortunately, this has not happened. Our understanding of the underlying factors responsible in African-Americans for higher incidence and mortality from colorectal carcinoma remains minimal. In this review, we aim to summarize the available data on role of microbiome and cancer stem cells in racial disparity in CRC. This will provide a platform for further research on this topic.

Prognostic classification index in Iranian colorectal cancer patients: Survival tree analysis

Aims:

The aim of this study was to determine the prognostic index for separating homogenous subgroups in colorectal cancer (CRC) patients based on clinicopathological characteristics using survival tree analysis.

Methods:

The current study was conducted at the Research Center of Gastroenterology and Liver Disease, Shahid Beheshti Medical University in Tehran, between January 2004 and January 2009. A total of 739 patients who already have been diagnosed with CRC based on pathologic report were enrolled. The data included demographic and clinical-pathological characteristic of patients. Tree-structured survival analysis based on a recursive partitioning algorithm was implemented to evaluate prognostic factors. The probability curves were calculated according to the Kaplan-Meier method, and the hazard ratio was estimated as an interest effect size.

Result:

There were 526 males (71.2%) of these patients. The mean survival time (from diagnosis time) was 42.46± (3.4). Survival tree identified three variables as main prognostic factors and based on their four prognostic subgroups was constructed. The log-rank test showed good separation of survival curves. Patients with Stage I-IIIA and treated with surgery as the first treatment showed low risk (median = 34 months) whereas patients with stage IIIB, IV, and more than 68 years have the worse survival outcome (median = 9.5 months).

Conclusion:

Constructing the prognostic classification index via survival tree can aid the researchers to assess interaction between clinical variables and determining the cumulative effect of these variables on survival outcome.

Tissue microRNA-21 expression predicted recurrence and poor survival in patients with colorectal cancer - a meta-analysis

OBJECTIVE

MicroRNA-21 (miR-21) has been shown to play an important role in cancer prognosis. We performed a meta-analysis to evaluate the prognostic effect of miR-21 from tissues and serum on survival of the patients with colorectal cancer (CRC).

METHODS

Relevant studies were identified by searching PubMed, Embase, and Cochrane Library. Pooled hazard ratios (HRs) with 95% confidence intervals (CIs) of total and subgroup analyses, for overall survival (OS) and disease-free survival (DFS), were calculated to investigate the association between miR-21 expression and CRC prognosis.

RESULTS

Our analysis included eleven studies (3,669 subjects). In addition, four studies explored the association between miR-21 and DFS, and ten studies focused on the prognostic value of miR-21 for OS. Our results indicated that increased miR-21 expression of tissues predicted both poor DFS and OS in patients with CRC (DFS: HR =1.59, 95% CI =1.20-2.10; OS: HR =1.53, 95% CI =1.23-1.90). Consistent results were observed among colon cancer and quantitative real-time polymerase chain reaction subgroups.

CONCLUSION

Meta-analysis indicated that miR-21 predicted recurrence and poor survival in patients with CRC. miR-21 may be more suitable to predict cancer prognosis in colon cancer patients.

Molecular mechanism of adenomatous polyposis coli-induced blockade of base excision repair pathway in colorectal carcinogenesis

Colorectal cancer (CRC) is the third leading cause of death in both men and women in North America. Despite chemotherapeutic efforts, CRC is associated with a high degree of morbidity and mortality. Thus, to develop effective treatment strategies for CRC, one needs knowledge of the pathogenesis of cancer development and cancer resistance. It is suggested that colonic tumors or cell lines harbor truncated adenomatous polyposis coli (APC) without DNA repair inhibitory (DRI)-domain. It is also thought that the product of the APC gene can modulate base excision repair (BER) pathway through an interaction with DNA polymerase β (Pol-β) and flap endonuclease 1 (Fen-1) to mediate CRC cell apoptosis. The proposed therapy with temozolomide (TMZ) exploits this particular pathway; however, a high percentage of colorectal tumors continue to develop resistance to chemotherapy due to mismatch repair (MMR)-deficiency. In the present communication, we have comprehensively reviewed a critical issue that has not been addressed previously: a novel mechanism by which APC-induced blockage of single nucleotide (SN)- and long-patch (LP)-BER play role in DNA-alkylation damage-induced colorectal carcinogenesis.

Bisphosphonate and risk of cancer recurrence: protocol for a systematic review, meta-analysis and trial sequential analysis of randomised controlled trials

INTRODUCTION

No consensus exists on the associations between adjuvant treatment with bisphosphonates and cancer recurrence risk among patients with primary early-stage cancers. We plan to perform a comprehensive systematic review, study-level meta-analysis and trial sequential analysis of randomised controlled trials to comprehensively summarise evidence of the bisphosphonate treatment for difference cancers.

METHODS AND ANALYSES

We will report our results according to the PRISMA guideline. The primary outcomes include any cancer recurrence and bone metastasis and secondary outcomes include events of local recurrence, regional recurrence or non-skeletal distant metastasis, disease-free survival and overall survival. We will perform systematic electronic searches and other manual searches. To be conservative, all statistical analyses will be conducted with random-effects models. Cumulative meta-analyses and trial sequential analyses will be performed to assess whether and when firm evidence is reached. Various sensitivity analyses and rigid publication bias analyses will be performed to challenge the consistency and robustness of results. We will also grade the quality of evidence with the GRADE system.

ETHICS AND DISSEMINATION

Ethical approval is not required in this study. The findings will be submitted for publication in a peer-reviewed journal and also presented at relevant national and international conferences.

TRIAL REGISTRATION NUMBER

PROSPERO CRD42014014699.

miR-218 inhibits the invasion and migration of colon cancer cells by targeting the PI3K/Akt/mTOR signaling pathway

Colon cancer is one of the most common and lethal malignancies worldwide. Despite major advances in the treatment of colon cancer, the prognosis remains very poor. Thus, novel and effective therapies for colon cancer are urgently needed. In the present study, the expression status of miR-218 and the role of the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) pathway were investigated in colon cancer samples. Firstly, we observed that miR-218 expression was significantly reduced, while PI3K/Akt/mTOR pathway activity was enhanced. The overexpression of miR-218 suppressed the proliferation, migration and invasion of LoVo colon cancer cells, whereas the inhibition of miR-218 promoted these processes. Furthermore, the PI3K/Akt/mTOR signaling pathway was identified as a direct target of miR-218. The upregulation of miR-218 inhibited the activation of the PI3K/Akt/mTOR signaling pathway, as well as the expression of matrix metalloproteinase (MMP)9. The downregulation of miR-218 activated the PI3K/Akt/mTOR signaling pathway and promoted MMP9 expression. Taken together, our results demonstrate that miR-218 suppresses the proliferation, migration and invasion of LoVo colon cancer cells by targeting the PI3K/Akt/mTOR signaling pathway and MMP9. Our data indicate that miR-218 is a potential target in the treatment of colon cancer.

MiR-133b acts as a tumor suppressor and negatively regulates TBPL1 in colorectal cancer cells

INTRODUCTION

MicroRNAs have emerged as post-transcriptional regulators that are critically involved in tumorigenesis. This study was designed to explore the effect of miRNA 133b on the proliferation and expression of TBPL1 in colon cancer cells.

METHODS

Human colon cancer SW-620 cells and human colon adenocarcinoma HT-29 cells were cultured. MiRNA 133b mimcs, miRNA 133b inhibitors, siRNA for TBPL1 and scrambled control were synthesized and transfected into cells. MiR-133b levels in cells and CRC tumor tissue was measured by real-time PCR. TBPL1 mRNA was detected by RT-PCR. Cell proliferation was studied with MTT assay. Western blotting was applied to detect TBPL1 protein levels. Luciferase assays were conducted using a pGL3-promoter vector cloned with full length of 3'UTR of human TBPL1 or 3'UTR with mutant sequence of miR-133b target site in order to confirm if the putative binding site is responsible for the negative regulation of TBPL1 by miR- 133b.

RESULTS

Real time PCR results showed that miRNA 133b was lower in CRC tissue than that in adjacent tissue. After miR-133b transfection, its level was elevated till 48h, accompanied by lower proliferation in both SW-620 and HT-29 cells. According to that listed in http://www.targetscan.org, the 3'-UTR of TBPL1 mRNA (NM_004865) contains one putative binding site of miR-133b. This site was confirmed to be responsible for the negative regulation by miR-133b with luciferase assay. Further, Western blotting and immunohistochemistry both indicated a higher TBPL1 protein expression level in CRC tissue. Finally, a siRNA for TBPL1 transfection obviously slowed down the cell proliferation in both SW-620 and HT-29 cells.

CONCLUSION

MiR-133b might act as a tumor suppressor and negatively regulate TBPL1 in CRC.

Cancer treatment and survivorship statistics, 2014

The number of cancer survivors continues to increase due to the aging and growth of the population and improvements in early detection and treatment. In order for the public health community to better serve these survivors, the American Cancer Society and the National Cancer Institute collaborated to estimate the number of current and future cancer survivors using data from the Surveillance, Epidemiology, and End Results (SEER) program registries. In addition, current treatment patterns for the most common cancer types are described based on information in the National Cancer Data Base and the SEER and SEER-Medicare linked databases; treatment-related side effects are also briefly described. Nearly 14.5 million Americans with a history of cancer were alive on January 1, 2014; by January 1, 2024, that number will increase to nearly 19 million. The 3 most common prevalent cancers among males are prostate cancer (43%), colorectal cancer (9%), and melanoma (8%), and those among females are cancers of the breast (41%), uterine corpus (8%), and colon and rectum (8%). The age distribution of survivors varies substantially by cancer type. For example, the majority of prostate cancer survivors (62%) are aged 70 years or older, whereas less than one-third (32%) of melanoma survivors are in this older age group. It is important for clinicians to understand the unique medical and psychosocial needs of cancer survivors and to proactively assess and manage these issues. There are a growing number of resources that can assist patients, caregivers, and health care providers in navigating the various phases of cancer survivorship.

Future directions for the early detection of colorectal cancer recurrence

Surgical resection remains a mainstay of treatment and is highly effective for localized colorectal cancer. However, ~30-40% of patients develop recurrence following surgery and 40-50% of recurrences are apparent within the first few years after initial surgical resection. Several variables factor into the ultimate outcome of these patients, including the extent of disease, tumor biology, and patient co-morbidities. Additionally, the time from initial treatment to the development of recurrence is strongly associated with overall survival, particularly in patients who recur within one year of their surgical resection. Current post-resection surveillance strategies involve physical examination, laboratory, endoscopic and imaging studies utilizing various high and low-intensity protocols. Ultimately, the goal is to detect recurrence as early as possible, and ideally in the asymptomatic localized phase, to allow initiation of treatment that may still result in cure. While current strategies have been effective, several efforts are evolving to improve our ability to identify recurrent disease at its earliest phase. Our aim with this article is to briefly review the options available and, more importantly, examine emerging and future options to assist in the early detection of colon and rectal cancer recurrence.

Predictive factors and the prognosis of recurrence of colorectal cancer within 2 years after curative resection

PURPOSE

Because predicting recurrence intervals and patterns would allow for appropriate therapeutic strategies, we evaluated the clinical and pathological characteristics of early and late recurrences of colorectal cancer.

METHODS

Patients who developed recurrence after undergoing curative resection for colorectal cancer stage I-III between January 2000 and May 2006 were identified. Early recurrence was defined as recurrence within 2 years after primary surgery of colorectal cancer. Analyses were performed to compare the clinicopathological characteristics and overall survival rate between the early and late recurrence groups.

RESULTS

One hundred fifty-eight patients experienced early recurrence and 64 had late recurrence. Multivariate analysis revealed that the postoperative elevation of carbohydrate antigen 19-9 (CA 19-9), venous invasion, and N stage correlated with the recurrence interval. The liver was the most common site of early recurrence (40.5%), whereas late recurrence was more common locally (28.1%), or in the lung (32.8%). The 5-year overall survival rates for early and late recurrence were significantly different (34.7% vs. 78.8%; P < 0.001). Survival rates after the surgical resection of recurrent lesions were not different between the two groups.

CONCLUSION

Early recurrence within 2 years after surgery was associated with poor survival outcomes after colorectal cancer recurrence. An elevated postoperative CA 19-9 level, venous invasion, and advanced N stage were found to be significant risk factors for early recurrence of colorectal cancer.

Hydroxycamptothecin induces apoptosis and inhibits tumor growth in colon cancer by the downregulation of survivin and XIAP expression

BACKGROUND

10-Hydroxycamptothecin (10-HCPT), isolated from a Chinese tree Camptotheca acuminate, inhibits the activity of topoisomerase I and has a broad spectrum of anticancer activity in vitro and in vivo. It has been shown that HCPT is more active and less toxic than conventional camptothecins and can induce cancer cell apoptosis. However, the mechanisms of HCPT-induced apoptosis in colon cancer cells remain unclear. In this study, we investigated the effects of HCPT on apoptosis of colon cancer and underlying mechanism.

METHODS

Cell proliferation was measured by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide) assay, and apoptosis was measured using terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) assay. Expression of genes was detected using real-time reverse transcription-polymerase chain reaction (real time-PCR) and Western blot. Tumor growth in vivo was evaluated using a nude mouse xenograft model.

RESULTS

HCPT could significantly inhibit cell proliferation and induce apoptosis in colon cancer SW1116 and Colo 205 cells in dose- and time-dependent manners. HCPT treatment activated the activities of caspase 3, 7, 8 and 9, downregulated the expression of survivin, survivinΔEx3, survivin-3B and XIAP, and upregulated expression of surviving 2B. Moreover, the combination of HCPT and 5-fluorouracial (5-FU) synergistically induced apoptosis and downregulated the expression of survivin and XIAP. Knockdown of survivin and XIAP by siRNA sensitized colon cancer to HCTP-induced apoptosis. Furthermore, HCPT treatment significantly inhibited SW1116 xenograft tumor growth.

CONCLUSIONS

Our results elucidate new mechanisms of HCPT antitumor by the downregulation of survivin and XIAP expression. The combination of HCPT with 5-FU or IAP inhibitors may be a potential strategy for colon cancer treatment.

Growth inhibition of different human colorectal cancer xenografts after a single intravenous injection of oncolytic vaccinia virus GLV-1h68

Background

Despite availability of efficient treatment regimens for early stage colorectal cancer, treatment regimens for late stage colorectal cancer are generally not effective and thus need improvement. Oncolytic virotherapy using replication-competent vaccinia virus (VACV) strains is a promising new strategy for therapy of a variety of human cancers.

Methods

Oncolytic efficacy of replication-competent vaccinia virus GLV-1h68 was analyzed in both, cell cultures and subcutaneous xenograft tumor models.

Results

In this study we demonstrated for the first time that the replication-competent recombinant VACV GLV-1h68 efficiently infected, replicated in, and subsequently lysed various human colorectal cancer lines (Colo 205, HCT-15, HCT-116, HT-29, and SW-620) derived from patients at all four stages of disease. Additionally, in tumor xenograft models in athymic nude mice, a single injection of intravenously administered GLV-1h68 significantly inhibited tumor growth of two different human colorectal cell line tumors (Duke’s type A-stage HCT-116 and Duke’s type C-stage SW-620), significantly improving survival compared to untreated mice. Expression of the viral marker gene ruc-gfp allowed for real-time analysis of the virus infection in cell cultures and in mice. GLV-1h68 treatment was well-tolerated in all animals and viral replication was confined to the tumor. GLV-1h68 treatment elicited a significant up-regulation of murine immune-related antigens like IFN-γ, IP-10, MCP-1, MCP-3, MCP-5, RANTES and TNF-γ and a greater infiltration of macrophages and NK cells in tumors as compared to untreated controls.

Conclusion

The anti-tumor activity observed against colorectal cancer cells in these studies was a result of direct viral oncolysis by GLV-1h68 and inflammation-mediated innate immune responses. The therapeutic effects occurred in tumors regardless of the stage of disease from which the cells were derived. Thus, the recombinant vaccinia virus GLV-1h68 has the potential to treat colorectal cancers independently of the stage of progression.

Regulation of colon cancer recurrence and development of therapeutic strategies

Recurrence of colon cancer still remains a major issue which affects nearly 50% of patients treated by conventional therapeutics. Although the underlying causative factor(s) is not fully understood, development of drug-resistance has been associated with induction of cancer stem or stem-like cells (CSCs) which constitute a small sub-population of tumor cells known to be highly resistant to chemotherapy. In fact, the discovery of CSCs in a variety of tumors (including colon cancer) has changed the view of carcinogenesis and therapeutic strategies. Emerging reports have indicated that to improve patient outcomes, conventional anticancer therapies should be replaced with specific approaches targeting CSCs. Thus, therapeutic strategies that specifically target CSCs are being sought to reduce the risk of relapse and metastasis. In order to specifically target colon CSCs (while sparing somatic intestinal stem cells), it is critical to identify unique deregulated pathways responsible for self-renewal of CSCs and colon cancer recurrence. Colon CSCs present a unique opportunity to better understand the biology of solid tumors. Thus, a better understanding of the clinical signs and symptoms of colon cancer patients (undergoing surgery or chemotherapy) during perioperative periods, along with the underlying regulatory events affecting the stem/progenitor cell self-renewal and differentiation of colon epithelial cells, is of immense importance. In this review we discuss the implication of clinical factors and the emerging role of CSCs during recurrence of colon cancer along with the development of new therapeutic strategies involving the use of natural agents.

Clinicopathologic factors affecting recurrence after curative surgery for stage I colorectal cancer

PURPOSE

The objective of the current study was to identify the clinicopathological risk factors affecting recurrence after a curative resection for stage I colorectal cancer.

METHODS

We retrospectively studied 434 patients who underwent a curative resection for stage I colorectal cancer between January 1999 and December 2004. Postoperative oral chemotherapy was performed in 189 patients (45.3%). The following prognostic factors were correlated with recurrence: age, gender, preoperative carcinoembryonic antigen level, location of tumor, T stage, size of tumor, histologic differentiation, growth pattern, and lymphovascular invasion. The median follow-up duration was 65 months.

RESULTS

The overall recurrence rate was 4.6% (20/434). The median time to recurrence was 33 months. Two-thirds of the recurrence occurred more than two years after surgery. Risk factors associated with recurrence were rectal cancer (P = 0.009), T2 stage (P = 0.010), and infiltrative growth pattern (P = 0.020). A Cox proportional hazards regression analysis demonstrated that the infiltrative growth pattern was an independent predictor for recurrence. Tumor cell budding was observed in all pathologic reviews with recurrence.

CONCLUSION

Long-term follow-up is necessary for stage I colorectal patients with high risk factors like rectal cancer, T2 stage, and infiltrative growth pattern.