P53 and bcl-2 in colorectal cancer arising in patients under 40 years of age: distribution and prognostic relevance

Quality of life assessment for rectal cancer patients: A comparison between sphincter preservation and permanent colostomy

"This study aims to compare the quality of life in patients with rectal cancer between sphincter preservation and permanent colostomy. The present study is a cross-sectional study that was performed on 120 patients (60 cases in the sphincter maintenance group and 60 cases in the permanent colostomy group) who underwent surgery from February 2017 to November 2016. Quality of life assessment was provided with QLQ-C30 and QLQ-CR29 questionnaires. Finally, the collected data were analyzed using SPSS23 software. According to the results of the QLQ-C30 questionnaire, there was no statistically significant difference in patients' quality of life in terms of performance in the study groups (P˃0.05). Symptoms such as nausea, pain, shortness of breath, sleep disturbance, loss of appetite, constipation and economic problems in the study groups were not statistically significant (P˃0.05). But the mean symptoms of fatigue (P=0.038) and diarrhea (P=0.037) were significantly higher in the sphincter maintenance group than the permanent colostomy group. The mean score of patients' quality of life was 53.43 ± 8.40 in the sphincter retention group and 52.23 ± 11.45 in the permanent colostomy group (P = 0.556). According to the results, the quality of life in the two surgical methods of sphincter preservation and permanent colostomy was not statistically significant. Therefore, treatment decisions should be made by informing patients, both based on their preferences and the physician's clinical judgment."

Targeting Bcl-2 for cancer therapy

Apoptosis deficiency is one of the most important features observed in neoplastic diseases. The Bcl-2 family is composed of a subset of proteins that act as decisive apoptosis regulators. Research and clinical studies have both demonstrated that the hyperactivation of Bcl-2-related anti-apoptotic effects correlates with cancer occurrence, progression and prognosis, also having a role in facilitating the radio- and chemoresistance of various malignancies. Therefore, targeting Bcl-2 inactivation has provided some compelling therapeutic advantages by enhancing apoptotic sensitivity or reversing drug resistance. Therefore, this pharmacological route turned into one of the most promising routes for cancer treatment. This review discusses some of the well-defined and emerging roles of Bcl-2 as well as its potential clinical value in cancer therapeutics.

Personalized Medicine-Current and Emerging Predictive and Prognostic Biomarkers in Colorectal Cancer

Colorectal cancer (CRC) is the third most common cancer diagnosed worldwide and is heterogeneous both morphologically and molecularly. In an era of personalized medicine, the greatest challenge is to predict individual response to therapy and distinguish patients likely to be cured with surgical resection of tumors and systemic therapy from those resistant or non-responsive to treatment. Patients would avoid futile treatments, including clinical trial regimes and ultimately this would prevent under- and over-treatment and reduce unnecessary adverse side effects. In this review, the potential of specific biomarkers will be explored to address two key questions—1) Can the prognosis of patients that will fare well or poorly be determined beyond currently recognized prognostic indicators? and 2) Can an individual patient’s response to therapy be predicted and those who will most likely benefit from treatment/s be identified? Identifying and validating key prognostic and predictive biomarkers and an understanding of the underlying mechanisms of drug resistance and toxicity in CRC are important steps in order to personalize treatment. This review addresses recent data on biological prognostic and predictive biomarkers in CRC. In addition, patient cohorts most likely to benefit from currently available systemic treatments and/or targeted therapies are discussed in this review.

MicroRNA-498 reduces the proliferation and invasion of colorectal cancer cells via targeting Bcl-2

Colorectal cancer (CRC) remains a major cause of carcinoma-related deaths worldwide. MicroRNA-498 (miR-498) modulates the development of a variety of biological events, including tumorigenesis. Nevertheless, it is unclear whether miR-498 plays a role in CRC. This study was designed to elucidate the underlying mechanism and role of miR-498 in modulation of the viability and invasiveness of CRC cells. We report that CRC tissues and cells exhibited decreased expression of miR-498, and that overexpression of miR-498 resulted in reduced proliferation of CRC cells, concomitant with increased apoptosis. Furthermore, bioinformatic prediction and dual-luciferase reporter assay revealed that miR-498 targeted the 3'-UTR of Bcl-2 for silencing. However, Bcl-2 overexpression suppressed the proapoptosis of miR-498 on CRC cells. In summary, we describe a possible role of miR-498 in CRC, which may lead to the identification of new targets for treatment of this malignancy.

Is colorectal cancer a more aggressive disease in young patients? A population-based study from the Czech Republic

INTRODUCTION

The incidence of colorectal cancer in young patients is increasing. The goal of this study was to investigate whether clinicopathological features and survival differed between young, middle-aged and elderly patients.

METHODS

The Czech National Cancer Registry was searched to identify all cases of colorectal cancer between 1982 and 2014. Three subgroups of patients were created: young patients, defined as being between 18 and 40 years of age, middle-aged patients, defined as being between 41 and 74 years of age, and elderly patients, defined as being over the age of 75 years.

RESULTS

A total of 192,241 patients diagnosed with colorectal cancer between the years 1982 and 2014 were included in the study. Out of these, 3,287 patients (1.7%) were between 18 and 40 years of age, 134,139 patients (69.8%) were between 41 and 74 years of age and 54,815 patients (28.5%) were 75 years of age or older. The young patients had a higher incidence of mucinous adenocarcinoma and signet ring cell carcinoma, more advanced disease and more rectal tumours than elderly patients. Nonetheless, young patients received treatment more frequently and had better cancer-specific survival than the older patients.

CONCLUSION

The better prognosis in young patients is presumably due to their better physiological reserve and lower incidence of comorbidities. Efforts should be made in younger patients to diagnose early and treat aggressively.

LIN28B promotes the progression of colon cancer by increasing B-cell lymphoma 2 expression

RNA-binding protein LIN28B is frequently overexpressed in human colon cancer and is associated with the tumor progression and poor prognosis. The potential molecular mechanisms underlying the role of LIN28B in colon cancer remain unclear. The present study aimed to explore the role of B-cell lymphoma 2 (BCL-2) in promoting colon cancer development associated with LIN28B. The expression pattern of LIN28B in colon cancer tissues and cell lines was detected by RT-PCR, Western blotting analysis, and immunohistochemical staining. A log rank test was carried out to compare the survival times of patients with high/low levels of LIN28B. The effects of LIN28B on cell clonal formation, growth, and apoptosis were detected by clone formation, MTT and flow cytometry assays, respectively. BCL-2 expression and protein stability after LIN28B up-regulation were assessed by Western blotting. The effects of LIN28B and BCL-2 on tumorigenesis were evaluated by an in vivo xenograft assay. The results showed that LIN28B was highly expressed in colon cancer tissues and cell lines, which could promote cell clonal formation and growth and inhibit cell apoptosis. Up-regulation of LIN28B increased BCL-2 expression, enhanced its stability, and reduced its ubiquitination. Overexpression of LIN28B promoted cell tumorigenesis, whereas this effect was repressed by knockdown of BCL-2. This study suggests that overexpression of LIN28B promotes colon cancer development by increasing BCL-2 expression, potentially opening up new avenues for therapeutic approaches to colon cancer treatment.

Angiodrastic Chemokines in Colorectal Cancer: Clinicopathological Correlations

Aim

To study the expression of angiodrastic chemokines in colorectal tumors and correlate findings with clinicopathological parameters and survival.

Methods

The proangiogenic factor VEGF, the angiogenic chemokines CXCL8 and CXCL6, and the angiostatic chemokine CXCL4 were measured by ELISA in tumor and normal tissue of 35 stage II and III patients and correlated with the histopathology markers Ki67, p53, p21, bcl2, EGFR, and MLH1 and 5-year survival. The Wilcoxon and chi-square tests were used for statistical comparisons.

Results

There was a significant increase of CXCL6 (p = 0.005) and VEGF (p = 0.003) in cancerous tissue compared to normal. Patients with lower levels of CXCL8 and CXCL4 lived significantly longer. Patients with loss of EGFR expression had higher levels of CXCL8 while p21 loss was associated with higher levels of CXCL6. Chemokine levels were not correlated with TNM or Dukes classification. Strong expression of p53 was accompanied by decreased survival.

Conclusions

(1) The angiogenic factors CXCL6 and VEGF are increased in colorectal cancer tissue with no association with the clinical stage of the disease or survival. (2) However, increased levels of tissue CXCL8 and CXCL4 are associated with poor survival. (3) Strong expression of p53 is found in patients with poor survival.

Gender-related prognostic significance of clinical and biological tumor features in rectal cancer patients receiving short-course preoperative radiotherapy

AIM

To study the prognostic value of clinical and biological features of rectal cancer and potential gender differences in patients' overall survival (OS), local recurrence-free survival (RFS) and metastasis-free survival (MFS) after short-course preoperative radiotherapy (SCRT) with short or long interval between RT and surgery (break).

BACKGROUND

The length of the interval between RT and surgery in SCRT is debatable and gender-related differences in patients survival are not established yet.

MATERIALS AND METHODS

126 patients received SCRT with 5 Gy dose per fraction during 5 days, followed by radical surgery after short break ≤17 days, and a long break >17 days. Pretreatment tumor proliferation (bromodeoxyuridine labeling index, BrdUrdLI and S-phase fraction) was evaluated by flow cytometry and proteins: CD34, Ki-67, GLUT-1, Ku70, BCL-2, P53 expression was studied immunohistochemically.

RESULTS

The studied group included 84 men and 42 women. There were 33, 76, and 17 cTNM (AJCC) tumor stages I, II, III, respectively. The median follow-up time was 53.3 months (range 2-142 months). For the whole group Cox multivariate analysis revealed that tumor grade (G > 1), interval between RT and surgery >17 days, pTNM stage >1 and P53 positivity + BrdUrdLI > 7.9% were negative prognostic factors for OS. Tumor aneuploidy and MVD > 140.8 vessels/mm² were important for RFS. pTNM stage > 1 and P53 positivity combined with BrdUrdLI > 7.9% were risk predictors for MFS. Based on tumor biological features, gender-related difference in OS, RFS, and MFS were observed. In multivariate analysis, male patients age > 62 years and break >17 days only appeared to be significant for OS.

CONCLUSIONS

In male rectal patients treated with SCRT, breaks between RT and surgery >17 days should be avoided because they negatively influence patients' survival.

High expression of anti-apoptotic protein Bcl-2 is a good prognostic factor in colorectal cancer: Result of a meta-analysis

AIM

To systematically evaluate the prognostic-predictive capability of Bcl-2 in colorectal cancer (CRC).

METHODS

A systematic literature search was conducted using PubMed, Web of Science and EMBASE databases. Any eligible study must meet the following criteria: (1) bcl-2 expression was evaluated in human CRC tissues by immunohistochemistry; (2) assessment of the relationships between bcl-2 expression and overall survival (OS), disease free survival (DFS), recurrent free survival (RFS) or clinic-pathological characteristics of CRC was included; (3) sufficient information was provided to estimate the hazard ratio (HR) or odds ratio and their 95% confidence intervals (CIs); and (4) the study was published in English. The impact of Bcl-2 expression on survival of CRC patients were evaluated through this meta-analysis.

RESULTS

A total of 40 eligible articles involving 7658 patients were enrolled in our final analysis. We drew the conclusion that Bcl-2 high expression was significantly correlated with favorable OS (pooled HR = 0.69, 95%CI: 0.55-0.87, P = 0.002) and better DFS/RFS (pooled HR = 0.65, 95%CI: 0.50-0.85, P = 0.001). Additionally, the subgroup analysis suggested that Bcl-2 overexpression was significantly associated with prognosis (OS) especially in patients came from Europe and America but not Asian and patients who did not receive any adjuvant therapy before surgery. Finally, our present results indicated that expression of bcl-2 protein was associated with high differentiation grade and A/B Ducks’ stage.

CONCLUSION

Bcl-2 high expression was significantly correlated with favorable OS and better DFS/RFS. Hence, we propose that Bcl-2 may be a valuable prognostic-predictive marker in CRC.

Study of apoptosis-related interactions in colorectal cancer

Abnormalities in apoptotic functions contribute to the pathogenesis of colorectal cancer. In this study, molecular interactions behind the apoptotic regulation have been explored. For this purpose, enrichment analysis was performed considering microRNAs (miRNAs) that putatively target TP53 and altered during colon cancer. This revealed gene associated with both TP53 and miRNAs. Further analysis showed that a significant molecular interaction between the shortlisted candidates (TP53, miR-143, KRAS, BCL2, and PLK1) exists. Mutation study was conducted to confirm the clinical relevance of candidates. It showed that the mutation extent does not significantly alter survival in patients thus making these candidates suitable as drug targets. Overall, we showed the importance of interactions between TP53, miR-143, KRAS, BCL2, and PLK1 with respect to colorectal cancer using bioinformatics approach.

DNA hypermethylation and decreased mRNA expression of MAL, PRIMA1, PTGDR and SFRP1 in colorectal adenoma and cancer

Background

Colorectal cancer (CRC) development is accompanied by changes in expression for several genes; but the details of the underlying regulatory procesess remain unknown. Our aims were to assess the role of epigenetic processes in tumour formation and to identify characteristic DNA methylation and miRNA alterations in the colorectal adenoma-carcinoma sequence.

Methods

Whole genome expression profiling was performed on colonic biopsy samples (49 healthy normal, 49 colorectal adenoma (AD), 49 CRC); on laser capture microdissected (LCM) epithelial and stromal cells from 6 CRC-normal adjacent tissue (NAT) samples pairs, and on demethylated human CRC cell lines using HGU133 Plus 2.0 microarrays (Affymetrix). Methylation status of genes with gradually altering expression along the AD-CRC sequence was further analysed on 10–10 macrodissected and 5–5 LCM samples from healthy colon, from adenoma and from CRC biopsy samples using bisulfite-sequencing PCR (BS-PCR) followed by pyrosequencing. In silico miRNA prediction for the selected genes was performed with miRWALK algorithm, miRNA expression was analysed on 3 CRC-NAT sample pairs and 3 adenoma tissue samples using the Human Panel I + II (Exiqon). SFRP1 immunohistochemistry experiments were performed.

Results

A set of transcripts (18 genes including MAL, SFRP1, SULT1A1, PRIMA1, PTGDR) showed decreasing expression (p < 0.01) in the biopsy samples along the adenoma-carcinoma sequence. Three of those (COL1A2, SFRP2, SOCS3) showed hypermethylation and THBS2 showed hypomethylation both in AD and in CRC samples compared to NAT, while BCL2, PRIMA1 and PTGDR showed hypermethylation only in the CRC group. miR-21 was found to be significantly (p < 0.01) upregulated in adenoma and tumour samples compared to the healthy colonic tissue controls and could explain the altered expression of genes for which DNA methylation changes do not appear to play role (e.g. BCL2, MAL, PTGS2). Demethylation treatment could upregulate gene expression of genes that were found to be hypermethylated in human CRC tissue samples. Decreasing protein levels of SFRP1 was also observed along the adenoma-carcinoma sequence.

Conclusion

Hypermethylation of the selected markers (MAL, PRIMA1, PTGDR and SFRP1) can result in reduced gene expression and may contribute to the formation of colorectal cancer.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1687-x) contains supplementary material, which is available to authorized users.

The prognostic factors and multiple biomarkers in young patients with colorectal cancer

The incidence of colorectal cancer (CRC) in young patients (≤50 years of age) appears to be increasing. However, their clinicopathological characteristics and survival are controversial. Likewise, the biomarkers are unclear. We used the West China (2008-2013, China), Surveillance, Epidemiology, and End Results program (1973-2011, United States) and Linköping Cancer (1972-2009, Sweden) databases to analyse clinicopathological characteristics, survival and multiple biomarkers of young CRC patients. A total of 509,934 CRC patients were included from the three databases. The young CRC patients tended to have more distal location tumours, fewer tumour numbers, later stage, more mucinous carcinoma and poorer differentiation. The cancer-specific survival (CSS) of young patients was significantly better. The PRL (HR = 12.341, 95% CI = 1.615-94.276, P = 0.010), RBM3 (HR = 0.093, 95% CI = 0.012-0.712, P = 0.018), Wrap53 (HR = 1.952, 95% CI = 0.452-6.342, P = 0.031), p53 (HR = 5.549, 95% CI = 1.176-26.178, P = 0.045) and DNA status (HR = 17.602, 95% CI = 2.551-121.448, P = 0.001) were associated with CSS of the young patients. In conclusion, this study suggests that young CRC patients present advanced tumours and more malignant pathological features, while they have a better prognosis. The PRL, RBM3, Wrap53, p53 and DNA status are potential prognostic biomarkers for the young CRC patients.

Genetic dissimilarity between primary colorectal carcinomas and their lymph node metastases: ploidy, p53, bcl-2, and c-myc expression--a pilot study

The current paradigm of metastasis proposes that rare cells within primary tumors acquire metastatic capability via sequential mutations, suggesting that metastases are genetically dissimilar from their primary tumors. This study investigated the changes in the level of expression of a well-defined panel of cell proliferation, differentiation, and apoptosis markers between the primary colorectal cancer (CRC) and the corresponding synchronous lymph node (LN) metastasis from the same patients. DNA flow cytometry and immunostaining of p53, bcl-2, and c-myc were carried out on 36 cases of CRC radical resection specimens with their corresponding LN metastases. There was very low probability that the histological patterns of primary tumors and LN metastases are independent (p < 0.001). Metastatic tumors were significantly more diffusely positive for p53 than the primary tumors (p < 0.001). Conversely, primary tumors were significantly more diffusely positive for c-myc than metastatic tumors (p = 0.011). No significant difference was found between the LNs and the primary tumors in bcl-2 positivity (p = 0.538) and DNA aneuploidy (p = 0.35), with a tendency towards negative bcl-2 and less aneuploidy in LN metastases than primary tumors. In conclusion, LN metastatic colorectal carcinomas have a tendency of being less differentiated, with a higher incidence of diffuse p53 staining, lower incidence of bcl-2 staining, and less aneuploidy in comparison to their primary counterparts suggesting a more aggressive biological behavior, which could indicate the necessity for more aggressive adjuvant therapy.

Early-onset colorectal cancer: A sporadic or inherited disease?

Colorectal cancer is the third most common cancer diagnosed worldwide. Although epidemiology data show a marked variability around the world, its overall incidence rate shows a slow but steady decrease, mainly in developed countries. Conversely, early-onset colorectal cancer appears to display an opposite trend with an overall prevalence in United States and European Union ranging from 3.0% and 8.6%. Colorectal cancer has a substantial proportion of familial cases. In particular, early age at onset is especially suggestive of hereditary predisposition. The clinicopathological and molecular features of colorectal cancer cases show a marked heterogeneity not only between early- and late-onset cases but also within the early-onset group. Two distinct subtypes of early-onset colorectal cancers can be identified: a “sporadic” subtype, usually without family history, and an inherited subtype arising in the context of well defined hereditary syndromes. The pathogenesis of the early-onset disease is substantially well characterized in the inherited subtype, which is mainly associated to the Lynch syndrome and occasionally to other rare mendelian diseases, whereas in the “sporadic” subtype the origin of the disease may be attributed to the presence of various common/rare genetic variants, so far largely unidentified, displaying variable penetrance. These variants are thought to act cumulatively to increase the risk of colorectal cancer, and presumably to also anticipate its onset. Efforts are ongoing in the attempt to unravel the intricate genetic basis of this “sporadic” early-onset disease. A better knowledge of molecular entities and pathways may impact on family-tailored prevention and clinical management strategies.

The prognostic value of the apoptosis pathway in colorectal cancer: a review of the literature on biomarkers identified by immunohistochemistry

Research towards biomarkers that predict patient outcome in colorectal cancer (CRC) is rapidly expanding. However, none of these biomarkers have been recommended by the American Association of Clinical Oncology or the European Group on Tumor Markers. Current staging criteria result in substantial under-and over-treatment of CRC patients. Evasion of apoptosis, a characteristic feature of tumorigenesis, is known to correlate with patient outcome. We reviewed the literature on immunohistochemistry-based studies between 1998 and 2011 describing biomarkers in this pathway in CRC and identified 26 markers. Most frequently described were p53, Bcl-2, survivin, and the Fas and TRAILR1 receptors and their ligands. None of the studies reviewed provided sufficient support for implementing a single marker into current clinical practice. This is likely due to the complex biology of this pathway. We suggest focusing on the combination of key markers within the apoptosis pathway that together represent an ‘apoptotic tumor profile’, which better reflects the status of this pathway in a tumor.

Decrease of survivin, p53 and Bcl-2 expression in chemorefractory colorectal liver metastases may be predictive of radiosensivity radiosensivity after radioembolization with yttrium-90 resin microspheres

In a prospective multicenter phase II trial of radioembolization with yttrium-90 (⁹⁰Y-RE) in chemorefractory liver-dominant metastatic colorectal cancer (mCRC), we showed that median survival was 12.6 months (95% CI 7.0–18.3) with 48% of 50 patients achieving disease control. In this extension retrospective study, we analyzed whether a panel of biomarkers, known to be associated to an adverse clinical outcome, underwent variations in CRC liver metastases pre and post ⁹⁰Y-RE.

Of the 50 patients included in the study, 29 pre-⁹⁰Y-RE therapy and 15 post-⁹⁰Y-RE had liver biopsy specimens available. In these series we investigated survivin, p53, Bcl-2 and Ki-67 expression pre- and post-⁹⁰Y-RE by immuhistochemistry (IHC). Our findings evidenced a decrease of survivin (77% vs 33%), p53 (93% vs 73%), Bcl-2 (37% vs 26%) expression as well as of Ki-67 proliferation index (62.5% vs 40%) on liver biopsies collected post-⁹⁰Y-RE as compared to pre-⁹⁰Y-RE. In the subset of 13 matched liver metastases we further confirmed the reduction of survivin (92.3% vs 53.8%; p = 0.06), p53 (100% vs 69.2%; p = 0.05) and Bcl-2 (69.2% vs 53.8%; p = 0.05) expression post-⁹⁰Y-RE. This biomarker modulation was accompanied by morphological changes as steatohepatitis, hepatocyte necrosis, collagen deposition, proliferating and/or bile duct ectasia, focal sinusoidal dilatation and fibrosis.

Although our analysis was conducted in a very limited number cases, these changes appear strictly related to the response to ⁹⁰Y-RE therapy and may deserve further investigation on a larger series of patients.

Cliques for the identification of gene signatures for colorectal cancer across population

Background

Colorectal cancer (CRC) is one of the most commonly diagnosed cancers worldwide. Studies have correlated risk of CRC development with dietary habits and environmental conditions. Gene signatures for any disease can identify the key biological processes, which is especially useful in studying cancer development. Such processes can be used to evaluate potential drug targets. Though recognition of CRC gene-signatures across populations is crucial to better understanding potential novel treatment options for CRC, it remains a challenging task.

Results

We developed a topological and biological feature-based network approach for identifying the gene signatures across populations. In this work, we propose a novel approach of using cliques to understand the variability within population. Cliques are more conserved and co-expressed, therefore allowing identification and comparison of cliques across a population which can help researchers study gene variations. Our study was based on four publicly available expression datasets belonging to four different populations across the world. We identified cliques of various sizes (0 to 7) across the four population networks. Cliques of size seven were further analyzed across populations for their commonality and uniqueness. Forty-nine common cliques of size seven were identified. These cliques were further analyzed based on their connectivity profiles. We found associations between the cliques and their connectivity profiles across networks. With these clique connectivity profiles (CCPs), we were able to identify the divergence among the populations, important biological processes (cell cycle, signal transduction, and cell differentiation), and related gene pathways. Therefore the genes identified in these cliques and their connectivity profiles can be defined as the gene-signatures across populations. In this work we demonstrate the power and effectiveness of cliques to study CRC across populations.

Conclusions

We developed a new approach where cliques and their connectivity profiles helped elucidate the variation and similarity in CRC gene profiles across four populations with unique dietary habits.

Negative prognostic factors in colorectal carcinoma: An analysis of 448 patients

BACKGROUND AND AIMS

Colorectal carcinoma (CRC) is the most frequent malignancy of the gastrointestinal tract. Prognostic researches are carried out for choosing the optimum therapy, evaluating therapy results and comparing multicentre results for better qualification in the therapy of the disease.

PATIENTS AND METHODS

In this study, 448 patients, whose surgery and follow-up was performed by the same correspondent surgeon between the years 1995 and 2003, were retrospectively analyzed.

RESULTS

Age, presence of comorbidity, weight loss, emergency admission, high serum CEA and CA 19-9 levels, neighboring organ invasion, operation type, major morbidity, tumor size and type, lymph node metastases, venous and perineural invasion, Dukes' classification and local recurrence and distant metastasis during follow-up are found to be significant negative factors affecting prognosis of the CRC patient.

CONCLUSION

Therapy results of the CRC are evaluated by survival times regardless of the therapy method selected for each individual. In our study we tried to find out negative prognostic factors by researching possible factors affecting disease free survival time for CRC. Since our understanding of factors that have an impact on prognosis increases, we are hoping to improve survival.