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

Profiles of immune infiltration in colorectal cancer and their clinical significant: A gene expression-based study

Immune infiltration of colorectal cancer (CRC) is closely associated with clinical outcome. However, previous work has not accounted for the diversity of functionally distinct cell types that make up the immune response. In this study, based on a deconvolution algorithm (known as CIBERSORT) and clinical annotated expression profiles, we comprehensively analyzed the tumor‐infiltrating immune cells present in CRC for the first time. The fraction of 22 immune cells subpopulations was evaluated to determine the associations between each cell type and survival and response to chemotherapy. As a result, profiles of immune infiltration vary significantly between paired cancer and paracancerous tissue and the variation could characterize the individual differences. Of the cell subpopulations investigated, tumors lacking M1 macrophages or with an increased number of M2 macrophages, eosinophils, and neutrophils were associated with the poor prognosis. Unsupervised clustering analysis using immune cell proportions revealed five subgroups of tumors, largely defined by the balance between macrophages M1, M2, and NK resting cells, with distinct survival patterns, and associated with well‐established molecular subtype. Collectively, our data suggest that subtle differences in the cellular composition of the immune infiltrate in CRC appear to exist, and these differences are likely to be important determinants of both prognosis and response to treatment.

Evaluation of appropriate follow-up after curative surgery for patients with colorectal cancer using time to recurrence and survival after recurrence: a retrospective multicenter study

INTRODUCTION

The follow-up schedule for colorectal cancer patients after curative surgery is inconsistent among the guidelines. Evaluation of time to recurrence (TTR) and survival after recurrence (SAR) may provide evidence for appropriate follow-up.

METHODS

We assessed 3039 colon cancer (CC) and 1953 rectal cancer (RC) patients who underwent curative surgery between 2007 and 2008. We evaluated the pre- and post-recurrent clinicopathological factors associated with TTR and SAR in each stage of CC and RC.

RESULTS

The recurrence rates of stages I, II, and III were 1.2%, 13.1%, and 26.3%, respectively, for CC, and 8.4%, 20.0%, and 30.4%, respectively, for RC. In CC patients, high carcinoembryonic antigen (CEA) level and lymphovascular invasion were independent predictors of short TTR. In RC patients, metastatic factors (liver metastasis in stage III) and venous invasion (stage III) were independent predictors of short TTR. The prognostic factors of SAR were age (stage II CC and stage III RC), female gender (stage III RC), high CEA level (stage II RC), histological type (stage III CRC), nodal status (stage III CC), recurrence within 1 year (stage III RC), M1b recurrence (stage II CRC), local recurrence (stage II CC), and no surgical resection after recurrence (stage II and III CRC).

CONCLUSIONS

The follow-up schedule for stage I should be different from that for the other stages. We recommend that intensive follow-up is appropriate in stage III CC patients with undifferentiated adenocarcinoma or N2 nodal status, stage II RC patients with high preoperative CEA level, and stage III RC patients.

Postoperative CEA is a better prognostic marker than CA19-9, hCGβ or TATI after resection of colorectal liver metastases

Liver metastases of colorectal cancer can be operated with a curative intent in selected cases. However, more than half of the patients have a recurrence. The aim of this study was to evaluate the prognostic and predictive value of carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA19-9), human chorionic gonadotropin β (hCGβ) and tumour-associated trypsin-inhibitor (TATI) in colorectal cancer patients before and 3 months after resection of liver metastases. Marker concentrations were determined in blood samples from 168 colorectal cancer patients, who underwent liver resection between the years 1998 and 2007 at Helsinki University Hospital, Finland. The samples were taken before and 3 months after curative resection. Increased concentrations of CEA (>5 µg/L) and hCGβ (>1 pmol/L) 3 months after liver resection correlated with recurrence and impaired overall survival and increased CA19-9 (>26 kU/L) with impaired overall survival, but postoperative TATI was not prognostic. Preoperatively elevated CEA and CA19-9 correlated with impaired overall survival, but not with recurrence. Neither preoperative hCGβ nor TATI was prognostic. In conclusion, CEA is a useful prognostic marker, when measured 3 months after resection of colorectal liver metastases. CA19-9 also has prognostic significance and may have additional value.

Design, expression and evaluation of novel chimeric protein constructed from colorectal tumor-associated antigen

There were 134,000 new diagnosis and 49,000 deaths in 2016 due to colorectal cancer. Similar to most cancers, early diagnosis increases the chance of successful treatment. Detection of tumor-associated antigens or the immune response against such markers is one of the most common methods of diagnosis. In that regard, we aimed to design and express a chimeric protein from the most common tumor-associated antigens in colorectal cancer and assess its ability to detect the immune response in comparison with the parental tumor-associated antigens in patient's sera. Through bioinformatics approaches a chimeric protein from carcinoembryonic antigen (CEA) and carbohydrate antigen 19.9 (CA19-9) was designed and expressed in E. coli (BL21DE3). Proper folding, expression levels and immune reactivity were assessed by western blot, ELISA and immunohistochemistry. Recombinant proteins functionality and immune reactivity were confirmed by ELISA and Western blot. Results showed that recombinant CEA, recombinant CA19.9 and chimeric protein of CEA- CA19.9 have strong reactivity with antibodies in the sera of colorectal cancer patients, whereas no reactivity was seen with the sera of healthy volunteers. Significantly stronger immune reactivity was seen with the chimeric protein than each of the CEA or CA19.9 alone. Overall, it was concluded that the designed recombinant proteins in this study could be used to detect autoantibodies produced against the colorectal tumor-associated antigens. The chimeric CEA-CA19.9 protein shows a stronger reactivity with the sera antibodies of colorectal cancer patients that CEA or CA19.9 alone.

Normalization of the microbiota in patients after treatment for colonic lesions

BACKGROUND

Colorectal cancer is a worldwide health problem. Despite growing evidence that members of the gut microbiota can drive tumorigenesis, little is known about what happens to it after treatment for an adenoma or carcinoma. This study tested the hypothesis that treatment for adenoma or carcinoma alters the abundance of bacterial populations associated with disease to those associated with a normal colon. We tested this hypothesis by sequencing the 16S rRNA genes in the feces of 67 individuals before and after treatment for adenoma (N = 22), advanced adenoma (N = 19), and carcinoma (N = 26).

RESULTS

There were small changes to the bacterial community associated with adenoma or advanced adenoma and large changes associated with carcinoma. The communities from patients with carcinomas changed significantly more than those with adenoma following treatment (P value < 0.001). Although treatment was associated with intrapersonal changes, the change in the abundance of individual OTUs in response to treatment was not consistent within diagnosis groups (P value > 0.05). Because the distribution of OTUs across patients and diagnosis groups was irregular, we used the random forest machine learning algorithm to identify groups of OTUs that could be used to classify pre and post-treatment samples for each of the diagnosis groups. Although the adenoma and carcinoma models could reliably differentiate between the pre- and post-treatment samples (P value < 0.001), the advanced-adenoma model could not (P value = 0.61). Furthermore, there was little overlap between the OTUs that were indicative of each treatment. To determine whether individuals who underwent treatment were more likely to have OTUs associated with normal colons we used a larger cohort that contained individuals with normal colons and those with adenomas, advanced adenomas, and carcinomas. We again built random forest models and measured the change in the positive probability of having one of the three diagnoses to assess whether the post-treatment samples received the same classification as the pre-treatment samples. Samples from patients who had carcinomas changed toward a microbial milieu that resembles the normal colon after treatment (P value < 0.001). Finally, we were unable to detect any significant differences in the microbiota of individuals treated with surgery alone and those treated with chemotherapy or chemotherapy and radiation (P value > 0.05).

CONCLUSIONS

By better understanding the response of the microbiota to treatment for adenomas and carcinomas, it is likely that biomarkers will eventually be validated that can be used to quantify the risk of recurrence and the likelihood of survival. Although it was difficult to identify significant differences between pre- and post-treatment samples from patients with adenoma and advanced adenoma, this was not the case for carcinomas. Not only were there large changes in pre- versus post-treatment samples for those with carcinoma, but also these changes were toward a more normal microbiota.

Low acyl-CoA synthetase 5 expression in colorectal carcinomas is prognostic for early tumour recurrence

It has been shown that the metabolism of long chain fatty acids is involved in colorectal carcinogenesis. Acyl-CoA synthetases (ACSL) activate free fatty acids by synthesis of acyl-CoA thioesters. ACSL isoform 5 (ACSL5) is involved in enterocytic differentiation and maturation by regulating both pro-apoptotic and anti-proliferative effects. Whilst impaired expression of ACSL5 has been associated with sporadic colorectal carcinogenesis, little is known about ACSL5 as a prognostic factor. Aim of this retrospective study was to characterize the prognostic impact of ACSL5 expression levels in sporadic colorectal adenocarcinomas. A total of 72 patients with a median follow-up of 54 months was included. Using a standardized immunohistochemical approach, colorectal adenocarcinomas with low (n=41; group 1) or high (n=31; group 2) ACSL5 levels were identified. In a one-year follow-up, tumour recurrence was significantly increased in group 1 (p=0.0279). The finding was independent of the TNM- and UICC-stage in the surgical resections. Frequency of lymph node metastasis and mortality was not different between the groups. In a long-time follow-up no differences were found between the ACSL5 groups. The data indicate that ACSL5 could be an independent prognostic factor for early recurrence of sporadic colorectal adenocarcinoma.

Follow-up strategies for patients treated for non-metastatic colorectal cancer

BACKGROUND

It is common clinical practice to follow patients with colorectal cancer (CRC) for several years following their curative surgery or adjuvant therapy, or both. Despite this widespread practice, there is considerable controversy about how often patients should be seen, what tests should be performed, and whether these varying strategies have any significant impact on patient outcomes. This is the second update of a Cochrane Review first published in 2002 and first updated in 2007.

OBJECTIVES

To assess the effects of intensive follow-up for patients with non-metastatic colorectal cancer treated with curative intent.

SEARCH METHODS

For this update, we searched CENTRAL (2016, Issue 3), MEDLINE (1950 to May 20th, 2016), Embase (1974 to May 20th, 2016), CINAHL (1981 to May 20th, 2016), and Science Citation Index (1900 to May 20th, 2016). We also searched reference lists of articles, and handsearched the Proceedings of the American Society for Radiation Oncology (2011 to 2014). In addition, we searched the following trials registries (May 20th, 2016): ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform. We further contacted study authors. No language or publication restrictions were applied to the search strategies.

SELECTION CRITERIA

We included only randomised controlled trials comparing different follow-up strategies for participants with non-metastatic CRC treated with curative intent.

DATA COLLECTION AND ANALYSIS

Two authors independently determined trial eligibility, performed data extraction, and assessed methodological quality.

MAIN RESULTS

We studied 5403 participants enrolled in 15 studies. (We included two new studies in this second update.) Although the studies varied in setting (general practitioner (GP)-led, nurse-led, or surgeon-led) and "intensity" of follow-up, there was very little inconsistency in the results.Overall survival: we found no evidence of a statistical effect with intensive follow-up (hazard ratio (HR) 0.90, 95% confidence interval (CI) 0.78 to 1.02; I² = 4%; P = 0.41; high-quality evidence). There were 1098 deaths among 4786 participants enrolled in 12 studies.Colorectal cancer-specific survival: this did not differ with intensive follow-up (HR 0.93, 95% CI 0.78 to 1.12; I² = 0%; P = 0.45; moderate-quality evidence). There were 432 colorectal cancer deaths among 3769 participants enrolled in seven studies.Relapse-free survival: we found no statistical evidence of effect with intensive follow-up (HR 1.03, 95% CI 0.90 to 1.18; I² = 5%; P = 0.39; moderate-quality evidence). There were 1416 relapses among 5253 participants enrolled in 14 studies.Salvage surgery with curative intent: this was more frequent with intensive follow-up (risk ratio (RR) 1.98, 95% CI 1.53 to 2.56; I² = 31%; P = 0.14; high-quality evidence). There were 457 episodes of salvage surgery in 5157 participants enrolled in 13 studies.Interval (symptomatic) recurrences: these were less frequent with intensive follow-up (RR 0.59, 95% CI 0.41 to 0.86; I² = 66%; P = 0.007; moderate-quality evidence). Three hundred and seventy-six interval recurrences were reported in 3933 participants enrolled in seven studies.Intensive follow-up did not appear to affect quality of life, anxiety, nor depression (reported in three studies).Harms from colonoscopies did not differ with intensive follow-up (RR 2.08, 95% CI 0.11 to 40.17; moderate-quality evidence). In two studies, there were seven colonoscopic complications in 2112 colonoscopies.

AUTHORS' CONCLUSIONS

The results of our review suggest that there is no overall survival benefit for intensifying the follow-up of patients after curative surgery for colorectal cancer. Although more participants were treated with salvage surgery with curative intent in the intensive follow-up group, this was not associated with improved survival. Harms related to intensive follow-up and salvage therapy were not well reported.

Combined detection of preoperative serum CEA, CA19-9 and CA242 improve prognostic prediction of surgically treated colorectal cancer patients

We assessed the prognostic significance of preoperative serum carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA19-9) and carbohydrate antigen 242 (CA242) levels in surgically treated colorectal cancer patients. The relationship of preoperative serum CEA, CA19-9 and CA242 levels with disease characteristics was investigated in 310 patients. Correlation between tumor markers was investigated using Pearson correlation test. Univariate and multivariate survival analyses were used to study the relationship between preoperative tumor markers and prognosis [disease free survival (DFS) and overall survival (OS)]. Kaplan-Meier analysis with log rank test was used to assess the impact of tumor marker levels on survival. Positive rate of preoperative serum CEA, CA19-9 and CA242 were 54.84%, 47.42% and 37.10%, respectively. High preoperative CEA level was associated with tumor size (P = 0.038), T stage (P < 0.001) and AJCC stage (P = 0.002). High preoperative CA19-9 level was associated with tumor AJCC stage (P = 0.023). Preoperative CA242 positively correlated with CEA (P < 0.001) and CA19-9 (P < 0.001). Combining the three markers was of independent prognostic value in CRC (HR = 2.532, 95% CI: 1.400-4.579, P = 0.002 for OS; and HR = 2.366, 95% CI: 1.334-4.196, P = 0.003 for DFS). Combined detection of preoperative serum CEA, CA19-9 and CA242 is of independent prognostic value for management of CRC patients treated surgically.

Neutrophil to lymphocyte ratio is a strong predictor of tumor recurrence in early colon cancers: A propensity score-matched analysis

BACKGROUND

Systemic inflammation and immune response play a crucial role in tumor growth, and the neutrophil to lymphocyte ratio (NLR) may be a simple way to assess the host inflammatory response. The NLR has been shown to be a prognostic indicator in many human tumors; in early colon cancers, it has been evaluated only in a few studies and its role remains controversial.

METHODS

We analyzed data from 503 colon cancer patients. The best cutoff value for NLR was defined by receiver operating characteristic curve analysis. We grouped 276 Dukes A/B colon cancers, not receiving adjuvant chemotherapy, into low (<2.36) and high (>2.36) NLR and subjected to further analyses related to disease-free survival (DFS). A propensity score-matched analysis and the inverse probability of treatment weighting (IPTW) were performed to avoid confounding bias.

RESULTS

The NLR correlated with tumor stage and oncologic outcome. The best NLR cutoff value was identical in the whole cohort and in Dukes A/B patients. Low NLR patients had a significantly better DFS rate than high NLR patients (hazard ratio [HR], 0.27; P = .0001); along with elevated carcinoembryonic antigen levels and Dukes B stage, high NLR was an independent prognostic factor of worse prognosis (HR, 2.86; P = .0033). Even in Dukes A patients, NLR discriminated between relapsing and nonrelapsing patients. Propensity score and IPTW analyses confirmed such results, thus excluding possible misinterpretation.

CONCLUSION

Preoperative NLR, an inexpensive and readily available biomarker, can predict tumor relapse and should be assessed for implementation of tailored therapy in early stage colon cancer.

Hepatectomy vs radiofrequency ablation for colorectal liver metastasis: A propensity score analysis

AIM: To compare outcomes from radiofrequency ablation (RFA) and hepatectomy for treatment of colorectal liver metastasis (CRLM).

METHODS: From January 2000 to December 2009, 408 patients underwent curative intent treatment for CRLM. We excluded patients using the criteria: size of CRLM > 3 cm, number of CRLM ≥ 5, percutaneous RFA, follow-up period < 12 mo, double primary cancer, or treatment with both RFA and hepatectomy. We matched 51 patients who underwent RFA with 102 patients who underwent hepatectomy by propensity scores.

RESULTS: The median follow-up period was 45 mo (range, 12 mo to 158 mo). Hepatic recurrence was more frequent in the RFA than the hepatectomy group (P = 0.021) although extrahepatic recurrence curves were similar (P = 0.716). Survival curves of hepatectomy group were better than that of RFA for multiple, large (> 2 cm) CRLM (P = 0.034). However, survival curves were similar for single or small (≤ 2 cm) CRLM (P = 0.714, P = 0.740).

CONCLUSION: Hepatectomy is better than RFA for the treatment of CRLM. However, RFA might be suitable for selected patients with single, small (≤ 2 cm) CRLM.