Impact of Primary Tumor Location on Postoperative Recurrence and Subsequent Prognosis in Nonmetastatic Colon Cancers: A Multicenter Retrospective Study Using a Propensity Score Analysis

Right-sided versus left-sided colorectal cancer in elderly patients: a sub-analysis of a large multicenter case-control study in Japan

PURPOSE

This study investigated the impact of sidedness of colorectal cancer (CRC) in elderly patients on the prognosis.

METHODS

In a sub-analysis of a multicenter case-control study of CRC patients who underwent surgery at ≥ 80 years old conducted in Japan between 2003 and 2007, both short- and long-term outcomes were compared between right-sided colon cancers (RCCs) and left-sided colorectal cancers (LCCs). RCCs were defined as those located from the cecum to the transverse colon.

RESULTS

Among the 1680 patients who underwent curative surgery, 812 and 868 had RCCs and LCCs, respectively. RCCs were more frequent than LCCs in those who were female, had renal comorbidities, and had a history of abdominal surgery. Regarding tumor characteristics, RCCs were larger, invaded more deeply, and were diagnosed as either mucinous or signet ring-cell carcinoma more frequently than LCCs. Regarding the prognosis, patients with RCCs had a significantly longer cancer-specific survival (CS-S) and cancer-specific relapse-free survival (CS-RFS) than those with LCCs. Furthermore, sidedness was determined to be an independent prognostic factor for CS-S and CS-RFS.

CONCLUSION

RCCs, which accounted for half of the cases in patients ≥ 80 years old, showed better long-term outcomes than LCCs.

Identification and validation of a prognostic signature based on six immune-related genes for colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is a prevalent malignancy with high mortality and morbidity rates. Although the significant efficacy of immunotherapy is well established, it is only beneficial for a limited number of individuals with CRC.

METHODS

Differentially expressed immune-related genes (DE-IRGs) were retrieved from The Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO), and ImmPort databases. A prognostic signature comprising DE-IRGs was developed using univariate, LASSO, and multivariate Cox regression analyses. A nomogram integrating the independent prognostic factors was also developed. CIBERSORT was used to assess immune cell infiltration (ICI). Furthermore, wound-healing, colony formation, migration, and invasion assays were performed to study the involvement of ACTG1 in CRC.

RESULTS

A signature including six DE-IRGs was developed. The overall survival (OS) rate was accurately estimated for TCGA and GSE38832 cohorts. The risk score (RS) of the signature was an independent factor for OS. Moreover, a nomogram encompassing age, RS, and pathological T stage accurately predicted the long-term OS probability of individuals with CRC. The high-risk group had an elevated proportion of patients treated with ICIs, including native B cells, relative to the low-risk group. Additionally, ACTG1 expression was upregulated, which supported the proliferation, migration, and invasion abilities of CRC cells.

CONCLUSIONS

An immune-related prognostic signature was developed for predicting OS and for determining the immune status of individuals with CRC. The present study provides new insights into accurate immunotherapy for individuals with CRC. Moreover, ACTG1 may serve as a new immune biomarker.

Association of primary tumor location with long-term oncological prognosis following hepatectomy for hepatocellular carcinoma:A multicenter propensity score matching analysis

PURPOSE

There is a striking laterality in the site of hepatocellular carcinoma (HCC), with a strong predominance for the right side; however, the impact of primary tumor location on long-term prognosis after hepatectomy of HCC remains unclear. This study aimed to investigate the effect of primary tumor location on long-term oncological prognosis after hepatectomy for HCC.

PATIENTS AND METHODS

Data of consecutive patients undergoing curative hepatectomy for HCC between 2008 and 2017 were analyzed. Overall survival (OS) and recurrence-free survival (RFS) of left-sided HCC (LS group) and right-sided HCC (RS group) were compared by using propensity score matching (PSM) analysis. COX regression analysis was performed to assess the adjusted effect of tumor location on long-term oncological prognosis.

RESULTS

Of the 2799 included patients, 707 (25.3%) and 2092 (74.7%) were in the LS and RS groups, respectively. Using PSM analysis, 650 matched pairs of patients were created. In the PSM cohort, median OS (66.0 vs. 72.0 months, P = 0.001) and RFS (28.0 vs. 51.0 months, P < 0.001) were worse among patients in the LS group compared to individuals in the RS group. After further adjustment for other confounders using multivariable COX regression analyses, HCC located on the left side remained independently associated with worse OS and RFS.

CONCLUSION

Tumors located on the left side are associated with poorer OS and RFS after hepatectomy for HCC. Careful surgical options selection and frequent follow-up to improve long-term survival may be justified for HCC patients with left-sided primary tumors.

Genomic landscape and its prognostic significance in stage III colorectal cancer: JCOG1506A1, an ancillary of JCOG0910

Large-scale genomic sequencing of colorectal cancers has been reported mainly for Western populations. Differences by stage and ethnicity in the genomic landscape and their prognostic impact remain poorly understood. We investigated 534 Japanese stage III colorectal cancer samples from the Phase III trial, JCOG0910. Targeted-capture sequencing of 171 potentially colorectal cancer-associated genes was performed, and somatic single-nucleotide variants and insertion-deletions were determined. Hypermutated tumors were defined as tumors with MSIsensor score >7 and ultra-mutated tumors with POLE mutations. Genes with alterations associated with relapse-free survival were analyzed using multivariable Cox regression models. In all patients (184 right-sided, 350 left-sided), mutation frequencies were TP53, 75.3%; APC, 75.1%; KRAS, 43.6%; PIK3CA, 19.7%; FBXW7, 18.5%; SOX9, 11.8%; COL6A3, 8.2%; NOTCH3, 4.5%; NRAS, 4.1%; and RNF43, 3.7%. Thirty-one tumors were hypermutated (5.8%; 14.1% right-sided, 1.4% left-sided). Modest associations were observed: poorer relapse-free survival was seen with mutant KRAS (hazard ratio 1.66; p = 0.011) and mutant RNF43 (2.17; p = 0.055), whereas better relapse-free survival was seen with mutant COL6A3 (0.35; p = 0.040) and mutant NOTCH3 (0.18; p = 0.093). Relapse-free survival tended to be better for hypermutated tumors (0.53; p = 0.229). In conclusion, the overall spectrum of mutations in our Japanese stage III colorectal cancer cohort was similar to that in Western populations, but the frequencies of mutation for TP53, SOX9, and FBXW7 were higher, and the proportion of hypermutated tumors was lower. Multiple gene mutations appeared to impact relapse-free survival, suggesting that tumor genomic profiling can support precision medicine for colorectal cancer.

The impact of adjuvant oxaliplatin and tumor sidedness on the overall survival of stage IIB colon cancer patients: a multicentre study

The aim of this multicentre retrospective study was to compare the efficacy of adjuvant chemotherapy regimens both with and without oxaliplatin and tumor sidedness in stage IIB (pT4aN0) colon cancer patients. This study included patients with stage IIB colon cancer who underwent curative surgery and received adjuvant chemotherapy. The patients were divided into two groups (one with and one without oxaliplatin) to compare the overall survival (OS) in right- and left-sided tumors. The study population included 298 patients with stage IIB colon cancer (median age: 57) of whom 69.1% were male. Forty-four per cent of these patients (n = 131) were diagnosed with right-sided colon cancer. The median follow-up duration was 35.9 months. In the entire population, a median OS was not reached, and the five-year OS was 83%. The median disease-free survival (DFS) was 12 months. There was no significant difference in terms of the five-year OS between right- (82%) and left-sided (84%) colon tumors (p = 0.67). In addition, the five-year OS of patients treated with and without oxaliplatin were 76% and 89%, respectively, and there was no statistically significant difference (p = 0.23). The five-year OS of the patients treated with and without oxaliplatin were 83% and 96.5%, respectively, (p = 0.8) in right-sided colon tumors, while it was 75% and 93% (p = 0.06), respectively, in left-sided colon tumors. Tumor sidedness and the addition of oxaliplatin to adjuvant chemotherapy were not found to be associated with the OS in stage IIB colon cancer patients in our study. Further large prospective studies that also include MSI, RAS and BRAF status data are warranted in colon cancer patients.

Co-delivery of sorafenib and metformin from amphiphilic polypeptide-based micelles for colon cancer treatment

Colorectal cancer (CRC) is a common clinical disease with a poor prognosis and a high recurrence rate. Chemotherapy is important to inhibit the post-surgical recurrence of CRC patients. But many limitations restrict the further application of chemotherapy. In this study, sorafenib (Sor) and metformin (Met) co-loaded poly(ethylene glycol)-block-poly(L-glutamic acid-co-L-phenylalanine) [mPEG-b-P(Glu-co-Phe)] micelles were developed. The characterizations, drug release, in vivo biodistribution, and pharmacokinetics of the micelles were analyzed. The treatment efficacy of the dual-drug loaded micelles was evaluated in a subcutaneous colon cancer mice model. Sor is a common molecular target agent that can inhibit the mitogen-activated protein kinase (MAPK) pathway to treat solid tumors. Met can also regulate the MAPK pathway and inhibit the expression of the phosphorylated extracellular signal-regulated kinase (p-ERK). Moreover, both Sor and Met play important roles in cell cycle arrest. The integration of these two drugs aims to achieve synergistic effects against colon cancer. The micelles can be targeted to cancer cells and possess longer blood circulation time. The two agents can be released rapidly in the tumor sites. The in vivo study showed that the micelles can prevent tumor progression by inhibiting the expressions of p-ERK and cyclin D1. This study indicated that the Sor/Met-loaded micelles are suitable for CRC treatment.

Clinical impact of primary tumor sidedness and sex on unresectable post-recurrence survival in resected pathological stage II-III colorectal cancers: a nationwide multicenter retrospective study

Background

Several studies have demonstrated that right-sided tumors have poorer prognosis than left-sided tumors in patients with unresectable colorectal cancer (CRC). The predictive ability of the tumor sidedness in CRC treated with chemotherapy in each sex is unclear.

Methods

Subjects were 964 unresectable recurrent patients treated with chemotherapy with stage II-III CRC after curative resection between 2004 and 2012. Post-recurrence cancer-specific survival (CSS) for each sex was examined.

Results

Patients were 603 males (222 right-side tumors (cecum to transverse colon) and 381 left-sided tumors (descending colon to rectum)), and 361 females (167 right-side tumors and 194 left-sided tumors). Right-sided tumors developed peritoneal recurrences in males and females. Left-sided tumors were associated with locoregional recurrences in males and with lung recurrences in females. Right-sided tumors were associated with shorter post-recurrence CSS in both sexes. In males, multivariate analyses showed that right-sided tumors were associated with shorter post-recurrence CSS (HR: 1.53, P < 0.0001) together with the presence of regional lymph node metastasis histopathological type of other than differentiated adenocarcinoma, the recurrence of liver only, the recurrence of peritoneal dissemination only, and relapse-free interval less than one-year. In females, multivariate analyses showed that right-sided tumors were associated with shorter post-recurrence CSS (HR: 1.50, P = 0.0019) together with advanced depth of invasion, the presence of regional lymph node metastasis, and recurrence of liver only.

Conclusions

Primary tumor sidedness in both sexes in unresectable recurrent CRC patients treated with chemotherapy may have prognostic implications for post-recurrence CSS.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09615-z.

Prognostic Factors of Recurrence and Survival in Operated Patients with Colorectal Cancer

BACKGROUND: The recurrence of colorectal cancers is considered to be one of the greatest post-surgical complications that is affected by various factors. This study was designed to investigate the prognostic factors that affect the recurrence and survival of patients with colon and rectal cancers. METHODS: A retrospective study was performed on 380 patients with colorectal cancers who underwent surgery were enrolled in the study (152 patients with colon cancer and 228 patients with rectal cancer). Preoperative serum albumin level, type of surgery, tumor size, differentiation grade, proximal, distal and radial, and marginal involvement, the total number of excised lymph nodes, the number of involved lymph nodes, and tumor stage were recorded. Also, the incidences of recurrence and metastasis were recorded during the study. RESULTS: 380 patients with a mean age of 57.11 years were enrolled in the study. 152 patients with an average age of 57.57 years were diagnosed as having colon cancer. Recurrence and metastasis occurred in two patients (1.3%) and five patients (3.3%), respectively. 18 patients (11.8%) died because of colon cancer. 228 patients with a mean age of 56.81 had rectal cancer. Recurrence was seen in 19 patients (8.3%) and metastasis in 33 patients (14.5%). 38 patients (16.7%) died because of rectal cancer. Tumor size and involved lymph nodes were independent prognostic factors for the recurrence and metastases of colon cancer. Only involved lymph nodes were associated with death due to colon cancer. Independent prognostic factors for rectal cancer metastasis include serum albumin level and age. The total number of excised lymph nodes was the only predictor of tumor recurrence and death in rectal cancer. The median survival times of colon and rectal cancers were 90 and 110 months, respectively. CONCLUSION: The size of the tumor and the number of involved lymph nodes were independent prognostic factors for recurrence and metastasis of colon cancer. Also, the number of involved lymph nodes was associated with colon cancer-related deaths. In the case of rectal cancer, serum albumin levels and age predicted metastases. Only the total number of excised lymph nodes had a reverse relationship with recurrence and rectal cancer-related death.

The primary tumor location in colorectal cancer: A focused review on its impact on surgical management

The primary tumor location (PTL) has attracted increasing attention in recent years for colorectal cancer (CRC) patients. Although the underlying mechanisms for differences caused by PTL remain still unclear, right-sided colon (RCC) and left-sided colon (LCC) are now considered as distinct entities because of their different molecular profile and clinical response to surgery and chemotherapy. In this article, we review the influence of PTL particularly on surgical management of primary and metastatic CRC settings. For nonmetastatic CRC, RCC could be a slightly superior prognostic factor after curative resection in stage I-II CRC, while RCC could be an inferior prognostic factor in stage III CRC with worse survival after recurrence, suggesting the oncological aggressiveness of recurrent RCC. For metastatic CRC, RCC could be a predictor of worse survival after hepatectomy of liver metastases from CRC with aggressive recurrence pattern and lower chance of re-resection. In lung metastases from CRC, the role of PTL still remains uncertain because of the limited number of studies. As to the impact of PTL on survival outcome after cytoreductive surgery plus hyperthermic intraperitoneal chemotherapy for peritoneal metastases from CRC, a discrepancy exists among studies and further investigation will be needed. The very simple clinical factor of PTL could provide important information for the prediction of the survival outcome after surgery in CRC. Further clinical and basic research will facilitate the clinical application of PTL in a more specified and personalized manner.

Pathological Features and Prognostication in Colorectal Cancer

The prognostication of colorectal cancer (CRC) has traditionally relied on staging as defined by the Union for International Cancer Control (UICC) and American Joint Committee on Cancer (AJCC) TNM staging classifications. However, clinically, there appears to be differences in survival patterns independent of stage, suggesting a complex interaction of stage, pathological features, and biomarkers playing a role in guiding prognosis, risk stratification, and guiding neoadjuvant and adjuvant therapies. Histological features such as tumour budding, perineural invasion, apical lymph node involvement, lymph node yield, lymph node ratio, and molecular features such as MSI, KRAS, BRAF, and CDX2 may assist in prognostication and optimising adjuvant treatment. This study provides a comprehensive review of the pathological features and biomarkers that are important in the prognostication and treatment of CRC. We review the importance of pathological features and biomarkers that may be important in colorectal cancer based on the current evidence in the literature.

Current treatment and surveillance modalities are not sufficient for advanced stage III colon cancer: Result from a multicenter cohort analysis

OBJECTIVE

We conducted this multicenter cohort study to evaluate the current tumor-node-metastasis staging system and treatment modality by analyzing the survival outcomes of patient groups with stage III and IV colon cancer.

PATIENTS AND METHODS

Stage III and IV colon cancer patients from the Surveillance, Epidemiology, and End Results (SEER) database (SEER cohort) and prospectively maintained Sun Yat-sen University (SYSU) cohort were included in this study. Kaplan-Meier method was used to estimate the cumulative rate of overall survival (OS) between patient groups, and the inverse probability weighting method was used to calculated age and sex-adjusted survival curves. The Cox regression model was used to identify the risk factors for OS.

RESULTS

A total of 17,911 and 1135 stage III-IV cases were included in the SEER and SYSU cohorts, respectively. Among them, 1448 and 124 resectable stage IV cases underwent curative-intent treatment in the SEER and SYSU cohorts, respectively. The T4N2b group showed a significantly worse survival outcome compared with the M1a subset receiving curative-intent treatment (HR, 1.46; p < 0.001). This finding was validated in the SYSU cohort, in which the T4N2 group had a worse outcome than that of the M1 group receiving curative-intent treatment (HR, 2.44; p < 0.001). These findings were confirmed in the adjusted survival analysis. In the multivariate analysis, the right-side tumor, poor-undifferentiated tumor, and age over 60 years were identified as independent risk factors for T4N2b patients. Based on this multivariate model, the high-risk T4N2b subgroup had a worse survival outcome compared with resectable M1b patients (HR, 1.24; p = 0.03).

CONCLUSION

By comparing stage III with stage IV colon cancer patients, we identified a subgroup of stage III patients at a higher risk of death than more advanced stages, implying that current cancer care modalities are not sufficient for these high-risk substages.

Survival outcomes for right-versus left-sided colon cancer and rectal cancer in England: A propensity-score matched population-based cohort study

INTRODUCTION

The aim of this study was to evaluate 5-year overall survival (OS) in patients operated on for potentially curable right versus left-sided colon cancer and rectal cancer in England.

MATERIALS AND METHODS

A retrospective propensity-score matched population-based cohort study was performed using data from English Hospital Episode Statistics, Office for National Statistics and National Bowel Cancer Audit dataset. Patients ≥18 who underwent elective resection for right-colon, left-colon, or rectal cancer between 2000 and 2015 were included. Patients were matched using propensity scores with the dependant variable being site of primary tumour (right-colon, left-colon, or rectum) and independent variables age, Charlson comorbidity index, operation year and Duke's stage. The primary outcome was 5-year overall survival (OS).

RESULTS

A total of 167,606 patients were included. Following propensity-score matching 26,662 patients remained in each group (right-colon, left-colon, and rectum). 5-year OS was significantly worse for patients with Duke's A-C right-sided primaries compared to left-sided and rectal cancers in the unmatched (58.8% vs 66.7% vs 70.0% p=<0.001) and matched cohorts (62.6%, 66.8%, 65.8% p=<0.001). Superior OS for patients with left-sided colon cancer was demonstrated across all stages (Duke's A HR 0.845, p = 0.003; Duke's B HR 0.947, p = 0.045; Duke's C HR 0.783, p < 0.0001). Secondary analysis demonstrated equivalent OS between study groups when ≥22 lymph nodes were harvested.

CONCLUSION

There is a significant difference in survival between comparable patients with right and left sided colon cancers in England. The quality and/or extent of mesenteric resection may be of particular importance in right-sided colon cancer.

Genomic Analysis Reveals Heterogeneity Between Lesions in Synchronous Primary Right-Sided and Left-Sided Colon Cancer

Background: The synchronous primary right-sided and left-sided colon cancer (sRL-CC) is a peculiar subtype of colorectal cancer. However, the genomic landscape of sRL-CC remains elusive. Methods: Twenty-eight paired tumor samples and their corresponding normal mucosa samples from 14 patients were collected from the Second Affiliated Hospital of Harbin Medical University from 2011 to 2018. The clinical-pathological data were obtained, and whole-exome sequencing was performed based on formalin-fixed and paraffin-embedded samples of these patients, and then, comprehensive bioinformatic analyses were conducted. Results: Both the lesions of sRL-CC presented dissimilar histological grade and differentiation. Based on sequencing data, few overlapping SNV signatures, onco-driver gene mutations, and SMGs were identified. Moreover, the paired lesions harbored a different distribution of copy number variants (CNVs) and loss of heterozygosity. The clonal architecture analysis demonstrated the polyclonal origin of sRL-CC and inter-cancerous heterogeneity between two lesions. Conclusion: Our work provides evidence that lesions of sRL-CC share few overlapping mutational signatures and CNVs, and may originate from different clones.

Long-term Results of Surgery for Colorectal Liver Metastases in Terms of Primary Tumour Location and Clinical Risk Factors

BACKGROUND/AIM

The aim of the study was to evaluate the influence of primary tumour location and clinical risk factors for long-term results of surgery for colorectal liver metastases (CLMs).

PATIENTS AND METHODS

Overall survival (OS) and recurrence-free survival (RFS) were evaluated in 636 patients. Patients were divided by tumour location (right-/left-sided colorectal cancer: RCRC/LCRC; rectal cancer), and age, gender, number and size of CLMs, type of liver surgery and interval from primary operation were evaluated.

RESULTS

One-, 3- and 5-year OS and RFS were independent of primary tumour location (p<0.59). CLM diameter was negatively associated with OS for the whole cohort (p<0.002), and RCRC (p<0.03) and LCRC (p<0.04) groups, as well as for RFS of those with LCRC (p<0.04). CLM number was negatively associated with RFS for the whole cohort (p<0.0001), RCRC (p<0.02), LCRC (p<0.0001) and RC (p<0.02). Radiofrequency ablation and combined procedures led to worse OS for the whole cohort (p<0.03), and to worse RFS for the whole cohort (p<0.0003) and for those with LCRC (p<0.03). A shorter interval between primary colorectal cancer surgery and CLMs procedure was risky for poor OS and RFS of patients with CLMs from RCRC (p<0.05), LCRC (p<0.05) and RC (p<0.02).

CONCLUSION

Primary tumour location together with clinical risk factors are important for long-term results of surgery CLMs.

High-Grade Inflammation Attenuates Chemosensitivity and Confers to Poor Survival of Surgical Stage III CRC Patients

Background: Heterogeneous clinical and molecular characteristics are reported in colorectal cancer (CRC) with different tumor laterality. However, the outcome of left- and right-sided patients with stage I–III CRC and the role of chronic inflammation in survival differences between them remain unclear.

Method: A prospective study including 1,181 surgical patients with stage I–III CRC was carried out to investigate the involvement of circulating fibrinogen-to-pre-albumin (Alb) ratio (FPR) and primary tumor sidedness in the clinical outcome of those patients. We further investigated the effect of FPR on adjuvant chemotherapy response and recurrence in stage III patients.

Results: Our study showed that the right tumor location was significantly associated with poor recurrence-free survival (RFS) (p = 0.04, adjusted HR = 1.41, 95% CI = 1.02–1.94) and overall survival (OS) (p = 0.04, adjusted HR = 1.55, 95% CI = 1.01–2.38) only in the stage III disease. In these patients, T4 stage distribution (83.39 vs. 70.94%, p < 0.01) within right-sided cases was significantly higher than left-sided patients. Moreover, preoperative FPR within right-sidedness (p < 0.01), T4 stage (p < 0.05), and large cancer bulk (≥5 cm) (p < 0.05) subgroups was significantly elevated compared to their counterparts, and it was gradually rising following the increased cancer bulk (p trend < 0.01). High-FPR distribution (52.30 vs. 27.00%, p < 0.01) within right-sided patients with the stage III disease was significantly higher than that in the left-sided cases. RFS (p_log−rank < 0.01) and OS (p_log−rank < 0.01) of the high-FPR patients were extremely inferior to the low-FPR cases, and the significant associations were observed when they were adjusted by other confounders including primary tumor location (p < 0.01, adjusted HR = 1.96, 95% CI = 1.42–2.70 for RFS; p < 0.01, adjusted HR = 2.44, 95% CI = 1.59–3.75 for OS). Additionally, RFS of adjuvant chemotherapy-treated high-FPR patients was superior to the patients without chemotherapy (p_log−rank = 0.01) but was inferior to the low-FPR patients undergoing the treatment, especially in the 5-FU- and XELOX-treated subgroup.

Conclusion: These findings indicate that chronic high-grade inflammation weakens chemotherapy efficacy and contributes to the poor prognosis of stage III surgical CRC patients.

The impact of molecular profile on the lymphatic spread pattern in stage III colon cancer

The anatomical spread of lymph node (LN) metastasis is of practical importance in the surgical management of colon cancer (CC). We examined the effect of KRAS, BRAF, and microsatellite instability (MSI) on LN count and anatomical spread pattern in stage III CC. We determined KRAS, BRAF, and MSI status from stage III CC patients. Biomarker status was correlated with LN count and anatomical spread pattern, which was classified as sequential or skipped. Relapse-free survival (RFS) was estimated using Kaplan-Meier method, and correlations were assessed using log-rank and Cox regression analyses. We analyzed 369 stage III CC patients. The proportion of KRAS mutant (mt), BRAF mt, and MSI-high (H) were 44.2% (163/344), 6.8% (25/344), and 6.8% (25/344), respectively. The mean number of metastatic LN was higher in microsatellite-stable (MSS) compared with MSI patients (3.5 vs. 2.7, P = .0406), although no differences were observed in accordance with KRAS or BRAF status. Interestingly, patients with BRAF mt and MSI-H were less likely to harbor skipped metastatic LN (9.3% vs 20% and 4% vs 10.5% compared with BRAF wild-type (wt) and MSS, respectively), but KRAS status did not predict anatomical spread pattern. Patients with KRAS wt and MSI-H showed superior RFS compared with KRAS mt and MSS patients, respectively, whereas BRAF status did not affect RFS. Differences exist in the anatomical pattern of invaded LN in accordance with the molecular status of stage III CC. Patients with MSI-H CC have less invaded and skipped LN, suggesting that a tailored surgical approach is possible.

Survival rates and prognostic factors in right- and left-sided colon cancer stage I-IV: an unselected retrospective single-center trial

PURPOSE

Colorectal cancer revealed over the last decades a remarkable shift with an increasing proportion of a right- compared to a left-sided tumor location. In the current study, we aimed to disclose clinicopathological differences between right- and left-sided colon cancer (rCC and lCC) with respect to mortality and outcome predictors.

METHODS

In total, 417 patients with colon cancer stage I-IV were analyzed in the present retrospective single-center study. Survival rates were assessed using the Kaplan-Meier method and uni/multivariate analyses were performed with a Cox proportional hazards regression model.

RESULTS

Our study showed no significant difference of the overall survival between rCC and lCC stage I-IV (p = 0.354). Multivariate analysis revealed in the rCC cohort the worst outcome for ASA (American Society of Anesthesiologists) score IV patients (hazard ratio [HR]: 16.0; CI 95%: 2.1-123.5), CEA (carcinoembryonic antigen) blood level > 100 µg/l (HR: 3.3; CI 95%: 1.2-9.0), increased lymph node ratio of 0.6-1.0 (HR: 5.3; CI 95%: 1.7-16.1), and grade 4 tumors (G4) (HR: 120.6; CI 95%: 6.7-2179.6) whereas in the lCC population, ASA score IV (HR: 8.9; CI 95%: 0.9-91.9), CEA blood level 20.1-100 µg/l (HR: 5.4; CI 95%: 2.4-12.4), conversion to laparotomy (HR: 14.1; CI 95%: 4.0-49.0), and severe surgical complications (Clavien-Dindo III-IV) (HR: 2.9; CI 95%: 1.5-5.5) were identified as predictors of a diminished overall survival.

CONCLUSION

Laterality disclosed no significant effect on the overall prognosis of colon cancer patients. However, group differences and distinct survival predictors could be identified in rCC and lCC patients.

GABRD promotes progression and predicts poor prognosis in colorectal cancer

Little is known about the functional roles of gamma-aminobutyric acid type A receptor subunit delta (GABRD) in colorectal cancer (CRC). The expression of GABRD between CRCs and adjacent normal tissues (NTs), metastasis and primary tumors was compared using public transcriptomic datasets. A tissue microarray and immunohistochemical staining (IHC) were used to determine the clinical and prognostic significance of the GABRD in CRC. We used gain-of-function and loss-of-function experiments to investigate the in vitro roles of GABRD in cultured CRC cells. We characterized the potential mechanism of GABRD’s activities in CRC using a Gene Set Enrichment Analysis (GSEA) with The Cancer Genome Atlas Colon Adenocarcinoma (TCGA-COAD) dataset. We found that the GABRD expression was significantly increased in CRCs compared to that in NTs, but was similar between metastasis and primary tumors. Overexpression of GABRD was significantly associated with later pTNM stages and unfavorable patient survival. Overexpression of GABRD accelerated while knock-down of GABRD inhibited cell growth and migration. Mechanistically, the function of GABRD might be ascribed to its influence on major oncogenic events such as epithelial–mesenchymal transition (EMT), angiogenesis, and hedgehog signaling. Collectively, GABRD could be a novel prognostic predictor for CRC that deserves further investigation.

Recurrence Risk after Radical Colorectal Cancer Surgery-Less Than before, But How High Is It?

Simple Summary

Evidence indicates that recurrence risk after colon cancer today is less than it was when trials performed decades ago showed that adjuvant chemotherapy reduces the risk and prolong disease-free and overall survival. After rectal cancer surgery, local recurrence rates have decreased but it is unclear if systemic recurrences have. After a systematic review of available literature reporting recurrence risks after curative colorectal cancer surgery we report that the risks are lower today than they were in the past and that this risk reduction is not solely ascribed to the use of adjuvant therapy. Adjuvant therapy always means overtreatment of many patients, already cured by the surgery. Fewer recurrences mean that progress in the care of these patients has happened but also that the present guidelines giving recommendations based upon old data must be adjusted. The relative gains from adding chemotherapy are not altered, but the absolute number of patients gaining is less.

Abstract

Adjuvant chemotherapy aims at eradicating tumour cells sometimes present after radical surgery for a colorectal cancer (CRC) and thereby diminish the recurrence rate and prolong time to recurrence (TTR). Remaining tumour cells will lead to recurrent disease that is usually fatal. Adjuvant therapy is administered based upon the estimated recurrence risk, which in turn defines the need for this treatment. This systematic overview aims at describing whether the need has decreased since trials showing that adjuvant chemotherapy provides benefits in colon cancer were performed decades ago. Thanks to other improvements than the administration of adjuvant chemotherapy, such as better staging, improved surgery, the use of radiotherapy and more careful pathology, recurrence risks have decreased. Methodological difficulties including intertrial comparisons decades apart and the present selective use of adjuvant therapy prevent an accurate estimate of the magnitude of the decreased need. Furthermore, most trials do not report recurrence rates or TTR, only disease-free and overall survival (DFS/OS). Fewer colon cancer patients, particularly in stage II but also in stage III, today display a sufficient need for adjuvant treatment considering the burden of treatment, especially when oxaliplatin is added. In rectal cancer, neo-adjuvant treatment will be increasingly used, diminishing the need for adjuvant treatment.

Impact of Primary Tumor Location on Survival After Curative Resection in Patients with Colon Cancer: A Meta-Analysis of Propensity Score-Matching Studies

BACKGROUND

Recent retrospective subgroup analyses of patients with unresectable colon cancer (CC) receiving systemic chemotherapy have demonstrated that there is a significant difference in treatment outcome between patients with right-sided CC (RSCC) and those with left-sided CC (LSCC). However, it is impossible to divide patients with CC randomly into RSCC and LSCC groups before surgery. Therefore, the aim of this study is to explore the impact of primary tumor location (PTL) on survival after curative surgery for patients with CC using propensity score-matching (PSM) studies instead of randomization.

MATERIALS AND METHODS

We performed a comprehensive electronic search of the literature up to January 2019 to identify studies that had used databases allowing comparison of postoperative survival between patients with RSCC and those with LSCC. To integrate the impact of PTL on 5-year overall survival (OS) after curative surgery, a meta-analysis was performed using random-effects models to calculate the risk ratio (RR) and 95% confidence interval (CI) for the selected PSM studies.

RESULTS

Five studies involving a total of 398,687 patients with CC were included in this meta-analysis. Among 205,641 patients with RSCC, 69,091 (33.6%) died during the observation period, whereas among 193,046 patients with LSCC, 63,380 (32.8%) died during the same period. These results revealed that patients with RSCC and those with LSCC had almost the same 5-year OS (RR, 0.98; 95% CI, 0.89-1.07; p = .64; I² = 97%).

CONCLUSION

This meta-analysis has demonstrated that there was no significant difference in 5-year OS between patients with RSCC and those with LSCC after curative resection.

IMPLICATIONS FOR PRACTICE

To integrate the impact of primary tumor location (PTL) on 5-year overall survival (OS) after curative surgery, five propensity score-matching (PSM) studies involving a total of 398,687 patients with colon cancer (CC) were included in this meta-analysis. Among 205,641 patients with right-sided CC (RSCC), 69,091 (33.6%) died during the observation period, whereas among 193,046 patients with left-sided CC (LSCC), 63,380 (32.8%) died during the same period. These results revealed that patients with RSCC and those with LSCC had almost the same 5-year OS (risk ratio, 0.98; 95% confidence interval, 0.89-1.07; p = .64; I² = 97%).

Prognostic impact of primary tumor location in Stage III colorectal cancer-right-sided colon versus left-sided colon versus rectum: a nationwide multicenter retrospective study

BACKGROUND

Previous studies investigating the impact of tumor location on colorectal cancer prognosis only compared two groups by location, e.g., 'right-sided colon vs. left-sided colon,' 'colon vs. rectum,' and 'right-sided (right-sided colon) vs. left-sided (left-sided colon and rectum).' This nationwide multicenter retrospective study aimed to clarify the prognostic impact of tumor location in patients with stage III colorectal cancer by classifying tumors into three groups: right-sided colon, left-sided colon, and rectum.

METHODS

Subjects were 9194 patients with stage III colorectal cancer who underwent curative surgery from 1997 to 2012. Relapse-free survival (RFS) after primary surgery and overall survival (OS) after recurrence were examined.

RESULTS

Rectal cancer (n = 2922) was associated with worse RFS compared to right-sided colon cancer (n = 2362) (hazard ratio (HR) 0.65; 95% CI 0.59-0.72; p < 0.001) and left-sided colon cancer (n = 3910) (HR 0.72; 95% CI 0.66-0.78; p < 0.001) after adjusting for key clinical factors (i.e., sex, age, histological type, CEA, adjuvant therapy, T category, and N category). Among patients with recurrence (n = 2823), rectal cancer was associated with better OS compared to right-sided colon cancer (HR 1.23; 95% CI 1.08-1.40; p = 0.002) and worse OS compared to left-sided colon cancer (HR 0.88; 95% CI 0.79-0.99; p = 0.029). Twenty percent of right-sided colon cancer recurrences exhibited peritoneal dissemination, 42% of left-sided colon cancer recurrences were liver metastases, and 33% of rectal cancer recurrences were local recurrences.

CONCLUSIONS

The three tumor locations (right-sided colon, left-sided colon, rectum) had different prognostic implications for recurrence after curative resection and overall mortality, suggesting that tumor location serves as a prognostic biomarker in stage III colorectal cancer.

Colorectal cancer treated by resection and extended lymphadenectomy: patterns of spread in left- and right-sided tumours

BACKGROUND

Whether tumour side affects the anatomical extent and distribution of lymph node metastasis in colon cancer is unknown. The impact of tumour side on the anatomical pattern of lymphatic spread in colon cancer was assessed.

METHODS

Patients with stage III colon cancer from a Japanese multi-institutional database who underwent extensive (D3) lymphadenectomy, which is similar in concept to complete mesocolic excision with central venous ligation, were divided into groups with right- and left-sided tumours. Based on location, mesenteric lymph nodes were categorized as paracolic (L1), intermediate (L2) or central (L3). The Kaplan-Meier method was used to evaluate disease-free survival (DFS) and overall survival (OS), and multivariable Cox models were used to evaluate the association between anatomical lymph node level, metastatic pattern and outcome.

RESULTS

A total of 4034 patients with stage III colon cancer (right 1618, left 2416) were included. Unadjusted OS was worse in patients with right colon cancer (hazard ratio 1·23, 95 per cent c.i. 1·08 to 1·40; P = 0·002), but DFS was similar. Right-sided tumours more frequently invaded L3 nodes than left-sided lesions (8·5 versus 3·7 per cent; P < 0·001). The proportion of patients with a skipped pattern of lymphatic spread was higher in right than in left colon cancer (13·7 versus 9·0 per cent; P < 0·001). In multivariable analysis, invasion of L3 nodes was associated with worse OS in left but not in right colon cancer. The presence of skipped metastasis was associated with worse DFS in left, but not right, colon cancer.

CONCLUSION

There are significant differences in the pattern of lymph node invasion between right- and left-sided stage III colon cancer, and in their prognostic significance, suggesting that tumour side may dictate the operative approach.

RNF43 mutation is associated with aggressive tumor biology along with BRAF V600E mutation in right-sided colorectal cancer

Right-sided colorectal cancer (RCRC) demonstrates worse survival outcome compared with left-sided CRC (LCRC). Recently, the importance of RNF43 mutation and BRAF V600E mutation has been reported in the serrated neoplasia pathway, which is one of the precancerous lesions in RCRC. It was hypothesized that the clinical significance of RNF43 mutation differs according to primary tumor sidedness. To test this hypothesis, the clinicopathological characteristics and survival outcome of patients with RNF43 mutation in RCRC and LCRC were investigated. Stage I–IV CRC patients (n=201) were analyzed. Genetic alterations including RNF43 using a 415-gene panel were investigated. Clinicopathological characteristics between RNF43 wild-type and RNF43 mutant-type were analyzed. Moreover, RNF43 mutant-type was classified according to primary tumor sidedness, i.e., right-sided RNF43 mutant-type or left-sided RNF43 mutant-type, and the clinicopathological characteristics between the two groups were compared. RNF43 mutational prevalence, spectrum and frequency between our cohort and TCGA samples were compared. RNF43 mutation was observed in 27 out of 201 patients (13%). Multivariate analysis revealed that age (≥65), absence of venous invasion, and BRAF V600E mutation were independently associated with RNF43 mutation. Among the 27 patients with RNF43 mutation, 12 patients were right-sided RNF43 mutant-type and 15 left-sided RNF43 mutant-type. Right-sided RNF43 mutant-type was significantly associated with histopathological grade 3, presence of lymphatic invasion, APC wild, BRAF V600E mutation, microsatellite instability-high (MSI-H), and RNF43 nonsense/frameshift mutation compared with left-sided RNF43 mutant-type. Similarly, RNF43 nonsense/frameshift mutations were more frequently observed in RCRC compared with LCRC in the TCGA cohort (P=0.042). Right-sided RNF43 mutant-type exhibited significantly worse overall survival than RNF43 wild-type and left-sided RNF43 mutant-type (P=0.001 and P=0.023, respectively) in stage IV disease. RNF43 mutation may be a distinct molecular subtype which is associated with aggressive tumor biology along with BRAF V600E mutation in RCRC.

Clinical and prognostic differences between surgically resected right-sided and left-sided colorectal cancer

PURPOSE

A growing body of evidence suggests that right-sided colorectal cancer (RCRC) differs from left-sided colorectal cancer (LCRC) in certain clinicopathological features. Therefore, we investigated the difference between RCRC and LCRC in a series of 899 patients.

METHODS

We reviewed data retrospectively, from 899 patients who underwent R0-resection for stage II and III CRC and compared the clinicopathological factors between patients with RCRC and LCRC.

RESULTS

The patients with RCRC tended to be older, more likely female, with a larger tumor, higher pathological T stage, and a greater proportion of their tumors were poorly differentiated adenocarcinoma, mucinous adenocarcinoma, or signet ring cell carcinoma than the patients with LCRC,. Recurrence-free survival (RFS) of the patients with RCRC tended to be higher than that of the patients with LCRC and was significantly better among patients with stage II cancer. The overall survival (OS) was similar for patients with RCRC and LCRC, irrespective of cancer stage.

CONCLUSION

Compared with the patients with LCRC, those with RCRC had several oncologically unfavorable factors, with better RFS in stage II and similar OS in stages II and III. These results suggest that the biological aggressiveness of RCRC is lower than that of LCRC in stage II; however, it can increase after relapse.

Marked impact of tumor location on the appropriate cutoff values and the prognostic significance of the lymph node ratio in stage III colon cancer: a multi-institutional retrospective analysis

BACKGROUND

The prognostic significance of lymph node ratio (LNR) is not constant among studies. Exploration of appropriate location-specific cutoffs might be necessary because the number of lymph nodes harvested is generally higher in right than in left colon cancer. We aimed to determine appropriate cutoff values of LNR in right and left colon cancer and to clarify its clinical significance.

METHODS

The clinicopathologic data of 5463 patients with stage III colon cancer were collected. The best cutoff for LNR as a prognostic indicator for patients with right and left colon cancer was studied separately. We compared the prognostic impact between LNR and the number of lymph node metastasis using the Akaike information criterion (AIC), and evaluated the prognostic significance of LNR in each stage III subcategory.

RESULTS

The best performance was noted when LNR was categorized by cutoffs of 0.16 and 0.22 for right and left colon cancer, respectively. AIC scores were better with these categorizations than with subgrouping by number of positive nodes. LNR-low right colon cancer patients showed better cancer-specific survival than LNR-high in stage IIIA (95.7% vs. 89.3%), IIIB (86.7% vs. 77.2%), and IIIC (71.2% vs. 58.7%). The same results were obtained in left colon cancer patients with stage IIIB (88.3% vs. 80.7%) and IIIC (79.8% vs. 68.4%).

CONCLUSIONS

We demonstrated the difference in the appropriate cutoffs of LNR between right and left colon cancer. Categorization by location-specific cutoff of LNR may be useful for risk stratification of patients with stage III cancer.

The impact of resection margin on overall survival for patients with colon cancer liver metastasis varied according to the primary cancer location

INTRODUCTION

Investigation into right and left-sided primary colon liver metastasis (CLM) has revealed differences in the tumor biology and prognosis. This indicates that preoperative and operative factors may affect outcomes of right-sided primary CLM differently than left. This retrospective analysis investigated the effects of resection margin stratified by left and right-sided primary CLM on overall survival (OS) for patients undergoing hepatectomy.

METHODS

A total of 732 patients undergoing hepatic resection for CLM at the Cleveland Clinic and Johns Hopkins were identified between 2002 and 2016. Clinically significant variables were analyzed using Cox proportional hazard regression. The cohort was then divided into patients with right and left-sided CLM and analyzed separately using Kaplan Meier analysis and Cox proportional hazard regression.

RESULTS

Cox proportional hazard regression showed that left-sided CLM with an R0 margin was a statistically significant predictor of OS even after controlling for other important factors (HR = 0.629, P = 0.024) but right-sided CLM with R0 margin was not (HR = 0.788, P = 0.245). Kaplan-Meier analysis demonstrated that patients with a left-sided CLM and R0 margin had the best prognosis (P = 0.037).

CONCLUSION

Surgical margin is an important prognostic factor for left-sided primary CLM but tumor biology may override surgical technique for right-sided CLM.

Impact of tumor sidedness on survival and recurrence patterns in colon cancer patients

Purpose

Previous studies have reported conflicting results regarding the prognostic value of tumor sidedness in colon cancer. We investigated the oncologic impact of tumor location and examined whether recurrence patterns were related to tumor sidedness in colon cancer patients.

Methods

We identified stage I-III colon adenocarcinoma patients from a prospective colorectal cancer registry at Severance Hospital, Seoul, Korea, who underwent complete mesocolic excision between 2005 and 2012. Adjusted hazard ratios (HRs) and 95% confidence intervals (CI) for predictors of cancer-specific survival (CSS), recurrence-free survival (RFS), and cumulative recurrence at specific anatomic sites were examined using Cox proportional hazard regression analysis.

Results

Overall, 1,912 patients, 1,077 (56.3%) with left-sided colon cancer (LCC), and 835 (43.7%) with right-sided colon cancer (RCC), at a median follow-up of 59 months, were eligible and included in the study. In univariate analysis, similar 5-year CSS and RFS were observed for LCC and RCC in the total patient population, and when stratified by stage for stage I and II patients. For stage III patients, an adjusted Cox regression analysis indicated that RCC patients had a higher risk of cancer-specific mortality (HR, 1.75; 95% CI, 1.07-2.86; P = 0.024) and recurrence (HR, 1.78; 95% CI, 1.22-2.60; P = 0.003). Furthermore, RCC was an independent predictor of peritoneal recurrence (HR, 1.86; 95% CI, 1.05-3.29; P = 0.031) in stage III patients.

Conclusion

RCC correlated with worse CSS and RFS than LCC. In stage III patients, RCC correlated with increased risk of peritoneal recurrence. The reasons for these differences remain to be investigated.

Does the Different Locations of Colon Cancer Affect the Oncologic Outcome? A Propensity-Score Matched Analysis

PURPOSE

We evaluate the prognostic value of primary tumor location for oncologic outcomes in patients with colon cancer (CC).

METHODS

CC patients treated with curative surgery between 2009 and 2012 were classified into 2 groups: right-sided colon cancer (RCC) and left-sided colon cancer (LCC). Recurrence-free survival (RFS) and overall survival (OS) were examined based on tumor stage. Propensity scores were created using eight variables (age, sex, T stage, N stage, histologic grade, presence of lymphovascular invasion/perineural invasion, and microsatellite instability status).

RESULTS

Overall, 2,329 patients were identified. The 5-year RFSs for RCC and LCC patients were 89.7% and 88.4% (P = 0.328), respectively, and their 5-year OSs were 90.9% and 93.4% (P = 0.062). Multivariate survival analyses were carried out by using the Cox regression proportional hazard model. In the unadjusted analysis, a marginal increase in overall mortality was seen in RCC patients (hazard ratio [HR], 1.297; 95% confidence interval [CI], 0.987-1.704, P = 0.062); however, after multivariable adjustment, similar OSs were observed in those patients (HR, 1.219; 95% CI, 0.91-1.633; P = 0.183). After propensity-score matching with a total of 1,560 patients, no significant difference was identified (P = 0.183). A slightly worse OS was seen for stage III RCC patients (HR, 1.561; 95% CI, 0.967-2.522; P = 0.068) than for stage III LCC patients. The 5-year OSs for patients with stage III RCC and stage III LCC were 85.5% and 90.5%, respectively (P = 0.133).

CONCLUSION

Although the results are inconclusive, tumor location tended to be associated with OS in CC patients with lymph node metastasis, but it was not related to oncologic outcome.

Impact of primary tumor location as a predictive factor in patients suffering from colorectal cancer treated with cytotoxic anticancer agents based on the collagen gel droplet-embedded drug sensitivity test

In recent studies, better clinical outcomes for patients with left-sided colon cancer (CC) compared with right-sided CC have been reported; however, in such investigations, the chemotherapy regimens included molecular-targeting agents. To the best of our knowledge, the impact of primary tumor location as a predictive factor in patients suffering from CC treated with cytotoxic anticancer agents alone has not been investigated. The aim of the present study was to determine the impact of the primary tumor location as a predictive factor of patients undergoing the following cytotoxic anticancer agent regimens: Leucovorin and fluorouracil + oxaliplatin (FOLFOX) or Leucovorin and fluorouracil + irinotecan (FOLFIRI), using the collagen gel droplet-embedded drug sensitivity test (CD-DST). Between March 2008 and April 2017, tumor specimens were obtained from 133 patients suffering from colorectal cancer (CRC) who had not received preoperative chemotherapy. CD-DST was performed and the growth inhibition rate (IR) was determined in FOLFOX and FOLFIRI regimens. The associations between tumor location and IR values for each condition were evaluated. In the present study, the prognosis of patients receiving palliative chemotherapy as well as treatment with molecularly-targeted agents was also investigated. There were no significant differences in the IRs (%) of the two regimens using CD-DST for right-sided tumors compared with left-sided tumors, including or excluding the rectum. The median survival times of patients with right CC and left CC who had received palliative chemotherapy and treatment with molecularly-targeted agents were 960 and 1,348 days, respectively. Primary tumor location did not represent a predictive factor for the efficacy of treatment with cytotoxic anticancer agent regimens using CD-DST. However, patients suffering from left-sided CC were revealed to exhibit better clinical outcomes compared with patients suffering from right-sided CC when molecularly-targeted agent regimens were administered. Therefore, the results of the present study suggested that molecularly-targeted agents rather than cytotoxic anticancer agents may result in improved clinical outcomes for patients with CRC suffering from left-sided tumors.

Significance of Glisson's capsule invasion in patients with colorectal liver metastases undergoing resection

BACKGROUND

Significance of Glisson's capsule invasion in colorectal liver metastases (CLM) patients undergoing resection has been little investigated.

METHODS

CLM patients (244) with curative resection (2011-2016) were divided into two groups: patients with (Group 1; n = 49 [20%]) and without (Group 2; n = 195 [80%]) histologically-proven Glisson invasion. Eight (16%) Group 1 patients were identified by pre- or intra-operative findings. We compared characteristics between Groups 1 and 2 and determined independent prognosticators.

RESULTS

Group 1 was more commonly associated with right-sided primary, CLM>5 cm, and R1 resections. Independent factors on reduced OS in entire cohort were pre-surgical chemotherapy [hazard ratio (HR): 2.68, P = 0.001], CLM>5 cm (HR: 4.39, P = 0.002), moderate or poor differentiation (HR: 2.38, P = 0.004), and R1 resection (HR: 1.92, P = 0.035).

CONCLUSIONS

CLM Glisson invasion was significantly associated with R1 resection. Advancements in determining Glisson invasion pre- or intra-operatively might produce benefits for CLM patients undergoing resection by reducing R1 resection.

Impact of primary tumor location as a predictive factor in patients suffering from colorectal cancer treated with cytotoxic anticancer agents based on the collagen gel droplet-embedded drug sensitivity test

In recent studies, better clinical outcomes for patients with left-sided colon cancer (CC) compared with right-sided CC have been reported; however, in such investigations, the chemotherapy regimens included molecular-targeting agents. To the best of our knowledge, the impact of primary tumor location as a predictive factor in patients suffering from CC treated with cytotoxic anticancer agents alone has not been investigated. The aim of the present study was to determine the impact of the primary tumor location as a predictive factor of patients undergoing the following cytotoxic anticancer agent regimens: Leucovorin and fluorouracil + oxaliplatin (FOLFOX) or Leucovorin and fluorouracil + irinotecan (FOLFIRI), using the collagen gel droplet-embedded drug sensitivity test (CD-DST). Between March 2008 and April 2017, tumor specimens were obtained from 133 patients suffering from colorectal cancer (CRC) who had not received preoperative chemotherapy. CD-DST was performed and the growth inhibition rate (IR) was determined in FOLFOX and FOLFIRI regimens. The associations between tumor location and IR values for each condition were evaluated. In the present study, the prognosis of patients receiving palliative chemotherapy as well as treatment with molecularly-targeted agents was also investigated. There were no significant differences in the IRs (%) of the two regimens using CD-DST for right-sided tumors compared with left-sided tumors, including or excluding the rectum. The median survival times of patients with right CC and left CC who had received palliative chemotherapy and treatment with molecularly-targeted agents were 960 and 1,348 days, respectively. Primary tumor location did not represent a predictive factor for the efficacy of treatment with cytotoxic anticancer agent regimens using CD-DST. However, patients suffering from left-sided CC were revealed to exhibit better clinical outcomes compared with patients suffering from right-sided CC when molecularly-targeted agent regimens were administered. Therefore, the results of the present study suggested that molecularly-targeted agents rather than cytotoxic anticancer agents may result in improved clinical outcomes for patients with CRC suffering from left-sided tumors.

Primary tumor location in stage III colon cancer has prognostic impact on subsequent liver metastasis

BACKGROUND AND OBJECTIVES

We aim to investigate whether a difference exists between right-sided and left-sided colon cancer at the same disease stage and subsequent liver metastasis and identify whether tumor location can independently influence survival.

METHODS

Right-sided colon cancer was defined as malignancy arising from the cecum to the transverse colon; left-sided colon cancer was defined as malignancy arising from the splenic flexure to the sigmoid colon. Clinicopathological features and survival data were collected for analysis.

RESULTS

Overall, 1442 patients were included for analysis. The median follow-up time was 58.2 months. Patients with left-sided colon cancer had better 5-year overall survival (75.2% vs 61.7%, P = 0.005), 5-year cancer-specific survival (81.6% vs 73.4%, P = 0.001), and 5-year recurrence-free survival (70.9% vs 66.5%, P = 0.033) compared with patients having right-sided colon cancer. After the presentation of subsequent liver metastasis, patients with primary left-sided colon cancer had better 3-year cancer-specific survival ( P < 0.001). In the multivariate analysis, cancer location was an independent prognostic factor for cancer-specific survival (right vs left, HR: 1.276, 95% CI: 1.002-1.625).

CONCLUSIONS

The primary tumor location can serve as a prognostic factor for treatment outcomes either in primary stage III colon cancer or subsequent liver metastasis.

The prognostic implications of primary tumor location on recurrence in early-stage colorectal cancer with no associated risk factors

PURPOSE

Recently, several reports have suggested that tumor location serves as a prognostic biomarker in advanced colorectal cancer. However, the prognostic implication of tumor location in patients with early-stage colorectal cancer remains unclear. This study was aimed to examine the prognostic implication of tumor location in patients with early-stage colorectal cancer.

METHODS

Patients with stage I and low-risk stage II colorectal cancer, treated with radical surgery in a hospital setting between May 2003 and September 2014, were retrospectively reviewed. Patients who underwent (neo) adjuvant chemotherapy and/or radiotherapy and whose microsatellite instability (MSI) status was lacked were excluded. Distal colon cancer was defined as tumors located from the splenic flexure colon to the sigmoid colon.

RESULTS

A total of 712 patients were included in this study. Of these patients, 23 (3.2%) had a recurrence at a median follow-up time of 46 months. The tumor recurrence rate was significantly low in patients with proximal colon cancer. In the multivariate analysis, tumors located in the distal colon or rectum (distal colon, hazard ratio [HR] 9.213, P = 0.035; rectum, HR 15.366, P = 0.009) and T3 tumors (HR 4.590, P = 0.017) were related to tumor recurrence. A higher prevalence of tumor recurrence was found in patients with two recurrence factors than those who had only one factor or none (P < 0.001).

CONCLUSIONS

Tumor location, as well as T stage, had prognostic implication in patients with early-stage colorectal cancer. Validation of our results is needed in a large cohort with genetic characterization.

Characteristic proteins in the plasma of postoperative colorectal and liver cancer patients with Yin deficiency of liver-kidney syndrome

Systems biology and bioinformatics provide the feasibility for the basic research associated with “same traditional Chinese medicine (TCM) syndrome in different diseases”. In this study, the plasma proteins in postoperative colorectal (PCC) and postoperative liver cancer (PLC) patients with YDLKS (Yin deficiency of liver-kidney syndrome) were screened out using iTRAQ combined with LC-MS/MS technology. The results demonstrated that, KNG1, AMBP, SERPING1, etc, were all differentially expressed in both PCC and PLC patients with YDLKS, and associated closely with complement and coagulation cascades pathway. C7 and C2 were another two representative factors involving in former pathway. Further validation showed that, the C7 levels were increased significantly in PLC (P < 0.05) and PCC (P < 0.05) with YDLKS group compared to those of NS (no obvious TCM syndromes) group. The AMBP levels were down-regulated significantly in PLC with YDLKS group compared to those of PCC with YDLKS group (P < 0.05). The significant differences of SERPING1 levels (and C2 levels) were shown between YDLKS and NS in PCC (P < 0.01). There were also significant differences of C2 levels between PCC and PLC patients with YDLKS (P < 0.05). Moreover, significant differences of C2 levels were also found between PLC and PCC patients with YDLKS (P < 0.01). ROC curves indicated that, C7 and SERPING1 independently had a potential diagnostic value in distinguishing YDLKS from NS in PLC and PCC, providing the evidences for the material basis of “same TCM syndrome in different diseases” in PCC and PLC patients with YDLKS.

Mucosa-associated microbiota signature in colorectal cancer

The aim of this study was to explore the gut microbiota profiles of colorectal cancer (CRC) patients and to examine the relationship between gut microbiota and other key molecular factors involved in CRC tumorigenesis. In this study, a 16S rDNA sequencing platform was used to identify possible differences in the microbiota signature between CRC and adjacent normal mucosal tissue. Differences in the microbiota composition in different anatomical colorectal tumor sites and their potential association with KRAS mutation were also explored. In this study, the number of Firmicutes and Actinobacteria decreased, while the number of Fusobacteria increased in the gut of CRC patients. In addition, at the genus level, Fusobacterium was identified as the key contributor to CRC tumorigenesis. In addition, a different distribution of gut microbiota in ascending and descending colon cancer samples was observed. Lipopolysaccharide biosynthesis-associated microbial genes were enriched in tumor tissues. Our study suggests that specific mucosa-associated microbiota signature and function are significantly changed in the gut of CRC patients, which may provide insight into the progression of CRC. These findings could also be of value in the creation of new prevention and treatment strategies for this type of cancer.