Tumour sidedness and intrinsic subtypes in patients with stage II/III colon cancer: analysis of NSABP C-07 (NRG Oncology)

Prognostic impact of primary tumour location after curative resection in Stage I-III colorectal cancer: a single-centre retrospective study

OBJECTIVE

The relationship of tumour site with post-recurrence course and outcome after primary surgery in resectable colorectal cancer is unclear. This study investigated the prognostic impact of primary tumour location following radical resection without preoperative treatment in Stage I-III colorectal cancer.

METHODS

We analyzed 3770 patients with Stage I-III colorectal cancer who underwent curative resection at our hospital during 2000-15. We defined the right-sided colon as the cecum, ascending colon and transverse colon, and the left-sided colon as the descending colon, sigmoid and rectosigmoid junction. Patients were divided into three groups according to tumour site: right-sided colon, left-sided colon and rectum. Endpoints were overall survival, recurrence-free survival by stage and survival after recurrence, respectively.

RESULTS

The 5-year overall survival rates of patients with stage I left-sided colon cancer, right-sided colon cancer and rectal cancer were 98.2, 97.3 and 97.2%, respectively (P = 0.488). The 5-year overall survival rates of patients with Stage II left-sided colon cancer, right-sided colon cancer and rectal cancer were 96.2, 88.7 and 83.0, respectively (P = 0.070). The 5-year overall survival rates of patients with Stage III left-sided colon cancer, right-sided colon cancer and rectal cancer were 88.7, 83.0 and 80.2, respectively (P = 0.001). The 5-year recurrence-free survival rates of patients with Stage I left-sided colon cancer, right-sided colon cancer and rectal cancer were 95.1, 94.5 and 90.6% (P = 0.027). The 5-year recurrence-free survival rates of patients with Stage II left-sided colon cancer, right-sided colon cancer and rectal cancer were 85.2, 90.2 and 76.1%, respectively (P < 0.001). The 5-year recurrence-free survival rates of patients with Stage III left-sided colon cancer, right-sided colon cancer and rectal cancer were 75.3, 75.3 and 59.8%, respectively (P < 0.001). Right-sided colon cancer was significantly associated with better recurrence-free survival compared with left-sided colon cancer (HR 1.29, 95% CI 1.03-1.63; P = 0.025) and rectal cancer (HR 1.89, 95% CI 1.51-2.38; P < 0.001) after adjusting for clinical factors. Amongst patients with recurrence, right-sided colon cancer was significantly associated with poorer survival after recurrence compared with left-sided colon cancer (HR 0.68, 95% CI 0.48-0.97; P = 0.036), and showed a tendency towards poorer survival after recurrence compared with rectal cancer (HR 0.79, 95% CI 0.57-1.10; P = 0.164).

CONCLUSIONS

In Stage I-III colorectal cancer without preoperative treatment, our results suggest that the three tumour sites (right-sided colon, left-sided colon or rectum) may have prognostic significance for recurrence-free survival and survival after recurrence, rather than sidedness alone.

Predictors of nodal positivity in clinically under-staged patients with colon cancer: A National Cancer Database study and proposal of a predictive scoring system

BACKGROUND

Colon cancer pathological and clinical staging may be disoncordant. This study assessed patients with colon cancer in whom the nodal status was clinically understaged.

METHODS

Patients with stage I-III clinical node-negative colon cancer from the National Cancer Database were included. Regression analyses were conducted to elucidate risk factors for clinical nodal understaging and a scoring system was developed to identify high-risk patients.

RESULTS

The study included 94,945 patients with 78.4 ​% of patients correctly staged and 21.6 ​% clinically understaged. The predictors of nodal positivity in clinically understaged patients were age <65 (OR 1.43), left-sided tumors (OR 1.41), elevated CEA (OR 2.03), moderately (OR 1.81) or poorly/undifferentiated tumors (OR 3.76), T1 tumors (OR 1.29), signet-ring cell histology (OR 2.26), and microsatellite-stable tumors (OR 1.4).

CONCLUSION

Patients with colon cancer and the above factors are more likely to have their nodal status clinically understaged. A scoring system has been developed to identify high-risk patients.

Prognostic Relevance of Primary Tumor Sidedness in Early-stage Colorectal Cancer: An Integrated Analysis of 4 Randomized Controlled Trials (JCOG2003A)

OBJECTIVE

The aim of this study was to determine the genuine prognostic relevance of primary tumor sidedness (PTS) in patients with early-stage colorectal cancer (CRC).

BACKGROUND

The prognostic relevance of PTS in early-stage CRC remains a topic of debate. Several large epidemiological studies investigated survival only and did not consider the risk of recurrence so far.

METHODS

Patients with stage II/III adenocarcinoma of the colon and upper rectum from 4 randomized controlled trials were analyzed. Survival outcomes were compared according to the tumor location: right-sided (cecum to transverse colon) or left-sided (descending colon to upper rectum).

RESULTS

A total of 4113 patients were divided into a right-sided group (N=1349) and a left-sided group (N=2764). Relapse-free survival after primary surgery was not associated with PTS in all patients and each stage [hazard ratio (HR) adjusted =1.024 (95% CI: 0.886-1.183) in all patients; 1.327 (0.852-2.067) in stage II; and 0.990 (0.850-1.154) in stage III]. Also, overall survival after primary surgery was not associated with PTS in all patients and each stage [HR adjusted =0.879 (95% CI: 0.726-1.064) in all patients; 1.517 (0.738-3.115) in stage II; and 0.840 (0.689-1.024) in stage III]. In total, 795 patients (right-sided, N=257; left-sided, N=538) developed recurrence after primary surgery. PTS was significantly associated with overall survival after recurrence (HR adjusted =0.773, 95% CI: 0.627-0.954).

CONCLUSIONS

PTS had no impact on the risk of recurrence for stage II/III CRC. Treatment stratification based on PTS is unnecessary for early-stage CRC.

Short- and long-term outcomes of transanal decompression tube and self-expandable metallic stent for obstructive colorectal cancer based on a multicenter database (KYCC2110)

AIM

There are well-known methods for decompressing the colorectal tract before surgery, including transanal decompression tubes (TDT) and self-expanding metallic stents (SEMS). This study aimed to compare the short and long-term results in patients with malignant large bowel obstruction in whom TDT or SEMS were placed before surgery.

METHODS

This retrospective observational study enrolled 225 patients with malignant large bowel obstruction in whom TDT or SEMS were placed preoperatively and underwent R0 resection between 2008 and 2020. One-to-two propensity score matching was performed according to patient characteristics. Short- and long-term outcomes were compared. The primary endpoint was relapse-free survival (RFS). The secondary endpoints were the overall survival (OS) and postoperative complication rate.

RESULTS

Fifty-seven patients in the TDT group and 114 in the SEMS group were matched. The 3-year RFS rates were 66.7% in the TDT group and 69.9% in the SEMS group (p = 0.54), and the 3-year OS rates were 90.5% in the TDT group and 87.1% in the SEMS group (p = 0.52). No significant differences in the long-term results were observed between the two groups. Regarding short-term results, the SEMS group had significantly fewer stoma construction (p = 0.007) and shorter postoperative hospitalization (p < 0.001). The incidence of postoperative complications (grade ≥ 2) was significantly lower in the SEMS group (p = 0.04).

CONCLUSION

No significant differences in the long-term results were observed between the TDT and SEMS group. The SEMS showed significant usefulness in terms of improving short-term outcomes.

Correlation between overall survival and quality of life in colon cancer patients with chemotherapy

BACKGROUND

Patients presenting with inoperable colon cancer at first onset (ICF) or at time of relapse (ICR) are considered in unrecoverable. The therapeutic goal for unrecoverable cancer is to prolong overall survival (OS) and maintain a high quality of life (QOL). As data on objective indicators of QOL in cancer patients, such as length of hospitalisation (LOH), outpatient consultation times (OCT), and hospital-free survival (HFS), is limited, this study compared ICF and ICR with respect to OS and QOL over the entire clinical course.

METHODS

We retrospectively evaluated 90 inoperable colon cancer patients with chemotherapy and compared ICF and ICR in terms of OS, LOH, OCT, and HFS.

RESULTS

Patients with ICF had a worse OS than those with ICR. In patients with ICF and ICR, OS and LOH were not correlated but OS and OCT and OS and HFS were strongly correlated. In patients with ICF and ICR, OCT and HFS accounted for approximately 8% and 90% of their OS, respectively.

CONCLUSIONS

The LOH, OCT, and HFS are important factors for evaluating objective QOL of patients with inoperable colon cancer and should be considered when making treatment decisions.

Association of tumor-infiltrating lymphocytes with survival depends on primary tumor sidedness in stage III colon cancers (NCCTG N0147) [Alliance]

BACKGROUND

Tumor-infiltrating lymphocytes (TILs) are a robust and independent prognostic variable in localized colon cancer. Given reported differences in molecular features and prognosis of right- versus left-sided tumors, we examined the association of TIL densities with patient survival by primary tumor sidedness in stage III cancers, including clinical low- (T1-3, N1) and high-risk (T4 and/or N2) groups.

PATIENTS AND METHODS

In a phase III trial of FOLFOX-based adjuvant chemotherapy, TIL densities were analyzed and dichotomized in colon carcinomas (N = 1532) based on a previously determined cut point optimized for disease-free survival (DFS). Right-sided tumors were defined as proximal to the splenic flexure. Associations of TILs and sidedness with 5-year DFS were examined using Kaplan-Meier methodology along with multivariable modeling and relative contribution analysis by Cox regression.

RESULTS

Lower TIL densities were found in left- versus right-sided tumors (P < 0.0001). The association of TIL densities with DFS differed significantly by tumor sidedness (Pinteraction = 0.045). Overall, patient tumors with low (versus high) TILs had significantly poorer DFS in right-sided (hazard ratio 2.02, 95% confidence interval 1.45-2.82; Padj < 0.0001), but not left-sided tumors (Padj = 0.1731). Among clinical low-risk patients, low (versus high) TILs were adversely prognostic only in right-sided tumors (Padj = 0.0058). Among high-risk patients, low TILs were prognostic independent of sidedness (Padj < 0.025). The relative contribution of TILs to DFS was substantially greater in right- versus left-sided tumors (24% versus 1.5%). In high-risk tumors, TILs had the highest relative contribution to DFS (42%) of all variables. In low-risk tumors, the contribution of TILs (16%) to DFS was second to KRAS.

CONCLUSIONS

The association of TIL densities with patient survival differed by primary tumor sidedness and clinical risk group, suggesting that TILs should be interpreted in this context among stage III colon cancers.

CLINICALTRIALS

GOV IDENTIFIER

NCT00079274; https://clinicaltrials.gov/ct2/show/NCT00079274.

Multifocal Organoid Capturing of Colon Cancer Reveals Pervasive Intratumoral Heterogenous Drug Responses

Intratumor heterogeneity (ITH) stands as one of the main difficulties in the treatment of colorectal cancer (CRC) as it causes the development of resistant clones and leads to heterogeneous drug responses. Here, 12 sets of patient-derived organoids (PDOs) and cell lines (PDCs) isolated from multiple regions of single tumors from 12 patients, capturing ITH by multiregion sampling of individual tumors, are presented. Whole-exome sequencing and RNA sequencing of the 12 sets are performed. The PDOs and PDCs of the 12 sets are also analyzed with a clinically relevant 24-compound library to assess their drug responses. The results reveal unexpectedly widespread subregional heterogeneity among PDOs and PDCs isolated from a single tumor, which is manifested by genetic and transcriptional heterogeneity and strong variance in drug responses, while each PDO still recapitulates the major histologic, genomic, and transcriptomic characteristics of the primary tumor. The data suggest an imminent drawback of single biopsy-originated PDO-based clinical diagnosis in evaluating CRC patient responses. Instead, the results indicate the importance of targeting common somatic driver mutations positioned in the trunk of all tumor subregional clones in parallel with a comprehensive understanding of the molecular ITH of each tumor.

Adjuvant treatment of colon cancer with microsatellite instability - the state of the art

Adjuvant chemotherapy with fluoropyrimidine (FP) plus oxaliplatin in stage III resected colorecatal cancer (RCRC) resulted in a 30% relative reduction of disease recurrence risk and mortality. The presence of altered mismatch repair genes identify tumors with microsatellite instability (MSI) that have a better prognosis than stable tumors, but data about adjuvant chemotherapy benefit in this subgroup are compelling. We investigate the role of adjuvant therapy in resected MSI RCRC. The standard treatment is the association of FP plus oxaliplatin, while it can avoided in low risk stage II, thanks to its good prognosis. We propose a practice strategy to approach MSI RCRC in line with the current knowledge. In consideration of the dramatic results in chemorefractory MSI metastatic CRC, there are assumptions that immunotherapy can become a potential alternative to classical systemic therapies also in the adjuvant setting. We await the results of ongoing studies to draw further conclusions."

Clinical Value of Consensus Molecular Subtypes in Colorectal Cancer: A Systematic Review and Meta-Analysis

Background

The consensus molecular subtypes (CMSs) of colorectal cancer (CRC) capture tumor heterogeneity at the gene-expression level. Currently, a restricted number of molecular features are used to guide treatment for CRC. We summarize the evidence on the clinical value of the CMSs.

Methods

We systematically identified studies in Medline and Embase that evaluated the prognostic and predictive value of CMSs in CRC patients. A random-effect meta-analysis was performed on prognostic data. Predictive data were summarized.

Results

In local disease, CMS4 tumors were associated with worse overall survival (OS) compared with CMS1 (hazard ratio [HR] = 3.28, 95% confidence interval = 1.27 to 8.47) and CMS2 cancers (HR = 2.60, 95% confidence interval = 1.93 to 3.50). In metastatic disease, CMS1 consistently had worse survival than CMS2-4 (OS HR range = 0.33-0.55; progression-free survival HR range = 0.53-0.89). Adjuvant chemotherapy in stage II and III CRC was most beneficial for OS in CMS2 and CMS3 (HR range = 0.16-0.45) and not effective in CMS4 tumors. In metastatic CMS4 cancers, an irinotecan-based regimen improved outcome compared with oxaliplatin (HR range = 0.31-0.72). The addition of bevacizumab seemed beneficial in CMS1, and anti-epidermal growth factor receptor therapy improved outcome for KRAS wild-type CMS2 patients.

Conclusions

The CMS classification holds clear potential for clinical use in predicting both prognosis and response to systemic therapy, which seems to be independent of the classifier used. Prospective studies are warranted to support implementation of the CMS taxonomy in clinical practice.

Prognostic impact of tumour sidedness in patients with stage II colon cancer: a single-centre retrospective study

BACKGROUND

The search for high-risk factors in stage II colon cancer (CC) is ongoing and several high-risk factors for stage II CC have been identified; however, the effects of tumour sidedness on prognosis are not clear. This study aims to determine whether tumour sidedness could be identified as another high-risk factor for stage II CC.

METHODS

We retrospectively analysed 189 patients with stage II CC and compared clinicopathological findings and long-term outcomes between the patients with right colonic cancer (RCC) and with left colonic cancer (LCC). Prognostic factors for survival were determined using univariate and Cox proportional regression analyses.

RESULTS

A total of 72 patients were diagnosed with RCC and 117 patients were diagnosed with LCC. Patients with RCC were significantly older (P < 0.001), and the number of harvested lymph nodes was greater in the RCC group (RCC: 25 versus LCC: 19; P = 0.003). The overall survival (OS) was worse in the RCC group than the OS in the LCC group (5-year survival rate - RCC: 81.3% versus LCC: 90.4%; P = 0.025). Cox proportional regression analysis showed that tumour sidedness was an independent prognostic factor for both OS (hazard ratio (HR) 3.78, 95% confidence interval (CI) 1.61-8.85, P = 0.022) and DFS (HR 2.58, 95% CI 1.33-4.99, P = 0.005).

CONCLUSION

Patients with RCC have more negative prognostic factors and worse long-term outcomes than those with LCC in stage II CC. Tumour sidedness is a high-risk factor in stage II CC patients.

Clinical significance of enterocyte-specific gene polymorphisms as candidate markers of oxaliplatin-based treatment for metastatic colorectal cancer

Colorectal cancer (CRC) can be classified into subtypes based on gene expression signatures. Patients with stage III enterocyte subtype of the CRC Assigner classifier have been shown to benefit from oxaliplatin adjuvant therapy. Here, we investigated whether single nucleotide polymorphisms (SNPs) in two enterocyte subtype-related genes, MS4A12 and CDX2, could predict the efficacy of oxaliplatin in first-line treatment for patients with metastatic CRC (mCRC). Three cohorts of patients were included: a discovery cohort receiving FOLFOX ± bevacizumab (BEV) (n = 146), a validation cohort receiving FOLFOXIRI + BEV (n = 230), and a control cohort receiving FOLFIRI + BEV (n = 228). SNPs were analyzed by PCR-based direct sequencing. In the discovery cohort, MS4A12 rs4939378 and CDX2 rs3812863 were identified as potential markers of efficacy. In the validation cohort, any G allele of MS4A12 rs4939378 was associated with longer progression-free survival (PFS) than the A/A variant in both univariate analysis (12.4 vs. 10.9 months, hazard ratio [HR] 0.70, 95% confidence interval [CI] 0.49-0.99, P = 0.033) and multivariable analysis (HR 0.65, 95%CI 0.44-0.97, P = 0.035) in patients expressing wild-type KRAS, but not mutant KRAS. In contrast, longer PFS was observed for patients expressing the CDX2 rs3812863 G/G variant than any A allele in univariate analysis (32.3 vs. 10.3 months, HR 0.39, 95%CI 0.19-0.81, P = 0.004) only in patients expressing mutant KRAS. These findings were not observed in the control cohort. Thus, MS4A12 and CDX2 SNPs may have utility as predictive biomarkers of response to oxaliplatin-based treatment in mCRC patients.

Clinicopathologic and Racial/Ethnic Differences of Colorectal Cancer Among Adolescents and Young Adults

Despite overall reductions in colorectal cancer burden, incidence rates continue to rise among younger patients, and causes remain unknown. We examined differences in clinicopathologic and racial/ethnic characteristics within the adolescent and young adult (AYA) population diagnosed with colorectal cancer in the United States.

ColoType: a forty gene signature for consensus molecular subtyping of colorectal cancer tumors using whole-genome assay or targeted RNA-sequencing

Colorectal cancer (CRC) tumors can be partitioned into four biologically distinct consensus molecular subtypes (CMS1-4) using gene expression. Evidence is accumulating that tumors in different subtypes are likely to respond differently to treatments. However, to date, there is no clinical diagnostic test for CMS subtyping. In this study, we used novel methodology in a multi-cohort training domain (n = 1,214) to develop the ColoType scores and classifier to predict CMS1-4 based on expression of 40 genes. In three validation cohorts (n = 1,744, in total) representing three distinct gene-expression measurement technologies, ColoType predicted gold-standard CMS subtypes with accuracies 0.90, 0.91, 0.88, respectively. To accommodate for potential intratumoral heterogeneity and tumors of mixed subtypes, ColoType was designed to report continuous scores measuring the prevalence of each of CMS1-4 in a tumor, in addition to specifying the most prevalent subtype. For analysis of clinical specimens, ColoType was also implemented with targeted RNA-sequencing (Illumina AmpliSeq). In a series of formalin-fixed, paraffin-embedded CRC samples (n = 49), ColoType by targeted RNA-sequencing agreed with subtypes predicted by two independent methods with accuracies 0.92, 0.82, respectively. With further validation, ColoType by targeted RNA-sequencing, may enable clinical application of CMS subtyping with widely-available and cost-effective technology.

Clinical characteristics and oncologic outcomes in patients with preoperative clinical T3 and T4 colon cancer who were staged as pathologic T3

Purpose

Clinically suspected T4 stage colon cancer from a preoperative exam is often diagnosed as T3 stage colon cancer pathologically after surgery, raising concerns about understaging. The aims of this study were to compare the survival of clinical T3 and T4 colon cancer patients who had received a pathologic T3 stage diagnosis postoperatively.

Methods

Patients who were diagnosed with pathologic T3 stage colon cancer postoperatively were reviewed. Patients with clinically suspected T3 or T4 stage cancer on preoperative exam were enrolled in the study. We compared patient demographics and survival of the cT3 and cT4 groups.

Results

Out of the 536 patients with pT3 colon cancer, 503 patients were cT3 (93.8%) and 33 patients were cT4 (6.2%) preoperatively. The most common reason for suspected clinical T4 stage cancer was free perforation (78.8%). There were no statistically significant differences between the 5-year overall survival and the total 5-year disease-free survival (DFS) between the cT3 and cT4 groups; however, local recurrence was significantly higher in the cT4 group (local 5-year DFS: 98.6% vs. 84.0%, P < 0.001). Multivariate analysis showed cT stage was associated with local recurrence, but the association was not statistically significant (P = 0.056).

Conclusion

Preoperative clinically suspected T4 stage colon cancer showed inferior local recurrence despite a postoperative pathologic diagnosis of T3 stage cancer. It is necessary to address the shortcomings of pathologic exams in the matter of the understaging of T4 colon cancer, and to reinforce the treatment for local control in patients with cT4 colon cancer.

Genetics of rectal cancer and novel therapies: primer for radiologists

Rectal cancer accounts for one-third of newly diagnosed colorectal cancer cases. Given its anatomical location and risk for local recurrence, a multidisciplinary treatment program including surgery, radiation therapy, and chemotherapy has demonstrated improved outcomes in localized disease. Genetic analysis has become part of the standard approach for management of advanced disease and new trials are considering tailored therapies for locally advanced disease. This review describes molecular subsets of colorectal cancer; implications for clinical management, including patterns of metastatic spread and response to therapies; and emerging matched therapies. During the last decade, significant biological differences have been noted based on colorectal cancer primary location and here we focus on rectal cancers and relevant markers for this disease. As more treatment for localized rectal cancer is shifted to the neoadjuvant setting and more targeted regimens are developed for metastatic disease, radiologists will increasingly see patients defined by molecular subsets and their awareness of the genetics of rectal cancer will help further refine our understanding of this disease.

Accuracy of nodal staging is influenced by sidedness in colon cancer

Background

Adequate lymph node (LN) sampling is critical for accurate nodal staging in colon cancer (CC), particularly for T3N0 disease as current guidelines recommend considering adjuvant chemotherapy when less than 12 LNs are examined. The impact of sidedness on nodal staging accuracy in patients with T3N0 disease has not been previously studied.

Methods

Patients with pathologic T3 CC were identified from a prospective multicenter international trial of ultrastaging in CC. The probability of true nodal negativity (TNN) based on the number of LN examined was calculated for right and left CC. These results were then validated in a cohort of patients with similar inclusion criteria selected from the National Cancer Database (NCDB) between 2006 and 2014.

Results

Three hundred and seventy patients met the inclusion criteria in the trial cohort; 48% were LN-negative. Of 153,945 patients in the NCDB, 57% were LN-negative. The probability of TNN when 12 LNs were examined was 68% for right and 64% for left CC in the trial cohort and 77% and 72% in the NCDB. The number of LNs needed to achieve any given probability of TNN was significantly different between right and left CC in both the trial (P<0.001) and the NCDB (P<0.001).

Conclusions

In both a prospective multicenter trial and the NCDB, sidedness influences the number of LNs needed to predict nodal negativity in CC. Current guidelines regarding the minimum number of LNs needed to accurately stage patients with T3N0 CC may need to be re-evaluated by taking into consideration the tumor sidedness.

Colorectal Cancer Biomarkers in the Era of Personalized Medicine

The 5-year survival probability for patients with metastatic colorectal cancer has not drastically changed over the last several years, nor has the backbone chemotherapy in first-line disease. Nevertheless, newer targeted therapies and immunotherapies have been approved primarily in the refractory setting, which appears to benefit a small proportion of patients. Until recently, rat sarcoma (RAS) mutations remained the only genomic biomarker to assist with therapy selection in metastatic colorectal cancer. Next generation sequencing has unveiled many more potentially powerful predictive genomic markers of therapy response. Importantly, there are also clinical and physiologic predictive or prognostic biomarkers, such as tumor sidedness. Variations in germline pharmacogenomic biomarkers have demonstrated usefulness in determining response or risk of toxicity, which can be critical in defining dose intensity. This review outlines such biomarkers and summarizes their clinical implications on the treatment of colorectal cancer. It is critical that clinicians understand which biomarkers are clinically validated for use in practice and how to act on such test results.