Prognostic significance of extramural vascular invasion in T4 rectal cancer

Sub-region based histogram analysis of amide proton transfer-weighted MRI for predicting tumor budding grade in rectal adenocarcinoma: a prospective study

OBJECTIVE

To explore the sub-regional histogram features of amide proton transfer-weighted (APTw) MRI, compared with those of diffusion-weighted imaging (DWI), in predicting the tumor budding (TB) grade of rectal cancer (RC).

MATERIALS AND METHODS

This study prospectively enrolled 74 patients with pathologically confirmed RC, who underwent APTw MRI before surgery from July 2022 to March 2023. Hematoxylin-eosin staining was used for TB scoring. K-means clustering (K = 4-6) was applied to obtain multiple sub-regions (n = 3-5), and corresponding histogram features (including mean, standard deviation, minimum, maximum, and 10th, 25th, 50th, 75th, and 90th quantile) of APT and apparent diffusion coefficient (ADC) maps were extracted and filtered using stepwise regression.

RESULTS

When K = 5, the K-means clustering is four sub-regions, showing the best prediction for TB grade compared to K = 4 or 6. When K = 5, there were significantly higher histogram features of the APT map in sub-regions 3 and 4 in the high TB grade group compared to the low-intermediate TB grade group. Receiver operating characteristic (ROC) curve and internal validation suggested that the predictive efficiency of the model was highest when K = 5, with AUC, sensitivity, specificity, accuracy, and kappa values of 0.92, 93%, 71%, 87%, and 0.65, respectively. There were no significant differences in the histogram features of each sub-region in the ADC map (p > 0.05).

CONCLUSION

The sub-regional histogram features of APTw images can help to distinguish the heterogeneous regions of RC, which can be used to predict the TB grade of RC.

KEY POINTS

Question Can the sub-regional histogram features of APTw MRI predict the tumor budding (TB) grade of rectal cancer (RC)? Findings Differences exist in histogram features of APT map subregions between high and low-intermediate TB grade groups; subregions of the APT map have different predictive abilities. Clinical relevance APT-weighted imaging might outperform DWI in predicting TB grade in RC.

Application of a combined clinical prediction model based on enhanced T1-weighted image(T1WI) full volume histogram in peripheral nerve invasion (PNI) and lymphatic vessel invasion (LVI) in rectal cancer

PURPOSE

This study aims to use a combined clinical prediction model based on enhanced T1-weighted image(T1WI) full volume histogram to predict preoperative peripheral nerve invasion (PNI) and lymphatic vessel invasion (LVI) in rectal cancer.

METHODS

We included a total of 68 PNI patients and 80 LVI patients who underwent surgical resection and pathological confirmation of rectal cancer. According to the PNI/LVI status, patients were divided into PNI positive group (n = 39), the PNI negative group (n = 29), LVI positive group (n = 48), and the LVI negative group (n = 32). External validation included a total of 42 patients with nerve and vascular invasion in patients with surgically resected and pathologically confirmed rectal cancer at another healthcare facility, with a PNI positive group (n = 32) and a PNI-negative group (n = 10) as well as an LVI positive group (n = 35) and LVI-negative group (n = 7). All patients underwent 3.0T magnetic resonance T1WI enhanced scanning. We use Firevoxel software to delineate the region of interest (ROI), extract histogram parameters, and perform univariate analysis, LASSO regression, and multivariate logistic regression analysis in sequence to screen for the best predictive factors. Then, we constructed a clinical prediction model and plotted it into a column chart for personalized prediction. Finally, we evaluate the performance and clinical practicality of the model based on the area under curve (AUC), calibration curve, and decision curve.

RESULTS

Multivariate logistic regression analysis found that variance and the 75th percentile were independent risk factors for PNI, while maximum and variance were independent risk factors for LVI. The clinical prediction model constructed based on the above factors has an AUC of 0.734 (95% CI: 0.591-0.878) for PNI in the training set and 0.731 (95% CI: 0.509-0.952) in the validation set; The training set AUC of LVI is 0.701 (95% CI: 0.561-0.841), and the validation set AUC is 0.685 (95% CI: 0.439-0.932). External validation showed an AUC of 0.722 (95% CI: 0.565-0.878) for PNI; and an AUC of 0.706 (95% CI: 0.481-0.931) for LVI.

CONCLUSIONS

This study indicates that the combination of enhanced T1WI full volume histogram and clinical prediction model can be used to predict the perineural and lymphovascular invasion status of rectal cancer before surgery, providing valuable reference information for clinical diagnosis.

CMTM4 promotes the motility of colon cancer cells under radiation and is associated with an unfavorable neoadjuvant chemoradiotherapy response and patient survival in rectal cancer

Neoadjuvant chemoradiotherapy (nCRT) is the standard treatment for locally advanced rectal cancer (LARC). Pathological complete regression is closely linked to disease outcomes. However, biomarkers predicting nCRT response and patient survival are lacking for LARC. In the present study, the clinical characteristics and follow-up information of 228 patients with LARC were retrospectively collected. Immunohistochemistry (IHC), reverse transcription-quantitative PCR (RT-qPCR), Kaplan-Meier and multivariate analyses were used to evaluate the expression and predict the role of CKLF-like MARVEL transmembrane domain member 4 (CMTM4) in LARC. Additionally, lentiviral short hairpin (sh)RNA was used to interfere with CMTM4 expression. The phenotype of CMTM4-knockdown LoVo cells was determined by colony formation, migration and invasion assays under irradiation (IR) treatment. RNA-sequencing (RNA-seq) analysis was also used to explore the CMTM4-regulated genes in LoVo-shCMTM4 cells compared with control cells. RT-qPCR was then used to confirm the expression of these CMTM4-regulated genes. CMTM4 expression in pre-nCRT tissues indicated an unfavorable response and a short disease-free survival (DFS) with LARC. The expression of CMTM4 significantly increased following nCRT treatment. Additionally, CMTM4 knockdown increased the proliferation, migration and invasion of colon cancer cells; however, IR disrupted the cell migration and invasion induced by CMTM4 knockdown. RNA-seq analysis, the Tumor Immune Estimation Resource database and RT-qPCR indicated that CMTM4 was involved in different signaling pathways and regulated immune-related genes such as cluster of differentiation 66b, chemokine (CXC motif) ligand 8 (CXCL8) and programmed cell death 1. Furthermore, CXCL8 expression was found to be negatively associated with CMTM4 expression in patients with LARC by IHC and RT-qPCR. CXCL8 expression on invasion margin regions in post-operative tissues was also an inferior predictor of DFS in patients with LARC. In conclusion, CMTM4 may predict the nCRT response and outcomes in patients with LARC.

CapeOX as neoadjuvant chemotherapy for locally advanced rectal cancer: might less be more?

BACKGROUND

Locally advanced rectal cancer (LARC) poses unique challenges in treatment, with current neoadjuvant chemoradiotherapy (NA-CRT) showing limitations. The CapeOX regimen emerges as a potential less aggressive neoadjuvant chemotherapy (NAC) for LARC.

METHODS

We conducted a retrospective study involving treatment-naïve patients with LARC from March 2014 to March 2021 who received 2-4 cycles of CapeOX NAC followed by radical surgery. Treatment response was evaluated using tumor regression grade (TRG), MRI-based TRG (MRI-TRG), and Neoadjuvant Rectal (NAR) score.

RESULTS

94.7% of patients experienced symptom improvement and 96.4% achieved sphincter-preserving surgery. Post-NAC showed significant tumor regression and MRI confirmed a tumor length reduction (P < 0.001). Clinical and pathological staging discrepancies post-NAC suggest broader therapeutic advantages. 5-year overall and disease-free survival rates were 78.4% and 73.4%. NAR scores provided better prognostic accuracy than MRI-TRG.

CONCLUSION

CapeOX NAC presents notable benefits for LARC patients and its clinical significance may be underestimated. The NAR score demonstrates superior prognostic value over MRI-TRG.

MicroRNA Expression Profiling Predicts Nodal Status and Disease Recurrence in Patients Treated with Curative Intent for Colorectal Cancer

Background: Approximately one-third of colorectal cancer (CRC) patients will suffer recurrence. MiRNAs are small non-coding RNAs that play important roles in gene expression. We aimed to correlate miRNA expression with aggressive clinicopathological characteristics and survival outcomes in CRC. Methods: Tumour samples were extracted from 74 CRC patients. MiRNAs were quantified using real-time reverse transcriptase polymerase chain reaction. Descriptive statistics and Cox regression analyses were performed to correlate miRNA targets with clinicopathological and outcome data. Results: Aberrant miR-21 and miR-135b expression correlate with increased nodal stage (p = 0.039, p = 0.022). Using univariable Cox regression analyses, reduced miR-135b (β-coefficient −1.126, hazard ratio 0.324, standard error (SE) 0.4698, p = 0.017) and increased miR-195 (β-coefficient 1.442, hazard ratio 4.229, SE 0.446, p = 0.001) predicted time to disease recurrence. Survival regression trees analysis illustrated a relative cut-off of ≤0.488 for miR-195 and a relative cut-off of >−0.218 for miR-135b; both were associated with improved disease recurrence (p < 0.001, p = 0.015). Using multivariable analysis with all targets as predictors, miR-195 (β-coefficient 3.187, SE 1.419, p = 0.025) was the sole significant independent predictor of recurrence. Conclusion: MiR-195 has strong value in predicting time to recurrence in CRC patients. Additionally, miR-21 and miR-135b predict the degree nodal burden. Future studies may include these findings to personalize therapeutic and surgical decision making.

Nomogram for predicting occurrence of synchronous liver metastasis in colorectal cancer: a single-center retrospective study based on pathological factors

Purpose

The purpose of this study was to explore the risk factors for synchronous liver metastasis (LM) of colorectal cancer (CRC) and to construct a nomogram for predicting the occurrence of synchronous LM based on baseline and pathological information.

Methods

The baseline and pathological information of 3190 CRC patients were enrolled in the study from the Department of Colorectal Surgery, the Second Affiliated Hospital of Harbin Medical University between 2012 and 2020. All patients were divided into development and validation cohorts with the 1:1 ratio. The characters of LM and none-LM patients in newly diagnosed colorectal cancer were utilized to explore the risk factors for synchronous LM with the univariate and multivariate logistic regression analyses. A predictive nomogram was constructed by using an R tool. In addition, receiver operating characteristic (ROC) curves was calculated to describe the discriminability of the nomogram. A calibration curve was plotted to compare the predicted and observed results of the nomogram. Decision-making curve analysis (DCA) was used to evaluate the clinical effect of nomogram.

Results

The nomogram consisted of six features including tumor site, vascular invasion (VI), T stage, N stage, preoperative CEA, and CA-199 level. ROC curves for the LM nomogram indicated good discrimination in the development (AUC = 0.885, 95% CI 0.854–0.916) and validation cohort (AUC = 0.857, 95% CI 0.821–0.893). The calibration curve showed that the prediction results of the nomogram were in good agreement with the actual observation results. Moreover, the DCA curves determined the clinical application value of predictive nomogram.

Conclusions

The pathologic-based nomogram could help clinicians to predict the occurrence of synchronous LM in postoperative CRC patients and provide a reference to perform appropriate metastatic screening plans and rational therapeutic options for the special population.

Prognostic Significance of EMVI in Rectal Cancer in a Tertiary Cancer Hospital in India

Background  Presence of extramural venous invasion (EMVI) is a poor prognostic factor for rectal cancer as per literature. However, India-specific data are lacking. Aim  The aim of the study is to determine the prognostic significance of EMVI in locally advanced rectal cancer on baseline MRI. Materials and Methods  We retrospectively reviewed 117 MRIs of operable non-metastatic locally advanced rectal cancers in a tertiary cancer institute. Three dedicated oncoradiologists determined presence or absence of EMVI, and its length and thickness, in consensus. These patients were treated as per standard institutional protocols and followed up for a median period of 37 months (range: 2-71 months). Kaplan-Meier curves (95% CI) were used to determine disease-free survival (DFS), distant-metastases free survival (DMFS), and overall survival (OS). Univariate analysis was performed by comparing groups with log-rank test. Results  EMVI positive cases were 34/114 (29%). More EMVI-positive cases developed distant metastasis compared with EMVI-negative cases (14/34-41% vs. 22/83-26%). The difference, however, was not statistically significant ( p  = 0.146). After excluding signet-ring cell cancers ( n  = 14), EMVI showed significant correlation with DMFS ( p  = 0.046), but not with DFS or OS. The median thickness and length of EMVI was 6 and 14 mm, respectively in patients who developed distant metastasis, as compared with 5 and 11 mm in those who did not, although this difference was not statistically significant. Conclusion  EMVI is a predictor of distant metastasis in locally advanced non-metastatic, non-signet ring cell rectal cancers. EMVI can be considered another high-risk feature to predict distant metastasis.

Risk of nodal disease in patients with MRI-detected extramural vascular invasion in rectal cancer: a systematic review and meta-analysis

BACKGROUND

The impact of magnetic resonance imaging-detected extramural vascular invasion (mrEMVI) in distant metastasis is well known but its correlation with prevalence of lymph node metastasis is less studied. The aim of this systematic review and meta-analysis was to assess the prevalence of nodal disease in mrEMVI-positive and negative cases in rectal cancer.

METHODS

Following guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analyses, a systematic literature search in PubMed, Web of Science, Cochrane Library, and EMBase was carried out to identify relevant studies published up to May 2019.

RESULTS

Our literature search generated 10 studies (863 and 1212 mrEMVI-positive and negative patients, respectively). The two groups (mrEMVI-positive and negative) were significantly different in terms of nodal disease status (odds ratio [OR] 3.15; 95% confidence interval [CI] 2.12-4.67; p < 0.001). The prevalence of nodal disease was 75.90% vs 52.56% in the positive mrEMVI vs negative mrEMVI group, respectively (p < 0.001). The prevalence of positive lymph node in positive mrEMVI patients treated with neoadjuvant/adjuvant chemoradiotherapy (nCRT/CRT) (OR 2.47; 95% CI 1.65-3.69; p < 0.001) was less compared with the patients who underwent surgery alone (OR 6.25; 95% CI 3.74-10.44; p < 0.001).

CONCLUSION

The probability of positive lymph nodes in cases of positive mrEMVI is distinctly greater compared with negative cases in rectal cancer. Positive mrEMVI indicates risk of nodal disease prevalence increased by threefold in rectal cancer.

A nomogram to predict vascular invasion before resection of colorectal cancer

Vascular invasion (VI) is an important feature for systemic recurrence and an indicator for the application of adjuvant therapy in colorectal cancer (CRC). Preoperative knowledge of VI is important in determining whether adjuvant therapy is necessary, as well as the adequacy of surgical resection. In the present study, a predictive nomogram for VI in patients with CRC was constructed. The prediction model consisted of 664 eligible patients with CRC, who were divided into a training set (n=468) and a validation set (n=196). Data were collected between August 2013 and April 2018. The feature selection model was established using the least absolute shrinkage and selection operator regression model. Multivariable logistic regression analysis was used to construct the predictive nomogram. The performance of the nomogram was evaluated by calibration, discrimination and clinical usefulness. Differentiation, computed tomography (CT)-based on N stage (CT N stage), hemameba and tumor distance from the anus (cm) were integrated into the nomogram. The nomogram exhibited good discrimination, with an area under the curve (AUC) of 0.731 and good calibration. Application of the nomogram in the validation cohort showed acceptable discrimination, with an AUC of 0.710 and good calibration. Decision curve analysis revealed that the nomogram was clinically useful. These findings suggests, to the best of our knowledge, that this may be the first nomogram for individual preoperative prediction of VI in patients with CRC, which may promote preoperative optimization strategies for this selected group of patients.

Early MRI predictors of disease-free survival in locally advanced rectal cancer from the GRECCAR 4 trial

BACKGROUND

Tailored neoadjuvant treatment of locally advanced rectal cancer (LARC) may improve outcomes. The aim of this study was to determine early MRI prognostic parameters with which to stratify neoadjuvant treatment in patients with LARC.

METHODS

All patients from a prospective, phase II, multicentre randomized study (GRECCAR4; NCT01333709) were included, and underwent rectal MRI before treatment, 4 weeks after induction chemotherapy and after completion of chemoradiotherapy (CRT). Tumour volumetry, MRI tumour regression grade (mrTRG), T and N categories, circumferential resection margin (CRM) status and extramural vascular invasion identified by MRI (mrEMVI) were evaluated.

RESULTS

A total of 133 randomized patients were analysed. Median follow-up was 41·4 (95 per cent c.i. 36·6 to 45·2) months. Thirty-one patients (23·3 per cent) developed tumour recurrence. In univariable analysis, mrEMVI at baseline was the only prognostic factor associated with poorer outcome (P = 0·015). After induction chemotherapy, a larger tumour volume on MRI (P = 0·019), tumour volume regression of 60 per cent or less (P = 0·002), involvement of the CRM (P = 0·037), mrEMVI (P = 0·026) and a poor mrTRG (P = 0·023) were associated with poor outcome. After completion of CRT, the absence of complete response on MRI (P = 0·004), mrEMVI (P = 0·038) and a poor mrTRG (P = 0·005) were associated with shorter disease-free survival. A final multivariable model including all significant variables (baseline, after induction, after CRT) revealed that Eastern Cooperative Oncology Group performance status (P = 0·011), sphincter involvement (P = 0·009), mrEMVI at baseline (P = 0·002) and early tumour volume regression of 60 per cent or less after induction (P = 0·007) were associated with relapse.

CONCLUSION

Baseline and early post-treatment MRI parameters are associated with prognosis in LARC. Future preoperative treatment should stratify treatment according to baseline mrEMVI status and early tumour volume regression.

Impact of intramural and extramural vascular invasion on stage II-III colon cancer outcomes

BACKGROUND AND OBJECTIVES

Vascular invasion, in particular extramural venous invasion (EMVI), is a pathologic characteristic that has been extensively studied in rectal cancer but rarely in colon cancer. This study aims to evaluate its prognostic role in stage II-III colon cancer.

METHODS

All stage II-III colon cancer patients who underwent surgery between 2004 and 2015 were reviewed. We compared patients without invasion, with intramural invasion only (IMVI), EMVI only, and both IMVI/EMVI (n = 923).

RESULTS

EMVI was associated with other high-risk features, including T4, N+ disease, lymphatic, and perineural invasion (P < 0.001). EMVI+ patients had higher rates of locoregional and distant recurrence and subsequently disease-specific mortality (stage-II, odds ratio [OR] 3.64; P = 0.001; stage-III OR, 1.94; P = 0.009), whereas outcomes were comparable between IMVI and no vascular invasion (OR, 1.21; P = 0.764; OR, 1.28, P = 0.607, respectively). The adjusted HRs for EMVI+ patients on disease-free survival, and disease-specific survival were 2.07 ( P < 0.001) and 1.67 ( P = 0.027), respectively. Moreover, EMVI+ stage-II patients fared worse than EMVI- stage-III patients, even after adjusting for adjuvant chemotherapy.

CONCLUSION

EMVI is a strong predictor for worse oncologic outcomes in stage II-III colon cancer patients, whereas IMVI is not. It is also associated with worse outcomes compared in patients with higher stage disease who are EMVI negative.

The impact of rectal cancer tumor height on recurrence rates and metastatic location: A competing risk analysis of a national database

BACKGROUND

The impact of rectal cancer tumor height on local recurrence and metastatic spread is unknown. The objective was to evaluate the impact of rectal cancer tumor height from the anal verge on metastatic spread and local recurrence patterns.

METHODS

The Norwegian nationwide surgical quality registry was reviewed for curative rectal cancer resections from 1/1/1996-12/15/2006. Cancers were stratified into five height groups: 0-3 cm, >3-5 cm, >5-9 cm, >9-12 cm, 12 cm-HI. Competing risk and proportional hazards models assessed the relationship between tumor height and patterns of metastasis and survival.

RESULTS

6859 patients were analyzed. After median follow-up of 52 months (IQR 20-96), 26.7% (n = 1835) experienced recurrence. With tumors >12 cm, the risk of liver metastases increased (crude HR 1.49, p = 0.03), while lung metastases decreased (crude HR 0.66, p = 0.03), and risk of death decreased (crude HR 0.81, p = 0.001) The cumulative incidence of pelvic recurrence were highest for the low tumors (p = 0.01). Median time to liver metastases was 14months (IQR 7-24), lung metastases 25months (IQR 13-39), pelvic recurrence 19months (IQR10-32), (p < 0.0001). Time to metastases in liver and lungs were significantly associated with tumor height (p < 0.001) CONCLUSION: There are distinct differences in metastatic recurrence patterns and time to recurrence from different anatomic areas of the rectum. In crude analyses, tumor height impacted metastatic spread to the liver and lungs. However, when adjusting for treatment variables, the hazard of metastatic spread to the liver and lungs are limited. Nevertheless, time to metastases in liver and lungs is significantly impacted by tumor height. Venous drainage of the rectal cancer may be a significant contributor of rectal cancer metastatic spread, but further research is warranted.

Extramural vascular invasion detected by contrast-enhanced multiple-row detectors computed tomography (ceMDCT) as a predictor of synchronous metastases in colon cancer

Background

Extramural Vascular Invasion (EMVI) is histologically defined as the presence of tumor cells beyond the muscularis propria in vessels resulting in disease metastases.

Objective

To determine whether EMVI, detected by contrast-enhanced multiple-row detectors computed tomography (MDCT), has closely association with synchronous metastases in colon cancer.

Methods

Patients with pathology proven colon cancer were included in this retrospective study. Preoperative imaging status, including Extramural tumor depth, Lymph nodes, tumor location, and ctEMVI status, were defined on MDCT. Postoperative pathological tumor stage, lymph node stage, and tumor differentiation, were defined in accordance with the American Joint Committee on Cancer (AJCC) 7^th Edition. Synchronous metastases were detected on follow-up MDCT 3 months after initial diagnosis or by surgery, if available. Associations between ctEMVI and other preoperative and postoperative factors were analyzed using Chi-squared tests. Logistic regression analyses were performed to analyze the preoperative and postoperative factors of synchronous metastases in colon cancer.

Results

ctEMVI was observed in 96 patients (96/241, 39.8%). The presence of ctEMVI varied significantly depending on ctEMD (χ2 = 66.557, P<0.001), lymph nodes status on MDCT (χ2 =24.533, P=0.001), pathological tumor status (χ2 = 36.267, P <0.001) and pathological lymph nodes status analyses (χ2 =32.103, P <0.001). Synchronous metastases were seen in 36 patients (36/96, 37.5%) with ctEMVI and 11 (11/145, 7.6%) patients without ctEMVI. The incidence of synchronous metastases was significantly higher in the cohort of positive ctEMVI with odds ratio (OR) of 7.309 (95% CI 3.485∼15.330, P<0.001). Positive ctEMVI (Odds ratio 4.654, 95%CI: 1.987∼10.898, P <0.001) and ctEMD larger than 5 mm (Odds ratio 2.654, 95%CI: 1.116∼6.309, P =0.027) were demonstrated to be significant preoperative factors in predicting synchronous metastases.

Conclusion

MDCT-detected EMVI could be used as a preoperative factor to predict synchronous metastases in colon cancer.

A meta-analysis comparing the risk of metastases in patients with rectal cancer and MRI-detected extramural vascular invasion (mrEMVI) vs mrEMVI-negative cases

BACKGROUND

Pathological extramural vascular invasion (EMVI) is an independent prognostic factor in rectal cancer, but can also be identified on MRI-detected extramural vascular invasion (mrEMVI). We perform a meta-analysis to determine the risk of metastatic disease at presentation and after surgery in mrEMVI-positive patients compared with negative tumours.

METHODS

Electronic databases were searched from January 1980 to March 2016. Conventional meta-analytical techniques were used to provide a summative outcome. Quality assessment of the studies was performed.

RESULTS

Six articles reported on mrEMVI in 1262 patients. There were 403 patients in the mrEMVI-positive group and 859 patients in the mrEMVI-negative group. The combined prevalence of mrEMVI-positive tumours was 0.346(range=0.198-0.574). Patients with mrEMVI-positive tumours presented more frequently with metastases compared to mrEMVI-negative tumours (fixed effects model: odds ratio (OR)=5.68, 95% confidence interval (CI) (3.75, 8.61), z=8.21, df=2, P<0.001). Patients who were mrEMVI-positive developed metastases more frequently during follow-up (random effects model: OR=3.91, 95% CI (2.61, 5.86), z=6.63, df=5, P<0.001).

CONCLUSIONS

MRI-detected extramural vascular invasion is prevalent in one-third of patients with rectal cancer. MRI-detected extramural vascular invasion is a poor prognostic factor as evidenced by the five-fold increased rate of synchronous metastases, and almost four-fold ongoing risk of developing metastases in follow-up after surgery.

Lymphovascular and perineural invasion in stage II rectal cancer: a report from the Swedish colorectal cancer registry

BACKGROUND

Adjuvant chemotherapy for stage II and III rectal cancer patients is a matter of discussion. The aim of the present study was to evaluate the prognostic value of lymphovascular (LVI) and perineural (PNI) invasion in stage II rectal cancer on a national level.

MATERIALS AND METHODS

Clinico-pathological factors associated with disease-free survival (DFS) and time to recurrence in stage II rectal cancer patients were analyzed from patient data registered in the Swedish Colorectal Cancer Registry between 2006 and 2012.

RESULTS

Of 2649 patients with TNM stage II disease, 1395 (53%) received preoperative radiotherapy and 456 (17%) preoperative chemoradiotherapy. LVI and PNI were detected in 387 (15%) and 269 (10%) patients, respectively. Adjuvant chemotherapy was planned in 14%, but more often if LVI or PNI was detected (25% and 31%, respectively, p < .001 for both). The three-year DFS and time to recurrence were 78% and 17%, respectively. Both LVI and PNI indicated worse outcome. In patients not receiving postoperative chemotherapy, the risks of recurrence after three years were 20% if LVI was seen and 22% if PNI was detected (p < .001 for both). In the absence of LVI and PNI, it was 13% and 12%, respectively. In a multivariate Cox regression analysis, patients with LVI (hazard ratio 1.44, 95% CI 1.09-1.90; p = .011) and PNI (hazard ratio 1.80, 95% CI 1.34-2.43, p < .001) had significantly increased risks of recurrence.

CONCLUSIONS

Stage II rectal cancer patients with LVI and PNI have an increased risk of recurrence which emphasizes the need to properly evaluate the role of adjuvant chemotherapy particularly in these subgroups.

Prognostic significance of computed tomography-detected extramural vascular invasion in colon cancer

AIM: To compare disease-free survival (DFS) between extramural vascular invasion (EMVI)-positive and -negative colon cancer patients evaluated by computed tomography (CT).

METHODS: Colon cancer patients (n = 194) undergoing curative surgery between January 2009 and December 2013 were included. Each patient’s demographics, cancer characteristics, EMVI status, pathological status and survival outcomes were recorded. All included patients had been routinely monitored until December 2015. EMVI was defined as tumor tissue within adjacent vessels beyond the colon wall as seen on enhanced CT. Disease recurrence was defined as metachronous metastases, local recurrence, or death due to colon cancer. Kaplan-Meier analyses were used to compare DFS between the EMVI-positive and -negative groups. Cox’s proportional hazards models were used to measure the impact of confounding variables on survival rates.

RESULTS: EMVI was observed on CT (ctEMVI) in 60 patients (30.9%, 60/194). One year after surgery, there was no statistically significant difference regarding the rates of progressive events between EMVI-positive and -negative patients [11.7% (7/60) and 6.7% (9/134), respectively; P = 0.266]. At the study endpoint, the EMVI-positive patients had significantly more progressive events than the EMVI-negative patients [43.3% (26/60) and 14.9% (20/134), respectively; odds ratio = 4.4, P < 0.001]. Based on the Kaplan-Meier method, the cumulative 1-year DFS rates were 86.7% (95%CI: 82.3-91.1) and 92.4% (95%CI: 90.1-94.7) for EMVI-positive and EMVI-negative patients, respectively. The cumulative 3-year DFS rates were 49.5% (95%CI: 42.1-56.9) and 85.8% (95%CI: 82.6-89.0), respectively. Cox proportional hazards regression analysis revealed that ctEMVI was an independent predictor of DFS with a hazard ratio of 2.15 (95%CI: 1.12-4.14, P = 0.023).

CONCLUSION: ctEMVI may be helpful when evaluating disease progression in colon cancer patients.

Prognostic value of lymph node ratio and extramural vascular invasion on survival for patients undergoing curative colon cancer resection

Background:

Increasing lymph node ratio (LNR) (ratio of metastatic lymph nodes to the total number of harvested lymph nodes) and extramural vascular invasion (EMVI) have been proposed as adverse prognostic indicators in colorectal cancer, although their use remains variable and controversial. The aim of the present study was to assess the prognostic value of LNR and EMVI in predicting survival for patients undergoing curative colon cancer resection.

Methods:

Between 2006 and 2012, 922 patients underwent curative colon cancer resection. Surgical technique and pathological assessment did not change during the study period. Clinical and pathological data were collected from a prospectively maintained database. The primary outcome measure was overall survival and disease-free survival. LNR was separated into five categories based on three previously calculated cutoff values: LNR 0 (no lymph nodes involved), LNR 1 (ratio 0.01<0.17), LNR 2 (ratio 0.18–0.41), LNR 3 (ratio 0.42–0.69), and LNR 4 (ratio >0.70).

Results:

Nine hundred and twenty-two patients underwent colon cancer resection. The median follow-up for survivors was 52.8 months (IQR 34.6–77.6). The median total number of lymph nodes harvested was 16 (IQR13-22). On multivariate analysis, both pN and LNR were strongly associated with overall and disease-free survival. Using the Akaike information criterion (AIC), LNR had greater prognostic value compared with pN. For overall survival, compared with patients in LNR category 0, hazard ratios (95% CI) for those in categories 1, 2, 3 and 4 were 1.37 (1.03,1.82), 2.37 (1.70,3.30), 2.40 (1.57,3.65) and 5.51 (3.16,9.58), respectively. For disease-free survival, patients had hazard ratios (95% CI) of 1.78 (1.25,2.52), 3.79 (2.56,5.61), 2.60 (1.50,4.48) and 4.76 (2.21,10.27), respectively. The presence of EMVI was a significant predictor of decreased overall and disease-free survival (P<0.001).

Conclusions:

This study demonstrated, in the presence of high surgical, oncology and pathological standards, EMVI and increasing LNR were independent predictors of decreased overall and disease-free survival for patients undergoing curative colon cancer resection. LNR was superior to pN stage in predicting overall and disease-free survival.

Factors affecting sphincter-preserving resection treatment for patients with low rectal cancer

The aim of the present study was to identify the factors associated with the use of sphincter-preserving resection (SPR) surgery for the treatment of low rectal cancer. A total of 330 patients with histopathologically confirmed low rectal cancer were divided into two groups, namely the abdominoperineal resection (APR) and sphincter-preserving (SP) groups. For SPR factor analysis, the χ² test was performed as the univariate analysis, while a logistic regression test was conducted as the multivariate analysis. Of the 330 patients, 192 cases (58.18%) received SPR surgery and 138 cases (41.82%) underwent an APR. Univariate analysis results revealed that the sphincter-preserving factor was significantly associated with age, gender, ethnicity, body mass index (BMI), total infiltrated circumference, distance of the tumor from the anal verge (DTAV), depth of invasion and tumor grade (P<0.05). However, there were no statistically significant associations with family medical history, diabetes history, venous tumor embolism, growth type, tumor length, lymphatic metastasis and level of preoperative carcinoembryonic antigen (P>0.05). Multivariate analysis indicated that the sphincter-preserving factor was strongly associated with DTAV and the depth of invasion, with significant statistical difference (P<0.05). Therefore, selecting SPR surgery for patients with low rectal cancer is dependent on age, gender, ethnicity, BMI, the total infiltrated circumference, DTAV, depth of invasion and tumor grade. In addition, DTAV and the depth of invasion are independent risk factors for the selection of SPR surgery.

Does rectal cancer height influence the oncological outcome?

AIM

The influence of the height of rectal cancer from the anal verge on the oncological outcome is controversial. This study aimed to determine the influence of the height of the tumour on the survival of patients treated in a specialized rectal cancer unit.

METHOD

Patients undergoing surgery for primary rectal cancer from 2006 to 2013 were identified from a prospectively maintained rectal cancer database. Those requiring total or multicompartmental pelvic exenteration were excluded. Low cancer was defined as tumour < 5 cm from the anal verge, as assessed by endoscopy and/or digital rectal examination. The primary outcome was 3-year disease-free survival (DFS).

RESULTS

Of 340 patients, 203 (59.7%) had low cancer. There were 302 (89%) restorative and 38 (11%) nonrestorative procedures. The rate of positive circumferential resection margin was similar for low compared with high cancer (3.4% vs 2.9%, P = 1.0) and for restorative compared with nonrestorative procedures in low cancer only (3.0% and 5.3%, P = 0.619). Low compared with high anterior resection was associated with increased anastomotic leakage (8.5% vs 2.2%, P = 0.023). Three-year DFS was similar for low and high resection (82% vs 86%, P = 0.305) and between restorative vs nonrestorative procedures in low cancer only (88% vs 77%, P = 0.215). In an adjusted model, low height did not lead to worse survival outcome (3-year DFS hazard ratio 0.54, 95% CI 0.24-1.24, P = 0.147).

CONCLUSION

With careful planning and a multidisciplinary approach, equivalent oncological outcome can be achieved for patients with rectal cancer who undergo curative surgery regardless of differences in tumour characteristics, location and operation performed.