Accuracy of Preoperative Local Staging of Primary Colorectal Cancer by Using Computed Tomography: Reappraisal Based on Data Collected at a Highly Organized Cancer Center

Stenting as bridge to surgery versus upfront emergency resection for non-metastatic left sided obstructing colorectal cancer: risk of peritoneal recurrence and long-term outcomes

BACKGROUND

Oncological outcomes of stenting as a bridge to surgery (SBTS) remain a major concern, despite perioperative benefits it offers. This study aims to evaluate the differences in recurrence patterns and survival in patients with non-metastatic, obstructing left sided colon cancers treated by SBTS versus upfront emergency surgery (ES).

METHODS

This is a retrospective, single-centre cohort study of 227 consecutive patients with non-metastatic, obstructing left sided colon cancer between 2007 and 2016. Primary outcomes were pattern of recurrence, and survival. Univariate, bivariate and multivariate logistic regression were done to determine relationships between factors and recurrence. Kaplan Meier curves and log rank tests were used to analyse survival outcomes.

RESULTS

Of the 227 patients included, 62 underwent SBTS and 165 underwent upfront ES. There was a higher rate of peritoneal recurrence in SBTS group (27.4 vs 15.2% p = 0.034), with no difference observed in overall, liver or lung recurrences. No significant difference in overall survival (p = 0.11), cancer specific survival (p = 0.35), or recurrence free survival (p = 0.107) was observed. Univariate analysis showed that SBTS (OR 2.12, p = 0.036), diabetes mellitus (DM) (OR 2.58, p = 0.013), T4 (OR 2.81, p = 0.001), N + (OR 4.02, p = 0.001), lymphovascular invasion (OR 2.43, p = 0.011) contributed to a higher rate of peritoneal recurrence. Bivariate analysis showed synergistic relationship between T4 tumors and SBTS: in T4 tumors that underwent SBTS, the odds of having peritoneal recurrence was 6.8 times higher when compared to ES (p = 0.004); whilst in T2/3 tumors there was no significant difference observed (OR 1.33, p = 0.55). Multivariable analysis showed SBTS (OR 2.60, p = 0.04), DM (OR 2.88, p = 0.012), N + (OR 2.97, p = 0.026) were significant predictors for peritoneal recurrence.

CONCLUSIONS

There are concerns over oncological safety of SBTS even with low rates of stent-related perforation. Higher rates of peritoneal recurrence are seen especially with T4 colon cancers treated with SBTS. SBTS, DM and nodal stage were significant predictors for peritoneal recurrence.

Do Laparoscopic Approaches Ensure Oncological Safety and Prognosis for Serosa-Exposed Colon Cancer? A Comparative Study against the Open Approach

The adoption of laparoscopic surgery in the management of serosa-exposed colorectal cancer has raised concerns. This study aimed to investigate whether laparoscopic surgery is associated with an increased risk of postoperative recurrence in patients undergoing resection for serosa-exposed colon cancer. A retrospective analysis was conducted on a cohort of 315 patients who underwent curative resection for pathologically confirmed T4a colon cancer without distant metastases at the Asan Medical Center between 2006 and 2015. Patients were categorized according to the surgical approach method: laparoscopic surgery (MIS group) versus open surgery (Open group). Multivariate analysis was employed to identify risk factors associated with overall survival (OS) and disease-free survival (DFS). The MIS group included 148 patients and the Open group had 167 patients. Of the total cohort, 106 patients (33.7%) experienced recurrence during the follow-up period. Rates, patterns, and time to recurrence were not different between groups. The MIS group (55.8%) showed more peritoneal metastasis compared to the Open group (44.4%) among recurrence sites, but it was not significant (p = 0.85). There was no significant difference in the five-year OS (73.5% vs. 78.4% p = 0.374) or DFS (62.0% vs. 64.6%; p = 0.61) between the Open and MIS groups. Age and the pathologic N stage were independently associated with OS, and the pathologic N stage was the only associated risk factor for DFS. The laparoscopic approach for serosa-exposed colon cancer did not compromise the DFS and OS. This study provides evidence that laparoscopic surgery does not compromise oncologic outcomes of patients with T4a colon cancer although peritoneal seeding is the most common type of disease failure of serosa-exposed colon cancer.

The impact of myosteatosis on outcomes following surgery for gastrointestinal malignancy: a meta-analysis

INTRODUCTION

The aim of this review was to evaluate the impact of preoperative myosteatosis on long-term outcomes following surgery for gastrointestinal malignancy.

METHODS

We conducted a systematic search of the electronic information sources, including PubMed MEDLINE, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), CINAHL and AMED. Studies were included if they reported the impact of preoperatively defined myosteatosis, or a similar term, on long-term survival outcomes following surgery for gastrointestinal malignancy. A subgroup analysis was performed for those studies reporting outcomes for colorectal cancer patients only.

FINDINGS

Thirty-nine full-text articles were reviewed for inclusion, with 19 being retained after the inclusion criteria were applied. The total number of included patients across all studies was 14,481. Patients with myosteatosis had significantly poorer overall survival, according to univariate (hazard ratio (HR) 1.82, 95% confidence interval (CI) 1.67-1.99) and multivariable (HR 1.66, 95% CI 1.49-1.86) analysis. This was also demonstrated for cancer-specific survival (univariate HR 1.62, 95% CI 1.18-2.22; multivariable HR 1.73, 95% CI 1.48-2.03) and recurrence-free survival (univariate HR 1.28, 95% CI 1.10-1.48; multivariable HR 1.38, 95% CI 1.07-1.77).

CONCLUSIONS

This meta-analysis demonstrates that patients with preoperative myosteatosis have poorer long-term survival outcomes following surgery for gastrointestinal malignancy. Therefore, myosteatosis should be used for preoperative optimisation and as a prognostic tool before surgery. More standardised definitions of myosteatosis and further cohort studies of patients with non-colorectal malignancies are required.

Intelligent diagnosis value of preoperative T staging of colorectal cancer based on MR medical imaging

Colorectal cancer is a common malignant tumor in clinic. With the change of people's diet, living environment and living habits, the incidence of colorectal cancer has risen sharply in recent years, which poses a great threat to people's health and quality of life. This paper aims to investigate the pathogenesis of colorectal cancer and improve the efficiency of clinical diagnosis and treatment. This paper firstly introduces MR Medical imaging technology and related theories of colorectal cancer through literature survey, and then applies MR technology to preoperative T staging of colorectal cancer. 150 patients with colorectal cancer admitted to our hospital every month from January 2019 to January 2020 were used as research objects to carry out the application experiment of MR Medical imaging in the intelligent diagnosis of preoperative T staging of colorectal cancer, and to explore the diagnostic sensitivity, specificity and histopathological T staging diagnosis coincidence rate of MR Staging. The final study results showed that there was no statistical significance in the general data of stage T1-2, T3 and T4 patients (p > 0.05); for patients with preoperative T stage of colorectal cancer, the overall diagnosis coincidence rate of MR Was 89.73%, indicating that it was highly consistent with pathological T stage; compared with MR Staging, the overall diagnosis coincidence rate of CT for preoperative T staging of colorectal cancer patients was 86.73%, which was basically consistent with the diagnosis of pathological T staging. At the same time, three different dictionary learning depth techniques are proposed in this study to solve the shortcomings of long MR Scanning time and slow imaging speed. Through performance testing and comparison, it is found that the structural similarity of MR Image reconstructed by depth dictionary method based on convolutional neural network is up to 99.67%, higher than that of analytic dictionary and synthetic dictionary, which proves that it has the best optimization effect on MR Technology. The study indicated the importance of MR Medical imaging in preoperative T staging diagnosis of colorectal cancer and the necessity of its popularization.

Long-term outcomes of D2 vs. D3 lymph node dissection for cT2N0M0 colorectal cancer: a multi‑institutional retrospective analysis

BACKGROUND

According to Japanese guidelines, D2 or D3 lymph node dissection (LND) is indicated for cT2N0M0 colorectal cancer (CRC). In this study, we retrospectively compared the long-term outcomes between D2 and D3 LND among patients with cT2N0M0 CRC.

METHODS

Our sample included 515 patients from the Japanese Study Group for Postoperative Follow-Up of Colorectal Cancer database, who underwent surgical resection for cT2N0M0 CRC between January 2009 and December 2012, 195 (37.9%) of whom underwent D2 LND and 320 (62.1%) D3 LND. The D2 and D3 groups were retrospectively compared in terms of long-term outcomes including overall survival (OS) and relapse-free survival (RFS). The prognostic factors for these outcomes were also evaluated.

RESULTS

The D2 group had significantly older patients and higher proportion of men than the D3 group. The rates of OS (5-year OS; 94.8% in the D3 group vs. 93.4% in the D2 group, p = 0.38) and RFS (5-year RFS; 89.3% in the D3 group vs. 89.1% in the D2 group, p = 0.91) were comparable for both groups. On multivariate analysis, age ≥ 80 years was significantly associated with poor OS. The extent of LND was not associated with either OS or RFS. Long-term outcomes were similar between the two groups, independent of tumor location.

CONCLUSION

The long-term outcomes did not differ between the D2 and D3 groups and the extent of LND was not associated with prognosis for cT2N0M0 CRC. Therefore, D2 LND may be sufficient for cT2N0N0 CRC treatment.

Colon cancer CT staging according to mismatch repair status: Comparison and suggestion of imaging features for high-risk colon cancer

BACKGROUND

Neoadjuvant treatment with either chemotherapy or immunotherapy is gaining momentum in colon cancers (CC). To reduce over-treatment, increasing staging accuracy using computed tomography (CT) is of high importance.

PURPOSE

To assess and compare CT imaging features of CC between mismatch repair-proficient (pMMR) and MMR-deficient (dMMR) tumours and identify CT features that can distinguish high-risk (pT3-4, N+) CC according to MMR status.

METHODS

Primary staging CTs of 266 patients who underwent primary surgical resection of a colon tumour were retrospectively and independently evaluated by two radiologists. Logistic regression analysis was performed to identify significant associations between imaging features and positive lymph node status. Receiver operating characteristic (ROC) curves of significantly associated features were assessed and validated in an external cohort of 104 patients.

RESULTS

Among pT3 tumours only, dMMR CC were significantly larger than pMMR CC in both length and thickness (length 59.39 ± 26.28 mm versus 48.70 ± 23.72, respectively, p = 0.031; thickness 20.54 mm ± 11.17 versus 16.34 ± 8.73, respectively, p = 0.027). For pMMR tumours, nodal internal heterogeneity on CT was significantly associated with a positive lymph node status (odds ratio (OR) = 2.66, p = 0.027), while for dMMR tumours, the largest short diameter of the nodes was associated with lymph node status (OR = 2.01, p = 0.049). The best cut-off value of the largest short diameter of involved nodes was 10.4 mm for dMMR and 7.95 mm for pMMR. In the external validation cohort, AUCs for predicting involved nodes based on the largest short diameter was 0.764 for dMMR tumours using 10 mm size cut-off and 0.624 for pMMR tumours using 7 mm cut-off.

CONCLUSION

These data show that CT imaging features of primary CC differ between dMMR and pMMR tumours, suggesting that the assessment of CT-based CC staging should take MMR status into consideration, especially for lymph node status, and thus may help in selecting patients for neoadjuvant treatment.

The Mesentery in Complete Mesocolic Excision

The following article summarizes technical aspects of how to operate in the mesentery during complete mesocolic excision (CME). Increasingly, CME is being adopted and as such it is important to establish the anatomical basis of the techniques involved. This review thus serves to provide that foundation and explains the surgical techniques built on it.

The impact of surgical delay on resectability of colorectal cancer: An international prospective cohort study

AIM

The SARS-CoV-2 pandemic has provided a unique opportunity to explore the impact of surgical delays on cancer resectability. This study aimed to compare resectability for colorectal cancer patients undergoing delayed versus non-delayed surgery.

METHODS

This was an international prospective cohort study of consecutive colorectal cancer patients with a decision for curative surgery (January-April 2020). Surgical delay was defined as an operation taking place more than 4 weeks after treatment decision, in a patient who did not receive neoadjuvant therapy. A subgroup analysis explored the effects of delay in elective patients only. The impact of longer delays was explored in a sensitivity analysis. The primary outcome was complete resection, defined as curative resection with an R0 margin.

RESULTS

Overall, 5453 patients from 304 hospitals in 47 countries were included, of whom 6.6% (358/5453) did not receive their planned operation. Of the 4304 operated patients without neoadjuvant therapy, 40.5% (1744/4304) were delayed beyond 4 weeks. Delayed patients were more likely to be older, men, more comorbid, have higher body mass index and have rectal cancer and early stage disease. Delayed patients had higher unadjusted rates of complete resection (93.7% vs. 91.9%, P = 0.032) and lower rates of emergency surgery (4.5% vs. 22.5%, P < 0.001). After adjustment, delay was not associated with a lower rate of complete resection (OR 1.18, 95% CI 0.90-1.55, P = 0.224), which was consistent in elective patients only (OR 0.94, 95% CI 0.69-1.27, P = 0.672). Longer delays were not associated with poorer outcomes.

CONCLUSION

One in 15 colorectal cancer patients did not receive their planned operation during the first wave of COVID-19. Surgical delay did not appear to compromise resectability, raising the hypothesis that any reduction in long-term survival attributable to delays is likely to be due to micro-metastatic disease.

Imaging of Colorectal Liver Metastasis

Colorectal cancer (CRC) is one of the most common cancers in the world. The most important determinant of survival and prognosis is the stage and presence of metastasis. The liver is the most common location for CRC metastasis. The only curative treatment for CRC liver metastasis (CRLM) is resection; however, many patients are ineligible for surgical resection of CRLM. Locoregional treatments such as ablation and intra-arterial therapy are also available for patients with CRLM. Assessment of response after chemotherapy is challenging due to anatomical and functional changes. Antiangiogenic agents such as bevacizumab that are used in the treatment of CRLM may show atypical patterns of response on imaging. It is vital to distinguish patterns of response in addition to toxicities to various treatments. Imaging plays a critical role in evaluating the characteristics of CRLM and the approach to treatment. CT is the modality of choice in the diagnosis and management of CRLM. MRI is best used for indeterminate lesions and to assess response to intra-arterial therapy. PET-CT is often utilized to detect extrahepatic metastasis. State-of-the-art imaging is critical to characterize patterns of response to various treatments. We herein review the imaging characteristics of CRLM with an emphasis on imaging changes following the most common CRLM treatments.

Clinical TNM staging for esophageal, gastric, and colorectal cancers in the era of neoadjuvant therapy: A systematic review of the literature

AIM

Clinical staging is vital for selecting appropriate candidates and designing neoadjuvant treatment strategies for advanced tumors. The aim of this review was to evaluate diagnostic abilities of clinical TNM staging for gastrointestinal, gastrointestinal cancers.

METHODS

We conducted a systematic review of recent publications to evaluate the accuracy of diagnostic modalities on gastrointestinal cancers. A systematic literature search was performed in PubMed/MEDLINE using the keywords "TNM staging," "T4 staging," "distant metastases," "esophageal cancer," "gastric cancer," and "colorectal cancer," and the search terms used in Cochrane Reviews between January 2005 to July 2020. Articles focusing on preoperative diagnosis of: (a) depth of invasion; (b) lymph node metastases; and (c) distant metastases were selected.

RESULTS

After a full-text search, a final set of 55 studies (17 esophageal cancer studies, 26 gastric cancer studies, and 12 colorectal cancer studies) were used to evaluate the accuracy of clinical TNM staging. Positron emission tomography-computed tomography (PET-CT) and/or magnetic resonance imaging (MRI) were the best modalities to assess distant metastases. Fat and fiber mode of CT may be useful for T4 staging of esophageal cancer, CT was a partially reliable modality for lymph node staging in gastric cancer, and CT combined with MRI was the most reliable modality for liver metastases from colorectal cancer.

CONCLUSION

The most reliable diagnostic modality differed among gastrointestinal cancers depending on the type of cancer. Therefore, we propose diagnostic algorithms for clinical staging for each type of cancer.

Impact of D3 lymph node dissection on upstaging and short-term survival in clinical stage I right-sided colon cancer

BACKGROUND

D3 lymph node dissection is becoming the standard procedure for the treatment of advanced right colon cancer and has shown increasing evidence of its oncologic benefit. However, a clear indication for its application is lacking and data on this topic is unsatisfactory. Thus, the necessity for D3 lymph node dissection in clinical stage I right colon cancer remains controversial.

METHODS

We retrospectively analyzed data from clinical stage I right colon cancer patients who underwent radical surgery at three hospitals of Korea university medical center between January 2015 and June 2018. We compared surgical complications and short-term oncologic outcomes between D2 and D3 lymph node dissections in these patients.

RESULTS

Among 512 patients, 122 (23.8%) were clinical stage I. Of these, 88 and 34 patients received D2 and D3 lymph node dissection, respectively. There were no statistically significant differences in clinicopathologic variables and surgical outcomes between the two groups. Upstaging occurred in 16 patients (47.1%) in the D3 group and 23 patients (26.1%) in the D2 group. There were four recurrences in the D2 group but no recurrence in the D3 group. Log-rank tests showed no statistically significant difference in disease-free survival rates between the two groups (p = 0.210).

CONCLUSION

There was no significant difference in disease-free survival rates between D2 and D3 lymph node dissection in clinical stage I right colon cancer patients. However, recurrence occurred in the D2 group. Efforts to improve the accuracy of clinical staging are required and more studies with better quality are needed.

Accuracy of preoperative staging with multidetector computed tomography in colon cancer

AIM

Multidetector computed tomography (MDCT) is the main preoperative decision-making tool in colon cancer treatment, thus the validation of daily clinical practice is warranted. The only published study validating the accuracy of MDCT in a national cohort was performed more than a decade ago. With neoadjuvant chemotherapy for patients with preoperatively assessed locally advanced cancer and the emergence of other personalized treatments we aimed to validate the accuracy of MDCT in a national cohort.

METHOD

The study is based on the Danish Colorectal Cancer Group (DCCG) database and included all Danish patients diagnosed with primary colon adenocarcinoma between January 2015 and December 2018. The primary study outcome was the accuracy of MDCT in identifying patients with locally advanced disease. The secondary outcomes were the accuracy of predicting UICC Stage I based on predicting the tumour category (pT3-T4 versus pT1-T2) and lymph node metastasis.

RESULTS

A total 3465 patients were included in the analyses regarding locally advanced colon cancer. The sensitivity and specificity were 0.61 (0.58-0.64) and 0.85 (0.83-0.86), respectively, for CT to predict locally advanced disease. The sensitivity and specificity were 0.63 (0.59-0.66) and 0.80 (0.78-0.81), respectively, for predicting UICC Stage I in 4496 patients. Thirty six per cent of the patients assessed as having locally advanced disease and 58% assessed as Stage I were misclassified by MDCT.

CONCLUSION

The present standard in Denmark questions whether the implementation of personalized medicine such as neoadjuvant adjuvant chemotherapy and tailor-made resections based on MDCT is justified.

[Preoperative imaging for colorectal cancer: surgeons' perspective]

Preoperative radiological diagnostics in patients with colorectal cancer has several objectives. The diagnostic localization of the colonic tumor is essential for planning the resection. The radiologically suspected infiltration of neighboring structures may lead to the decision for neoadjuvant treatment. In patients with rectal carcinomas, the T and N stages, the distance to the circumference resection margin (CRM), and the penetration of the tumor into the mesentery must be determined. This crucial to determine whether the patient should undergo neoadjuvant treatment. Prior to the planned relocation of an upstream stoma, radiological diagnostics may be added to clinical and endoscopic assessment but should not be routinely used.

The risk of nodal disease in patients with pathological complete responses after neoadjuvant chemoradiation for rectal cancer: a systematic review, meta-analysis, and meta-regression

BACKGROUND

This systematic review and meta-analysis seek to evaluate the prevalence of nodal disease in rectal cancer patients with pathological complete responses (pCR) after neoadjuvant chemoradiotherapy (ypT0N+).

METHODS

This study conformed to the PRISMA guidelines. A search was performed on major databases to identify relevant articles. Meta-analyses of pooled proportions were performed on rectal cancer with pCR and ypT0N+. Meta-regression was undertaken to identify sources of heterogeneity, and the Newcastle-Ottawa Scale (NOS) was employed to assess the risk of bias.

RESULTS

A total of 18 studies were included, totaling 7568 patients. The overall risk of bias was low, since all studies scored 6 and above out of 9 on the NOS. Preoperatively, the pooled proportions of patients with T3/T4 tumors and clinically positive nodal disease were 84.08% (95% CI 74.19 to 91.99%) and 52.14% (95% CI 35.02 to 69.00%) respectively. The prevalence of pCR in the whole pool was 18.52% (95% CI 13.31 to 24.35%; I² = 93.85%; P = 0.00), and meta-regression showed a significantly negative relationship with patient age (β = - 0.03, 95% CI - 0.03 to - 0.02; P = 0.00). The pooled prevalence of ypT0N+ was 4.61% (95% CI 2.41 to 7.28%; I² = 52.27%; P = 0.01), and meta-regression demonstrated a significantly positive relationship with male gender (β = 1.06, 95% CI 1.00 to 1.12; P = 0.04).

CONCLUSION

There is a small risk of ypN+ in patients with pCR after neoadjuvant CRT and surgery for rectal cancer. However, further research is warranted to establish these findings and to identify predictive factors for this specific group of patients.

Over-diagnosis for preoperative T staging of colorectal cancer - A case series

Introduction

Recent progressive imaging technology such as multiplanar reconstruction on computed tomography (CT) and colonoscopy has made preoperative T staging of colorectal cancer (CRC) more accurate. Nevertheless, it is still difficult to make a correct diagnosis in some cases. The aim of this case study was to investigate the accuracy of T staging diagnosis in patients with CRC who underwent curative operations and to identify the causes of preoperative over-diagnosis.

Method

Medical charts of 1013 colorectal cancer patients who underwent a curative operation in the University of Tokyo Hospital between January 2011 and December 2016 were analyzed retrospectively. We defined a two-level or more difference between clinical and pathological T stages as over-diagnosis or under-diagnosis.

Results

Nine patients were over-diagnosed in T stage preoperatively. The rate of over-diagnosis was 0.9%. At least three main factors for over-diagnosis were identified: close-to-circumferential or obstructive lesion; a rough appearance in the adipose tissues around the tumor on CT; and a tumor with a depressed structure.

Conclusions

Clinical T stage is overestimated with a marked difference from pathological T stage in approximately 1% of CRC patients. Further progress in diagnostic modalities is required for more accurate staging.

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The rate of one-level over-diagnosis in T stage was 14.8%.

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The rate of two-levels or more over-diagnosis in T stage was 0.9%.

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At least three main factors for two-levels or more over-diagnosis were identified.