Predicting systemic spread in early colorectal cancer: Can we do better?

Sporadic Polyps of the Colorectum

Colorectal polyps are common, and their diagnosis and classification represent a major component of gastrointestinal pathology practice. The majority of colorectal polyps represent precursors of either the chromosomal instability or serrated neoplasia pathways to colorectal carcinoma. Accurate reporting of these polyps has major implications for surveillance and thus for cancer prevention. In this review, we discuss the key histologic features of the major colorectal polyps with a particular emphasis on diagnostic pitfalls and areas of contention.

Are the width, length, depth, and area of submucosal invasion predictive of lymph node metastasis in pT1 colorectal cancer?

PURPOSE

Submucosa-limited (pathological T1, pT1) colorectal cancers (CRCs) pose a continuing challenge in the choice of treatment options, which range from local excision to radical surgery. The aim of this study was to evaluate the morphometric and morphologic risk factors associated with regional lymph node metastasis (LNM) in pT1 CRC.

METHODS

We performed a histological review of patients who underwent oncological resection between 2016 and 2022. Tumor grade, budding, poorly differentiated clusters (PDCs), cancer gland rupture, lymphovascular invasion (LVI), and presence of deep submucosal invasion (DSI), as well as width, length, total area, and area of DSI, were evaluated as potential risk factors for LNM.

RESULTS

A total of 264 cases of colon and rectal carcinomas with invasion into the submucosal layer (pT1) were identified. LNM was found in 46 of the 264 cases (17.4%). All morphometric parameters, as well as DSI (P=0.330), showed no significant association with LNM. High grade adenocarcinoma (P=0.050), budding (P=0.056), and PDCs (P<0.001) were associated with LNM. In the multivariate analysis, LVI presence remained the only significant independent risk factor (odds ratio, 15.7; 95% confidence interval, 8.5-94.9; P<0.001).

CONCLUSION

The DSI of T1 CRC, as well as other morphometric parameters of submucosal tumor spread, held no predictive value in terms of LNM. LVI was the only independent risk factor of LNM.

Differences in Factors Predicting Lymph Node Metastasis Between pT1 Rectal Cancer and pT1 Colon Cancer: A Retrospective Study

BACKGROUND

Studies have demonstrated conflicting results regarding factors that predict lymph node metastasis (LNM) in pT1 colorectal cancers. We hypothesized that these discrepancies could be related to different factors predicting LNM between rectal and colon cancer. This study aimed to compare predicting factors for LNM between pT1 rectal and colon cancer.

METHODS

This retrospective study evaluated a prospectively maintained database that included 380 patients with pT1 colorectal cancer from January 2010 to December 2020. Patients were grouped according to whether they had rectal or colon cancer, with or without LNM, and factors predicting LNM were analyzed.

RESULTS

In pT1 rectal cancer, LNM was associated with deeper submucosal (SM) invasion (P = .024) and a higher proportion of poorly differentiated tumors (P = .006). In pT1 colon cancer, LNM was associated with a higher proportion of moderately/poorly differentiated tumors (P = .002) and lymphatic invasion (P = .004). In the multivariate analysis for rectal cancer, depth of SM invasion (≥3000 μm) was an independent predictive factor for LNM (95% confidence interval [CI], 1.48-27.94; P = .013), whereas for colon cancer, moderately/poorly differentiated tumors (95% CI, 1.38-8.13; P = .008) and lymphatic invasion (95% CI, 1.44-11.78; P = .008) were independent predictive factors for LNM.

DISCUSSION

There were distinct differences in the factors predicting LNM between pT1 rectal cancer and colon cancer. These results suggest the necessity in differentiating between rectal and colon cancer when performing studies on LNM in pT1 colorectal cancer.

Lymph Node Molecular Analysis with OSNA Enables the Identification of pT1 CRC Patients at Risk of Recurrence: A Multicentre Study

Early-stage colorectal carcinoma (CRC)-pT1-is a therapeutic challenge and presents some histological features related to lymph node metastasis (LNM). A significant proportion of pT1 CRCs are treated surgically, resulting in a non-negligible surgical-associated mortality rate of 1.5-2%. Among these cases, approximately 6-16% exhibit LNM, but the impact on survival is unclear. Therefore, there is an unmet need to establish an objective and reliable lymph node (LN) staging method to optimise the therapeutic management of pT1 CRC patients and to avoid overtreating or undertreating them. In this multicentre study, 89 patients with pT1 CRC were included. All histological features associated with LNM were evaluated. LNs were assessed using two methods, One-Step Nucleic Acid Amplification (OSNA) and the conventional FFPE plus haematoxylin and eosin (H&E) staining. OSNA is an RT-PCR-based method for amplifying CK19 mRNA. Our aim was to assess the performance of OSNA and H&E in evaluating LNs to identify patients at risk of recurrence and to optimise their clinical management. We observed an 80.9% concordance in LN assessment using the two methods. In 9% of cases, LNs were found to be positive using H&E, and in 24.7% of cases, LNs were found to be positive using OSNA. The OSNA results are provided as the total tumour load (TTL), defined as the total tumour burden present in all the LNs of a surgical specimen. In CRC, a TTL ≥ 6000 CK19 m-RNA copies/µL is associated with poor prognosis. Three patients had TTL > 6000 copies/μL, which was associated with higher tumour budding. The discrepancies observed between the OSNA and H&E results were mostly attributed to tumour allocation bias. We concluded that LN assessment with OSNA enables the identification of pT1 CRC patients at some risk of recurrence and helps to optimise their clinical management.

Pathological features associated with metastasis in patients with early invasive (pT1) colorectal carcinoma in colorectal polyps

AIMS

Colorectal carcinoma (CRC) arising in a colorectal polyp with invasion limited to the submucosa is sufficiently treated by complete endoscopic resection alone in many cases. Histological features of the carcinoma including tumour size, vascular invasion and poor tumour differentiation or evidence of de-differentiation, such as tumour budding, are associated with a higher risk for metastasis such that oncological resection is recommended. However, most malignant polyps with these features do not have lymph node metastases at the time of resection, so there is a need for better refinement of the histological risk features.

METHODS AND RESULTS

A total of 437 consecutive colorectal polyps with submucosal invasive carcinoma from a single centre, 57 of which had metastatic disease, were supplemented by 30 cases with known metastatic disease from two additional centres. Clinical and histological features of the polyp cancers were reviewed looking for differences between the 87 cancers with metastatic disease and the remaining cases without metastasis. A subgroup of 204 polyps removed intact was also analysed to ensure maximum histological accuracy.

CONCLUSIONS

This study confirmed larger invasive tumour size, vascular invasion and poor tumour differentiation as adverse predictive features. Prominent peritumoral desmoplasia and high cytological grade were additional adverse features. A predictive logistic regression model comprised of (i) presence of any form of vascular invasion; (ii) presence of high tumour budding (BD3); (iii) width of invasive tumour component > 8 mm; (iv) depth of invasive tumour > 1.5 mm; and (v) the finding of prominent expansile desmoplasia located within and beyond the deep invasive edge of the carcinoma, showed excellent performance in predicting metastatic disease.

Diagnostic and Therapeutic Management of Early Colorectal Cancer

Background

Early colorectal cancer (eCRC) is defined as cancer that does not cross the submucosal layer of the colon or rectum, including carcinoma in situ (pTis), pT1a, and pT1b. Early carcinomas differ in their prognosis depending on the risk profile. The differentiation between low and high risk is essential. The low-risk group includes R0-resected, well (G1) or moderately (G2) differentiated tumors without lymphatic vessel invasion (L0), without blood vessel invasion (V0) and a tumor size ≤3 cm. In this constellation, the estimated risk of lymph node metastasis is around 1% or below. The high-risk group includes tumors with incomplete resection (Rx), poor (G3) or undifferentiated (G4) carcinomas, and/or lymphatic and blood vessel invasion (L1) and size ≥3 cm. In a "high-risk" situation, there is a risk for lymph node metastasis of up to 23%.

Summary

The incidence of eCRC is rising with a rate of 10% in all endoscopically removed lesions during colonoscopy. For a correct histological evaluation, all suspected lesions should be completely resected. In case of a pT1 lesion in the rectum, pelvic magnetic resonance imaging should be performed to evaluate for suspicious lymph nodes. The therapeutic approach for eCRC is based on histological assessment and ranges from endoscopic resection to radical oncological surgery. The advantages, disadvantages, and associated risks of the individual treatment strategy need to be carefully discussed on a tumor board and with the patient.

Key Messages

Treatment options for early colorectal cancer depend on the histological assessment. Poorly differentiated carcinomas, a Kudo ≥ SM2 classified lesion, and a Haggitt level 4 always represent a "high-risk" situation. It should also be mentioned that in rectal cancer, local surgical tumor excision (full-wall excision) is also sufficient for pT1 carcinomas with a "low-risk" constellation (G1/G2; L0, size <3 cm) and an R0 resection.

Missing parameters in malignant polyp histology reports: can appropriate decisions be made?

The treatment of colorectal malignant polyps is dependent upon quality reporting of the histopathological features known to predict the risk of residual disease or lymph node metastasis. The Royal College of Pathologists of Australasia (RCPA) has produced protocols covering mandatory and recommended pathological parameters to be included in the pathology reporting of malignant polyps. This paper aimed to assess the quality of the pathological reporting in a population-wide analysis from 2011-2019 in Queensland, Australia. A retrospective population-wide cohort study was performed using the Queensland Oncology Repository as a data source. The number of missing pathological parameters (assessed against the RCPA protocol standards and guidelines) for each patient was then summed. Demographic and other patient details were collated. The number of patients whose recommended treatment could theoretically be altered by the full reporting of missing parameters was calculated. A total of 1,646 histopathological reports of malignant polyps were reviewed. From this, 30.8% of all reports had a sufficient number of missing parameters that may have seen an alternate management strategy chosen. The most commonly under-reported parameter from the standards was either a Haggitt or Kikuchi level with 48.6% missing. Synoptic reporting significantly reduced the mean number of missing pathological parameters (p<0.001) There was a significant improvement in the number of missing pathological details over time (p<0.001). Accurate and complete pathology reports are essential to formulate appropriate surgical recommendations after the resection of malignant polyps. In this population-based study, pathology reports remain incomplete for the established parameters despite the introduction of an RCPA structured reporting protocol. Fortunately, the quality of pathological reporting has improved since the introduction of the first RCPA protocol covering reporting of malignant polyps.

Colorectal malignant polyps: a modern approach

Colorectal malignant polyps (MP) are polyps with invasive cancer into the submucosa harboring a variable risk of lymph node involvement, which can be estimated through evaluation of morphological, endoscopic, and histologic features. The recent advances in imaging endoscopic techniques have led to the possibility of performing an optical diagnosis of T1 colorectal cancer, allowing the selection of the best therapeutic modality to optimize outcomes for the patient. When MP are diagnosed after endoscopic removal, their management can be challenging. Differentiating low- and high-risk histologic features that influence the possibility of residual tumor, the risk of recurrence and the risk of lymph node metastasis, is crucial to further optimize treatment and surveillance plans. While the presence of high-risk features indicates a need for surgery in the majority of cases, location, comorbidities and the patient’s preference should be taken in account when making the final decision. This is a particularly important issue in the management of low rectal MP presenting with high-risk features, where chemoradiotherapy followed by a watch-and-wait strategy has demonstrated promising results. In this review we discuss the important prognostic features of MP and the most modern approaches regarding their management.

Pattern and Significance of Tumour Budding in Colorectal Carcinomas Using ITBCC Guidelines: a Low Resource Setting Practice Observation

PURPOSE

To determine the pattern and significance of tumour budding among colorectal carcinoma (CRC) Nigerian patients using the 2016 International Tumour Budding Consensus Conference (ITBCC) guidelines.

METHODS

H&E-stained slides of resected CRC at the University College Hospital and a private laboratory, both in Ibadan, Nigeria, from January 2008 to December 2017 were reviewed. Patient age, gender, tumour size and location were obtained from the surgical pathology records. Tumours were graded and staged according to the 2010 WHO and the 2017 UICC protocols, respectively. Tumour budding was determined at × 20 objective lens magnification with a 20-mm eyepiece field number diameter. Descriptive, Mann-Whitney U and chi-square test statistics were applied using SPSS 20; p < 0.05 was considered significant.

RESULTS

Ninety-six cases were included in this study. Fifty-one (53.1%) showed tumour budding. Tumour bud count was low (0-4) in 66 (68.8%), intermediate (5-9) in 12 (12.5%) and high (≥ 10) in 18 (18.8%) tumours. Four tumours had pT1 stage, 35 pT2, 37 pT3 and 20 pT4. Forty-three (44.8%) tumours were lymph node-positive, and 10 (10.4%) had metastasis. Patients' age and tumour size distribution were similar in the tumour budding and non-budding groups (52.4 ± 17.1/58.5 ± 13.9 years and 6.6 ± 2.9/6.6 ± 2.8 cm, respectively). There was significant association between tumour budding and tumour grade (p < 0.008), pT stage (p < 0.000), lymphovascular permeation (p < 0.000), perineural invasion (p < 0.003) and nodal status (p < 0.034), but not with gender (p = 0.588), metastasis (p = 0.327) and TNM group-stage (p = 0.062).

CONCLUSION

Tumour budding frequency is high among our CRC patients and is associated with poorer prognostic factors.

Development of a Novel Prognostic Model for Predicting Lymph Node Metastasis in Early Colorectal Cancer: Analysis Based on the Surveillance, Epidemiology, and End Results Database

Background

Identification of a simplified prediction model for lymph node metastasis (LNM) for patients with early colorectal cancer (CRC) is urgently needed to determine treatment and follow-up strategies. Therefore, in this study, we aimed to develop an accurate predictive model for LNM in early CRC.

Methods

We analyzed data from the 2004-2016 Surveillance Epidemiology and End Results database to develop and validate prediction models for LNM. Seven models, namely, logistic regression, XGBoost, k-nearest neighbors, classification and regression trees model, support vector machines, neural network, and random forest (RF) models, were used.

Results

A total of 26,733 patients with a diagnosis of early CRC (T1) were analyzed. The models included 8 independent prognostic variables; age at diagnosis, sex, race, primary site, histologic type, tumor grade, and, tumor size. LNM was significantly more frequent in patients with larger tumors, women, younger patients, and patients with more poorly differentiated tumor. The RF model showed the best predictive performance in comparison to the other method, achieving an accuracy of 96.0%, a sensitivity of 99.7%, a specificity of 92.9%, and an area under the curve of 0.991. Tumor size is the most important features in predicting LNM in early CRC.

Conclusion

We established a simplified reproducible predictive model for LNM in early CRC that could be used to guide treatment decisions. These findings warrant further confirmation in large prospective clinical trials.

A prognostic model for colorectal cancer based on CEA and a 48-multiplex serum biomarker panel

Mortality in colorectal cancer (CRC) remains high, resulting in 860,000 deaths annually. Carcinoembryonic antigen is widely used in clinics for CRC patient follow-up, despite carrying a limited prognostic value. Thus, an obvious need exists for multivariate prognostic models. We analyzed 48 biomarkers using a multiplex immunoassay panel in preoperative serum samples from 328 CRC patients who underwent surgery at Helsinki University Hospital between 1998 and 2003. We performed a multivariate prognostic forward-stepping background model based on basic clinicopathological data, and a multivariate machine-learned prognostic model based on clinicopathological data and biomarker variables, calculating the disease-free survival using the value of importance score. From the 48 analyzed biomarkers, only IL-8 emerged as a significant prognostic factor for CRC patients in univariate analysis (HR 4.88; 95% CI 2.00-11.92; p = 0.024) after correcting for multiple comparisons. We also developed a multivariate model based on all 48 biomarkers using a random survival forest analysis. Variable selection based on a minimal depth and the value of importance yielded two tentative candidate CRC prognostic markers: IL-2Ra and IL-8. A multivariate prognostic model using machine-learning technologies improves the prognostic assessment of survival among surgically treated CRC patients.

A prognostic model for colorectal cancer based on CEA and a 48-multiplex serum biomarker panel

Mortality in colorectal cancer (CRC) remains high, resulting in 860,000 deaths annually. Carcinoembryonic antigen is widely used in clinics for CRC patient follow-up, despite carrying a limited prognostic value. Thus, an obvious need exists for multivariate prognostic models. We analyzed 48 biomarkers using a multiplex immunoassay panel in preoperative serum samples from 328 CRC patients who underwent surgery at Helsinki University Hospital between 1998 and 2003. We performed a multivariate prognostic forward-stepping background model based on basic clinicopathological data, and a multivariate machine-learned prognostic model based on clinicopathological data and biomarker variables, calculating the disease-free survival using the value of importance score. From the 48 analyzed biomarkers, only IL-8 emerged as a significant prognostic factor for CRC patients in univariate analysis (HR 4.88; 95% CI 2.00–11.92; p = 0.024) after correcting for multiple comparisons. We also developed a multivariate model based on all 48 biomarkers using a random survival forest analysis. Variable selection based on a minimal depth and the value of importance yielded two tentative candidate CRC prognostic markers: IL-2Ra and IL-8. A multivariate prognostic model using machine-learning technologies improves the prognostic assessment of survival among surgically treated CRC patients.

The risk of lymph node metastasis in T1 colorectal cancer: new parameters to assess the degree of submucosal invasion

PURPOSE

In T1 colorectal cancer, the depth is the main factor assessing the degree of submucosal invasion (DSI) to predict the risk of lymph node metastasis (LNM). The width (WSI) and the area of submucosal invasion (ASI) have been suggested as additional parameters to assess the risk of LNM. A review of the literature was undertaken on the correlation between WSI and ASI parameters and the incidence of LNM.

METHODS

A Medline, PubMed, and Cochrane Library search was performed to retrieve all studies reporting correlation between WSI/ASI and risk of LNM in T1 colorectal cancer.

RESULTS

Eight studies including 1727 patients were identified. All considered the degree of WSI and its influence on LNM: seven assessed different width cut-off of submucosal invasion, and one study the mean width of submucosal invasion in patients having or not involved lymph nodes. The WSI was significantly a prognostic factor for LNM (p < 0.05) in four studies. Both 2 and 3 mm seem to be the most discriminatory cut-off values of submucosal width invasion in defining the risk difference of LNM above and below the cut-off (2 mm, OR = infinite; 3 mm, OR = 6.9). Patients having a cut-off ≤ 5 mm of WSI showed a low risk (5.6%) of LNM rendering radical surgery unnecessary. Four studies assessed the risk of LNM according to the involved submucosal area (width × depth). In two of these, the ASI was a significant prognostic factor for LNM (p < 0.05).

CONCLUSION

The WSI and ASI seem to be reliable prognostic factors for LNM in T1 colorectal cancer. There is no agreement on ideal cut-off value.

pT1 Colorectal Cancer Detected in a Colorectal Cancer Mass Screening Program: Treatment and Factors Associated with Residual and Extraluminal Disease

Simple Summary

Our study has evaluated the burden of pT1 CRC (confined to submucosa) detected during the first round of a CRC screening program, the surgery related complications and the factors related to four relevant outcomes: initial endoscopic resection, surgery rescue and residual disease after endoscopic resection and, finally, extraluminal disease after surgical resection. 38% of the CRC were detected in this stage.74.9% were initially resected endoscopically and 43.8% did not require surgery. There were inhospital surgical complications in 30.7%, mainly mild with no death and complications after discharge in 16.3% of the patients Residual disease was detected in 12 (4.3%) after endoscopic resection and extraluminal disease in 18 (8.6%) patients after surgery. We have determined several variables independently associated with the four outcome variables evaluated.

Abstract

The aim of this study is to describe the treatment of pT1 colorectal cancer (CRC) in a mass screening program, the surgery-related complications and the factors associated with residual disease after endoscopic resection and extraluminal disease after surgery. We included in this retrospective analysis all the pT1 CRC detected in the Galician CRC screening program between May 2013 and June 2019. We determined which variables were independently associated with the outcomes of the study through a multivariable logistic regression analysis. We included 370–354 pT1 N0(X), 16 pT1N1- out of the 971 CRC detected; 277 (74.9%) were resected endoscopically and 162 (43.8%) were not referred to surgery. There were surgical complications in 30.7% and 16.3% of the patients during hospitalization and after discharge. Residual disease was detected in 12 (4.3%) after endoscopic resection and extraluminal disease in 18 (8.6%) patients after surgery. The variables independently associated with initial endoscopic resection were a pedunculated morphology (OR 33.1, 95% CI 4.3–254), a diameter ≥ 20 mm (OR 3.94, 95% CI 1.39–11.18) and a Site–Morphology–Size–Access score < 9 (OR 428, 95% CI 42–4263). The variables related with surgery rescue were a piecemeal resection (OR 4.48, 95% CI 1.48–13.6), an infiltrated/nonevaluable resection border (OR 7.44, 95% CI 2.12–26.0), a non-well-differentiated histology (OR 4.76, 95% CI 1.07–20.0), vascular infiltration (OR 8.24, 95% CI 2.72–25.0) and a Haggitt 4 infiltration of the submucosa (OR 5.68, 95% CI 2.62–12.3). Residual disease after endoscopic resection was associated with an infiltrated/nonevaluable resection border (OR 34.9, 95% CI 4.08–298), a non-well-differentiated histology (OR 6.67, 95% CI 1.05–50.0), and the vascular infiltration of the submucosa (OR 7.61, 95% CI 1.55–37.4). The variables related with extraluminal disease after surgical resection were no endoscopic resection (OR 4.34, 95% CI 1.26–14.28), a non-well-differentiated histology (OR 4.35, 95% CI 1.39–14.29) and the lymphatic infiltration of the submucosa (OR 4.8, 95% CI 1.32–17.8). In a CRC screening program, although most of pT1 CRC are candidates for endoscopic treatment, surgery is a safe procedure. We have defined some easy to evaluate variables that can be used in the decision-making process.

Prognostic significance of venous invasion in node-negative head and neck squamous cell carcinoma

BACKGROUND

Venous invasion (VI) is not frequently evaluated on routine histologic examination of head and neck squamous cell carcinoma (HNSCC), and the prognostic significance is largely unknown. Studies have shown that extramural venous invasion is an adverse prognostic factor in colorectal carcinoma. To our knowledge, this is the first study evaluating the prognostic significance of venous invasion in node-negative (without clinical or pathologic evidence of lymph node involvement) HNSCC, utilizing the elastic stain.

METHODS

A total of 105 consecutive lymph node-negative (N0) HNSCC were evaluated for the presence of venous channel invasion by tumor utilizing the elastin stain. Clinical, demographic, and follow-up data were recorded.

RESULTS

Of 37 patients with venous invasion, 19% had loco-regional recurrence, as opposed to 12% of those without. Univariate analysis revealed statistically significant decreased recurrence-free survival in the presence of venous invasion (log-rank [Mantel-Cox] test P-value .025).

CONCLUSION

Identification of VI is greatly aided by elastic stain. In patients with node-negative HNSCC, presence of VI resulted in decreased recurrence-free survival on univariate analysis. The impact of VI as a prognostic marker should be further evaluated.