Biology of Nodal Spread in Colon Cancer: Insights from Molecular and Genetic Studies

The application of the combination between artificial intelligence and endoscopy in gastrointestinal tumors

Gastrointestinal (GI) tumors have always been a major type of malignant tumor and a leading cause of tumor‐related deaths worldwide. The main principles of modern medicine for GI tumors are early prevention, early diagnosis, and early treatment, with early diagnosis being the most effective measure. Endoscopy, due to its ability to visualize lesions, has been one of the primary modalities for screening, diagnosing, and treating GI tumors. However, a qualified endoscopist often requires long training and extensive experience, which to some extent limits the wider use of endoscopy. With advances in data science, artificial intelligence (AI) has brought a new development direction for the endoscopy of GI tumors. AI can quickly process large quantities of data and images and improve diagnostic accuracy with some training, greatly reducing the workload of endoscopists and assisting them in early diagnosis. Therefore, this review focuses on the combined application of endoscopy and AI in GI tumors in recent years, describing the latest research progress on the main types of tumors and their performance in clinical trials, the application of multimodal AI in endoscopy, the development of endoscopy, and the potential applications of AI within it, with the aim of providing a reference for subsequent research.

Variation in the detection of lymphovascular invasion in T1 colorectal cancer and its impact on treatment: A nationwide Dutch study

BACKGROUND

Lymphovascular invasion (LVI) plays an important role in determining the risk of lymph node metastasis (LNM) in T1 colorectal cancer (CRC) patients and influencing treatment decisions and patient outcomes.

OBJECTIVE

This study evaluated how the detection of LVI varies between Dutch laboratories and investigated its impact on the treatment and oncological outcomes of T1 CRC patients.

METHODS

Pathology reports and clinical data of T1 CRC patients who underwent local resection between 2015 and 2019 were obtained from the Dutch nationwide pathology databank (Palga cohort, n = 5513). Data on the standard of LVI diagnosis (H&E/Immunohistochemistry) were not available. We categorized laboratories as low, average, or high detectors and evaluated the impact of LVI detection practice on the surgical resection rate and the proportion of LNM-negative (LNM-) surgeries. In the second part of the study, we used the Dutch T1 CRC Working Group cohort (n = 1268) to evaluate the impact of LVI detection practice on cancer recurrences during follow-up. Multivariable logistic regression analyses and Cox proportional hazard regression were used to study the association between LVI detection practice and the outcomes.

RESULTS

In the PALGA cohort, the proportion of surgical resections after local resection of a T1 CRC was significantly higher among patients diagnosed by laboratories with a high LVI detection rate (high vs. low: adjusted OR [aOR] 1.87; 95% confidence interval [CI] 1.52-2.31) as was the proportion of LNM-surgeries (aOR 1.73; 95% CI 1.39-2.15). In the second cohort, no significant difference was observed in cancer recurrences among patients diagnosed in laboratories with high detection rates compared with low detection rates (aHR 2.23; 95% CI 0.94-5.23).

CONCLUSION

These findings suggest that a high detection rate of LVI does not improve oncological outcomes and may expose more patients to unnecessary oncological surgery, emphasizing the need for standardization of LVI diagnosis.

Clinical characteristics and prognostic impact of direct distant organ metastasis in colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is the third most common type of cancer worldwide, and distant metastasis is frequently noted at diagnosis or follow-up. Notably, some patients with CRC can present with distant organ metastasis without any nodal involvement, which was defined as direct distant organ metastasis (DDOM). In this study, we evaluated the prognostic significance of DDOM for patients with CRC.

METHODS

This study included 325 patients who had undergone primary colorectal cancer resection between August 2008 and December 2021. The patients with and without DDOM were compared (Kaplan-Meier analysis) in terms of overall survival (OS) and time to recurrence. Furthermore, the patients' clinicopathological risk factors and protective factors were analyzed (multivariate Cox proportional hazards model).

RESULTS

Of the 325 patients, 65 (20%) had DDOM (Direct+ group) and 260 (80%) did not (Direct- group). The Kaplan-Meier analysis revealed that OS was significantly better in the Direct+ group than in the Direct- group (p < 0.01). A subgroup analysis by CRC stage was performed; for the patients with non-stage-IV CRC, the rate of OS was significantly higher in the Direct+ group than in the Direct- group (p = 0.02). However, DDOM did not affect the OS of the patients with stage IV CRC. The multivariate analysis indicated DDOM, left colon tumor location, and postoperative adjuvant chemotherapy were significant protective factors for disease-related mortality in the patients with non-stage-IV CRC; by contrast, body mass index, curative resection, and postoperative adjuvant chemotherapy were identified to be significant protective factors in the patients with stage IV CRC.

CONCLUSIONS

DDOM appears to be significantly associated with improved OS in patients with non-stage-IV CRC but not in those with stage IV CRC. Furthermore, the time to cancer recurrence may not vary significantly between patients with DDOM and those without it.

The mesocolic apical fragment in complete mesocolic excision colectomies: Should it be analysed separately? A proof-of-concept study

AIM

The aim of this work is to describe a protocol and assess the feasibility of harvesting and analysing the mesocolic apical fragment (MAF) for the presence of central lymph node (LN) metastasis and extra lymphatic free tumour cells in a random subgroup extracted from a cohort of complete mesocolic excision colectomies with central vascular ligation.

METHOD

Forty-seven patients diagnosed with colorectal cancer were included. A 2/2 cm pyramid of tissue was cut around the central tie and sent for pathological examination. The MAF was sectioned into 16 slices. High-definition images were taken from the slices which were merged into a panoramic three-dimensional image of the MAF. The distribution of LNs in the MAF was quantified. Immunohistochemistry staining for cytokeratin 14 was used to identify isolated tumour cells and micrometastases in the extranodal tissue.

RESULTS

No tumoural cells migrating through the apical zone, outside of the LNs, were identified. Margins of resection, mesocolic tissue and LNs were all negative in the subgroup of ultrastaged MAFs. The number of examined central LNs varied between 0 and 24, with positive MAF LNs being identified only in pN2 stages. The rate of positive apical LNs in our cohort was 4.2% (n = 2).

CONCLUSIONS

The MAF can be easily extracted from standard specimens, allowing for accurate analysis of lymphatic and extra-nodal tumour cells on the central resection margins, in central LNs and in the apical mesocolic tissue. Future research on larger cohorts is required to establish if analysing the MAF has an impact on patient staging, prognosis and management.

Identification of Differently Expressed Genes Associated With Prognosis and Growth in Colon Adenocarcinoma Based on Integrated Bioinformatics Analysis

Latest statistics showed that the morbidity and mortality of colon adenocarcinoma (COAD) ranked fourth and fifth, respectively, around the world. COAD was a heterogeneous disease, and the high rates of recurrence, metastasis, and drug resistance still posed great challenges for treatment, which needs to further develop therapeutic and prognostic targets. In this study, we got the top 3,075 differentially expressed genes (DEGs) and 1,613 potential prognostic genes by GEPIA 2 and identified 1,166 fitness genes in COAD based on genome-scale CRISPR-Cas9 knockout (GeCKO) screening data. Excluding the genes already reported in the literatures, a total of nine DEGs overlapping with prognostic and fitness genes were further analyzed. High expression of CCT6A, RHOQ, and RRP12 promoted COAD cell growth and were relative to lower survival rate of COAD patients, while high expression of UTP18, DDOST, YRDC, ACTG1, RFT1, and NLE1 also promoted COAD cell growth, but were relative to higher survival rate. In addition, CCT6A, UTP18, YRDC, RRP12, RFT1, NLE1, as well as DDOST were essential genes across pan-cancer including COAD cells, and ACTG1 and RHOQ were less essential genes in cancer cells. In a word, we discovered nine novel potential genes that could serve as anticancer targets and prognostic markers in COAD and its subtypes.