Background/Objectives: Complete mesocolic excision (CME) has recently been proposed as a radical operation for the treatment of colon cancer. Increasing evidence suggests a survival benefit from this operation, although the exact reasons for this remain largely unknown. Methods: We have undertaken a comprehensive review of the literature in PubMed and Embase databases, examining the potential mechanisms explaining this oncologic benefit. Results: Complete mesocolic excision with central vascular ligation appears to improve the rates of radial margin negativity and is associated with increased lymph node yield and improved staging for colon cancer patients by removal of apical lymph nodes and removal of skip metastasis. The en bloc removal of the cancer-related mesentery along the interfascial plane between the mesocolon and retroperitoneal structures removes en bloc tumor deposits that appear to have a significant negative effect on cancer prognosis, irrespective of lymph node status. CME is associated with decreased rates of local recurrence and improved disease-free and overall survival. The existing literature suffers from a lack of data on molecular pathology and integration of prognostic pathologic factors such as tumor deposits in patients undergoing complete mesocolic excision. Conclusions: CME confers significant benefits in terms of local control of the disease and improves cancer-specific survival. Further research on the matter is necessary to incorporate prognostic pathologic and molecular parameters.

Background: The rectal cancer treatment paradigm is rapidly changing with the advent of total neoadjuvant therapy and non-operative management approaches in responders. A good clinical response to neoadjuvant treatment documented by magnetic resonance imaging, endoscopy and clinical examination corresponds, to a large extent, to a pathologic complete response, as assessed in surgical specimens. Methods: We undertook a systematic review and meta-analysis on the MRI-based omics approach to predicting pathologic complete responses. Results: A total of 29 studies with relevant data available reporting on a total of 4486 patients were eligible for meta-analysis. The calculated values for the area under the curve in receiver operator curves of diagnostic accuracy for radiomics-only and radiomics-combined-with-clinical-data models were 0.80 and 0.88, respectively, for studies incorporating baseline imaging data only. The value for studies using delta radiomic data was 0.86, and those for studies using data from the post-neoadjuvant setting were 0.75 and 0.83, respectively, for the radiomics-only and radiomics-combined-with-clinical-data models. Conclusions: Radiomics-based prediction models for pathologic complete response assessment might further enable individualized treatment decisions to be made in patients with rectal cancer.

Background/Objectives: Adenocarcinomas of the esophagogastric and gastric areas are often managed with a multimodal treatment including neoadjuvant chemotherapy and surgery. The impact of neoadjuvant chemotherapy on the host’s antitumoral immune response remains largely unknown. Methods: A retrospective review of a single-institution cohort of patients with adenocarcinoma of the stomach or esophagogastric area undergoing curative intent surgery after neoadjuvant chemotherapy FLOT (Fluorouracil, Leucovorin, Oxaliplatin, Docetaxel) was reviewed. After institutional ethics approval, pathologic slides were re-reviewed and tumor-infiltrating lymphocyte scores were calculated. Tumor-infiltrating lymphocytes (TILs) were studied in conjunction with tumor regression scores (TRG) and the degree of regression in the involved lymph nodes as well as in correlation with the lymph node ratio (the ratio of involved lymph nodes over the total number of lymph nodes resected). Results: A total of 106 patients were reviewed. No statistical correlation could be established between the tumor-infiltrating lymphocyte scores and the degree of regression in the primary tumor as well as with the partial response to chemotherapy of pathologically involved lymph nodes. The TIL score also did not correlate with the lymph node ratio in our patient cohort. A strong correlation was noted between TILs and lymph nodes that completely regressed after neoadjuvant chemotherapy. Conclusions: Tumor-infiltrating lymphocytes do not correlate with the response of the primary tumor or the partial response of the involved lymph nodes, but only with the complete response to neoadjuvant chemotherapy of tumor-involved lymph nodes. Our study focuses on the effects of neoadjuvant chemotherapy on tumor-infiltrating lymphocytes compared to the effects on the primary tumor and the involved lymph nodes.

Background and Objectives: Accurate endoscopic lesion localization is crucial for planning and performing curative-intent surgery in colorectal cancer management. The use of indocyanine green (ICG) has been described as a novel alternative for colorectal lesion marking. Materials and Methods: We have performed a systematic review of the literature on the use of ICG-based tattooing for patients with colorectal cancer undergoing surgery. Results: A total of 19 studies were identified. Seven studies reposted the rates of successful intraoperative localization following ICG tattooing. Additionally, six studies provided detailed descriptions of the administration protocols, including both timing and dosage. A total of twelve studies described the utility of ICG-based tattooing for subsequent lymphadenectomy and its oncologic implications. Lymphadenectomy under fluorescent guidance was associated with increased lymph node yields as well as a change to the surgical lymphadenectomy plan in a significant proportion of patients. Conclusions: ICG-based endoscopic tattooing has demonstrated significant value in facilitating precise lesion localization during curative-intent colorectal surgery. Moreover, its use has been extended to guiding lymphadenectomy, with reports indicating improved lymph node yields. Nevertheless, further research is required to standardize protocols and address existing limitations.