Novel AI Combining CNN and SVM to Predict Colorectal Cancer Prognosis and Mutational Signatures from HE Images.

Reducing recurrence following radical resection of colon cancer without over- or under-treatment remains a challenge. Postoperative adjuvant chemotherapy (Adj) is currently administered based solely on pathological tumor, node, and metastasis (TNM) stage. However, prognosis can vary significantly among patients with the same disease stage. Therefore, novel classification systems in addition to the TNM are necessary to inform decision-making regarding postoperative treatment strategies, especially stage II and III disease, and to minimize overtreatment and undertreatment with Adj. We developed a prognostic prediction system for colorectal cancer by using a combined convolutional neural network (CNN) and support vector machine (SVM) approach to extract features from hematoxyling and eosin staining (HE) images. We combined the TNM and our AI-based classification system into a TNM-AI (mTNM-AI) classification system with high discriminative power for recurrence-free survival (RFS). Furthermore, the cancer cell population recognized by this system as low risk of recurrence exhibited the mutational signature SBS87 as a genetic phenotype. The novel AI-based classification system developed here is expected to play an important role in prognostic prediction and personalized treatment selection in oncology.

Long-term outcomes of robot-assisted laparoscopic surgery versus conventional laparoscopic surgery for rectal cancer: single-center, retrospective, propensity score analyses.

Although the short-term outcomes of robot-assisted laparoscopic surgery (RALS) for rectal cancer are well known, the long-term oncologic outcomes of RALS compared with those of conventional laparoscopic surgery (CLS) are not clear. This study aimed to compare the long-term outcomes of RALS and CLS for rectal cancer using propensity score matching. This retrospective study included 185 patients with stage I-III rectal cancer who underwent radical surgery at our institute between 2010 and 2019. Propensity score analyses were performed with 3-year overall survival (OS) and relapse-free survival (RFS) as the primary endpoints. After case matching, the 3-year OS and 3-year RFS rates were 86.5% and 77.9% in the CLS group and 98.4% and 88.5% in the RALS group, respectively. Although there were no significant differences in OS (p = 0.195) or RFS (p = 0.518) between the groups, the RALS group had slightly better OS and RFS rates. 3-year cumulative (Cum) local recurrence (LR) and 3-year Cum distant metastasis (DM) were 9.7% and 8.7% in the CLS group and 4.5% and 10.8% in the RALS group, respectively. There were no significant differences in Cum-LR (p = 0.225) or Cum-DM (p = 0.318) between the groups. RALS is a reasonable surgical treatment option for patients with rectal cancer, with long-term outcomes similar to those of CLS in such patients.

[Significance of Colorectal Cancer Resection for the Elderly].

INTRODUCTION: Elderly patients requiring surgical treatment is increasing in Japan, and while surgical treatment is expected to be effective even in the very elderly, there is a lack of evidence for the safety and efficacy of surgical resection due to problems with perioperative management and operative tolerance. We therefore retrospectively examined the short-term and long-term outcomes of colorectal cancer surgery for the very elderly at our hospital. SUBJECTS: The study included 14 cases of colorectal cancer in the very elderly who underwent radical resection at our hospital between January 2010 and March 2020. RESULTS: The mean age was 92 years, PS; 1/2=8/6, ASA-PS; 2/3/4=8/4/2, primary site was C/A/T/S/R= 2/5/2/2/3, pStage; 1/2/3=1/9/4, and only 1 case of decompression with ileus tube due to obstructive symptoms was treated before surgery. All patients underwent radical surgery. Median blood loss was 61 mL, median operation time was 190.5 min, and median postoperative hospital stay was 16 days. 5 patients had CD≥2 complications. All patients did not receive adjuvant chemotherapy, and recurrence in was observed 3 patients. CONCLUSION: Surgical treatment of very elderly patients seems to be acceptable under appropriate patient selection.

[A Case of Pathologically Complete Response after Preoperative Chemotherapy in a Locally Advanced Rectal Cancer].

The case is a 78-year-old male. The chief complaint was melena and weight loss. After careful examination, the patient was diagnosed with advanced rectal cancer, and 3 courses of capecitabine plus oxaliplatin therapy were performed as preoperative chemotherapy. He underwent robot-assisted laparoscopic rectal resection, D3 lymphadenectomy, lateral lymphadenectomy, and temporary colostomy, and was discharged on hospital day 15. Postoperative pathological diagnosis showed only ulcerative lesions in the rectum, and malignant cells could not be confirmed. After postoperative adjuvant chemotherapy, the patient is alive without recurrence on an outpatient basis. There are many reports that it is slightly lower than radiotherapy. Therefore, it is important to select a more appropriate preoperative treatment, and the concentration of future cases is recognized.

Robotic True D3 Lymph Node Dissection With Superior Mesenteric Vein-Taping Technique for Right-Sided Colon Cancer.

BACKGROUND: D3 is unaffected by anatomic factors even when the ileocolic artery runs along the dorsal side of the superior mesenteric vein. Complete "true D3" lymph node dissection in minimally invasive surgery for right-sided colon cancer could be beneficial for certain patients with lymph node metastases. IMPACT OF INNOVATION: The study aimed to determine the safety and feasibility of robotic true D3 lymph node dissection for right-sided colon cancer using a superior mesenteric vein-taping technique. TECHNOLOGY, MATERIALS, AND METHODS: The superior mesenteric vein was slowly and gently separated from the surrounding tissues and taped. Lifting the tape with the robotic third arm and fixing it in place using rock-stable tractions provides a good surgical view, which cannot otherwise be obtained. As a result, the ileocolic artery that branches from the superior mesenteric artery can be accurately exposed. Handling of the taping then enables expansion to a different surgical view. As the lymph nodes are originally concealed on the dorsal side of the superior mesenteric vein, this technique provides a good view for lymph node dissection. The root of the ileocolic artery was clipped and separated, and true D3 was thus completed. PRELIMINARY RESULTS: Fourteen patients underwent robotic true D3 lymph node dissection for right-sided colon cancer. No Clavien-Dindo classification grade II or higher intraoperative or postoperative complications were observed. The 30-day mortality rate was 0%. CONCLUSIONS: Our robotic true D3 lymph node dissection with superior mesenteric vein-taping technique is considered safe and feasible; it might be a promising surgical procedure for treating advanced right-sided colon cancer. FUTURE DIRECTIONS: Even when the ileocolic artery runs along the dorsal aspect of the superior mesenteric vein, the technique seems promising for facilitating robotic D3 lymph node dissection.