Background: Transanal total mesorectal resection (taTME) has recently emerged as a promising surgical approach for the treatment of mid-low rectal cancer. However, there is limited evidence on the long-term survival outcomes associated with taTME. This retrospective study aimed to compare the overall survival (OS), disease-free survival (DFS), and cancer-specific survival of taTME and laparoscopic TME (laTME) in patients with mid-low rectal cancer. Materials and Methods: From July 2014 to June 2022, a total of 3627 patients were identified from two prospective cohorts: the laparoscopic rectal surgery cohort and the CNTAES cohort. To balance the baseline characteristics between the taTME and laTME groups, propensity score matching (PSM) was performed. Results: A total of 2502 patients were included in the study. Prior to PSM, the laTME group comprised 1853 patients, while the taTME group comprised 649 patients. The 5-year OS (82.9% vs. 80.4%, P=0.202) and 5-year DFS (74.4% vs. 72.5%, P=0.167) were comparable between the taTME and laTME groups. After PSM, the taTME group showed no statistically significant difference in the 5-year OS (83.1% vs. 79.2%, P=0.101) and 5-year DFS (74.8% vs. 72.1%, P=0.135) compared to the laTME group. Subgroup analysis further suggested that taTME may potentially reduce the risk of death [hazard ratio 0.652; (95% CI, 0.452–0.939)] and disease recurrence [hazard ratio 0.736; (95% CI, 0.562–0.965)] specifically in patients with low rectal cancer. Conclusion: In this study, taTME demonstrated comparable oncologic safety to laTME in patients with mid-low rectal cancer. Moreover, the results indicate that taTME may confer potential survival benefits for patients with low rectal cancer.

Purpose. To evaluate the safety and feasibility of transanal endoscopic surgery for diffuse cavernous hemangioma of the rectum (DCHR). Methods. All DCHR patients who underwent transanal endoscopic surgery in our hospital between January 2014 and June 2018 were reviewed. Results. A total of 7 patients with a diagnosis of DCHR underwent transanal endoscopic surgery during the study period. Four patients (57.1%) were male, with a mean age at surgery of 34.5±7.7 years, and three patients (42.9%) were female, with a mean age at surgery of 29.9±3.8 years. Recurrent painless rectal bleeding was the main symptom in all patients. The mean age was 32 years old (range 21-54 years). The median duration of symptoms was 10 years (range 1 month-50 years). The level of hemoglobin at admission ranged from 59.0 to 148.0 g/l (mean 106.6 g/l), and the level of mean corpuscular volume (MCV) ranged from 75.1 fl to 93.5 fl (mean 83.7 fl). Colonoscopy, computed tomography (CT), and magnetic resonance imaging (MRI) were important in the diagnosis of DCHR because of their high positive rates and accurate features. All of the lesions are between the anal canal and the descending colon. Two patients could be found with some enlarged serpentine vessels in the cervix, vagina, or corpus cavernosum by MRI. After admission, all the patients underwent transanal endoscopic surgery and four patients had simultaneous loop ileostomy. The mean operative time was 278 min (range 168-400 min). The median amount of intraoperative blood loss was 50 ml (range 10-300 ml). The mean distance from anal verge to anastomosis was 2.2±0.2cm. The anastomosis was fashioned with a stapler in two patients (28.6%). There were no intraoperative and postoperative complications. All the patients continued to recover well from the surgery, and nobody needed postoperative blood transfusions. Conclusions. The specific diagnosis rate of DCHR is low. Preoperative MRI and CT examination can make a definitive diagnosis and determine the extent of the lesions. DCHR is mostly restricted to the rectum, sigmoid colon, anal wall, and mesorectum. The best treatment for DCHR is complete lesion resection. It is safe and feasible to treat DCHR using transanal endoscopic surgery. Moreover, transanal endoscopic surgery might have a huge potential when used to treat other rectal diseases.

Background. Since Sylla and Lacy successfully reported the transanal total mesorectal excision in 2010, taTME was considered to have the potential to overcome some problematic laparoscopic cases in male, low advanced rectal cancer. However, the evidence is still lacking. This study compared the short and long outcomes of taTME with laTME in these “challenging” patients to explore the advantages of taTME among the patients. Method. After propensity score matching analysis, 106 patients were included in each group from 325 patients who met the including standard. Statistical analysis was used to compare the differences of perioperative outcomes, histopathological results, and survival results between taTME and laTME groups. Results. The mean time of pelvic operation in the taTME group was significantly shorter than in the laTME group ( mins vs mins, ). The complication incidence rate and the rate of protective loop ileostomy in the taTME group were significantly lower than those in the laTME group (19.8% vs 38.7%, and 70.8% vs 92.5%, ). In long-term result, there was no significant difference between the two groups for 3-year OS (87.3% vs 85.4%, ) or 3-year DFS (74.9% vs 70.1%, ). The 2-year cumulative local recurrence rate was similar between the two groups (1.1% vs 5.8%, ). Conclusion. This study demonstrated that taTME might reduce the incidence of postoperative complications, especially of anastomotic leakage in these “challenging” patients. taTME may be considered to have clear advantages for “challenging” patients.

N6-methyladenosine (m6A) modification serves as a crucial regulator of diverse biological processes and disease progression. A central player in m6A regulation is YT521-B homology domain family member 2 (YTHDF2), a well-characterized m6A-binding protein primarily involved in mRNA stabilization. This study identifies lysine 542 (K542) as a critical acetylation site on YTHDF2, regulated by p300 as the acetyltransferase and SIRT2 as the deacetylase. Notably, while K542 acetylation has minimal effects on YTHDF2's protein stability or subcellular localization, it significantly enhances the protein's binding affinity for m6A-modified mRNAs. This enhanced binding affinity has profound biological implications, as K542 acetylation promotes malignant phenotypes in colorectal cancer (CRC) cells in vitro and in vivo. Supporting its clinical relevance, analysis of CRC tissues reveals elevated levels of YTHDF2 acetylation in primary tumors, strongly associating this modification with CRC pathology. Collectively, these findings highlight K542 acetylation as a key enhancer of YTHDF2's m6A recognition and a critical driver of its oncogenic activity.

Background: MRI-detected circumferential resection margin (CRM) involvement, extramural venous invasion (EMVI), and tumor deposits (TDs) are established high-risk features associated with poor prognosis in rectal cancer. These features may help identify patients who are more likely to benefit from neoadjuvant therapy (NAT). However, the prognostic significance of changes in these MRI high-risk features after NAT remains unclear. The objective of this study was to determine whether baseline MRI high-risk features can identify patients likely to benefit from NAT and whether their changes after NAT predict treatment response and prognosis in rectal cancer. Methods: This retrospective single-center cohort study included patients who underwent curative resection for rectal adenocarcinoma and received neoadjuvant therapy (NAT) at Sun Yat-sen University, Sixth Affiliated Hospital, between 2017 and 2019. Patients with MRI-detected CRM involvement, EMVI, or TDs were classified as MRI high-risk. Those who showed a shift from MRI high-risk to MRI low-risk—defined by the absence of CRM involvement, EMVI, or TDs—on post-treatment scans were considered good responders. The survival outcomes of good responders were then compared to those of poor responders, who remained persistently MRI high-risk. Additional analyses were performed within the baseline MRI high-risk subgroup to determine which MRI high-risk features were most strongly associated with prognosis. Results: The study included 302 patients in total. Of these, 146 (48.3%) were classified as MRI high-risk and 156 (51.7%) as MRI low-risk based on pre-treatment imaging. The high-risk group had significantly worse outcomes: three-year disease-free survival (DFS) was 54.8% compared with 93.6% in the low-risk group (p < 0.001), three-year overall survival (OS) was 76% versus 98.1% (p < 0.001), and the rate of local recurrence (LR) at three years was 10.9% compared to 1.3% (p = 0.002). Among the 146 patients initially identified as MRI high-risk, those who converted to low-risk status after treatment showed improved outcomes, with a three-year DFS of 82.9%, OS of 94.3%, and LR rate of 2.9%. Within the baseline MRI high-risk subgroup, baseline mrEMVI and mrTD, as well as post-treatment ymrMRF, ymrEMVI, and ymrTD, were associated with worse DFS. Conclusions: Baseline MRI high-risk features and their persistence after NAT were associated with poor prognosis in rectal cancer. MRI risk conversion after NAT may help identify a subgroup of initially high-risk patients with more favorable outcomes.