Objective To explore risk factors for metachronous tumor lesions after radical resection of rectal cancer (RC). Methods A retrospective study was conducted on 757 RC patients who underwent RC radical surgery at the Sixth Affiliated Hospital, Sun Yat-sen University from October 2012 to June 2018. The patients were divided into early-onset RC group (EO-RC group, ＜50 years old, n=228) and average-onset RC group (AO-RC group, ≥ 50 years old, n=529) based on their age of diagnosis, and were followed up until March 2025. General information, initial colonoscopy, follow-up colonoscopy, and other relevant clinical information were collected from all patients. The risk of developing metachronous tumor lesions was compared between two groups using Kaplan Meier (K-M) risk function; univariate and multivariate Cox proportional hazards models were used to analyze the influencing factors of metachronous tumor lesions after RC radical surgery. Results The median follow-up time was 30 (15, 58) months. The K-M risk function showed that the risk of developing metachronous tumor lesions in the EO-RC group was significantly lower than that in the AO-RC group (P＜0.001). The results of the multivariate Cox proportional hazards model showed that the risk of metachronous tumor lesions after RC surgery in the EO-RC group was 50.8% of that in the AO-RC group (P＜0.001); PIK3CA mutation and synchronous advanced adenoma were independent risk factors for metachronous tumor lesions after RC surgery (HR=2.360, 2.094; P=0.003, P＜0.001). Conclusions RC patients with advanced age, PIK3CA mutations, and synchronous advanced adenomas are prone to developing metachronous tumor lesions after surgery. Patients with EO-RC may not require intensified colonoscopy surveillance postoperatively. However, intensified surveillance strategies should be considered for RC patients harboring PIK3CA mutations or presenting with synchronous advanced adenomas.

Objective:This report presents the initial outcomes of endoscopic intermuscular dissection (EID), a novel technique introduced by our team for the diagnostic resection of early rectal cancer, focusing on the postoperative status of the vertical margins.Methods:On January 26, 2024, a patient with early rectal cancer (cT1-2N0M0) underwent Endoscopic Intermuscular Dissection. The EID procedure consists of six steps: (1) mucosal incision; (2) submucosal dissection; (3) superficial muscular layer incision; (4) intermuscular dissection; (5) complete tumor removal; (6) wound management.Results:The patient was a 70-year-old male with rectal cancer (cT1-2N0M0). The tumor was located on the left anterior wall of the rectum, approximately 9 cm from the anal margin, and measured 20mm in size. The dissection rate was 2.68 mm2/minute, and the total duration of the surgery was 109 minutes. The patient was successfully discharged on the fifth day after surgery. Pathological examination of the post-endoscopic surgery specimen revealed pT1b, with negative vertical margins. Follow-up after more than one month showed good recovery with no complications such as bleeding, perforation, infection, or stricture occurring. Colonoscopy indicated the presence of a granulation tissue suggestive of inflammation.Conclusion:Endoscopic Intermuscular Dissection for the diagnostic resection of early rectal cancer is potentially safe and may achieve negative vertical margins.

Objective:This report presents the initial outcomes of endoscopic intermuscular dissection (EID), a novel technique introduced by our team for the diagnostic resection of early rectal cancer, focusing on the postoperative status of the vertical margins.Methods:On January 26, 2024, a patient with early rectal cancer (cT1-2N0M0) underwent Endoscopic Intermuscular Dissection. The EID procedure consists of six steps: (1) mucosal incision; (2) submucosal dissection; (3) superficial muscular layer incision; (4) intermuscular dissection; (5) complete tumor removal; (6) wound management.Results:The patient was a 70-year-old male with rectal cancer (cT1-2N0M0). The tumor was located on the left anterior wall of the rectum, approximately 9 cm from the anal margin, and measured 20mm in size. The dissection rate was 2.68 mm2/minute, and the total duration of the surgery was 109 minutes. The patient was successfully discharged on the fifth day after surgery. Pathological examination of the post-endoscopic surgery specimen revealed pT1b, with negative vertical margins. Follow-up after more than one month showed good recovery with no complications such as bleeding, perforation, infection, or stricture occurring. Colonoscopy indicated the presence of a granulation tissue suggestive of inflammation.Conclusion:Endoscopic Intermuscular Dissection for the diagnostic resection of early rectal cancer is potentially safe and may achieve negative vertical margins.

Objective:To examine follow-up data of different subgroups in order to further evaluate the performance and practical value of community colorectal cancer screening by detection of stool methylation syndecan-2 gene (m SDC2) among residents of Shipai Town, Dongguan City. Methods:This was an observational study. From May 2021 to February 2022, the Shipai Town government of Dongguan City completed screening for colorectal cancer by detection of stool m SDC2 in 10,708 residents from 18 villages who had met the initial screening criteria and been selected using whole population sampling. From May 2022 to February 2023, the research group conducted follow-up of participants about one year after the initial screening. Residents in the gray zone according to the initial screening were followed up by colonoscopy. Additionally, 1,000 residents with negative results on the initial screening were randomly sampled to undergo colonoscopy. Stool m SDC2 detection was performed again on residents who had had positive results on the initial screening, and colonoscopy was performed on those who again tested positive. Compliance with colonoscopy and detection of gastrointestinal lesions during follow-up were assessed in different subgroups. Results:Of the 438 residents in the gray zone on the initial screening, 155 underwent colonoscopy follow-up (colonoscopy compliance rate 35.4% [155/438]). These colonoscopies revealed that 27 (17.4%) of the participants had gastrointestinal lesions, including advanced adenomas in 22 cases (14.2%) and non-adenomatous polyps in two cases (3.2%). No colorectal carcinomas was identified. Of the 1, 000 randomly sampled residents with negative results on initial screening, 286 underwent colonoscopy follow-up (colonoscopy compliance rate 28.6% [286/1000]), These colonoscopies revealed that 11 (3.8%)of these individuals had gastrointestinal lesions, including three advanced adenomas (1.0%), five non-advanced adenomas (1.7%), one serrated adenoma or polyp (0.3%), and two non-adenomatous polyps (0.7%), but no colorectal carcinomas. Of the 821 residents who tested positive in the initial screening, 511 again underwent stool mSDC2 detection one year later (follow-up rate 62.2% [511/821]). Of these participants, 66 tested positive again (rate of 12.9% [66/511]), 39 (7.6%) of them in the gray zone, whereas 406(79.5%) tested negative. Forty-seven of the residents with positive results underwent colonoscopy (colonoscopy compliance rate 71.2% [47/66]), which revealed 36 (76.6%) gastrointestinal lesions, including 10 advanced adenomas (21.3%), nine non-advanced adenomas (19.1%) and 17 non-adenomatous polyps (36.2%).Conclusion:Stool m SDC2 detection performs well as a screening tool. In our study, colorectal cancer or precancerous lesions were extremely rare in participants who tested negative on the initial screening. However, some of the participants who tested in the gray zone on initial screening had precancerous colorectal lesions, particularly advanced adenomas, which would have been missed without follow-up colonoscopy. Of note, stool m SDC2 detection has good follow-up value in individuals who test positive on initial screening.

Objective:To examine follow-up data of different subgroups in order to further evaluate the performance and practical value of community colorectal cancer screening by detection of stool methylation syndecan-2 gene (m SDC2) among residents of Shipai Town, Dongguan City. Methods:This was an observational study. From May 2021 to February 2022, the Shipai Town government of Dongguan City completed screening for colorectal cancer by detection of stool m SDC2 in 10,708 residents from 18 villages who had met the initial screening criteria and been selected using whole population sampling. From May 2022 to February 2023, the research group conducted follow-up of participants about one year after the initial screening. Residents in the gray zone according to the initial screening were followed up by colonoscopy. Additionally, 1,000 residents with negative results on the initial screening were randomly sampled to undergo colonoscopy. Stool m SDC2 detection was performed again on residents who had had positive results on the initial screening, and colonoscopy was performed on those who again tested positive. Compliance with colonoscopy and detection of gastrointestinal lesions during follow-up were assessed in different subgroups. Results:Of the 438 residents in the gray zone on the initial screening, 155 underwent colonoscopy follow-up (colonoscopy compliance rate 35.4% [155/438]). These colonoscopies revealed that 27 (17.4%) of the participants had gastrointestinal lesions, including advanced adenomas in 22 cases (14.2%) and non-adenomatous polyps in two cases (3.2%). No colorectal carcinomas was identified. Of the 1, 000 randomly sampled residents with negative results on initial screening, 286 underwent colonoscopy follow-up (colonoscopy compliance rate 28.6% [286/1000]), These colonoscopies revealed that 11 (3.8%)of these individuals had gastrointestinal lesions, including three advanced adenomas (1.0%), five non-advanced adenomas (1.7%), one serrated adenoma or polyp (0.3%), and two non-adenomatous polyps (0.7%), but no colorectal carcinomas. Of the 821 residents who tested positive in the initial screening, 511 again underwent stool mSDC2 detection one year later (follow-up rate 62.2% [511/821]). Of these participants, 66 tested positive again (rate of 12.9% [66/511]), 39 (7.6%) of them in the gray zone, whereas 406(79.5%) tested negative. Forty-seven of the residents with positive results underwent colonoscopy (colonoscopy compliance rate 71.2% [47/66]), which revealed 36 (76.6%) gastrointestinal lesions, including 10 advanced adenomas (21.3%), nine non-advanced adenomas (19.1%) and 17 non-adenomatous polyps (36.2%).Conclusion:Stool m SDC2 detection performs well as a screening tool. In our study, colorectal cancer or precancerous lesions were extremely rare in participants who tested negative on the initial screening. However, some of the participants who tested in the gray zone on initial screening had precancerous colorectal lesions, particularly advanced adenomas, which would have been missed without follow-up colonoscopy. Of note, stool m SDC2 detection has good follow-up value in individuals who test positive on initial screening.

Ionizing radiation can induce the death of lymphatic endothelial cells, leading to structural damage, dysfunction, and reduction of lymphatic vessels, which poses a negative impact on radiotherapy. However, it can also induce tumor cells and tumor-infiltrated immune cells to secrete various cytokines and promote tumor-associated lymphangiogenesis, which favors anti-tumor therapy and improve anti-tumor immunity. Studying the changes in lymphatic vessels after ionizing radiation may be a way to explore the synergistic anti-tumor effects of radiotherapy and immunotherapy. This review summarized the morphological changes in lymphatics after ionizing radiation, the molecular mechanisms for the effects of ionizing radiation on lymphatic vessels, and the clinical value of lymphatic changes after ionizing radiation, aiming to provide ideas for the study of the effects of ionizing radiation on lymphatic vessels.