Objective:To investigate the genetic subtypes and drug resistance monitoring of newly reported human immunodeficiency virus (HIV) infection/AIDS virus in Anhui Province from 2020 to 2023.Methods:An observational design study was used to collect blood samples from patients diagnosed with HIV/AIDS in the AIDS Prevention and Control Department of Anhui Provincial Center for Disease Control and Prevention from January 2020 to December 2023.The HIV-1 pol gene was amplified by reverse transcription-nested PCR, and the genetic subtypes were identified by phylogenetic tree analysis using MEGA 7.0 software. The mutation sites of drug resistance were analyzed by the online software tool of Stanford University′s HIV Drug resistance database. The influencing factors of drug resistance before treatment were analyzed by multivariate logistic analysis.Results:A total of 335 plasma samples were collected, and 332 HIV-1 pol gene sequences were obtained successfully. The main gene subtypes were CRF01-AE, accounting for 35.55% (118/332), followed by CRF07-BC, B and B+C types [29.22% (97/332), 11.74% (39/332), 9.93% (33/332)]. The total drug resistance rate before treatment was 30.12%(32/100), and the drug resistance rate of protease inhibitor (PIs) in HIV-1 was 6.33% (21/332). The drug resistance rate of nucleoside reverse transcriptase inhibitors (NRTI) before treatment was 6.33% (21/332). The drug resistance rate of non-nucleoside reverse transcriptase inhibitors (NNRTI) before treatment was 17.47% (58/332).The comparison of drug resistance rate of different drug types showed statistical significance ( χ2=30.435, P<0.05).Among the 100 cases of drug resistance, the main mutation point of HIV-1 protease inhibitor was Q58E (21.00%), and the main mutation point of nucleoside reverse transcriptase inhibitor was M184V/I (6.00%). Non-nucleoside reverse transcriptase inhibitor resistance mutation points mainly K103N (22.00%).There were statistically significant differences in the starting time of antiviral therapy, the number of CD4 +T cells at baseline and the drug resistance rate of gene subtypes (the chi-square values are respectively 24.152, 32.516, 11.652, P<0.05).Multivariate logistic analysis showed that the baseline CD4 +T cell count was <200/μl, subtype B, subtype B+C, CRF01-AE subtype, CRF55-01B subtype and 01-BC subtype was the influential factor of drug resistance before treatment (the chi-square values are respectively 4.577, 8.202, 4.416, 5.206, 7.603 and 4.804, P<0.05). Conclusion:The newly reported HIV/AIDS population in Anhui Province from 2020 to 2023 has a variety of viral gene subtypes, and NNRTIs are the main types of drug resistance gene mutations before treatment. Attention should be paid to the number of baseline CD4 +T cells, the duration of antiviral treatment, and the distribution of gene subtypes to reduce the drug resistance of HIV/AIDS patients before treatment.

Objective:To investigate the genetic subtypes and drug resistance monitoring of newly reported human immunodeficiency virus (HIV) infection/AIDS virus in Anhui Province from 2020 to 2023.Methods:An observational design study was used to collect blood samples from patients diagnosed with HIV/AIDS in the AIDS Prevention and Control Department of Anhui Provincial Center for Disease Control and Prevention from January 2020 to December 2023.The HIV-1 pol gene was amplified by reverse transcription-nested PCR, and the genetic subtypes were identified by phylogenetic tree analysis using MEGA 7.0 software. The mutation sites of drug resistance were analyzed by the online software tool of Stanford University′s HIV Drug resistance database. The influencing factors of drug resistance before treatment were analyzed by multivariate logistic analysis.Results:A total of 335 plasma samples were collected, and 332 HIV-1 pol gene sequences were obtained successfully. The main gene subtypes were CRF01-AE, accounting for 35.55% (118/332), followed by CRF07-BC, B and B+C types [29.22% (97/332), 11.74% (39/332), 9.93% (33/332)]. The total drug resistance rate before treatment was 30.12%(32/100), and the drug resistance rate of protease inhibitor (PIs) in HIV-1 was 6.33% (21/332). The drug resistance rate of nucleoside reverse transcriptase inhibitors (NRTI) before treatment was 6.33% (21/332). The drug resistance rate of non-nucleoside reverse transcriptase inhibitors (NNRTI) before treatment was 17.47% (58/332).The comparison of drug resistance rate of different drug types showed statistical significance ( χ2=30.435, P<0.05).Among the 100 cases of drug resistance, the main mutation point of HIV-1 protease inhibitor was Q58E (21.00%), and the main mutation point of nucleoside reverse transcriptase inhibitor was M184V/I (6.00%). Non-nucleoside reverse transcriptase inhibitor resistance mutation points mainly K103N (22.00%).There were statistically significant differences in the starting time of antiviral therapy, the number of CD4 +T cells at baseline and the drug resistance rate of gene subtypes (the chi-square values are respectively 24.152, 32.516, 11.652, P<0.05).Multivariate logistic analysis showed that the baseline CD4 +T cell count was <200/μl, subtype B, subtype B+C, CRF01-AE subtype, CRF55-01B subtype and 01-BC subtype was the influential factor of drug resistance before treatment (the chi-square values are respectively 4.577, 8.202, 4.416, 5.206, 7.603 and 4.804, P<0.05). Conclusion:The newly reported HIV/AIDS population in Anhui Province from 2020 to 2023 has a variety of viral gene subtypes, and NNRTIs are the main types of drug resistance gene mutations before treatment. Attention should be paid to the number of baseline CD4 +T cells, the duration of antiviral treatment, and the distribution of gene subtypes to reduce the drug resistance of HIV/AIDS patients before treatment.

Gastrointestinal tumors have been widely concerned because of increasing morbidity and mortality. In the process of exploring the therapeutic patterns of gastrointestinal tumors, patients treated with neoadjuvant therapies have good effect of tumor regression and favorable prognosis. Thus, neoadjuvant therapy strategies are recommended by major guidelines of gastrointestinal tumors in the world. Meanwhile, they have a great impact on the traditional methods of surgery, the influence mainly involves the reduction of the surgical margin and the scope of lymph node dissection in gastric cancer, while involves performing organ preservation and watch & wait in selective patients with colorectal cancer. These effects and changes were based on effective control of local recurrence by neoadjuvant therapies, and the advantages of neoadjuvant therapy in terms of tumor regression and survival supported by many studies. It is also based on the patient's desire for organ preservation and non-surgical treatment. Meanwhile, application of neoadjuvant therapy strategies increase surgical difficulty and postoperative complications, but the overall impact on patient prognosis is weak. Therefore, the selection of an appropriate treatment model after neoadjuvant therapy requires an effective overall post-treatment evaluation. In particular, it is necessary to pay attention to the evaluation of imaging, endoscopy, etc., while effectively performing monitoring and follow-up, and finally establishing an appropriate salvage treatment. This article will review the status and problems of individualized treatment after neoadjuvant therapy of gastrointestinal tumor.

Objective:To report the long-term outcomes of Chinese rectal cancer patients after adopting a Watch and Wait (W&W) strategy following neoadjuvant therapy (NAT).Methods:This multicenter, cross-sectional study was based on real-world data. The study cohort comprised rectal cancer patients who had achieved complete or near complete clinical responses (cCRs, near-cCRs) after NAT and were thereafter managed by a W&W approach, as well as a few patients who had achieved good responses after NAT and had then undergone local excision for confirmation of pathological complete response. All participants had been followed up for ≥2 years. Patients with distant metastases at baseline or who opted for observation while living with the tumor were excluded. Data of eligible patients were retrospectively collected from the Chinese Wait-and-Watch Data Collaboration Group database. These included baseline characteristics, type of NAT, pre-treatment imaging results, evaluation of post-NAT efficacy, salvage measures, and treatment outcomes. We herein report the long-term outcomes of Chinese rectal cancer patients after NAT and W&W and the differences between the cCR and near-cCR groups.Results:Clinical data of 318 rectal cancer patients who had undergone W&W for over 2 years and been followed up were collected from eight medical centers (Peking University Cancer Hospital, Fudan University Shanghai Cancer Center, Sun Yat-sen University Cancer Center, Shanghai Changhai Hospital, Peking Union Medical College Hospital, Liaoning Cancer Hospital, the First Hospital of Jilin University, and Yunnan Cancer Hospital.) The participants comprised 221 men (69.4%) and 107 women (30.6%) of median age 60 (26-86) years. The median distance between tumor and anal verge was 3.4 (0-10.4) cm. Of these patients, 291 and 27 had achieved cCR or near-cCR, respectively, after NAT. The median duration of follow-up was 48.4 (10.2-110.3) months. The 5-year cumulative overall survival rate was 92.4% (95%CI: 86.8%-95.7%), 5-year cumulative disease-specific survival (CSS) rate 96.6% (95%CI: 92.2%-98.5%), 5-year cumulative organ-preserving disease-free survival rate 86.6% (95%CI: 81.0%-90.7%), and 5-year organ preservation rate 85.3% (95%CI: 80.3%-89.1%). The overall 5-year local recurrence and distant metastasis rates were 18.5% (95%CI: 14.9%-20.8%) and 8.2% (95%CI: 5.4%-12.5%), respectively. Most local recurrences (82.1%, 46/56) occurred within 2 years, and 91.0% (51/56) occurred within 3 years, the median time to recurrence being 11.7 (2.5-66.6) months. Most (91.1%, 51/56) local recurrences occurred within the intestinal lumen. Distant metastases developed in 23 patients; 60.9% (14/23) occurred within 2 years and 73.9% (17/23) within 3 years, the median time to distant metastasis being 21.9 (2.6-90.3) months. Common sites included lung (15/23, 65.2%), liver (6/23, 26.1%), and bone (7/23, 30.4%) The metastases involved single organs in 17 patients and multiple organs in six. There were no significant differences in overall, cumulative disease-specific, or organ-preserving disease-free survival or rate of metastases between the two groups (all P>0.05). The 5-year local recurrence rate was higher in the near-cCR than in the cCR group (41.6% vs. 16.4%, P<0.01), with a lower organ preservation rate (69.2% vs. 88.0%, P<0.001). The success rates of salvage after local recurrence and distant metastasis were 82.1% (46/56) and 13.0% (3/23), respectively. Conclusion:Rectal cancer patients who achieve cCR or near-cCR after NAT and undergo W&W have favorable oncological outcomes and a high rate of organ preservation. Local recurrence and distant metastasis during W&W follow certain patterns, with a relatively high salvage rate for local recurrence. Our findings highlight the importance of close follow-up and timely intervention during the W&W process.

Objective:To investigate perspectives and changes in treatment selection by Chinese surgeons since introduction of the watch-and-wait approach after neoadjuvant therapy for rectal cancer.Methods:A cross-sectional survey was conducted using a questionnaire distributed through the "Wenjuanxing" online survey platform. The survey focused on the recognition and practices of Chinese surgeons regarding the strategy of watch-and-wait after neoadjuvant therapy for rectal cancer and was disseminated within the China Watch-and-Wait Database (CWWD) WeChat group. This group targets surgeons of deputy chief physician level and above in surgical, radiotherapy, or internal medicine departments of nationally accredited tumor-specialist or comprehensive hospitals (at provincial or municipal levels) who are involved in colorectal cancer diagnosis and treatment. From 13 to 16 December 2023, 321 questionnaires were sent with questionnaire links in the CWWD WeChat group. The questionnaires comprised 32 questions encompassing: (1) basic physician characteristics (including surgical volume); (2) assessment methods and criteria for clinical complete response (cCR); (3) patients eligible for watch-and-wait; (4) neoadjuvant therapies and other measures for achieving cCR; (5) willingness to implement watch-and-wait and factors influencing that willingness; (6) risks and monitoring of watch-and-wait; (7) subsequent treatment and follow-up post watch-and-wait; (8) suggestions for development of the CWWD. Descriptive statistics were employed for data analysis, with intergroup comparisons conducted using the χ 2 or Fisher's exact probability tests. Results:The response rate was 31.5%, comprising 101 responses from the 321 individuals in the WeChat group. Respondents comprised 101 physicians from 70 centers across 23 provinces, municipalities, and autonomous regions nationwide, 85.1% (86/101) of whom represented provincial tertiary hospitals. Among the respondents, 87.1% (88/101) had implemented the watch-and-wait strategy. The approval rate (65.6%, 21/32) and proportion of patients often informed (68.8%, 22/32) were both significantly higher for doctors in oncology hospitals than for those in general hospitals (27.7%, 18/65; 32.4%, 22/68) (χ 2=12.83, P<0.001; χ 2=11.70, P=0.001, respectively). The most used methods for diagnosing cCR were digital rectal examination (90.1%, 91/101), colonoscopy (91.1%, 92/101), and rectal T2-weighted magnetic resonance imaging (86.1%, 87/101). Criteria used to identify cCR comprised absence of a palpable mass on digital rectal examination (87.1%, 88/101), flat white scars or new capillaries on colonoscopy (77.2%, 78/101), absence of evident tumor signals on rectal T2-weighted sequences or T2WI low signals or signals equivalent to the intestinal wall (83.2%, 84/101), and absence of tumor hyperintensity on diffusion-weighted imaging with no corresponding hypointensity on apparent diffusion coefficient maps (66.3%, 67/101). As for selection of neoadjuvant regimen and assessment of cCR, 57.4% (58/101) of physicians preferred a long course of radiotherapy with or without induction and/or consolidation capecitabine + oxaliplatin, whereas 25.7% (26/101) preferred immunotherapy in combination with chemotherapy and concurrent radiotherapy. Most (96.0%, 97/101) physicians believed that the primary lesion should be assessed ≤12 weeks after completion of radiotherapy. Patients were frequently informed about the possibility of achieving cCR after neoadjuvant therapy and the strategy of watch-and-wait by 43.6% (44/101) of the responding physicians and 38.6% (39/101) preferred watch-and-wait for patients who achieved cCR or near cCR after neoadjuvant therapy for rectal cancer. Capability for multiple follow-up evaluations (70.3%, 71/101) was a crucial factor influencing physicians' choice of watch-and-wait after cCR. The proportion who patients who did not achieve cCR and underwent surgical treatment was lower in provincial tertiary hospitals (74.2%, 23/31) than in provincial general hospitals (94.5%, 52/55) and municipal hospitals (12/15); these differences are statistically significant (χ 2=7.43, P=0.020). The difference between local recurrence and local regrowth was understood by 88.1% (89/101) of respondents and 87.2% (88/101) agreed with monitoring every 3 months for 5 years. An increase in local excision or puncture rates to reduce organ resections in patients with pCR was proposed by 64.4% (65/101) of respondents. Conclusion:Compared with the results of a previous survey, Chinese surgeons' awareness of the watch-and-wait concept has improved significantly. Oncologists in oncology hospitals are more aware of the concept of watch-and-wait.

Objective:To evaluate the short-term efficacy and safety of a preoperative combination of programmed cell death protein-1 (PD-1) inhibitor with either oxaliplatin + capecitabine (CapeOx) or oxaliplatin + tegafur gimeracil oteracil potassium (SOX) in the treatment of locally advanced immunotherapy-sensitive gastric cancer (LAGC) or adenocarcinoma of the esophagogastric junction (AEG).Methods:The cohort of this retrospective descriptive case series comprised patients with LAGC or AEG whose cancers had been determined to be immunotherapy- sensitive by endoscopic biopsy before treatment in the Gastrointestinal Cancer Center, Unit III, Peking University Cancer Hospital and Institute from 1 August 1 2021 to 31 January 2024. Patients with any one of the following three characteristics were immunotherapy-sensitive: (i) PD-L1 combined positive score (CPS) ≥5; (ii) microsatellite instability-high (MSI-H) / mismatch repair deficiency (dMMR); or (iii) Epstein-Barr virus-encoded RNA (EBER) positivity. All study patients received PD-1 inhibitors combined with CapeOx or SOX as a neoadjuvant or conversion treatment strategy before surgery. Patients with immune system diseases, distant metastases, or human epidermal growth factor receptor 2 positivity were excluded. Factors analyzed included pathological complete response, clinical complete response, major pathological response, R0 resection rate, surgical conversion rate, and safety of the treatment, including immune-related adverse events (irAEs) and surgical complications.Results:The study cohort comprised 39 patients (28 men and 11 women) of median age 62 (range 44–79) years. After the above-described preoperative treatment, radical resection of the 14 tumors that were initially considered unresectable was achieved (surgical conversion rate: 14/14). Twenty-three of the remaining 25 patients underwent radical resection. The last two patients achieved clinical complete responses and opted for a "non-surgical strategy" (watch and wait). Overall, 37 patients (94.9%) underwent radical resection, with an R0 resection rate of 100% (37/37), pathological complete response rate of 48.6% (18/37), and major pathological response rate of 62.2% (23/37). Of the 24 patients with CPS ≥ 5 (non-MSI-H/dMMR and non-EBER positive), 11 achieved pathological complete responses and one with CPS=95 achieved a clinical complete response. Of the eight patients with MSI-H/dMMR, six achieved pathological complete responses and one a clinical complete response. Of the seven patients with EBER positivity, one achieved a pathological complete response. After excluding patients with major pathological complete responses, there was a statistically significant difference in CPS scores between preoperative biopsy specimens and postoperative surgical specimens in 13 patients (7.769±5.570 vs. 15.538±16.870, t=2.287, P=0.041). All patients tolerated preoperative immunotherapy well; nine patients (9/39, 23.1%) had Grade I–II irAEs. There were no Grade III–IV irAEs. The five patients with pyloric obstruction before treatment tolerated normal diets after treatment. The incidence of postoperative complications among all patients who underwent surgery was 18.9% (7/37), including one case of Grade IIIA anastomotic leakage, one of Grade IIIA intestinal obstruction, one of Grade II abdominal hemorrhage, two of Grade II abdominal infection, one of Grade I intestinal obstruction. Additionally, one patient developed COVID-19 postoperatively. All patients recovered with symptomatic treatment. Conclusion:We found that preoperative treatment of patients with LAGC or AEG of one of three types (CPS≥5, dMMR+MSI-H, and EBER positivity) with a PD-1 inhibitor combined with CapeOx or SOX chemotherapy achieved promising effectiveness and safety, with high surgical conversion, R0 resection, and complete response rates.

Gastrointestinal tumors have been widely concerned because of increasing morbidity and mortality. In the process of exploring the therapeutic patterns of gastrointestinal tumors, patients treated with neoadjuvant therapies have good effect of tumor regression and favorable prognosis. Thus, neoadjuvant therapy strategies are recommended by major guidelines of gastrointestinal tumors in the world. Meanwhile, they have a great impact on the traditional methods of surgery, the influence mainly involves the reduction of the surgical margin and the scope of lymph node dissection in gastric cancer, while involves performing organ preservation and watch & wait in selective patients with colorectal cancer. These effects and changes were based on effective control of local recurrence by neoadjuvant therapies, and the advantages of neoadjuvant therapy in terms of tumor regression and survival supported by many studies. It is also based on the patient's desire for organ preservation and non-surgical treatment. Meanwhile, application of neoadjuvant therapy strategies increase surgical difficulty and postoperative complications, but the overall impact on patient prognosis is weak. Therefore, the selection of an appropriate treatment model after neoadjuvant therapy requires an effective overall post-treatment evaluation. In particular, it is necessary to pay attention to the evaluation of imaging, endoscopy, etc., while effectively performing monitoring and follow-up, and finally establishing an appropriate salvage treatment. This article will review the status and problems of individualized treatment after neoadjuvant therapy of gastrointestinal tumor.

Objective:To report the long-term outcomes of Chinese rectal cancer patients after adopting a Watch and Wait (W&W) strategy following neoadjuvant therapy (NAT).Methods:This multicenter, cross-sectional study was based on real-world data. The study cohort comprised rectal cancer patients who had achieved complete or near complete clinical responses (cCRs, near-cCRs) after NAT and were thereafter managed by a W&W approach, as well as a few patients who had achieved good responses after NAT and had then undergone local excision for confirmation of pathological complete response. All participants had been followed up for ≥2 years. Patients with distant metastases at baseline or who opted for observation while living with the tumor were excluded. Data of eligible patients were retrospectively collected from the Chinese Wait-and-Watch Data Collaboration Group database. These included baseline characteristics, type of NAT, pre-treatment imaging results, evaluation of post-NAT efficacy, salvage measures, and treatment outcomes. We herein report the long-term outcomes of Chinese rectal cancer patients after NAT and W&W and the differences between the cCR and near-cCR groups.Results:Clinical data of 318 rectal cancer patients who had undergone W&W for over 2 years and been followed up were collected from eight medical centers (Peking University Cancer Hospital, Fudan University Shanghai Cancer Center, Sun Yat-sen University Cancer Center, Shanghai Changhai Hospital, Peking Union Medical College Hospital, Liaoning Cancer Hospital, the First Hospital of Jilin University, and Yunnan Cancer Hospital.) The participants comprised 221 men (69.4%) and 107 women (30.6%) of median age 60 (26-86) years. The median distance between tumor and anal verge was 3.4 (0-10.4) cm. Of these patients, 291 and 27 had achieved cCR or near-cCR, respectively, after NAT. The median duration of follow-up was 48.4 (10.2-110.3) months. The 5-year cumulative overall survival rate was 92.4% (95%CI: 86.8%-95.7%), 5-year cumulative disease-specific survival (CSS) rate 96.6% (95%CI: 92.2%-98.5%), 5-year cumulative organ-preserving disease-free survival rate 86.6% (95%CI: 81.0%-90.7%), and 5-year organ preservation rate 85.3% (95%CI: 80.3%-89.1%). The overall 5-year local recurrence and distant metastasis rates were 18.5% (95%CI: 14.9%-20.8%) and 8.2% (95%CI: 5.4%-12.5%), respectively. Most local recurrences (82.1%, 46/56) occurred within 2 years, and 91.0% (51/56) occurred within 3 years, the median time to recurrence being 11.7 (2.5-66.6) months. Most (91.1%, 51/56) local recurrences occurred within the intestinal lumen. Distant metastases developed in 23 patients; 60.9% (14/23) occurred within 2 years and 73.9% (17/23) within 3 years, the median time to distant metastasis being 21.9 (2.6-90.3) months. Common sites included lung (15/23, 65.2%), liver (6/23, 26.1%), and bone (7/23, 30.4%) The metastases involved single organs in 17 patients and multiple organs in six. There were no significant differences in overall, cumulative disease-specific, or organ-preserving disease-free survival or rate of metastases between the two groups (all P>0.05). The 5-year local recurrence rate was higher in the near-cCR than in the cCR group (41.6% vs. 16.4%, P<0.01), with a lower organ preservation rate (69.2% vs. 88.0%, P<0.001). The success rates of salvage after local recurrence and distant metastasis were 82.1% (46/56) and 13.0% (3/23), respectively. Conclusion:Rectal cancer patients who achieve cCR or near-cCR after NAT and undergo W&W have favorable oncological outcomes and a high rate of organ preservation. Local recurrence and distant metastasis during W&W follow certain patterns, with a relatively high salvage rate for local recurrence. Our findings highlight the importance of close follow-up and timely intervention during the W&W process.

Objective:To investigate perspectives and changes in treatment selection by Chinese surgeons since introduction of the watch-and-wait approach after neoadjuvant therapy for rectal cancer.Methods:A cross-sectional survey was conducted using a questionnaire distributed through the "Wenjuanxing" online survey platform. The survey focused on the recognition and practices of Chinese surgeons regarding the strategy of watch-and-wait after neoadjuvant therapy for rectal cancer and was disseminated within the China Watch-and-Wait Database (CWWD) WeChat group. This group targets surgeons of deputy chief physician level and above in surgical, radiotherapy, or internal medicine departments of nationally accredited tumor-specialist or comprehensive hospitals (at provincial or municipal levels) who are involved in colorectal cancer diagnosis and treatment. From 13 to 16 December 2023, 321 questionnaires were sent with questionnaire links in the CWWD WeChat group. The questionnaires comprised 32 questions encompassing: (1) basic physician characteristics (including surgical volume); (2) assessment methods and criteria for clinical complete response (cCR); (3) patients eligible for watch-and-wait; (4) neoadjuvant therapies and other measures for achieving cCR; (5) willingness to implement watch-and-wait and factors influencing that willingness; (6) risks and monitoring of watch-and-wait; (7) subsequent treatment and follow-up post watch-and-wait; (8) suggestions for development of the CWWD. Descriptive statistics were employed for data analysis, with intergroup comparisons conducted using the χ 2 or Fisher's exact probability tests. Results:The response rate was 31.5%, comprising 101 responses from the 321 individuals in the WeChat group. Respondents comprised 101 physicians from 70 centers across 23 provinces, municipalities, and autonomous regions nationwide, 85.1% (86/101) of whom represented provincial tertiary hospitals. Among the respondents, 87.1% (88/101) had implemented the watch-and-wait strategy. The approval rate (65.6%, 21/32) and proportion of patients often informed (68.8%, 22/32) were both significantly higher for doctors in oncology hospitals than for those in general hospitals (27.7%, 18/65; 32.4%, 22/68) (χ 2=12.83, P<0.001; χ 2=11.70, P=0.001, respectively). The most used methods for diagnosing cCR were digital rectal examination (90.1%, 91/101), colonoscopy (91.1%, 92/101), and rectal T2-weighted magnetic resonance imaging (86.1%, 87/101). Criteria used to identify cCR comprised absence of a palpable mass on digital rectal examination (87.1%, 88/101), flat white scars or new capillaries on colonoscopy (77.2%, 78/101), absence of evident tumor signals on rectal T2-weighted sequences or T2WI low signals or signals equivalent to the intestinal wall (83.2%, 84/101), and absence of tumor hyperintensity on diffusion-weighted imaging with no corresponding hypointensity on apparent diffusion coefficient maps (66.3%, 67/101). As for selection of neoadjuvant regimen and assessment of cCR, 57.4% (58/101) of physicians preferred a long course of radiotherapy with or without induction and/or consolidation capecitabine + oxaliplatin, whereas 25.7% (26/101) preferred immunotherapy in combination with chemotherapy and concurrent radiotherapy. Most (96.0%, 97/101) physicians believed that the primary lesion should be assessed ≤12 weeks after completion of radiotherapy. Patients were frequently informed about the possibility of achieving cCR after neoadjuvant therapy and the strategy of watch-and-wait by 43.6% (44/101) of the responding physicians and 38.6% (39/101) preferred watch-and-wait for patients who achieved cCR or near cCR after neoadjuvant therapy for rectal cancer. Capability for multiple follow-up evaluations (70.3%, 71/101) was a crucial factor influencing physicians' choice of watch-and-wait after cCR. The proportion who patients who did not achieve cCR and underwent surgical treatment was lower in provincial tertiary hospitals (74.2%, 23/31) than in provincial general hospitals (94.5%, 52/55) and municipal hospitals (12/15); these differences are statistically significant (χ 2=7.43, P=0.020). The difference between local recurrence and local regrowth was understood by 88.1% (89/101) of respondents and 87.2% (88/101) agreed with monitoring every 3 months for 5 years. An increase in local excision or puncture rates to reduce organ resections in patients with pCR was proposed by 64.4% (65/101) of respondents. Conclusion:Compared with the results of a previous survey, Chinese surgeons' awareness of the watch-and-wait concept has improved significantly. Oncologists in oncology hospitals are more aware of the concept of watch-and-wait.

Objective:To evaluate the short-term efficacy and safety of a preoperative combination of programmed cell death protein-1 (PD-1) inhibitor with either oxaliplatin + capecitabine (CapeOx) or oxaliplatin + tegafur gimeracil oteracil potassium (SOX) in the treatment of locally advanced immunotherapy-sensitive gastric cancer (LAGC) or adenocarcinoma of the esophagogastric junction (AEG).Methods:The cohort of this retrospective descriptive case series comprised patients with LAGC or AEG whose cancers had been determined to be immunotherapy- sensitive by endoscopic biopsy before treatment in the Gastrointestinal Cancer Center, Unit III, Peking University Cancer Hospital and Institute from 1 August 1 2021 to 31 January 2024. Patients with any one of the following three characteristics were immunotherapy-sensitive: (i) PD-L1 combined positive score (CPS) ≥5; (ii) microsatellite instability-high (MSI-H) / mismatch repair deficiency (dMMR); or (iii) Epstein-Barr virus-encoded RNA (EBER) positivity. All study patients received PD-1 inhibitors combined with CapeOx or SOX as a neoadjuvant or conversion treatment strategy before surgery. Patients with immune system diseases, distant metastases, or human epidermal growth factor receptor 2 positivity were excluded. Factors analyzed included pathological complete response, clinical complete response, major pathological response, R0 resection rate, surgical conversion rate, and safety of the treatment, including immune-related adverse events (irAEs) and surgical complications.Results:The study cohort comprised 39 patients (28 men and 11 women) of median age 62 (range 44–79) years. After the above-described preoperative treatment, radical resection of the 14 tumors that were initially considered unresectable was achieved (surgical conversion rate: 14/14). Twenty-three of the remaining 25 patients underwent radical resection. The last two patients achieved clinical complete responses and opted for a "non-surgical strategy" (watch and wait). Overall, 37 patients (94.9%) underwent radical resection, with an R0 resection rate of 100% (37/37), pathological complete response rate of 48.6% (18/37), and major pathological response rate of 62.2% (23/37). Of the 24 patients with CPS ≥ 5 (non-MSI-H/dMMR and non-EBER positive), 11 achieved pathological complete responses and one with CPS=95 achieved a clinical complete response. Of the eight patients with MSI-H/dMMR, six achieved pathological complete responses and one a clinical complete response. Of the seven patients with EBER positivity, one achieved a pathological complete response. After excluding patients with major pathological complete responses, there was a statistically significant difference in CPS scores between preoperative biopsy specimens and postoperative surgical specimens in 13 patients (7.769±5.570 vs. 15.538±16.870, t=2.287, P=0.041). All patients tolerated preoperative immunotherapy well; nine patients (9/39, 23.1%) had Grade I–II irAEs. There were no Grade III–IV irAEs. The five patients with pyloric obstruction before treatment tolerated normal diets after treatment. The incidence of postoperative complications among all patients who underwent surgery was 18.9% (7/37), including one case of Grade IIIA anastomotic leakage, one of Grade IIIA intestinal obstruction, one of Grade II abdominal hemorrhage, two of Grade II abdominal infection, one of Grade I intestinal obstruction. Additionally, one patient developed COVID-19 postoperatively. All patients recovered with symptomatic treatment. Conclusion:We found that preoperative treatment of patients with LAGC or AEG of one of three types (CPS≥5, dMMR+MSI-H, and EBER positivity) with a PD-1 inhibitor combined with CapeOx or SOX chemotherapy achieved promising effectiveness and safety, with high surgical conversion, R0 resection, and complete response rates.