Objective:To explore the clinicopathological features of rectal neuroendocrine tumor (R-NET) G2, identify prognostic factors, and summarize treatment experience.Methods:The clinical data of patients diagnosed with R-NET G2 by pathological diagnosis admitted to Cancer Hospital of the Chinese Academy of Medical Sciences from January 2003 to September 2023 were retrospectively analyzed. The Fisher's exact test and Kaplan-Meier curves were performed to analyze the association between pathological features and prognosis.Results:A total of 22 patients were enrolled in this study and 21 patients were followed up for a period of 6-98 months with a median follow-up time of 42 months. 5 patients died due to tumor progression during the follow-up period. The 1-, 3-, and 5-year cancer-specific survival (CSS) of the whole group were 100.0%, 92.9%, and 69.6%, respectively. Of the 22 patients, 20 underwent surgical treatment, of which 15 underwent postoperative adjuvant therapy; 2 underwent medical treatment for liver and bone multiple metastases. The 5-year survival rates of patients with tumours ≥2 cm in length, T2-3 stage, lymph node metastasis, and distant metastasis (57.1%, 68.8%, 66.7%, and 63.6%, respectively) were shorter than those of patients with tumours <2 cm in length, T1 stage, no lymph node metastasis, and no distant metastasis (all 100.0%, P＜0.001). In addition, patients with liver metastases had larger primary tumor diameters and higher T-stages compared with those without distant metastasis ( P＜0.05). Conclusions:R-NET G2 has a high degree of malignancy compared with G1 and a high propensity for metastasis. Clinicians should formulate appropriate diagnostic and treatment strategies based on factors such as tumor size, depth of invasion, lymph node status, presence of distant metastasis, and the location and extent of distant metastasis.

Objective To investigate the proportions of myeloid-derived suppressor cells(MDSCs)and their subsets,including poly-morphonuclear MDSCs(PMN-MDSCs),early-stage MDSCs(e-MDSCs),monocytic MDSCs(M-MDSCs),and lectin-like oxidized low-density lipoprotein receptor-1(LOX-1)positive PMN-MDSCs,in the peripheral blood of ovarian cancer(OC)patients and ana-lyze their correlations with clinicopathological parameters of the patients.Methods The proportions of MDSCs and their subsets in the peripheral blood of 38 OC patients(OC group)and 46 healthy individuals(healthy control group)were detected by flow cytometry.The levels of serum IL-10 and TGF-β were detected using ELISA.The OC group was further divided into LOX-1 high and low expres-sion subgroups based on the median proportion of LOX-1+PMN-MDSCs in MDSCs.Results The proportions of MDSCs,PMN-MDSCs,and LOX-1+PMN-MDSCs in the peripheral blood mononuclear cells(PBMCs)of the OC group were significantly higher than those in the healthy control group(U=492,P＜0.001;t=8.741,P＜0.000 1;U=223,P＜0.000 1).The proportions of M-MDSCs and e-MDSCs in the OC group were significantly lower than those in the healthy control group(t=4.366,P＜0.000 1;t=6.927,P＜0.000 1).The proportion of LOX-1+PMN-MDSCs in the lymph node metastasis group of OC patients was significantly higher than that in the non-metastasis group(t=2.249,P＜0.05).The levels of serum IL-10 and TGF-β in the OC group were significantly higher than those in the healthy control group(P＜0.05).In addition,the level of serum TGF-β in the LOX-1 high expression group was significantly higher than that in the LOX-1 low expression group(t=2.302,P＜0.05).Conclusion The proportion of LOX-1+PMN-MDSCs in the peripheral blood of OC patients is significantly increased and closely related to lymph node metastasis.

Objective To investigate the proportions of myeloid-derived suppressor cells(MDSCs)and their subsets,including poly-morphonuclear MDSCs(PMN-MDSCs),early-stage MDSCs(e-MDSCs),monocytic MDSCs(M-MDSCs),and lectin-like oxidized low-density lipoprotein receptor-1(LOX-1)positive PMN-MDSCs,in the peripheral blood of ovarian cancer(OC)patients and ana-lyze their correlations with clinicopathological parameters of the patients.Methods The proportions of MDSCs and their subsets in the peripheral blood of 38 OC patients(OC group)and 46 healthy individuals(healthy control group)were detected by flow cytometry.The levels of serum IL-10 and TGF-β were detected using ELISA.The OC group was further divided into LOX-1 high and low expres-sion subgroups based on the median proportion of LOX-1+PMN-MDSCs in MDSCs.Results The proportions of MDSCs,PMN-MDSCs,and LOX-1+PMN-MDSCs in the peripheral blood mononuclear cells(PBMCs)of the OC group were significantly higher than those in the healthy control group(U=492,P＜0.001;t=8.741,P＜0.000 1;U=223,P＜0.000 1).The proportions of M-MDSCs and e-MDSCs in the OC group were significantly lower than those in the healthy control group(t=4.366,P＜0.000 1;t=6.927,P＜0.000 1).The proportion of LOX-1+PMN-MDSCs in the lymph node metastasis group of OC patients was significantly higher than that in the non-metastasis group(t=2.249,P＜0.05).The levels of serum IL-10 and TGF-β in the OC group were significantly higher than those in the healthy control group(P＜0.05).In addition,the level of serum TGF-β in the LOX-1 high expression group was significantly higher than that in the LOX-1 low expression group(t=2.302,P＜0.05).Conclusion The proportion of LOX-1+PMN-MDSCs in the peripheral blood of OC patients is significantly increased and closely related to lymph node metastasis.

Objective:To explore the clinicopathological features of rectal neuroendocrine tumor (R-NET) G2, identify prognostic factors, and summarize treatment experience.Methods:The clinical data of patients diagnosed with R-NET G2 by pathological diagnosis admitted to Cancer Hospital of the Chinese Academy of Medical Sciences from January 2003 to September 2023 were retrospectively analyzed. The Fisher's exact test and Kaplan-Meier curves were performed to analyze the association between pathological features and prognosis.Results:A total of 22 patients were enrolled in this study and 21 patients were followed up for a period of 6-98 months with a median follow-up time of 42 months. 5 patients died due to tumor progression during the follow-up period. The 1-, 3-, and 5-year cancer-specific survival (CSS) of the whole group were 100.0%, 92.9%, and 69.6%, respectively. Of the 22 patients, 20 underwent surgical treatment, of which 15 underwent postoperative adjuvant therapy; 2 underwent medical treatment for liver and bone multiple metastases. The 5-year survival rates of patients with tumours ≥2 cm in length, T2-3 stage, lymph node metastasis, and distant metastasis (57.1%, 68.8%, 66.7%, and 63.6%, respectively) were shorter than those of patients with tumours <2 cm in length, T1 stage, no lymph node metastasis, and no distant metastasis (all 100.0%, P＜0.001). In addition, patients with liver metastases had larger primary tumor diameters and higher T-stages compared with those without distant metastasis ( P＜0.05). Conclusions:R-NET G2 has a high degree of malignancy compared with G1 and a high propensity for metastasis. Clinicians should formulate appropriate diagnostic and treatment strategies based on factors such as tumor size, depth of invasion, lymph node status, presence of distant metastasis, and the location and extent of distant metastasis.

Background::The differential diagnosis of mucoepidermoid carcinoma (MEC) from neoplasm undergoing mucinous features brings more pitfalls to pathologists. Combining specific MAML2 gene rearrangement and histological characteristics may be the solution. Methods::Twenty-five tumors with mucinous components were selected for differential diagnosis of MEC. All the cases were detected for MAML2 gene rearrangement. The cases diagnosed as MEC were classified into four variants: classic, oncocytic, Warthin-like, and nonclassified, and they were graded using the Brandwein system. The histological characteristics of non-MECs were summarized for differential diagnosis. Univariate survival analysis was performed on MECs. Results::There were 16 MECs; 62.5% were MAML2 rearranged. For the low-, intermediate-, and high-grade MECs, the rate of rearrangement was 83.3%, 100%, and 28.6%, respectively. Both the oncocytic and Warthin-like MECs were MAML2 rearranged. For the classic and nonclassified MECs without MAML2 rearrangement, non-keratinized squamoid cells and distinctive mucinous cells were essential diagnostic criteria. On survival analysis, all the disease progression occurred in high-grade MECs ( p = 0.038). Nine cases were diagnosed as non-MECs: pleomorphic adenoma with mucinous metaplasia showed no ex-capsular involvement; metaplastic Warthin tumor appeared with overt keratinization and residual oncocytic bilayered epithelium; mix squamous cell and glandular papilloma showed an endobronchial papillary growing pattern; adenosquamous carcinoma was accompanied by squamous carcinoma in situ of the overlying mucosa. All the non-MECs were negative for MAML2 rearrangement. Conclusion::The application of combining MAML2 rearrangement and histological characteristics is helpful in the differential diagnosis between MEC and other tumors with mucinous components.

Background::The differential diagnosis of mucoepidermoid carcinoma (MEC) from neoplasm undergoing mucinous features brings more pitfalls to pathologists. Combining specific MAML2 gene rearrangement and histological characteristics may be the solution. Methods::Twenty-five tumors with mucinous components were selected for differential diagnosis of MEC. All the cases were detected for MAML2 gene rearrangement. The cases diagnosed as MEC were classified into four variants: classic, oncocytic, Warthin-like, and nonclassified, and they were graded using the Brandwein system. The histological characteristics of non-MECs were summarized for differential diagnosis. Univariate survival analysis was performed on MECs. Results::There were 16 MECs; 62.5% were MAML2 rearranged. For the low-, intermediate-, and high-grade MECs, the rate of rearrangement was 83.3%, 100%, and 28.6%, respectively. Both the oncocytic and Warthin-like MECs were MAML2 rearranged. For the classic and nonclassified MECs without MAML2 rearrangement, non-keratinized squamoid cells and distinctive mucinous cells were essential diagnostic criteria. On survival analysis, all the disease progression occurred in high-grade MECs ( p = 0.038). Nine cases were diagnosed as non-MECs: pleomorphic adenoma with mucinous metaplasia showed no ex-capsular involvement; metaplastic Warthin tumor appeared with overt keratinization and residual oncocytic bilayered epithelium; mix squamous cell and glandular papilloma showed an endobronchial papillary growing pattern; adenosquamous carcinoma was accompanied by squamous carcinoma in situ of the overlying mucosa. All the non-MECs were negative for MAML2 rearrangement. Conclusion::The application of combining MAML2 rearrangement and histological characteristics is helpful in the differential diagnosis between MEC and other tumors with mucinous components.

Objective:To explore the clinicopathological and prognostic features of young onset patients with middle-low rectal cancer who received neoadjuvant chemoradiotherapy (NCRT).Methods:After NCRT, a total of 441 patients with primary middle-low rectal cancer treated with radical surgery at the Cancer Hospital, Chinese Academy of Medical Sciences (CHCAMS) from January 2004 to December 2016 were included. According to the age of disease onset, the patients were divided into the young group (51cases) and the middle-old group (390 cases), and the clinicopathological characteristics and survival of these patients were analyzed.Results:In the young group, 68.6% of patients received radical surgery within 7 weeks after NCRT, which was higher than 52.8% in the middle-old group ( P=0.047). The stage ypTNM Ⅲ in the young group was 51.0%, higher than 34.1% in the middle-old group ( P=0.027). The stage ypN+ in the young group was 51.0%, higher than 34.1% in the middle-old group ( P=0.047), The incidence of disease progression in the young group was 39.2%, higher than 25.1% in the middle-old group ( P=0.049). The incidence of distant metastasis in the young group was 35.3%, higher than 21.5% in the middle-old group( P=0.044). Most cases of disease progression occurred in the first 3 years after surgery for the young group, especially in the second year after surgery, the incidence of disease progression in the young group was 55.0%, higher than 26.5% in middle-old group ( P=0.025). The 3-year and 5-year disease-free survival (DFS) rates for the young group were 63.7% and 58.2%, lower than 81.0% and 74.3% in the middle-old group ( P=0.016), respectively. The 3-year and 5-year overall survival in the middle-old group (OS) rates for the young group were 85.4% and 69.2%, lower than 93.6% and 84.1% in the middle-old group ( P=0.033), respectively. The multivariate analysis showed that, response of primary tumor ( HR=4.804, 95% CI: 1.360-16.973) and total number of dissected lymph nodes ( HR=4.336, 95% CI: 1.739-10.809) in the young group were independent prognostic factors related to DFS. The total dissected number of lymph nodes( HR=3.295, 95% CI: 1.076-10.091)was an independent prognostic factor related to OS. In the middle-old group, response of primary tumor ( HR=2.626, 95% CI: 1.354-5.091), ypTNM stage (ypTNM Ⅲ: HR=5.837, 95% CI: 2.968-11.479) and tumor location distance from the anal verge ( HR=0.500, 95% CI: 0.308-0.812) were independent prognostic factors related to DFS. Lymphovascular invasion ( HR=0.500, 95% CI: 0.308-0.812) and ypTNM stage (ypTNM Ⅲ: HR=16.322, 95% CI: 5.049-52.771) were independent prognostic factors related to OS. Conclusions:Young onset rectal cancer patients are associated with shorter operation time interval, advanced pathological stage and poorer prognosis. More intensive adjuvant treatment and post-treatment surveillance should be conducted to young onset rectal cancer with NCRT.

Objective:To explore the risk factors for regional lymph node (RLN) metastasis in colorectal cancer patients with mismatch repair deficiency (dMMR).Methods:The data of 357 dMMR colorectal cancer patients who underwent surgery in National Cancer Center from January 2012 to December 2016 was retrospectively analyzed. Univariate and multivariate analysis were used to identify the risk factors for RLN metastasis.Results:Among the 357 patients, 204 were male and 153 were female, 61.6% (220/357) lesion located in right half colon, while the other 16.2% (58/357) located in rectum. Univariate analysis showed that tumor size, differentiation, lymphovascular invasion, tumor deposit, postoperative pathologic T stage (pT), the number of negative lymph nodes and the expression of the MSH6 protein were significantly associated with RLN metastasis ( P<0.05). All of the patients with well differentiation tumors (15 patients) or staged pT1 (13 patients) had no RLN metastasis. Multivariate analysis showed that tumor differentiation ( OR=2.582, 95% CI=1.567-4.274, P<0.001), pT ( OR=3.778, 95% CI=1.448-12.960, P=0.015) and the expression of MSH6 protein ( OR=2.188, 95% CI=1.159-4.401, P=0.021) were independent risk factors for RLN metastasis. Conclusions:The postoperative pT stage, tumor differentiation and the expression of MSH6 protein are independent risk factors for RLN metastasis of dMMR colorectal cancer. Preoperative assessment of these factors may further improve the accuracy of predicting the risk of RLN metastasis.

Objective:To explore the application value of the conditional disease-free survival (cDFS) analysis in predicting prognosis of stage-specific rectal cancer patients underwent neoadjuvant chemoradiotherapy (nCRT).Methods:Clinicopathologic data of 436 patients with rectal cancer received nCRT and radical operation in Cancer Hospital, Chinese Academy of Medical Sciences between January 2004 and December 2016 were retrospectively reviewed. With reference to conditional probability, the 3-year cDFS of patients at different ypTNM stage after completion of nCRT was estimated using the Kaplan-Meier method.Results:There were 66 patients of ypTNM stage 0 (pathological complete response), 87 patients of ypTNM stage Ⅰ, 135 patients of ypTNM stage Ⅱ and 148 patients of ypTNM stage Ⅲ. The 3-year accumulated DFS of patients with ypTNM stage 0, ypTNM stage Ⅰ, ypTNM stage Ⅱ, and ypTNM stage Ⅲ were 97.0%, 93.1%, 85.2%, and 64.2%, respectively. On the condition of postoperactive disease-free survival for 1 year, 2 years, 3 years, 4 years, and 5 years, the corresponding 3-year cDFS of patients at ypTNM stage 0 were 97.0%, 95.5%, 96.9%, 98.4%, 100.0%, respectively. The corresponding 3-year cDFS of patients at ypTNM Ⅲ were 68.2%, 79.3%, 86.3%, 92.1%, 96.4%, respectively. The more advanced ypTNM staging resulted in the more improvement of 3-year cDFS being acquired.Conclusion:cDFS is a better method to reflect the dynamic changes of the prognosis of rectal cancer patients with nCRT in different ypTNM stage, and it is useful to guide the clinicians to assess the prognosis and propose appropriate surveillance.

Objective:To explore the clinicopathological and prognostic features of young onset patients with middle-low rectal cancer who received neoadjuvant chemoradiotherapy (NCRT).Methods:After NCRT, a total of 441 patients with primary middle-low rectal cancer treated with radical surgery at the Cancer Hospital, Chinese Academy of Medical Sciences (CHCAMS) from January 2004 to December 2016 were included. According to the age of disease onset, the patients were divided into the young group (51cases) and the middle-old group (390 cases), and the clinicopathological characteristics and survival of these patients were analyzed.Results:In the young group, 68.6% of patients received radical surgery within 7 weeks after NCRT, which was higher than 52.8% in the middle-old group ( P=0.047). The stage ypTNM Ⅲ in the young group was 51.0%, higher than 34.1% in the middle-old group ( P=0.027). The stage ypN+ in the young group was 51.0%, higher than 34.1% in the middle-old group ( P=0.047), The incidence of disease progression in the young group was 39.2%, higher than 25.1% in the middle-old group ( P=0.049). The incidence of distant metastasis in the young group was 35.3%, higher than 21.5% in the middle-old group( P=0.044). Most cases of disease progression occurred in the first 3 years after surgery for the young group, especially in the second year after surgery, the incidence of disease progression in the young group was 55.0%, higher than 26.5% in middle-old group ( P=0.025). The 3-year and 5-year disease-free survival (DFS) rates for the young group were 63.7% and 58.2%, lower than 81.0% and 74.3% in the middle-old group ( P=0.016), respectively. The 3-year and 5-year overall survival in the middle-old group (OS) rates for the young group were 85.4% and 69.2%, lower than 93.6% and 84.1% in the middle-old group ( P=0.033), respectively. The multivariate analysis showed that, response of primary tumor ( HR=4.804, 95% CI: 1.360-16.973) and total number of dissected lymph nodes ( HR=4.336, 95% CI: 1.739-10.809) in the young group were independent prognostic factors related to DFS. The total dissected number of lymph nodes( HR=3.295, 95% CI: 1.076-10.091)was an independent prognostic factor related to OS. In the middle-old group, response of primary tumor ( HR=2.626, 95% CI: 1.354-5.091), ypTNM stage (ypTNM Ⅲ: HR=5.837, 95% CI: 2.968-11.479) and tumor location distance from the anal verge ( HR=0.500, 95% CI: 0.308-0.812) were independent prognostic factors related to DFS. Lymphovascular invasion ( HR=0.500, 95% CI: 0.308-0.812) and ypTNM stage (ypTNM Ⅲ: HR=16.322, 95% CI: 5.049-52.771) were independent prognostic factors related to OS. Conclusions:Young onset rectal cancer patients are associated with shorter operation time interval, advanced pathological stage and poorer prognosis. More intensive adjuvant treatment and post-treatment surveillance should be conducted to young onset rectal cancer with NCRT.