[Clinicopathological features of gastric alpha-fetoprotein-producing adenocarcinoma with SWI/SNF complex deletion].

Objective: To investigate the clinicopathological features and treatment of gastric alpha-fetoprotein (AFP)-producing adenocarcinoma with SWI/SNF complex deletion. Methods: Four cases of gastric AFP-producing adenocarcinoma with SWI/SNF complex deletion diagnosed in Zhongshan Hospital of Fudan University from January 2021 to December 2022 were collected, and their histomorphological characteristics, immunohistochemical (IHC), in situ hybridization of Epstein-Barr virus-encoded RNA (EBER), next-generation sequencing results, clinicopathological features and treatment were summarized, and literature review was conducted. Results: Among the 4 patients, there were three males and one female. They presented with abdominal pain, belching and melena. Serum AFP was significantly elevated in three patients, and endoscopy showed ulcerative lesions. Microscopically, the tumor cells showed mainly diffuse flaky or nest-like growth and typical characteristics of hepatoid adenocarcinoma. In two cases there were adenoid growth, and the tumor cells in these areas possessed clear cytoplasm, suggesting enteroblastic differentiation. The tumor cell nuclei were pleomorphic with large nucleoli and brisk mitoses. The IHC results showed that the tumor cells expressed AFP, GPC3 and SALL4, and there was retained expression of broad-spectrum keratin (CKpan) and E-cadherin. IHC detection of SWI/SNF complex subunits, namely INI1 (SMARCB1), BRG1 (SMARCA4), BRM (SMARCA2), ARID1A protein was performed. In all four cases the hepatoid adenocarcinoma region and enteroblastic differentiation region showed SMARCA2 deletion, and one case with enteroblastic differentiation also showed ARID1A deletion. SMARCB1 and SMARCA4 deletions were not seen. All the four cases were diffusely positive for p53 protein, and the Ki-67 proliferation index was 80%-90%. There were no mismatch repair deletion detected; one cases showed HER2 was strongly positive (3+), and EBER was negative. None of the four cases had mutations in the SWI/SNF complex-related subunits detected by next-generation sequencing. Among the four patients, two underwent palliative surgery due to distant metastasis at the time of surgery, two underwent radical resection. Postoperative adjuvant chemotherapy was given to three patients. Conclusions: AFP-producing adenocarcinoma is a rare subtype of gastric cancer, which can be combined with SWI/SNF complex deletion, and the pathomorphological manifestations are different from the classical SWI/SNF complex deletion of undifferentiated carcinoma with rhabdoid phenotype.

[Reappraisals of biological behaviors of PDGFRA mutant gastrointestinal stromal tumor].

Objective: To investigate the biological behavior spectrum of platelet-derived growth factor alpha receptor (PDGFRA)-mutant gastrointestinal stromal tumor (GIST), and to compare the clinical values of the Zhongshan method of benign and malignant evaluation with the modified National Institutes of Health (NIH) risk stratification. Methods: A total of 119 cases of GIST with PDGFRA mutation who underwent surgical resection at Zhongshan Hospital, Fudan University from 2009 to 2020 were collected. The clinicopathological data, follow-up records, and subsequent treatment were reviewed and analyzed statistically. Results: There were 79 males and 40 females. The patients ranged in age from 25 to 80 years, with a median age of 60 years. Among them, 115 patients were followed up for 1-154 months, and 13 patients progressed to disease. The 5-year disease-free survival (DFS) and overall survival (OS) were 90.1% and 94.1%, respectively. According to the modified NIH risk stratification, 8 cases, 32 cases, 38 cases, and 35 cases were very-low risk, low risk, intermediate risk, and high risk, and 5-year DFS were 100.0%, 95.6%, 94.3%, and 80.5%, respectively. There was no significant difference in prognosis among the non-high risk groups, only the difference between high risk and non-high risk groups was significant (P=0.029). However, the 5-year OS was 100.0%, 100.0%, 95.0% and 89.0%, and there was no difference (P=0.221). According to the benign and malignant evaluation Zhongshan method, 43 cases were non-malignant (37.4%), 56 cases were low-grade malignant (48.7%), 9 cases were moderately malignant (7.8%), and 7 cases were highly malignant (6.1%). The 5-year DFS were 100.0%, 91.7%, 77.8%, 38.1%, and the difference was significant (P<0.001). The 5-year OS were 100.0%, 97.5%, 77.8%, 66.7%, the difference was significant (P<0.001). Conclusions: GIST with PDGFRA gene mutation shows a broad range of biological behavior, ranging from benign to highly malignant. According to the Zhongshan method, non-malignant and low-grade malignant tumors are common, the prognosis after surgery is good, while the fewer medium-high malignant tumors showed poor prognosis after surgical resection. The overall biological behavior of this type of GIST is relatively inert, which is due to the low proportion of medium-high malignant GIST. The modified NIH risk stratification may not be effective in risk stratification for PDGFRA mutant GIST.

[Clinicopathological features and prognostic factors of gastric intermediate-risk gastrointestinal stromal tumor after surgical resection: a retrospective study].

Objective: To investigate the clinicopathological features, treatment and prognosis of gastric intermediate-risk gastrointestinal stromal tumor (GIST), so as to provide a reference for clinical management and further research. Methods: A retrospective observational study of patients with gastric intermediate-risk GIST, who underwent surgical resection between January 1996 and December 2019 at Zhongshan Hospital of Fudan University, was carried out. Results: Totally, 360 patients with a median age of 59 years were included. There were 190 males and 170 females with median tumor diameter of 5.9 cm. Routine genetic testing was performed in 247 cases (68.6%, 247/360), and 198 cases (80.2%) showed KIT mutation, 26 cases (10.5%) showed PDGFRA mutation, and 23 cases were wild-type GIST. According to "Zhongshan Method"(including 12 parameters), there were 121 malignant and 239 non-malignant cases. Complete follow-up data were available in 241 patients; 55 patients (22.8%) received imatinib therapy, 10 patients (4.1%) experienced tumor progression, and one patient (PDGFRA mutation, 0.4%) died. Disease-free survival (DFS) and overall survival rate at 5 years was 96.0% and 99.6%, respectively. Among the intermediate-risk GIST, there was no difference in DFS between the overall population, KIT mutation, PDGFRA mutation, wild-type, non-malignant and malignant subgroups (all P>0.05). However, the non-malignancy/malignancy analysis showed that there were significant differences in DFS among the overall population (P<0.01), imatinib treatment group (P=0.044) and no imatinib treatment group (P<0.01). Adjuvant imatinib resulted in potential survival benefit for KIT mutated malignant and intermediate-risk GIST in DFS (P=0.241). Conclusions: Gastric intermediate-risk GIST shows a heterogeneous biologic behavior spectrum from benign to highly malignant. It can be further classified into benign and malignant, mainly nonmalignant and low-grade malignant. The overall disease progression rate after surgical resection is low, and real-world data show that there is no significant benefit from imatinib treatment after surgery. However, adjuvant imatinib potentially improves DFS of intermediate-risk patients with tumors harboring KIT mutation in the malignant group. Therefore, a comprehensive analysis of gene mutations in benign/malignant GIST will facilitate improvements in therapeutic decision-making.

[Selection and application of implementation strategies in implementation research].

Implementation research is a discipline that attempts to promote the application of evidence-based interventions in different settings and populations by using various methods and measures. Implementation strategies are the central part of implementation research, and as the field of implementation science evolves, more and more implementation strategies have been developed to facilitate the application of evidence-based interventions in the real world. To help researchers better understand and apply implementation strategies, this study will introduce implementation strategies in three aspects: classification, selection and application, and report.

[Clinical significance of pathological diagnosis and genetic abnormalities detection in gastrointestinal stromal tumor using endoscopic biopsy].

Objective: To investigate the clinical significance of pathological diagnosis and genetic abnormalities detection of gastrointestinal stromal tumor (GIST) using endoscopic biopsy. Methods: Patients with GIST diagnosed by endoscopic biopsy (from January 1st, 2016 to August 1st, 2018, at Zhongshan Hospital, Fudan University) were included in this study. This retrospective study evaluated the histopathologic and immunohistochemical (IHC) features, genetic abnormalities of the tumors and the treatment and clinical course of the patients. Results: Totally 4 095 cases of GIST were collected, among which 67 patients (67/4 095, 1.6%) underwent endoscopic biopsy. Forty-eight patients (71.6%) were male and 19 (28.4%) were female, with a mean age of 61 years (range 31-90 years). Fifty-nine lesions were located in stomach and eight in duodenum. Of all the 67 cases, 47 were spindle type, 14 were epithelioid type, and 6 mixed type. IHC staining showed the positive rates were 100.0% (64/64) for DOG1, 98.4% (62/63) for CD117, 87.5% (56/64) for CD34, 3.6% (2/56) for S-100 protein, 12.1% (7/58) for α-SMA, 12.3% (7/57) for desmin and 4.0% (2/50) for CKpan. Morphologically, 34 cases were malignant; three cases (all epithelioid type) were originally misdiagnosed as poorly differentiated carcinoma; missed-diagnosis were found in four cases (spindle type) due to the insufficient diagnostic tumor cells. The genetic abnormality detection rate in the biopsy tissue was 38.8% (26/67),among them two patients were lost to follow up after biopsy, 33 patients received surgical resection, 16 cases underwent operation after neoadjuvant therapy and 16 patients with advanced disease underwent continuous imatinib therapy, with the genetic testing rate of 6.1% (2/33), 10/16 and 14/16, respectively. Conclusions: Endoscopic biopsy is a useful but rare method for the preoperative diagnosis of GIST. For majority of biopsy, accurate pathological diagnosis and auxiliary examination can be completed to guide clinical treatment. A thorough history in combination with endoscopic finding is essential to avoid misdiagnosis (epithelioid type) and missed diagnosis (spindle type) in suspicious cases. Genetic testing should be recommended in patients who will undergo targeted therapy after endoscopic biopsy, and it can provide valuable information and guidance for clinical treatment.

Neoadjuvant chemoradiotherapy versus neoadjuvant chemotherapy followed by minimally invasive esophagectomy for locally advanced esophageal squamous cell carcinoma: a prospective multicenter randomized clinical trial.

BACKGROUND: Neoadjuvant therapy is recommended for locally advanced esophageal cancer, but the optimal strategy remains unclear. We aimed to evaluate the safety and efficacy of neoadjuvant chemoradiotherapy (nCRT) versus neoadjuvant chemotherapy (nCT) followed by minimally invasive esophagectomy (MIE) for locally advanced esophageal squamous cell carcinoma (ESCC). PATIENTS AND METHODS: Eligible patients staged as cT3-4aN0-1M0 ESCC were randomly assigned (1 : 1) to the nCRT or nCT group stratified by age, cN stage, and centers. The chemotherapy, based on paclitaxel and cisplatin, was administered to both groups, while concurrent radiotherapy was added for the nCRT group; then MIE was carried out. The primary endpoint was 3-year overall survival. This study is registered with ClinicalTrials.gov (NCT03001596). RESULTS: A total of 264 patients were eligible for the intention-to-treat analysis. By 30 November 2021, 121 deaths had occurred. The median follow-up was 43.9 months (interquartile range 36.6-49.3 months). The overall survival in the intention-to-treat population was comparable between the nCRT and nCT strategies [hazard ratio (HR) 0.82, 95% confidence interval (CI) 0.58-1.18; P = 0.28], with a 3-year survival rate of 64.1% (95% CI 56.4% to 72.9%) versus 54.9% (95% CI 47.0% to 64.2%), respectively. There were also no differences in progression-free survival (HR 0.83, 95% CI 0.59-1.16; P = 0.27) and recurrence-free survival (HR 1.07, 95% CI 0.71-1.60; P = 0.75), although the pathological complete response in the nCRT group (31/112, 27.7%) was significantly higher than that in the nCT group (3/104, 2.9%; P < 0.001). Besides, a trend of lower risk of recurrence was observed in the nCRT group (P = 0.063), while the recurrence pattern was similar (P = 0.802). CONCLUSIONS: NCRT followed by MIE was not associated with significantly better overall survival than nCT among patients with cT3-4aN0-1M0 ESCC. The results underscore the pending issue of the best strategy of neoadjuvant therapy for locally advanced bulky ESCC.

[Sex disparities in clinical characteristics of Chinese patients with systemic sclerosis].

Objective: To evaluate the differences in clinical characteristics between different genders of Chinese patients with systemic sclerosis(SSc). Methods: The data of SSc patients registered in Chinese Rheumatism Data Center between August 2008 and June 2020 were retrospectively analyzed. Results: A total of 1 844 patients with SSc were enrolled in the study. The ratio of males to females was 289 to 1 555. The onset age was (48.6±13.7) years in males and (45.5±13.1) years in females(P<0.001). Male patients represented shorter disease duration [2.0(0.0, 4.0)years vs.3.0(1.0, 7.0) years, P<0.001],higher proportion of diffuse cutaneous SSc (dcSSc) [63.0% (182/289)vs.44.2%(688/1 555), P<0.001]. Although more man patients experienced smoking [47.4%(137/289) vs. 1.7%(27/1 555), P<0.001] and exposure to harmful environments [7.6%(22/289) vs. 2.1%(33/1 555), P<0.001], there was no statistically significant difference in interstitial lung disease between male and female patients [69.3%(181/261) vs. 74.5%(1 085/1 457), P=0.084].Otherwise, Raynaud's phenomenon [87.7% (1 364/1 555) vs.75.4%(218/289), P<0.001], arthritis [11.1%(173/1 555) vs.6.9%(20/289), P=0.032], gastroesophageal reflux disease [22.0%(342/ 1 555) vs.13.1%(38/289), P=0.001], and leucopoenia [10.7(161/1 511)% vs. 6.1%(17/279), P=0.019] were more common in female patients, but finger ulcer was less common [22.5%(350/1 555) vs. 30.4%(88/289), P=0.004]. Antinuclear antibody(ANA) positivity rate [85.6%(1 310/1 531) vs. 78.6%(221/281), P=0.003], anti-RNP antibody positivity rate [23.1%(342/1 479) vs.14.0%(38/271), P=0.001], anti-SSA antibody positivity rate [28.2%(419/1 487) vs.13.9%(38/274), P<0.001] were higher in female patients. Physician's global assessment(PGA) scores [1.4 (1.0, 2.0) vs. 1.0 (0.3, 1.6), P<0.001] and modified Rodnan Skin Score(mRSS) [18.0 (9.5, 28.0) vs. 14.0 (5.0, 28.0), P=0.003] were higher in males. Conclusion: Even though male SSc patients account for a small proportion, more extensive skin involvement, finger ulcers and higher PGA are manifested in males. Physicians need pay attention to these clinical disparities between different genders in SSc.

[Clinicopathological features and prognosis of gastrointestinal stromal tumors with KIT/PDGFRA gene "homozygous mutation": a multicenter retrospective cohort study].

Objective: To investigate the clinicopathological features of gastrointestinal stromal tumor (GIST) with KIT/PDGFRA "homozygous mutation", the efficacy of targeted therapy and the prognosis. Methods: A retrospective cohort study and propensity score matching were used. "Homozygous mutation" was defined as the detection of KIT/PDGFRA gene status of GIST by Sanger sequencing, which showed that there was only mutant gene sequence in the sequencing map, lack of wild-type sequence or the peak height of mutant gene sequence was much higher than that of wild-type gene sequence (> 3 times). "Heterozygous mutation" was defined as the mutant gene sequences coexisted with wild type gene sequences, and the peak height was similar (3 times or less). The clinicopathological data and follow-up information of 92 GIST patients with KIT/PDGFRA "homozygous mutation" were collected from 4 hospitals in Shanghai from January 2008 to May 2021 (Renji Hospital, Shanghai Jiaotong University School of Medicine: 70 cases; Zhongshan Hospital, Fudan University: 14 cases; Changhai Hospital, Naval Military Medical University: 6 cases and Ruijin Hospital, Shanghai Jiaotong University School of Medicine: 2 cases). Patients with perioperative death, other malignancies, and incomplete clinicopathological information were excluded. The clinicopathological features of the patients and the efficacy of targeted drug therapy were observed and analyzed. The efficacy was evaluated using Choi criteria, which were divided into complete response (CR), partial response (PR), stable disease (SD) and progressive disease (PD). In addition, a total of 230 patients with high-risk GIST with "heterozygous mutation" in exon 11 of KIT gene and 117 patients with recurrent or metastatic GIST with "heterozygous mutation" in exon 11 of KIT gene were included. The propensity score matching method was used to match GIST patients with "heterozygous" and "homozygous" mutations in exon 11 of KIT gene (1∶1) for survival analysis. The disease-free survival (DFS) between two groups of high-risk GIST patients who underwent complete surgical resection were compared. And progression-free survival (PFS) in patients with recurrent or metastatic GIST were compared. Results: Of the 92 GIST cases with KIT/PDGFRA "homozygous mutation", 58 were males and 34 were females, with a median onset age of 62 (31-91) years. Primary GIST 83 cases. Primary high-risk GIST (53 cases), metastatic GIST (21 cases) and recurrent GIST (9 cases) accounted for 90.2% (83/92). There were 90 cases of KIT gene"homozygous mutation" (exon 11 for 88 cases, exon 13 for 1 case, exon 17 for 1 case), and 2 cases of PDGFRA gene "homozygous mutation" (exon 12 for 1 case, exon 18 for 1 case). The median follow-up time was 49 (8-181) months. Among the 61 cases of primary localized GIST undergoing complete surgical resection, 2 cases were intermediate-risk GIST, 5 cases were low-risk GIST, and 1 case was very low-risk GIST, of whom 1 case of intermediate-risk GIST received 1-year adjuvant imatinib mesylate (IM) therapy after operation, and no tumor recurrence developed during the follow-up period. The remaining 53 cases were high-risk GIST, and follow-up data were obtained from 50 cases, of whom 22 developed tumor recurrence during follow-up. Of 9 patients directly receiving neoadjuvant targeted therapy (IM or avapritinib), 5 had complete imaging follow-up data, and the evaluation of efficacy achieved PR. Of all the 92 GIST cases with KIT/PDGFRA "homozygous mutation", 50 (54.4%) had tumor metastasis or tumor recurrence or progression during follow-up, and 12 (13.0%) died of the tumor. Survival analysis combined with propensity score showed that in 100 cases of high-risk GISTs with complete resection, GISTs with "homozygous mutation" in exon 11 of KIT gene had shorter disease-free survival (DFS) than GISTs with "heterozygous mutation" in exon 11 of KIT gene (median DFS: 72 months vs. 148 months, P=0.015). In 60 cases of recurrent or metastatic GISTs with KIT gene exon 11 mutation, IM was used as the first-line treatment, and the progression-free survival (PFS) of GISTs with "homozygous mutation" was shorter compared to GISTs with "heterozygous mutation" (median PFS: 38 months vs. 69 months, P=0.044). The differences were statistically significant. Conclusions: "Homozygous mutation" in KIT/PDGFRA gene is associated with the progression of GIST. The corresponding targeted therapeutic drugs are still effective for GIST with KIT/PDGFRA gene "homozygous mutation". Compared with GIST patients with "heterozygous mutation" in KIT exon 11, GIST patients with "homozygous mutation" in KIT exon 11 are more likely to relapse after surgery and to develop resistance to IM. Therefore, it is still necessary to seek more effective treatment methods for this subset of cases.

[MAML2 gene rearrangement, fusion patterns and clinicopathological characteristics in primary pulmonary mucoepidermoid carcinoma].

Objective: To investigate MAML2 gene rearrangement, gene fusion patterns, and the clinicopathological characteristics of primary pulmonary mucoepidermoid carcinoma (PMEC). Methods: Forty-six cases of primary PMEC from Fudan University Zhongshan Hospital and Fudan University Shanghai Cancer Center between 2017 and 2020 were collected. MAML2 gene rearrangement in all cases was detected by fluorescence in situ hybridization (FISH). In 20 cases, MAML2 fusion patterns were detected by targeted RNA sequencing (RNAseq). The relationship between MAML2 gene rearrangement, fusion patterns, clinicopathological characteristics, and prognosis was analyzed. Results: The average age of PMEC patients was 41 years (range 15-71 years); the ratio of male to female was about 1.1 ∶ 1.0. Most PMECs were low grade in histopathology with an early clinical stage (stageⅠ-Ⅱ).The overall positive rate of MAML2 gene rearrangement detected by FISH was about 80.4% (37/46), and the rate was higher in low-grade PMEC (91.7%, 33/36). Of the 20 cases detected by RNAseq, all the 19 FISH positive cases showed gene fusion, mainly CRTC1-MAML2 fusion (16/19), the other three cases showed CRTC3-MAML2 fusion (3/19), the break point of all the fusion patterns was CRTC1/3 (exon 1)-MAML2 (exon 2); No gene fusion was detected in the single FISH negative case; Compared with the MAML2 FISH negative patients, the PMECs carrying CRTC1-MAML2 fusion were more commonly found in patients age ≤ 40 years, maximum tumor diameter ≤ 2 cm, low histopathological grade and early clinical stage (all P<0.05); The three PMECs carrying CRTC3-MAML2 fusion gene were all female with early clinical stage; Univariate analysis showed that MAML2 gene rearrangement/fusion, onset age ≤ 40 years old, smaller tumor size, low histopathological grade, early clinical stage, no metastasis at diagnosis and surgical treatment were significantly correlated with overall survival (P<0.05), but Cox regression analysis suggested that none of the above indicators were the independent prognostic factors for the survival of PMEC. Conclusions: The high incidence of MAML2 gene rearrangement in PMEC suggests that it is an important molecular diagnostic marker of PMEC. RNAseq confirms that CRTC1/3-MAML2 is the main fusion pattern in PMEC, suggesting that MAML2 fusion transcription may be an important driving factor of PMEC. MAML2 rearrangement/fusion and related clinicopathological characteristics are associated with good prognosis.

Barriers to early diagnosis and treatment of severely immunosuppressed patients with HIV-1 infection: A quantitative and qualitative study.

OBJECTIVES: To explore the barriers to early diagnosis of HIV infection and timely initiation of antiretroviral therapy (ART). METHODS: We assessed the annual number and proportion of ART-naïve people living with HIV infection (PLWH) with severe immunosuppression in Shenzhen, China, from 2008 to 2019. Selected ART-naïve PLWHs with severe immunosuppression who were seeking treatment for the first time in the hospital in 2019 were subjected to an in-depth interview. RESULTS: The proportion of severely immunosuppressed, ART-naïve PLWH decreased from 36.73% in 2008 to 8.94% in 2015, and then plateaued at approximately 10% from 2015 to 2019. Overall, 55 patients, 70% of whom were men who had sex with men, participated in the qualitative interviews. Ten of them delayed treatment after diagnosis, with a median [interquartile range (IQR)] interval of 5.83 (3.98-8.54) years between diagnosis and ART. More than 80% of the patients reported casual sexual contact within a median period of 6 years and with a median (IQR) of nine (4-20) casual sex partners. The major barriers to HIV testing and diagnosis included lack of knowledge about HIV and high-risk behaviours, low awareness about HIV testing, and resistance to HIV testing. The major barriers to ART initiation included lack of knowledge about the importance of ART and change of national ART eligibility policy, and HIV-related stress. CONCLUSIONS: The number of PLWHs with severe immunosuppression who seek treatment remains high in Shenzhen, China. Thus, current HIV-related care programmes targeting access to early diagnosis and treatment need to be improved.

[Clinicopathological features and prognosis of 59 patients with platelet-derived growth factor α-mutant gastrointestinal stromal tumor].

Objective: Platelet-derived growth factor α (PDGFRA)-mutant gastrointestinal stromal tumor (GIST) is a relatively rare disease, whose clinicopathological characteristics and prognosis have been poorly studied. In this paper, the clinicopathological features and prognostic factors of PDGFRA-mutant GIST are investigated to provide more data for its understanding and treatment. Methods: A retrospective case-control study was used to collect the medical records of patients with GIST who underwent surgical resection in Zhongshan Hospital of Fudan University from January 2015 to August 2019. Patients with PDGFRA-mutant GIST were enrolled, and those with synonymous PDGFRA mutations, non-tumor-related deaths, and lack of clinicopathological data were excluded. The clinicopathological data were collected and the risk factors associated with prognosis were analyzed. Results: Among the enrolled 59 patients, there were 41 males (69.5%) and 18 females (30.5%) with the median age of 60 (25-79) years. All tumors originated from the stomach. The tumor size was 5 (3-7) cm, and the mitotic count was 2 (1-4)/50 high-power fields (HPF). According to the modified NIH risk stratification, 8 cases were classified as very low risk (13.6%), 25 cases as low risk (42.4%), 14 cases as moderate risk (23.7%), and 12 cases as high risk (20.3%). There were 7 cases of exon 12 mutation and 52 cases of exon 18 mutation (including 36 cases of D842V mutation). A comparison of clinicopathological features between the D842V mutation group and the non-D842V mutation group showed no statistically significant difference (all P>0.05). During a median follow-up of 21 (0-59) months, the 1- and 3-year relapse-free survival (RFS) rates of all the patients were 96.6% and 91.5%, respectively. There were 8 cases of recurrence and 3 cases of death. Six GIST patients with D842V mutation had tumor recurrence after operation, of whom 4 cases achieved varying degrees of tumor remission after being treated with dasatinib or avapritinib. Log-rank analysis showed that the overall survival (OS) of male was better than that of female (100% vs. 83.3%, P=0.046), but there was no significant difference in OS among patients with different risk grades (P=0.057). The RFS and OS of patients with D842V mutation and non-D842V mutation, exon 12 and exon 18 mutation were similar (all P>0.05). Univariate Cox analysis showed that RFS was associated with gender (P=0.010), tumor size (P=0.042), mitotic count (P=0.003), and the modified NIH risk stratification (P=0.042), while multivariate analysis revealed that higher risk grade was an independent risk factor for recurrence of PDGFRA-mutant GIST (HR=12.796, 95%CI: 1.326-123.501, P=0.028). Gender was an independent factor for recurrence, and the risk of recurrence in males was lower than that in females (HR=0.154, 95%CI: 0.028-0.841, P=0.031). Conclusions: Gender and the modified NIH risk stratification are independent risk factors for recurrence of PDGFRA-mutant GIST, while patients with D842V and non-D842V mutation, and exon 12 and exon 18 mutation have a similar risk of recurrence and death.

[Pathological features of immune-mediated hepatitis due to immune checkpoint inhibitors and anti-angiogenesis targeted therapy].

Objective: To compare the histologic features of immune-mediated hepatitis (IMH) due to immune checkpoint inhibitors (ICIs) monotherapy and combined ICIs anti-angiogenesis tyrosine kinases (TKIs) targeted therapy. Methods: Twenty-one IMH patients who had liver biopsy during ICIs treatment in Zhongshan Hospital of Fudan University from 2015 to 2019 were included. Among them, ten were treated with ICIs monotherapy, and 11 were treated with combined ICIs and anti-angiogenesis targeted therapy. The histologic features of IMH were assessed by HE staining and PD-L1/2 was evaluated by immunohistochemical staining. Results: Patients treated with monotherapy ICIs presented with different levels of lobular hepatitis and portal inflammation. Besides, there were also cholangitis, endothelialitis, Kupffer cells activation and peliosisi hepatitis. Eight cases (8/10) showed mild and two cases (2/10) showed moderate hepatic injury. As for patients receiving combined ICIs and TKIs therapy, the extent of IMH was more severe, with four cases (4/11) showing moderate-severe liver injury, with confluent or bridging necrosis, portal inflammation, cholangitis, interface hepatitis. Among these, one patient developed acute severe hepatitis with massive hepatocyte necrosis and died of multisystem dysfunction. In those cases with severe liver injury, many CD8 positive lymphocytes aggregated in the portal area and hepatic sinusoid, and PD-L1 was expressed in many endothelial cells. There were both 2 cases of death in ICIs monotherapy and combination therapy group. Among the latter group, 1 patient developed acute severe hepatitis with massive hepatocyte necrosis and died of multisystem dysfunction. Conclusion: Compared with ICIs monotherapy, combined ICIs and anti-angiogenesis targeted TKIs therapy may cause overlapping hepatic injury, leading to severe IMH.