[Colorectal adenocarcinoma with enteroblastic differentiation: a clinicopathological analysis of eight cases].

Objective: To investigate the clinicopathological features of colorectal adenocarcinoma with enteroblastic differentiation (CAED). Methods: Eight cases of CAED diagnosed at the Department of Pathology, Fudan University Shanghai Cancer Center, Shanghai, China from January 2017 to August 2023 were collected. The histopathological, immunohistochemical, molecular and prognostic features of 8 CAED cases were analyzed. The relevant studies were also reviewed. Results: Among the eight patients, there were six males and two females, with an average age of 58 years (range: 29-77 years, median age: 61.5 years). Preoperative serum alpha-fetoprotein levels were elevated in five patients (14.0-286.6 µg/L). Four tumors were located in the colon, and four tumors in the rectum. Two patients were clinically staged as advanced stage (stage Ⅳ), and distant metastasis occurred at the initial diagnosis (one case had liver metastasis, and the other had lung, bone and multiple lymph nodes metastases). Six patients were clinically staged as locally-advanced stage (Stage Ⅱ-Ⅲ). Three of them developed distant metastases after surgery (one case had liver metastasis, one case had lung metastasis, and one case had peritoneal metastasis). Additionally, two patients died at 9 months and 24 months after surgery, respectively. The tumors were composed of various proportions of adenocarcinoma components with enteroblastic differentiation (30%-100%) and classical tubular adenocarcinoma components. The component with enteroblastic differentiation exhibited morphology similar to embryonic intestinal epithelium: cuboidal or columnar tumor cells arranged in tubular, papillary, cribriform, or solid nest patterns, with clear cytoplasm. Immunohistochemical studies showed that tumor cells expressed at least one oncofetal protein (SALL4, Glypican-3, and AFP). In addition, focal squamous differentiation was observed in 3 cases (3/8). Compared to the primary tumor, both CAED and squamous differentiation components were increased in the metastatic tumors. Based on the sequencing results of KRAS, NRAS and BRAF of the primary and/or metastatic tumors, 5 cases were wild-type, while KRAS exon 2 (G13D) mutations were identified in 2 cases. Conclusions: CAED is a rare colorectal malignancy with a dismal prognosis. Accurate pathological diagnosis is prognostically valuable. The histological features of enteroblastic differentiation, elevated serum AFP levels, and the expression of oncofetal proteins play an important role in the tumor diagnosis.

[Short-course radiotherapy combined with CAPOX and PD-1 inhibitor for the total neoadjuvant therapy of locally advanced rectal cancer: the preliminary single-center findings of a prospective, multicentre, randomized phase II trial (TORCH)].

Objective: Total neoadjuvant therapy has been used to improve tumor responses and prevent distant metastases in patients with locally advanced rectal cancer (LARC). Patients with complete clinical responses (cCR) then have the option of choosing a watch and wait (W&W) strategy and organ preservation. It has recently been shown that hypofractionated radiotherapy has better synergistic effects with PD-1/PD-L1 inhibitors than does conventionally fractionated radiotherapy, increasing the sensitivity of microsatellite stable (MSS) colorectal cancer to immunotherapy. Thus, in this trial we aimed to determine whether total neoadjuvant therapy comprising short-course radiotherapy (SCRT) combined with a PD-1 inhibitor improves the degree of tumor regression in patients with LARC. Methods: TORCH is a prospective, multicenter, randomized, phase II trial (TORCH Registration No. NCT04518280). Patients with LARC (T3-4/N+M0, distance from anus ≤10 cm) are eligible and are randomly assigned to consolidation or induction arms. Those in the consolidation arm receive SCRT (25Gy/5 Fx), followed by six cycles of toripalimab plus capecitabine and oxaliplatin (ToriCAPOX). Those in the induction arm receive two cycles of ToriCAPOX, then undergo SCRT, followed by four cycles of ToriCAPOX. Patients in both groups undergo total mesorectal excision (TME) or can choose a W&W strategy if cCR has been achieved. The primary endpoint is the complete response rate (CR, pathological complete response [pCR] plus continuous cCR for more than 1 year). The secondary endpoints include rates of Grade 3-4 acute adverse effects (AEs) etc. Results: Up to 30 September 2022, 62 patients attending our center were enrolled (Consolidation arm: 34, Induction arm:28). Their median age was 53 (27-69) years. Fifty-nine of them had MSS/pMMR type cancer (95.2%), and only three MSI-H/dMMR. Additionally, 55 patients (88.7%) had Stage III disease. The following important characteristics were distributed as follows: lower location (≤5 cm from anus, 48/62, 77.4%), deeper invasion by primary lesion (cT4 7/62, 11.3%; mesorectal fascia involved 17/62, 27.4%), and high risk of distant metastasis (cN2 26/62, 41.9%; EMVI+ 11/62, 17.7%). All 62 patients completed the SCRT and at least five cycles of ToriCAPOX, 52/62 (83.9%) completing six cycles of ToriCAPOX. Finally, 29 patients achieved cCR (46.8%, 29/62), 18 of whom decided to adopt a W&W strategy. TME was performed on 32 patients. Pathological examination showed 18 had achieved pCR, four TRG 1, and 10 TRG 2-3. The three patients with MSI-H disease all achieved cCR. One of these patients was found to have pCR after surgery whereas the other two adopted a W&W strategy. Thus, the pCR and CR rates were 56.2% (18/32) and 58.1% (36/62), respectively. The TRG 0-1 rate was 68.8% (22/32). The most common non-hematologic AEs were poor appetite (49/60, 81.7%), numbness (49/60, 81.7%), nausea (47/60, 78.3%) and asthenia (43/60, 71.7%); two patients did not complete this survey. The most common hematologic AEs were thrombocytopenia (48/62, 77.4%), anemia (47/62, 75.8%), leukopenia/neutropenia (44/62, 71.0%) and high transaminase (39/62, 62.9%). The main Grade III-IV AE was thrombocytopenia (22/62, 35.5%), with three patients (3/62, 4.8%) having Grade IV thrombocytopenia. No Grade V AEs were noted. Conclusions: SCRT-based total neoadjuvant therapy combined with toripalimab can achieve a surprisingly good CR rate in patients with LARC and thus has the potential to offer new treatment options for organ preservation in patients with MSS and lower-location rectal cancer. Meanwhile, the preliminary findings of a single center show good tolerability, the main Grade III-IV AE being thrombocytopenia. The significant efficacy and long-term prognostic benefit need to be determined by further follow-up.

[A novel attention fusion network-based multiple instance learning framework to automate diagnosis of chronic gastritis with multiple indicators].

Objective: To explore the performance of the attention-multiple instance learning (MIL) framework, an attention fusion network-based MIL, in the automated diagnosis of chronic gastritis with multiple indicators. Methods: A total of 1 015 biopsy cases of gastritis diagnosed in Fudan University Cancer Hospital, Shanghai, China and 115 biopsy cases of gastritis diagnosed in Shanghai Pudong Hospital, Shanghai, China were collected from January 1st to December 31st in 2018. All pathological sections were digitally converted into whole slide imaging (WSI). The WSI label was based on the corresponding pathological report, including "activity" "atrophy" and "intestinal metaplasia". The WSI were divided into a training set, a single test set, a mixed test set and an independent test set. The accuracy of automated diagnosis for the Attention-MIL model was validated in three test sets. Results: The area under receive-operator curve (AUC) values of Attention-MIL model in single test sets of 240 WSI were: activity 0.98, atrophy 0.89, and intestinal metaplasia 0.98; the average accuracy of the three indicators was 94.2%. The AUC values in mixed test sets of 117 WSI were: activity 0.95, atrophy 0.86, and intestinal metaplasia 0.94; the average accuracy of the three indicators was 88.3%. The AUC values in independent test sets of 115 WSI were: activity 0.93, atrophy 0.84, and intestinal metaplasia 0.90; the average accuracy of the three indicators was 85.5%. Conclusions: To assist in pathological diagnosis of chronic gastritis, the diagnostic accuracy of Attention-MIL model is very close to that of pathologists. Thus, it is suitable for practical application of artificial intelligence technology.

[Gastric SWI/SNF-complex deficient undifferentiated/rhabdoid carcinoma: a clinicopathological study].

Objective: To investigate the clinicopathological features, immunohistochemical characteristics, differential diagnosis and prognosis of gastric SWI/SNF-complex deficient undifferentiated/rhabdoid carcinomas. Methods: Two cases of gastric SWI/SNF-complex deficient undifferentiated/rhabdoid carcinoma were collected at Fudan University Shanghai Cancer Center, Shanghai, China from 2017 to 2018. The clinicopathological characteristics were analyzed. Hematoxylin and eosin, and immunohistochemical stains were performed, and the relevant literatures were reviewed. Results: The two patients were both male, aged 60 and 74 years, respectively. Their symptoms were both abdominal pain. The tumor arose in the esophagogastric junction in case 1, and the cardia to the fundus and the posterior wall of the upper part of gastric body in case 2. Both tumors were present as an ulcerative mass. The patients died of tumor 11 months and 8 months after surgery, respectively. Histologically, the tumor cells arranged in sheets, nests, cords or trabecular patterns, and pseudoavleolar structure. The tumor cells were epithelioid with uniform morphology, while the tumors showed scant stroma and massive necrosis. Variable rhabdoid cells and multinucleated giant cells were seen in both cases. SMARCA4 encoding protein BRG1 was undetectable in both tumors, while SMARCB1 encoding protein INI1 was detected. The tumor cells were diffusely positive for vimentin and negative for epithelial marker (CKpan), gastrointestinal stromal tumor markers (CD117 and DOG1), myogenic markers (desmin and myogenin), melanoma markers (S-100 protein, SOX10 and HMB45), and lymphohematopoietic markers (LCA and CD20). Conclusions: Gastric SWI/SNF-complex deficient undifferentiated/rhabdoid carcinoma is a rare and highly aggressive tumor with poor prognosis. The detection of subunits protein expression of SWI/SNF complex is important for diagnosis of the tumor.

[Clinicopathological features and outcome of gastroenteropancreatic high-grade (WHO G3) neuroendocrine tumors: a study of 60 cases].

Objective: To investigate the clinicopathological features and outcome of gastroenteropancreatic high-grade neuroendocrine tumors. Methods: A total of 60 gastroenteropancreatic high-grade neuroendocrine tumors were collected from January 1st, 2013 to December 31th, 2018 at Fudan University Shanghai Cancer Center, with available pathology databases and clinic follow-up information. At the same time, 157 cases of gastrointestinal pancreatic neuroendocrine neoplasm (NEN) diagnosed at the hospital in 2018 were collected and the incidence of NEN at all grades was compared. Results: There were 32 males and 28 females, aged 13-80 years (mean 54 years). Pancreas primary was the most common (48%, 29/60). Nodal metastatic rate was 9/16 and distant metastatic rate was 41%(18/44). Liver was the most common site of metastasis. Among all the gastroenteropancreatic neuroendocrine neoplasms diagnosed in the hospital in 2018, the incidence of high-grade neuroendocrine tumors was the lowest (7%, 11/157). High-grade neuroendocrine tumors had typical pathologic features of well-differentiated/moderate neuroendocrine tumors, but with significant differences in mitotic rates. By immunohistochemical staining, most of the tumors expressed neuroendocrine markers and somatostatin receptor 2 was positive in 60% (12/20) of the cases. The average Ki-67 index was 30%-40%, and there was significant difference between cases (18%-80%). The overall survival of high-grade neuroendocrine tumors was 43 months, and the disease-free survival was 12 months. Conclusions: High-grade neuroendocrine tumor is a rare group of neuroendocrine tumors, with unique clinicopathological features and good prognosis. Pathological classification and grading of gastroenteropancreatic neuroendocrine neoplasms can help clinicians to select appropriate treatment and accurately evaluate prognosis.

[HER2 status in gastric adenocarcinoma of Chinese: a multicenter study of 40 842 patients].

Objective: To investigation HER2 status in gastric adenocarcinoma of Chinese and contributing factors to the HER2 expression. Methods: HER2 status of 40 842 gastric adenocarcinomas and clinical data were retrospectively collected from 23 hospitals dated from 2013 to 2016. The association between HER2 positivity and clinicopathologic features was analyzed. Results: Of the 40 842 patients the median age was 62 years, the male female ratio was 2.6∶1.0. The rate of HER2 positivity was 8.8% (3 577/40 842). HER2 expression was related to the tissue type, tumor location, Lauren classification and tumor differentiation (P values: 0.009, 0.001, <0.01 and <0.01, respectively). Different HER2 expression status was observed between primary and recurrent tumors in 7.6% (48/635) cases. The rates of HER2 positivity ranged from 2% to 10% among different institutions. The rates of HER2 FISH amplification were dramatically different among the 23 hospitals (0-100%) with an average rate of 10% (810/8 156) in patients with HER2 IHC 2+ . Conclusions: HER2 expression is associated with clinicopathologic characteristics. HER2 re-assessment of tumor tissue and use of in situ hybridization techniques increase HER2 positivity. The current retrospective study should reflect the HER2 status in gastric adenocarcinoma of Chinese patients.

Prognostic significance of Versican expression in gastric adenocarcinoma.

Gastric cancer (GC) is the leading malignancy in the digestive system. Versican is a ubiquitous component of the extracellular matrix and has a role in tumor progression. We aim to examine the expression of Versican in GC and the relationship between Versican levels and patient survival. We detected the mRNA expression of Versican in tumorous pairs and adjacent normal tissues (ANTs) of 78 GC patients by quantitative real-time polymerase chain reaction. The protein expression of Versican in 101 cases of matched GC and ANT, as well as in 27 intraepithelial neoplastic (IN) samples, was evaluated by immunohistochemistry. We analyzed the correlation between Versican levels and clinical outcomes. Finally, we performed CCK-8 cell counting assay and transwell assay in GC cell lines. Versican mRNA expression was significantly greater in tumor tissues (P<0.001) than in ANT. Versican was majorly expressed in the stroma surrounding tumor epithelium and minorly some areas of tumor epithelium. The Versican expression level was higher in GC than in ANT (P=0.004), but no significant difference was observed between ANT and IN (P=0.517). The Versican mRNA and protein levels were consistent in GC. High Versican mRNA and protein expression correlated with greater tumor invasion depth (P=0.030, P=0.027). Univariate and multivariate analysis revealed that patients with high Versican mRNA expression exhibited poor disease-specific survival (P<0.001). In vitro experiments showed that Versican overexpression promoted cell proliferation and invasion. Our data indicate that Versican may be a novel prognostic indicator in GC and may be a potential target for clinical diagnosis.

HER2 status in gastric cancers: a retrospective analysis from four Chinese representative clinical centers and assessment of its prognostic significance.

BACKGROUND: HER2 has a predictive value in gastric cancer. However, its association with prognosis remains uncertain. The aim of our study was to estimate the HER2-positive rate in Chinese gastric cancers, compare the classical fluorescence in situ hybridization (FISH) method with the novel bright-field dual color silver-enhanced in situ hybridization (DSISH) detection system, and evaluate the relationship between the HER2 status and prognosis. PATIENTS AND METHODS: Seven hundred and twenty-six resected gastric cancers separately from four clinical centers in China were examined for HER2 by immunohistochemistry (IHC), FISH, and DSISH. RESULTS: The HER2-positive rate was 13%. The consistency between FISH and DSISH results was high (99%; κ = 0.958; P < 0.001). Tumor heterogeneity and polysomy were the main reasons for inconsistency. There was no significant difference in the 3-year overall survival (OS) between HER2-positive and -negative patients (P = 0.959). Multivariate analysis showed that HER2 was not an independent prognostic factor. CONCLUSION(S): HER2 overexpression and amplification occur in a significant number of Chinese gastric cancer patients. Given the obvious advantages and high consistency with FISH, DSISH was superior for evaluating HER2 amplification in gastric cancer. HER2 was not a prognostic factor for gastric cancer in our study.

Clinicopathological features and prognostic factors of rectal gastrointestinal stromal tumors.

AIM: Rectal gastrointestinal stromal tumor (GIST) was a rare disease. This study sought to summarize clinicopathological features and prognostic factors of rectal GISTs. METHODS: Clinicopathological characteristics and prognostic factors of rectal GISTs were investigated by reviewing patients undergoing curative resection at the Fudan University Shanghai Cancer Center between 1986 and 2010. RESULTS: Twenty-one patients, 15 male and 6 female, were included. The mean age of onset was 51 years. The most common initial presentation was hematochezia (7 cases). Eleven patients underwent radical resection, and the other 10 received local resection. No lymph node metastases were identified. All cases were positive for CD117. Seventeen patients were classified as high National Institutes of Health (NIH) risk category. The 5-year disease-free survival (DFS) and overall survival were 33 and 46 %, respectively. Fifteen cases had recurrence postoperatively. Both univariate and multivariate analyses demonstrated the NIH risk category (p = 0.028) and hematochezia symptom (p = 0.014) were independent prognostic factors of the DFS of patients. CONCLUSIONS: Hematochezia was the most common initial symptom. Over 50 % of patients received radical surgery. More than 80 % of patients were at high NIH risk of recurrence. Hematochezia symptom and high NIH risk category indicated poor prognosis of rectal GISTs.

Primary pseudomyogenic haemangioendothelioma of bone.

AIMS: Pseudomyogenic haemangioendothelioma is a recently described vascular neoplasm that occurs most commonly in the soft tissue of distal extremities of young adults. Occurrence outside the somatic soft tissue has not been described thus far. We present here a unique case of pseudomyogenic haemangioendothelioma that arose in the long tubular bones of the lower extremity. METHODS AND RESULTS: The initial open biopsy was interpreted as a fibrous histiocytoma. However, the curettage specimen showed prominent epithelioid cytomorphology with a striking rhabdomyoblast-like appearance. By immunohistochemistry, the linear membranous staining of CD31 was highly suggestive of endothelial differentiation of the tumour cells. CONCLUSIONS: To the best of our knowledge, this case represents the first example of primary pseudomyogenic haemangioendothelioma of bone. Clinical and pathological correlation with application of immunohistochemistry is mandatory in establishing the correct diagnosis and excluding tumours with overlapping features.

Expression of COL1A1-PDGFB fusion transcripts in superficial adult fibrosarcoma suggests a close relationship to dermatofibrosarcoma protuberans.

The diagnosis of fibrosarcoma has become relatively rare since the recognition and definition of certain adult spindle-cell sarcomas, such as monophasic synovial sarcoma, malignant peripheral nerve sheath tumour (MPNST), and malignant fibrous histiocytoma (MFH). Although most adult fibrosarcomas occur within intra- or inter-muscular fibrous tissues, some originate from superficial soft tissues (superficially located adult fibrosarcomas) (SAFs). Recently, the COL1A1-PDGFB chimeric gene resulting from a reciprocal translocation, t(17;22), and/or a supernumerary ring chromosome, r(17;22), has been identified, not only in conventional dermatofibrosarcoma protuberans (DFSP) but also in areas of DFSP with progression to fibrosarcoma (so-called fibrosarcomatous transformation) (FS-DFSP). Since many SAFs are clinically and histologically similar to DFSP or FS-DFSP, this study postulated that the two groups may be interrelated histogenetically. To test this hypothesis, a reverse transcription-polymerase chain reaction (RT-PCR) assay was conducted to determine whether COL1A1-PDGFB fusion transcripts could be detected in six cases of SAF, using archival formalin-fixed, paraffin-embedded tissues. COL1A1-PDGFB fusion transcripts were detected in four of six SAFs, whereas no such fusion transcripts could be amplified in five deep-seated fibrosarcomas, eight congenital/infantile fibrosarcomas or 28 other spindle-cell tumours and tumour-like lesions. These results show that at least some cases of SAF are genetically similar to DFSP and FS-DFSP, suggesting that some SAFs originate from DFSP or involve similar pathogenetic mechanisms.

Congenital-infantile fibrosarcoma. A clinicopathologic study of 10 cases and molecular detection of the ETV6-NTRK3 fusion transcripts using paraffin-embedded tissues.

Congenital-infantile fibrosarcoma (CIFS) is a relatively indolent sarcoma that should be distinguished from more aggressive spindle cell sarcomas of childhood. CIFSs have been found to have a novel recurrent reciprocal translocation t(12;15)(p13;q25) resulting in the gene fusion ETV6-NTRK3 (ETS variant gene 6; neurotrophic tyrosine kinase receptor type 3). We studied immunohistochemical expression of NTRK3, and conducted a reverse transcription-polymerase chain reaction (RT-PCR) assay to detect the ETV6-NTRK3 fusion transcripts using archival formalin-fixed paraffin-embedded tissues from 10 CIFSs. Thirty-eight other spindle cell tumors were included as controls. The ETV6-NTRK3 fusion transcripts were identified in 7 (70%) of 10 CIFSs. Nucleotide sequence analysis showed that the fusion occurred between ETV6 exon 5 and NTRK3 exon 13. The 38 control tumors were negative for the fusion transcript. Immunohistochemically, CIFSs consistently expressed NTRK3. But the expression of NTRK3 also was observed in 22 of 38 control tumors. These results show the diagnostic usefulness of RT-PCR methods to detect ETV6-NTRK3 fusion transcripts in archival formalin-fixed paraffin-embedded tissue and the important role of NTRK3 in the development of CIFS, despite its being a protein of little importance in differential diagnosis.