[Detection and Significance of Molecular Markers in Immunotherapy and Targeted Therapy of Colorectal Cancer in Tibet].

Objective To study the expression of SWI/SNF-related,matrix-associated,actin-dependent regulator of chromatin,subfamily A,member 4(SMARCA4)/Brahma-related gene 1,V-raf murine sarcoma viral oncogene homolog B(BRAF),P53,programmed cell death protein-1(PD-1),and programmed death-ligand 1(PD-L1),and changes in the expression of BRAF and neurotrophic tyrosine receptor kinase(NTRK) in the patients with colorectal cancer in Tibet,thereby providing a basis for targeted therapy and immunotherapy for this disease in Tibet. Methods A total of 64 patients with colorectal cancer resected in the Tibet Autonomous Region People's Hospital from January 2015 to July 2021 were enrolled in this study.The expression of SMARCA4,BRAF,P53,PD-1,and PD-L1 was detected by immunohistochemical staining.The gene fusion involving NTRK1,NTRK2,and NTRK3 was detected by fluorescence in situ hybridization,and the BRAF V600E gene mutation by polymerase chain reaction. Results The 64 patients with colorectal cancer were at a male-to-female ratio of 1.21∶1,with the mean age of (56.59±13.27) years.The tumors were located in the colon in 46(71.88%) patients and in the rectum in 18(28.12%) patients.Sixty(93.75%) patients presented adenocarcinoma,and 4(6.25%) patients presented other types of tumors.The patients in T1/T2 and T3/T4 phases accounted for 17.19%(n=11) and 82.81%(n=53),respectively.Lymph node metastasis occurred in 24(37.50%) patients.The immunohistochemical staining results showed partially down-regulated or absent expression of SMARCA4 in 1(1.56%) patient,positive BRAF expression in 4(6.25%) patients,and mutant expression of P53 in 35(54.69%) patients.The PD-1-expressing tumor associated immune cell was proportion score<10% in 45(70.31%) patients and≥10% in 19(29.69%) patients.The PD-L1 combined positive score was<10 in 52(81.25%) patients and≥10 in 12(18.75%) patients.The gene fusion of NTRK1,NTRK2,and NTRK3 was negative in all the patients,and BRAF V600E gene mutation was positive in 4(6.25%) patients.The SMARCA4 gene alteration was not detected in the patient with partial expression missing of SMARCA4.The PD-L1 combine positive score was correlated with the deficient mismatch repair(dMMR)/microsatellite instability-high (MSI-H) and the PD-1 expression (χ2=10.223,P=0.001;χ2=11.979,P=0.001). Conclusions The down-regulated or absent SMARCA4 expression and NTRK gene fusion are rare in the patients with colorectal cancer in Tibet.A few patients present BRAF V600E gene mutations,and Pan-TRK and BRAF expression can be used for the primary screening of NTRK gene fusion and BRAF gene mutation.The patients with dMMR/MSI-H are prone to high expression of PD-L1 and expected to benefit from immunotherapy.No significant correlation exists between P53 mutation and PD-L1 expression.The high expression of PD-1 is positively correlated with the high expression of PD-L1.

[Pathological Types,Expression of Mismatch Repair Protein,Human Epidermal Growth Factor Receptor 2,and Pan-TRK,and Eostein-Barr Virus Infection in Patients With Colorectal Cancer Resected in Tibet].

Objective To study the pathological types,expression of mismatch repair protein,human epidermal growth factor receptor 2(HER2),and Pan-TRK,and Epstein-Barr virus(EBV)infection in patients with colorectal cancer resected in Tibet. Methods A total of 79 patients with colorectal cancer resected in Tibet Autonomous Region People's Hospital from December 2013 to July 2021 were enrolled in this study.The clinical and pathological data of the patients were collected.The expression of mismatch repair protein,HER2,and Pan-TRK was detected by immunohistochemical(IHC)staining,and detection of HER2 gene by fluorescence in situ hybridization(FISH)in the patients with HER2 IHC results of 2+ or above.EBV was detected by in situ hybridization with EBV-encoded small RNA. Results A total of 79 colorectal cancer patients were included in this study,with the male-to-female ratio of 1.26:1 and the mean age of(57.06±12.74)years(24-83 years).Among them,4 patients received preoperative neoadjuvant therapy.Colonic cancer and rectal cancer occurred in 57(57/79,72.15%,including 31 and 26 in the right colon and left colon,respectively)and 22(22/79,27.85%)patients,respectively.The maximum diameter of tumor varied within the range of 1-20 cm,with the mean of(6.61±3.33)cm.Among the 79 colorectal cancer patients,75(75/79,94.94%)patients showed adenocarcinoma.Lymph node metastasis occurred in 12(12/21,57.14%)out of the 21 patients with severe tumor budding,13(13/23,56.52%)out of the 23 patients with moderate tumor budding,and 2(2/31,6.45%)out of the 31 patients with mild tumor budding,respectively.The lymph node metastasis rate showed differences between the patients with severe/moderate tumor budding and the patients with mild tumor budding(all P<0.001).The IHC staining showed that mismatch repair protein was negative in 10(10/65,15.38%)patients,including 5 patients with both MSH2 and MSH6 negative,4 patients with both MLH1 and PMS2 negative,and 1 patient with MSH6 negative.Pan-TRK was negative in 65 patients.The IHC results of HER2 showed 0 or 1+ in 60 patients and 2+ in 5 patients.FISH showed no positive signal in the 5 patients with HER2 IHC results of 2+.The detection with EBV-encoded small RNA showed positive result in 1(1/65,1.54%)patient. Conclusions Non-specific adenocarcinoma of the right colon is the most common in the patients with colorectal cancer resected in Tibet,and 15% of the patients showed mismatch repair protein defects.EBV-associated colorectal carcer is rare,Pan-TRK expression and HER2 gene amplification are seldom.The colorectal cancer patients with moderate and severe tumor budding are more likely to have lymph node metastasis.

[Clinicopathological Features of Meningiomas in Tibet].

Objective To analyze the clinicopathological features and immunohistochemical expression of meningiomas in the Tibetan population in Tibet,and improve the understanding of meningiomas. Methods The clinical and pathological data of all the meningiomas diagnosed by pathology in Tibet Autonomous Region People's Hospital from April 2013 to March 2021 were analyzed retrospectively.All the cases underwent immunohistochemical staining of trimethylation of lysine 27 on histone H3 (H3K27me3),mucin 4 (MUC4),somatostatin receptor 2 (SSTR2),progesterone receptor,epithelial membrane antigen,glial fibrillary acidic protein,vimentin,S-100,P53,and Ki-67.The histopathological features and the staining results were observed under a light microscope. Results A total of 116 cases of meningiomas were included in this study,with the male-to-female ratio of 1.0∶2.6 and the age of 4-73 years.The main clinical symptom was headache.The imaging examination showed that 114 cases had single lesions and 2 cases had multiple lesions.The tumors were located in the cranium (108 cases) and spinal canal (8 cases).The maximum diameter of the tumors ranged from 0.3 cm to 10.0 cm,with a mean of (5.7±2.2) cm.In terms of microscopic grading and histological types,the 116 cases included 111 cases of WHO grade Ⅰ (including 53 cases of fibrous type,20 cases of meningothelial type,24 cases of transitional type,10 cases of psammomatous type,etc.),4 cases of WHO grade Ⅱ (3 cases of atypical type and 1 case of clear cell type),and 1 case of WHO grade Ⅲ (papillary type).The immunohistochemical staining showed H3K27me3 expression absent in 9 cases (9/116,7.8%),MUC4 positive in 64 cases (64/116,55.2%),SSTR2 positive in 101 cases (101/116,87.1%).Eighty cases had follow-up results,among which 71 cases had no recurrence,while 9 cases recurred. Conclusions Meningioma is the most common tumor in the central nervous system in the pathological file of Tibet.It mainly attacks the middle-aged female patients,occupying the parasagittal sinus,falx,and convex surface of the brain.Fibrous meningioma of WHO grade Ⅰ is common,while the meningiomas of WHO grades Ⅱ and Ⅲ are rare.The expression degree of MUC4 is higher in meningothelial and transitional meningiomas but lower in fibrous meningiomas.There may be no correlation between the absence of H3K27me3 expression and prognosis.

[Primary Cutaneous Anaplastic Large Cell Lymphoma:Report of One Case].

Primary cutaneous anaplastic large cell lymphoma is a rare non-Hodgkin's lymphoma.The tumor cells have the characteristics of anaplastic cells,expressing CD30 but not anaplastic lymphoma kinase.In this study,we reported a case of primary cutaneous anaplastic large cell lymphoma in a Tibetan child and summarized the clinicopathological features,aiming to strengthen the understanding of this disease.

[Retrospective Analysis of Pathological Diagnosis of Central Nervous System Diseases in Tibet].

Objective To analyze the disease spectrum and clinicopathological characteristics of central nervous system(CNS)diseases diagnosed based on pathological findings in Tibet. Methods We collected the data of all the cases with CNS lesions in Tibet Autonomous Region People's Hospital from January 2013 to December 2020.The clinicopathological features were analyzed via light microscopy,immunohistochemical staining,and special staining. Results A total of 383 CNS cases confirmed by pathological diagnosis were enrolled in this study,with a male-to-female ratio of 188∶195 and an average age of(40.03±17.39)years(0-74 years).Among them,127(33.2%)cases had non-neoplastic diseases,with a male-to-female ratio of 82∶45 and an average age of(31.99±19.29)years;256(66.8%)cases had neoplastic diseases,with a male-to-female ratio of 106∶150 and an average age of(44.01±14.87)years.The main non-neoplastic diseases were nervous system infectious diseases,cerebral vascular diseases,meningocele,cerebral cyst,and brain trauma.Among the infectious diseases,brain abscess,granulomatous inflammation,cysticercosis,and hydatidosis were common.The main neoplastic diseases included meningioma,pituitary adenoma,neuroepithelial tumor,schwannoma,metastatic tumor,and hemangioblastoma.The meningioma cases consisted of 95.4%(103/108)cases of grade Ⅰ,3.7%(4/108)cases of grade Ⅱ,and only 1(1/108,0.9%)case of grade Ⅲ.Among the neuroepithelial tumor cases,the top three were glioblastoma,grade Ⅲ diffuse glioma,and ependymoma. Conclusions There are diverse CNS diseases confirmed by pathological diagnosis in Tibet,among which non-neoplastic diseases account for 1/3 of all the cases.Infectious and vascular diseases are the most common non-neoplastic diseases in Tibet,and tuberculosis and parasitic infections are relatively common.The types and proportion of brain tumors in Tibet are different from those in other regions of China,and meningioma is the most common in Tibet,with higher proportion than neuroepithelial tumor.

[Correlations of Androgen Receptor Expression with Molecular Subtypes and Clinopathological Features of Invasive Breast Carcinoma of No Special Type in Tibet].

Objective To investigate the expression of androgen receptor(AR)and its correlations with different molecular subtypes and clinicopathological features of breast invasive carcinoma of no special type(IBC-NST)in females of Tibetan ethnic minority in Tibet.Methods This study enrolled 54 female patients of Tibetan ethnic minority with IBC-NST surgically removed in the Tibet Autonomous Region People's Hospital from December 2015 to March 2021 for retrospective analysis.The clinical and pathological data of all the enrolled patients were collected.The immunohistochemical method was employed to determine the expression of AR,cell proliferation marker antigen (Ki-67),estrogen receptor(ER),human epidermal growth factor receptor 2(HER-2),and progesterone receptor(PR).For those with unclear HER-2 results,fluorescence in situ hybridization was employed for the determination.The relationship of AR expression with molecular subtypes and clinicopathological features was then analyzed.Results The expression of AR in Tibetan female patients with IBC-NST was correlated with ER(χ2=8.200,P=0.004),PR(χ2=9.900,P=0.003),and molecular subtype(χ2=11.690,P=0.009)and not correlated with tumor location,age,size,histological grade,lymph node metastasis,vascular invasion,clinical stage,or expression of HER-2 and Ki-67(all P>0.05).Molecular subtype was correlated with histological grade(χ2=24.970, P=0.001),clinical stage(χ2=9.035, P=0.029),and lymph node metastasis(χ2=9.691,P=0.021).Conclusions The positive expression rate of AR in the triple-negative IBC-NST patients of Tibetan ethnic minority was significantly lower than that in ER-or PR-positive patients in Tibet.Molecular subtype was correlated with histological grade,clinical stage,and lymph node metastasis.

[Clinicopathological Features and Expression of P504s,E-cadherin,Erythroblast Transformation-specific Related Gene and Estrogen Receptor in Prostate Adenocarcinoma in Tibet].

Objective To investigate the clinicopathological features and immunohistochemical expression of P504s,E-cadherin,erythroblast transformation-specific related gene(ERG)and estrogen receptor(ER)in prostate adenocarcinoma in Tibet.Methods The clinical data of 15 patients with prostate adenocarcinoma diagnosed by the Department of Pathology of Tibet Autonomous Region People's Hospital from September 2013 to September 2020 were analyzed retrospectively.All patients were assigned to prognostic grade groups based on Gleason score according to the WHO 2016 criteria.Immunostaining of P504s,E-cadherin,ERG,and ER was performed.Results The age of all 15 patients ranged from 61 to 86 years.The serum prostate specific antigen(PSA)concentration was ≥20 ng/ml in 12 patients and<20 ng/ml in 3 patients.Among the 15 patients,11 underwent needle biopsy,1 transurethral resection of the prostate,and 3 radical prostatectomy.Prognostic grouping results revealed 5 cases in grade groups 1-3,4 cases in grade group 4,and 6 cases in grade group 5.Immunohistochemistrically,15 cases(100%)were positive for P504s,E-cadherin and PSA;one case(7%)was positive for ERG;all cases were negative for P63,ER and CK34ßE12.Thirteen cases were followed up for 2-48 months,with 2 cases treated with total prostatectomy and 11 cases with non-surgical treatment.Two cases were lost to follow-up. Conclusions Prostate adenocarcinoma is rare relatively in Tibet.The accuracy of diagnosis can be improved by using multiple immunohistochemical markers.The cases of grades 4 and 5 by pathological confirmed are relatively common in Tibet.P504s and E-cadherin are highly expressed in prostate adenocarcinoma patients in Tibet,while ERG presents low expression,ER is unexpressed.

[Clinicopathological Analysis of Brain Metastatic Carcinoma in Tibet].

Objective To investigate the clinicopathological features and immunohistochemical phenotypes of brain metastatic carcinoma in Tibetan patients. Methods The clinical and pathological data of all patients with brain metastases from 2014 to 2020 in Tibet Autonomous Region People's Hospital were retrospectively analyzed,including 13 cases of brain metastatic carcinoma.All cases were diagnosed and classified by immunohistochemical staining. Results 13 cases(9 males and 4 females)of brain metastatic carcinoma,aged 26-62 years old,present with headache,dizziness,nausea and vomiting clinically.Four patients had a medical history of tumor,and among the 9 patients with no history of tumor,7 present space occupying lesions in both the brain and other organs.Imaging data could be found in 10 cases,including 4 cases of single lesion and 6 cases of multiple lesions.Primary tumors were identified in 11 cases(8 located in the lung,including 4 cases of adenocarcinoma,3 cases of small cell carcinoma,and 1 case of squamous cell carcinoma;1 case of urothelial carcinoma of the renal pelvis;1 case of thyroid papillary carcinoma;1 case of uterine choriocarcinoma),whereas the primary tumor was unknown for the other 2 cases(1 case of small cell carcinoma and 1 case of adenocarcinoma). Conclusions Brain metastatic carcinoma are more common among middle-aged and elderly people in Tibet.Most of the cases have no history of tumor,with the initial site at the brain metastatic lesions.The most common primary site is the lung,and the primary site of some cases is unknown.Multiple lesions are common in brain metastatic carcinoma,especially in the cerebral hemisphere.For older patients with multiple brain space occupying lesions,the possibility of brain metastatic carcinoma increases.