Sentinel Lymph Node Positive Rate Predicts Non-Sentinel Lymph Node Metastasis in Breast Cancer.

BACKGROUND: To investigate retrospectively an association between the number of metastatic sentinel lymph nodes (SLNs) per total number of SLNs per patient (i.e., the SLN positive rate, or SLN-PR) and non-SLN metastasis in breast cancer. METHODS: A large population (n = 2250) underwent SLN dissection from January 1, 2014 to January 1, 2020; 627 (27.87%) had at least one positive SLN (SLN+). Among these, 283 underwent axillary lymph node (ALN) dissection, and formed the test group. Four external validation groups comprised 43 patients treated in 2019. SLN mappings were examined using methylene blue and indocyanine green. Lymph node ultrasound, SLN-PR, and pathological characteristics were compared between patients with and without non-SLN metastasis. An SLN-PR cutoff value was calculated using receiver operating characteristic (ROC) curves. Associations between clinicopathological variables and SLN-PR with non-SLN metastasis were analyzed by multivariate logistic regression model. RESULTS: The median age was 47 years (IQR: 42-56 y). The median number of resected SLNs was 4. Patients with positive non-SLNs (126/283, 44.52%) had a median of 2 positive node. SLN-PR > 0.333 was a risk factor for non-SLN positivity (area under the ROC curve, 0.726); and carried significantly higher risk of non-SLN metastasis (P < 0.001). This was validated in the external group. CONCLUSIONS: SLN-PR > 0.333 was associated with greater risk of non-SLN metastasis. This provides a reference to non-SLN metastasis in patients with SLN metastasis, an indication for ALN dissection and choice of adjuvant treatment.

HER2 double-equivocal breast cancer in Chinese patients: a high concordance of HER2 status between different blocks from the same tumor.

PURPOSE: Human epidermal growth factor receptor 2 (HER2) status is both an independent prognostic factor and a predictive factor for the efficacy of targeted therapy for breast cancer, so it is critical to accurately detect HER2 protein expression and/or gene amplification. According to the recommendations of the 2013 American Society of Clinical Oncology and College of American Pathologists (ASCO/CAP) guidelines for HER2 breast cancer testing, an additional test should be pursued on a different block from the same tumor as one of the options for patients with immunohistochemistry (IHC) 2+ and a HER2/CEP17 ratio of < 2.0 with an average HER2 signals per tumor cell of ≥ 4.0 and < 6.0 by reflex test using dual-probe fluorescence in situ hybridization (FISH) (double-equivocal HER2). Our aim in this study is to explore the consistency of HER2 status between the two blocks. METHODS: We retrospectively analyzed 5685 primary invasive breast cancers between April 2015 and January 2019 from Peking Union Medical College Hospital. For cases with double-equivocal HER2 revealed in initial blocks, HER2 gene status was evaluated by FISH in a different block from the same tumor. The FISH score was interpreted according to the 2013 ASCO/CAP guidelines for HER2 testing. RESULTS: In our cohort of 5685 specimens, the overall HER2 IHC3+, 2+, 1+ and 0 cases were 20.5%, 31.8%, 28.3%, and 19.5%, respectively. Then, 13.7%, 66.3%, and 20.0% of HER2 amplification, non-amplification, and equivocation rates were found, respectively, in IHC2+ patients (n = 1777) by reflex FISH assay. For specimens with double-equivocal HER2 (n = 333), HER2 status was assessed in another block from the same tumor by FISH and then the frequency of HER2 positive, negative, and equivocation was estimated at 5.7%, 22.5%, and 71.8%, respectively. Because double-equivocal HER2 cases are classified in the HER2 negative category by the 2018 ASCO/CAP HER2 testing guidelines, only 1.3% (19/1511) of HER2 positive patients were determined through additional HER2 testing in another block from the HER2 negative population. CONCLUSIONS: HER2 status in different blocks from the same tumor in primary invasive breast cancer was highly concordant. Our data supported the recommendation of the 2018 ASCO/CAP HER2 testing guidelines in breast cancer to remove the suggestion for additional HER2 testing using another block contained in the previous version.

Hormone receptors analysis in Chinese patients with dermatofibrosarcoma protuberans.

BACKGROUND AND OBJECTIVES: Dermatofibrosarcoma protuberans (DFSP) is a relatively rare skin tumor. Clinical observations indicated that DFSP has a more aggressive behavior during pregnancy, which suggest there might be a hormonal influence on this tumor. We evaluated the expression of estrogen receptor (ER) and progesterone receptor (PR) in DFSP patients. METHODS: In our present case series, patients with histopathological-confirmed DFSP at a single institution were identified. The clinical, pathological, and immunohistochemical data were gathered for each patient. Expression of ER and PR were determined on formalin-fixed, paraffin-embedded tissue sections using immunohistochemistry. Some objective clinical and pathological indicators were then selected to compare between ER and PR status. RESULTS: Immunoreactivity revealed none of these tumors stained positively for ER, while eight tumors (28.6%) stained positively for PR. There was a statistically significant difference in the distribution of tumor location between the PR-positive/negative groups. CONCLUSIONS: This finding suggests that progesterone may have potential effects in growth of DFSPs. Further studies are needed to fully address this question.

Fluorescence In Situ Hybridization with the UroVysion Kit for the Detection of Biliary Cancer in Chinese Patients.

BACKGROUND: Conventional biliary brush via ERCP has low clinical detection for biliary malignancy. Therefore, new approaches are needed to facilitate diagnosis. We therefore explored the application of fluorescent in situ hybrization (FISH) using a UroVysion kit for the detection of malignancy in the bile duct. METHODS: Genetic alterations of target chromosomes such as aneuploidy in Chinese biliary cancer cell lines and tissues were measured using a UroVysion kit. The diagnostic value of the FISH assay was assessed by probing 27 brush samples of biliary cytology and control routine cytology (RC) samples. The gold standard was established by the pathology or clinical outcomes at the 12-month follow-up. RESULTS: Aneuploidy is commonly found in cell lines and tissues of biliary cancers, but not in normal cells or tissues. Here we probed for aneuploidy in clinical biliary brush specimens obtained by ERCP using FISH and a UroVysion kit. The sensitivity, specificity, and positive and negative predictive values for biliary malignancy were found to be 50%, 100%, 100% and 31.3%, respectively. The sensitivity, specificity, and positive and negative predictive values by RC were found to be 22.7%, 100%, 100% and 22.7%, respectively. In combination with RC, FISH increased the diagnostic sensitivity to 63.6% although this difference was not found to be statistically significant. CONCLUSIONS: Aneuploidy is frequently present in bile duct carcinomas. Here we found that the FISH assay is useful for the detection of Chinese biliary cancers.

[Diagnostic value of MYB protein expression in adenoid cystic carcinoma and status of MYB gene copy number].

OBJECTIVE: To explore the diagnostic value of MYB protein expression for adenoid cystic carcinoma and its differential diagnosis from other salivary gland tumors, and to further investigate the status of MYB gene copy number. METHODS: MYB expression was studied by immunohistochemistry in 34 adenoid cystic carcinomas, 55 non-adenoid cystic carcinomas (other salivary gland tumors) including 10 pleomorphic adenomas, 10 basal cell adenomas, 10 epithelial-myoepithelial carcinomas, 9 basal cell adenocarcinomas, 8 mucoepidermoid carcinomas, 4 carcinoma in pleomorphic adenomas, and 4 polymorphous low-grade adenocarcinoma. MYB gene copy number status was detected by FISH in MYB protein-positive cases. RESULTS: 82.4% (28/34) of adenoid cystic carcinomas were MYB protein-positive, compared with 9.1% (5/55) of non-adenoid cystic carcinomas, and the difference between the two groups was statistically significant (P < 0.01). 2/18 of adenoid cystic carcinomas had duplication of MYB gene by FISH, and all non-adenoid cystic carcinomas were negative although the difference was not statistically significant (P = 0.435). CONCLUSIONS: MYB protein expression is a useful diagnostic marker for adenoid cystic carcinomas in its separation from other salivary gland tumors. In addition, duplication of MYB gene is no a major mechanism for the MYB protein overexpression.

[HER2 mRNA expression in breast cancers with equivocal immunohistochemical results using in situ mRNA hybridization].

OBJECTIVE: To investigate in situ mRNA expression of HER2 oncogene in breast cancers with equivocal immunohistochemical results, and to explore the potential feasibility of RNAscope technique in evaluating HER2 status in breast cancers. METHODS: Sixty-nine FFPE samples of invasive ductal breast cancer with equivocal HER2 immunohistochemistry results (IHC 2+) were collected from surgical excisions from Peking Union Medical College Hospital between June 2010 and June 2013. HER2 status and in situ mRNA expression were tested by fluorescence in situ hybridization (FISH) and RNAscope respectively using tissue microarray constructed from tumor paraffin blocks. The results of HER2 mRNA expression were scored 0 to 4 (from low to high levels) according to mRNA expression in 100 cancer cells. HER2 mRNA expression was evaluated in two groups of patients, with positive and negative FISH results. RESULTS: Twenty-three of the 69 samples were FISH positive, including 16 samples that were scored 4 by RNAscope (70%, 16/23), 6 samples were scored 3 (26%, 6/23) and one sample was scored 2 (4%, 1/23). High in situ mRNA expression (score 4 or 3) were observed in 96% of HER2 FISH positive samples. All of samples that were scored 4 by RNAscope were FISH positive. Forty-six samples were FISH negative, including 17 samples that were scored 3 by RNAscope (37%, 17/46), 25 samples were scored 2 (54%, 25/46), and 4 samples were scored 1 (9%, 4/46). CONCLUSIONS: Breast cancer with HER2 IHC 2+ could be further classified according to in situ mRNA expression status. Among them, RNAscope score of 4 could be one of the interpretation criteria for re-testing IHC 2+ samples. In situ detection of HER2 mRNA may be an additional candidate method of confirmation for HER2 gene amplification or protein overexpression, and has potential clinical utility.

[ALK protein expression and gene fusion in bronchoscopic specimens of lung adenocarcinoma].

OBJECTIVE: To explore ALK protein expression and gene fusion in formalin-fixed and paraffin-embedded (FFPE) specimens obtained from lung cancer by bronchoscopy, and to investigate the relationship between ALK status and clinicopathological characteristics of the patients. METHODS: Seventy-four FFPE samples obtained from lung adenocarcinoma by bronchoscopy were tested for ALK protein expression and gene fusion respectively by immunohistochemistry (IHC) using Ventana D5F3 antibody and fluorescence in situ hybridization (FISH) using ALK break apart probe. RESULTS: sixty-five of the 74 samples were successfully tested by FISH (87.8%, 65/74) . There were 5 FISH-positive cases (7.7%, 5/65) , all with advanced stage carcinoma. Among these five FISH-positive cases, 3 were IHC-positive (4.1%, 3/74) and 2 IHC-negative cases. All the other 69 samples were IHC-negative, including nine FISH-uninformative samples (7 samples were less than 50 tumor cells and 2 samples with weak FISH signal). Both ALK IHC and FISH results were not correlated with age, sex, history of smoking, histological classification, differentiation and lymph node metastasis. CONCLUSIONS: Bronchoscopic specimens of lung cancer can be used to detect ALK expression and gene fusion. Immunohistochemistry in combination with FISH test may be more favorable for ALK test.

[Clinicopathologic correlation and ALK rearrangement in adenocarcinoma of lung].

OBJECTIVE: To investigate ALK gene rearrangements in lung adenocarcinomas in correlation with clinicopathologic parameters including prognosis. METHODS: Fluorescence in situ hybridization (FISH) was used to detect ALK gene rearrangements in 53 cases of lung adenocarcinomas. Mutations in exons 18, 19, 20 and 21 of EGFR were analyzed by Scorpion amplification refractory mutation system (Scorpions ARMS). RESULTS: In a cohort of 53 lung adenocarcinomas, ALK gene rearrangements were identified in 6 tumors (11.3%), including 4 male and 2 female patients. Five were acinar predominant adenocarcinomas and one was mucinous adenocarcinoma (P=1.000). All tumors with the ALK rearrangements had the wild-type epidermal growth factor receptor (EGFR) gene (P=0.023). The median time of disease-free survival (DFS) in ALK positive patients and negative patients were 14 months (95%CI 8.0-20.0) and 31 months (95%CI 24.9-37.1), respectively and the difference was significant (Log-rank test, P=0.019). ALK gene rearrangements were significantly associated with early recurrence, but not tumor size, pathologic stages, histological differentiation and lymph node metastasis. CONCLUSIONS: ALK gene rearrangements are present at a higher frequency in lung adenocarcinomas of the Chinese patients. ALK gene rearrangements are mutually exclusive with EGFR mutations and associated with early tumor recurrence.

Molecular and Cytogenetic Features of NTRK Fusions Enriched in BRAF and RET Double-Negative Papillary Thyroid Cancer.

Rare NTRK-driven malignant neoplasms can be effectively inhibited by anti-TRK agents. The discovery of NTRK1/2/3-rich tumors in papillary thyroid cancer (PTC) patients is a precondition for the rapid identification of NTRK fusion tumors. Knowledge of NTRK gene activation is critical to accurately detect NTRK status. A total of 229 BRAF V600E-negative samples from PTC patients were analyzed in this study. Break-apart fluorescence in situ hybridization (FISH) was performed to detect RET fusion. NTRK status was analyzed using FISH, DNA- and RNA-based next-generation sequencing, and quantitative reverse transcription PCR. In 128 BRAF and RET double-negative cases, 56 (43.8%, 56/128) NTRK rearrangement tumors were found, including 1 NTRK2, 16 NTRK1, and 39 NTRK3 fusions. Two novel NTRK fusions, EZR::NTRK1 and EML4::NTRK2, were found in the NTRK rearrangement tumors. Dominant break-apart and extra 3' signal patterns accounted for 89.3% (50/56) and 5.4% (3/56) of all NTRK-positive cases, respectively, as determined by FISH. In this study's cohort, there were 2.3% (3/128) FISH false-negative and 3.1% (4/128) FISH false-positive cases identified. NTRK fusions are highly recurrent in BRAF and RET double-negative PTCs. FISH- or RNA-based next-generation sequencing is a reliable detection approach. NTRK rearrangement can be precisely, rapidly, and economically detected based on the developed optimal algorithm.

Elaboration of NTRK-rearranged colorectal cancer: Integration of immunoreactivity pattern, cytogenetic identity, and rearrangement variant.

Fused information from protein status, DNA breakage, and transcripts are still limited because of the low rate of activated-NTRK in colorectal cancer (CRC). In total, 104 archived CRC tissue samples with dMMR were analyzed using immunohistochemistry (IHC), polymerase chain reaction (PCR), and pyrosequencing to mine the NTRK-enriched CRC group, and then subjected to NTRK fusion detection using pan-tyrosine kinase IHC, fluorescence in situ hybridization (FISH), and DNA-/RNA-based next generation sequencing (NGS) assays. Of the 15 NTRK-enriched CRCs, eight NTRK fusions (53.3%, 8/15), including two TPM3(e7)-NTRK1(e10), one TPM3(e5)-NTRK1(e11), one LMNA(e10)-NTRK1(e10), two EML4(e2)-NTRK3(e14), and two ETV6(e5)-NTRK3(e15) fusions, were identified. There was no immunoreactivity for ETV6-NTRK3 fusion. In addition to cytoplasmic staining found in six specimens, membrane positive (TPM3-NTRK1 fusion) and nuclear positive (LMNA-NTRK1 fusion) were also observed in two of them. Atypical FISH-positive types were observed in four cases. Unlike IHC, NTRK-rearranged tumors appeared homogeneous on FISH. ETV6-NTRK3 may be missed in pan-TRK IHC screening for CRC. Regarding break-apart FISH, NTRK detection is difficult because of the diversity of signal patterns. Further research is warranted to identify the characteristics of NTRK-fusion CRCs.

A novel nomogram for the preoperative prediction of sentinel lymph node metastasis in breast cancer.

BACKGROUND OR PURPOSE: A practical noninvasive method to identify sentinel lymph node (SLN) status in breast cancer patients, who had a suspicious axillary lymph node (ALN) at ultrasound (US), but a negative clinical physical examination is needed. To predict SLN metastasis using a nomogram based on US and biopsy-based pathological features, this retrospective study investigated associations between clinicopathological features and SLN status. METHODS: Patients treated with SLN dissection at four centers were apportioned to training, internal, or external validation sets (n = 472, 175, and 81). Lymph node ultrasound and pathological characteristics were compared using chi-squared and t-tests. A nomogram predicting SLN metastasis was constructed using multivariate logistic regression models. RESULTS: In the training set, statistically significant factors associated with SLN+ were as follows: histology type (p < 0.001); progesterone receptor (PR: p = 0.003); Her-2 status (p = 0.049); and ALN-US shape (p = 0.034), corticomedullary demarcation (CMD: p < 0.001), and blood flow (p = 0.001). With multivariate analysis, five independent variables (histological type, PR status, ALN-US shape, CMD, and blood flow) were integrated into the nomogram (C-statistic 0.714 [95% CI: 0.688-0.740]) and validated internally (0.816 [95% CI: 0.784-0.849]) and externally (0.942 [95% CI: 0.918-0.966]), with good predictive accuracy and clinical applicability. CONCLUSION: This nomogram could be a direct and reliable tool for individual preoperative evaluation of SLN status, and therefore aids decisions concerning ALN dissection and adjuvant treatment.

[Clinicopathologic features and expression of epidermal growth factor receptor and vascular endothelial growth factor in adrenocortical tumors].

OBJECTIVE: To study the clinicopathologic features and expression of epidermal growth factor receptor (EGFR) and vascular endothelial growth factor (VEGF) in adrenocortical tumors. METHODS: Forty-two cases of adrenocortical tumors operated at the Beijing Union Medical College Hospital during the period from July, 2001 to July, 2010 were retrospectively reviewed. Immunohistochemical study for EGFR and VEGF was carried out. The clinical information and follow-up data were analyzed. RESULTS: The cases included 21 adrenocortical carcinomas (ACC) and 21 adrenocortical adenomas (ACA). Nine patients suffered from primary aldosterone syndrome, including 8 cases with ACA and 1 case with ACC. The average tumor size, tumor weight, and duration between disease onset and diagnosis in the 21 cases of ACC were 11.7 cm, 542 g and 8.5 months, respectively. This was in contrast to 3 cm, 9.8 g and 45.6 months, respectively in cases of ACA. Histologically, the WEISS score in all the 21 cases of ACA was ≤ 2 (average = 0.9). None of the ACC cases had score less than 4 (average = 6.6). The presence of sinus invasion correlated with tumor metastasis (P < 0.01). Immunohistochemical study showed that EGFR was expressed in 61.9% of ACC patients (13/21), whereas EGFR staining was mostly negative in ACA (except for weak staining in 5 cases and moderate staining in 1 case). The difference of EGFR expression between ACC and ACA was statistically significant (P = 0.030). On the other hand, the positive rate of VEGF in ACC was 71.4% (15/21), including 28.6% (6/21) with strong expression and 28.6% (6/21) with moderate expression. In contrast, the expression rate of VEGF in ACA was 30.0% (7/21), including 14.3% (3/21) with moderate expression. The difference of VEGF expression between ACC and ACA was statistically significant (P = 0.013). There was correlation between VEGF expression and venous invasion (P = 0.028). The average duration of survival in patients with ACC was shorter than that in ACA. The tumor weight in ACC also correlated with prognosis. CONCLUSIONS: Tumor size, weight and presence of endocrine symptoms may help in the differential diagnosis between ACC and ACA. A WEISS score of ≥ 3 highly suggests ACC. The presence of sinus invasion is associated with metastasis. EGFR or VEGF expression may also be important in differentiating ACC from ACA.

Abscopal effect of radiation therapy and nivolumab in a patient with combined small-cell lung cancer: a case report.

The paradigm for combined small-cell lung carcinoma (C-SCLC) is according to standard SCLC treatment with poor outcomes. The efficacy of immune checkpoint inhibitor (ICI) monotherapy for pretreated SCLC is still limited. Clinical researches exploring radiotherapy combined with immunotherapy showed promising synergistic effects in several tumors. We report one C-SCLC case after resistant to comprehensive treatment receiving nivolumab combined with radiotherapy achieving clinical complete remission (CCR). The combination module of ICI and radiation could be an option for relapsed C-SCLC, and the prognostic indicators need further research.

Combined small-cell lung carcinoma (C-SCLC) is a rare type of lung cancer that shows more than two types of mixed pathology within the same tumor with poor outcomes. The treatment regimen is a combination of surgery, chemotherapy, radiotherapy and immunotherapy. Clinical research exploring radiotherapy combined with immunotherapy showed promising synergistic effects in several tumors excluding C-SCLC. In the present case, we used immunotherapy and radiotherapy as salvage treatments for a pretreated C-SCLC patient and achieved clinical complete remission. We analyzed some biomarkers of the patient, to explain the mechanisms of efficacy for immunotherapy combined with radiotherapy. The module of immunotherapy combined with radiotherapy may provide a new option for the treatment of C-SCLC.

A comparative clinicopathological and survival analysis of synchronous bilateral breast cancers.

OBJECTIVE: The present study aimed to explore the clinicopathological characteristics, potential heterogeneity and prognostic factors in synchronous bilateral breast cancer (SBBC). METHODS: We performed a retrospective review and paired comparison of the clinicopathological characteristics of 114 patients with SBBC in the Peking Union Medical College Hospital from January 2008 to September 2019. The prognostic significance of triple negativity status and coexistence ductal carcinoma in situ (DCIS) with bilateral invasive ductal carcinomas of no special type (IDC-NST) was analyzed in SBBC. RESULTS: Most bilateral lesions on both sides were of IDC-NST, grade 2, luminal subtype, and stage I. Although most lesions were concordant between the left and right side, discordances were observed in histological type (25 cases, 21.9%), histological grade (31 cases, 27.2%), pTNM (61 cases, 53.5%), molecular subtypes (20 cases, 17.5%), and immunohistochemical staining of ER (18 cases, 15.8%), PR (26 cases, 22.8%), and HER2 (12 cases, 10.5%). Moreover, there was no significant difference in disease-free survival (DFS) and overall survival (OS) between IDC-NST with coexisting DCIS on both sides and IDC-NST with coexisting DCIS on one side or pure IDC-NST. SBBC with triple negativity on both sides exhibited a significantly shorter DFS and OS when compared with triple negativity on one side or non-triple negativity on both sides (p<0.001), and remained an independent prognostic factor by multivariate analysis. CONCLUSIONS: A considerable proportion of discordance in clinicopathological characteristics is observed in SBBC, supporting the necessity of comprehensive pathological examination including immunohistochemical testing on both sides in clinical practice. Moreover, SBBC with triple negativity on both sides is a prognostic for poor survival.

Pitfalls in RET Fusion Detection Using Break-Apart FISH Probes in Papillary Thyroid Carcinoma.

OBJECTIVE: A standardized procedure of fused REarranged during Transfection (RET) gene detection using fluorescence in situ hybridization (FISH) remains to be established in papillary thyroid carcinoma (PTC). Our purpose was to investigate false-negative and false-positive events and their FISH signal characteristics. METHODS: A total of 111 PTC cases were analyzed using break-apart FISH probes for RET status evaluation. All FISH results were validated using fusion-induced asymmetric transcription assay (FIATA)-based reverse transcription droplet digital PCR (RT-ddPCR). Then, suspected RET-positive cases were tested using quantitative reverse transcription-PCR (RT-qPCR), followed by next-generation sequencing (NGS) for recognizing fusion variants. RESULTS: Thirty RET+ cases were revealed, including 20 CCDC6 (exon 1)-RET (exon 12), 6 NCOA4 (exon 8)-RET (exon 12), 1 NCOA4 (exon 7)-RET (exon 12), 1 CCDC186 (exon 7)-RET (exon 12), 1 ERC1 (exon 12)-RET (exon 12) and 1 SPECC1L (exon 9)-RET (exon 12) tumors. All RET fusion cases occurred in the BRAF- population, with a prevalence of 41.7% (30/72). Four cases of 8% to 13% (cutoff was 7.6%) dominant isolated 3' green (IG) FISH signals were RET-. One FISH- case with isolated 5' red (IR) signals with 94% abnormal tumor cells was demonstrated to be positive, harboring the NCOA4 (exon 7)-RET (exon 12) variant. Compared with RET fusions characterized by dominant break-apart signals with 29% to 100% aberrant cells, RET + with dominant IG-signal patterns all showed more frequent FISH+ cells (84%-92%). RET+ PTC with a break-apart signal pattern was more frequently found in unifocal lesions than in multifocal/bilateral tumors (P = 0.049). CONCLUSIONS: A false-positive or false-negative event may exist for RET status detection in PTCs using the traditional FISH scoring method with break-apart probes.

Evaluation of NTRK Gene Fusion by Five Different Platforms in Triple-Negative Breast Carcinoma.

Triple-negative breast carcinoma (TNBC) is an aggressive disease that has a poor prognosis since it lacks effective treatment methods. Neurotrophic tyrosine receptor kinase (NTRK) fusion genes are excellent candidates for targeted RTK inhibitor therapies and there are available targeted therapy drugs for the treatment of TRK fusion-positive tumors in a tumor agnostic pattern. Our study was designed to investigate the NTRK gene fusion status in TNBC patients and to determine whether RTK-targeted therapies are suitable for TNBC patients. A total of 305 TNBC patients were enrolled in our study. IHC was employed as a prescreening method, and IHC positive cases were further submitted for evaluation by FISH, RT-PCR, and NGS methods. NTRK IHC was evaluated successfully in 287 of the 305 cases, and there were 32 (11.15%) positive cases. FISH was carried out in the 32 IHC positive cases. There were 13 FISH-positive cases if the threshold was set as >15% of the 100 counted tumor cells having a split orange and green signal with more than one signal diameter. There were only 2 FISH-positive cases if the cutoff value was defined as >15% of the counted tumor cells having a split signal with more than two signal diameter widths. One of the FISH-positive cases had a separate NTRK3 FISH signal in 88% of the tumor cells, and its IHC result was strong nuclear staining in all the tumor cells. After evaluation of the morphology, it was re-diagnosed as secretory breast carcinoma, and the NGS result confirmed that it had a NTRK3-ETV6 fusion gene. The other FISH-positive cases were all negative for NTRK gene fusion in the NGS or RT-PCR examination. The NTRK gene fusion rate was low in our TNBC cohort. NTRK gene fusion may be a rare event in TNBC. The high false-positive rate of NTRK gene fusion detected by IHC questions its role as a prescreening method in TNBC. More data may be needed to determine a suitable threshold for NTRK FISH in TNBC in the future. More studies are needed to confirm whether RTK-targeted therapies are appropriate treatments for TNBC patients.

PD-L1, Mismatch Repair Protein, and NTRK Immunohistochemical Expression in Cervical Small Cell Neuroendocrine Carcinoma.

BACKGROUND: Cervical small cell neuroendocrine carcinoma (SCNC) is a rare and aggressive disease that lacks a standard treatment strategy or effective methods of targeted therapy. PD-L1 inhibitors for DNA mismatch repair system-deficient (dMMR) tumors and neurotrophin receptor tyrosine kinase (NTRK) inhibitors offer potential pan-cancer treatments. METHODS: Immunohistochemistry was employed as the main detection method, and any NTRK positive cases, identified by immunohistochemistry, were further submitted for evaluation by fluorescence in situ hybridization (FISH) and real-time polymerase chain reaction (RT-PCR) methods. RESULTS: Forty-six patients were enrolled. Positive PD-L1 expression was seen in 22 of the 43 patients (51.16%) with an average combined positive score of 6.82. PD-L1-positive patients were more likely to have a higher proliferation rate in the tumor, and they experienced less recurrence and death (p = 0.048 and 0.033, respectively) compared with the patients with negative PD-L1 expression. However, in the multivariate analysis, none of the clinical parameters was associated with the expression of PD-L1. There was no association between PD-L1 expression and disease recurrence or overall survival in the Kaplan-Meier analysis. All cases were found to be MMR-stable and lacked NTRK gene fusion. However, pan-Trk expressed in 14 (32.56%) of the 43 tested cases, but FISH and RT-PCR failed to confirm any positive fusion signals in IHC-positive cases. CONCLUSIONS: PD-L1 may be an effective therapeutic target for cervical SCNC. Cervical SCNC is a MMR-stable tumor and lacks NTRK gene fusion. IHC isn't a reliable method in the detection of NTRK gene fusion in cervical SCNC.

Triple-Negative Breast Cancer: Intact Mismatch Repair and Partial Co-Expression of PD-L1 and LAG-3.

Background and Aim: Poor response to immune checkpoint inhibitors (ICIs) has been observed in most triple-negative breast cancer (TNBC) cases (around 80%). Our aim was to investigate the status of mismatch repair (MMR), microsatellite instability (MSI), programmed death-ligand 1 (PD-L1), and lymphocyte-activation gene 3 (LAG-3) in TNBC. Methods: A total of 74 TNBC samples were retrospectively analyzed. MMR and MSI were evaluated by immunohistochemistry (IHC) and polymerase chain reaction (PCR) using Promega 1.2 and NCI panels, respectively. PD-L1, LAG-3, and CD8 expression was assessed by IHC. Results: None of the cases demonstrated deficient MMR (dMMR) or MSI. In total, 43/74 cases (58.1%) were PD-L1+, including 1 tumor PD-L1+, 25 tumor-infiltrating lymphocytes (TILs) PD-L1+, and 17 cases involving concurrence of tumor and TIL PD-L1+. The rate of TIL PD-L1+ was remarkably higher than that of tumor PD-L1+ (P<0.001). We identified 20 LAG-3+ cases (27.0%, 20/74), all of which were PD-L1+. Co-expression of PD-L1 and LAG-3 was noted in 46.5% (20/43) of the PD-L1+ population. In the LAG-3+ subtype (co-expression of PD-L1 and LAG-3), high correlation between TILs PD-L1+ and LAG-3+ was observed (P<0.01). A high frequency of CD8+ (98.6%, 73/74) was observed. Conclusion: dMMR/MSI characteristics may not be a practical predictive marker for ICIs in TNBC. PD-L1+ is more common in TILs than in tumors. In the PD-L1+ population, approximately half of the cases showed LAG-3 co-expression. For patients with a poor response to PD-1(L1) mono ICI, dual blockade of PD-1(L1) and LAG-3 may be a viable option for the management of TNBC.

Relationship between EGFR expression, copy number and mutation in lung adenocarcinomas.

BACKGROUND: This study was designed to investigate EGFR protein expression, EGFR copy number and EGFR mutations in lung adenocarcinomas, to explore the relationship of the three markers. METHODS: EGFR status was analyzed in surgically resected lung adenocarcinoma samples from 133 Chinese patients by three methods: protein expression (n=133) by standardized immunohistochemistry (IHC), gene copy number (n=133) by fluorescence in situ hybridization (FISH), and mutation analysis using the Scorpion amplification refractory mutation system (ARMS) (n=133). RESULTS: The results showed that 68.4% of the samples were positive by IHC, 42.1% were positive by FISH, and 63.9% contained activating kinase domain mutations. EGFR mutations were more frequent in non-smoking patients (p=0.008), and EGFR mutations were associated with EGFR FISH positivity (p<0.0001). When using 10% positivity and 2+ as cutoffs, EGFR protein expression was significantly correlated with EGFR FISH positivity (p=0.012) and EGFR mutations (p=0.008) after Bonferroni correction. CONCLUSION: EGFR protein expression, EGFR copy number and EGFR mutations were closely related to each other. Standard methods and interpretation criteria need to be established.