The prognostic value of tumour-infiltrating lymphocytes, programmed cell death protein-1 and programmed cell death ligand-1 in Stage I-III triple-negative breast cancer.

BACKGROUND: Tumour-infiltrating lymphocytes (TILs) represent a robust biological prognostic biomarker in triple-negative breast cancer (TNBC); however, the contribution of different subsets of immune cells is unclear. We investigated the prognostic value of immune markers, including stromal TILs (sTILs), CD8+T and FOPX3+T cells, PD-1 and PD-L1 in non-metastatic TNBC. METHODS: In total, 259 patients with Stage I-III TNBC were reviewed. The density of sTILs along with the presence of total (t), stromal (s), and intratumoral (i) CD8+T cells and FOPX3+T cells were evaluated by haematoxylin and eosin and immunohistochemical staining. Immunohistochemical staining of PD-1, PD-L1 was also conducted. RESULTS: All immune markers were positively correlated with each other (P < 0.05). In the multivariate analysis, sTILs (P = 0.046), tCD8+T cells (P = 0.024), iCD8+T cells (P = 0.050) and PD-1 (P = 0.039) were identified as independent prognostic factors for disease-free survival (DFS). Further analysis showed that tCD8+T cells (P = 0.026), iCD8+T cells (P = 0.017) and PD-1 (P = 0.037) increased the prognostic value for DFS beyond that of the classic clinicopathological factors and sTILs. CONCLUSIONS: In addition to sTILs, inclusion of tCD8+T, iCD8+T cells, or PD-1 may further refine the prognostic model for non-metastatic TNBC beyond that including classical factors alone.

Case Report: An Internal Mammary Rhabdomyosarcoma After Mastectomy and Systemic and Radiation Therapy in a Patient With Breast Cancer.

Post-radiation soft tissue sarcomas (PRSTSs) are rare secondary malignancies. In this report, we describe the clinical presentation of a 52-year-old woman who underwent postmastectomy radiation therapy (PMRT) for left-sided breast cancer 2.7 years ago and presented with a left internal mammary mass and left interpectoral nodule on computed tomography. On further evaluation, she was diagnosed with internal mammary rhabdomyosarcoma and interpectoral nodal breast cancer relapse, and was treated with chemotherapy, followed by surgery and endocrine therapy. She developed left pleural metastases and is currently receiving targeted therapy. Internal mammary rhabdomyosarcomas are rare among PRSTSs and pose a diagnostic challenge for patients with breast cancer. Histological evaluation is important for the differential diagnosis of breast cancer relapses with secondary malignancies. The management of post-radiation thoracic rhabdomyosarcomas is challenging, and the prognosis is poor.

CD56+ lymphoepithelioma-like carcinoma of the lung: A case report and literature review.

BACKGROUND: Lymphoepithelioma-like carcinoma (LELC) is a non-keratinizing carcinoma with rich lymphocytic infiltration, which primarily originates from the nasopharynx. Primary lung LELC is a type of lung cancer with a relatively low incidence. Herein, we report a rare case of lung LELC with expression of CD56. We also performed a literature review to summarize the epidemiological, clinical, and prognostic features of this disease. CASE SUMMARY: A 51-year-old man was admitted to Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College due to cough and chest pain lasting > 2 mo and 1 wk, respectively. Positron emission tomography-computed tomography and magnetic resonance imaging examinations revealed the presence of a mass in the right upper lobe with enlargement of lymph nodes and multiple bone metastases. According to the results of bronchoscopy and cervical lymph node biopsy, a diagnosis of lung LELC with CD56-positive staining (CD56+ lung LELC) was made. In the literature, 458 cases of lung LELC have been reported. However, only one other case of CD56+ lung LELC has been reported thus far. CONCLUSION: The mechanism and potential role of CD56 expression in CD56+ lung LELC require further investigation.

Precise Detection of Gene Mutations in Fine-Needle Aspiration Specimens of the Papillary Thyroid Microcarcinoma Using Next-Generation Sequencing.

PURPOSE: To assess the feasibility of next-generation sequencing (NGS) to detect mutations in BRAF, RAS, TERT promoter, and TP53 genes in ultrasound-guided fine-needle aspiration (FNA) biopsy samples of the papillary thyroid microcarcinoma (PTMC). METHODS: A total of 135 FNA samples out of 135 patients with suspected PTMC were submitted for mutation testing using NGS. NGS was successfully performed in 114 specimens, while the remaining 21 samples were excluded due to insufficient amount/poor quality of DNA and sequencing failure. Of those 114 samples, 72 who were confirmed as having PTMC by postoperative histopathology were enrolled in our study, and the other 42 who had a follow-up with ultrasound were excluded. Mutations of genes including BRAF, NRAS, HRAS, KRAS, TERT promoter, and TP53 were evaluated using NGS. The associations of gene mutations and clinicopathological characteristics of PTMC were analyzed. RESULTS: BRAF mutation was observed in 59 (81.94%) of 72 specimens. This mutation detected in BRAF was p.V600E (c.1799T>A) in exon 15 of all 59 specimens. NRAS mutation was identified in 1 (1.39%) specimen classified as Bethesda III and pathologically confirmed as a follicular variant PTMC. There were no mutations found in TERT promoter or TP53. The tumor with a maximum diameter (D max) larger than 5 mm was shown to be significantly correlated with the BRAF mutation in a multivariate analysis (OR 5.52, 95% CI 1.51-26.42, P = 0.033). But the BRAF mutation was not found to be significantly associated with the gender or age of patients with PTMC (P > 0.05). CONCLUSIONS: This study demonstrated that gene mutations in FNA specimens of PTMC could be successfully analyzed with a higher sensitivity using NGS compared to conventional methods for mutation detection. BRAF mutation of p.V600E was statistically associated with PTMC with a D max larger than 5 mm.

Prevalence of recurrent oncogenic fusion in mismatch repair-deficient colorectal carcinoma with hypermethylated MLH1 and wild-type BRAF and KRAS.

Oncogenic fusions are rare in colorectal carcinomas, but may be important for prognosis and therapy. An effective strategy for screening targetable oncogenic fusions in colorectal carcinomas is needed. Here, we investigate molecular genetic alterations in colorectal carcinomas based on their DNA mismatch repair status, and to effectively screen for targetable oncogenic fusions in colorectal carcinomas. In this retrospective study, the initial cohort included 125 consecutive mismatch repair-deficient and 238 randomly selected mismatch repair-proficient colorectal carcinomas diagnosed between July 2015 and December 2017 at Peking Union Medical College Hospital. Targeted sequencing was performed. MLH1 promoter hypermethylation analysis was further employed for subgrouping dMMR colorectal carcinomas. Clinicopathological characteristics, molecular features, and survival outcome of colorectal carcinomas harboring oncogenic fusions were assessed. A multicenter cohort comprised of 227 colorectal carcinomas with dual loss of MLH1/PMS2 was used to validate the efficacy of the proposed screening strategy for oncogenic fusions. Of the 363 patients in the initial cohort, 11(3.0%) harbored oncogenic fusions and were all mismatch repair-deficient colorectal carcinomas with hypermethylated MLH1 and wild-type BRAF and KRAS, comprising 55% (11/20) of this subgroup. These patients with oncogenic fusions showed poorer 3-year cancer-specific survival compared with other Stage III/IV mismatch repair-deficient colorectal carcinoma patients (40% vs. 97%), and significantly higher CD274(PD-L1) expression in tumor cells compared with other dMMR colorectal carcinoma patients (46% vs. 6.1%, P < 0.001). An easy-to-perform and cost-efficient strategy for screening targetable fusions was proposed based on the current molecular testing algorithms for colorectal carcinomas, and validated in an independent multicenter cohort. In conclusion, oncogenic fusions were highly enriched and frequently detected in mismatch repair-deficient colorectal carcinomas with MLH1 hypermethylation and wild-type BRAF and KRAS, and were associated with poor prognosis and high tumor CD274(PD-L1) expression.

Clinicopathological parameters predicting recurrence of pT1N0 esophageal squamous cell carcinoma.

AIM: To identify the clinicopathological characteristics of pT1N0 esophageal squamous cell carcinoma (ESCC) that are associated with tumor recurrence. METHODS: We reviewed 216 pT1N0 thoracic ESCC cases who underwent esophagectomy and thoracoabdominal two-field lymphadenectomy without preoperative chemoradiotherapy. After excluding those cases with clinical follow-up recorded fewer than 3 mo and those who died within 3 mo of surgery, we included 199 cases in the current analysis. Overall survival and recurrence-free survival were assessed by the Kaplan-Meier method, and clinicopathological characteristics associated with any recurrence or distant recurrence were evaluated using univariate and multivariate Cox proportional hazards models. Early recurrence (≤ 24 mo) and correlated parameters were assessed using univariate and multivariate logistic regression models. RESULTS: Forty-seven (24%) patients had a recurrence at 3 to 178 (median, 33) mo. The 5-year recurrence-free survival rate was 80.7%. None of 13 asymptomatic cases had a recurrence. Preoperative clinical symptoms, upper thoracic location, ulcerative or intraluminal mass macroscopic tumor type, tumor invasion depth level, basaloid histology, angiolymphatic invasion, tumor thickness, submucosal invasion thickness, diameter of the largest single tongue of invasion, and complete negative aberrant p53 expression were significantly related to tumor recurrence and/or recurrence-free survival. Upper thoracic tumor location, angiolymphatic invasion, and submucosal invasion thickness were independent predictors of tumor recurrence (Hazard ratios = 3.26, 3.42, and 2.06, P < 0.001, P < 0.001, and P = 0.002, respectively), and a nomogram for predicting recurrence-free survival with these three predictors was constructed. Upper thoracic tumor location and angiolymphatic invasion were independent predictors of distant recurrence. Upper thoracic tumor location, angiolymphatic invasion, submucosal invasion thickness, and diameter of the largest single tongue of invasion were independent predictors of early recurrence. CONCLUSION: These results should be useful for designing optimal individual follow-up and therapy for patients with T1N0 ESCC.

Application of Ventana immunocytochemical analysis on ThinPrep cytology slides for detection of ALK rearrangement in patients with advanced non-small-cell lung cancer.

BACKGROUND: Ventana ALK (D5F3) screening of anaplastic lymphoma kinase (ALK) gene rearrangement in tissue specimens has been approved by US FDA (Food and Drug Administration) to select treatment for non-small-cell lung carcinoma (NSCLC). However, tumor tissues are often not readily obtainable, and cytology specimens and may be the only tumor material available for diagnosis and molecular marker analysis. In this study, we evaluated the feasibility of ALK immunocytochemistry (ICC) on ThinPrep slides and determined a suitable scoring system for interpretation of the results. METHODS: One hundred twenty-one fine-needle aspirate (FNA) specimens from metastatic lesions of NSCLC were analyzed. ALK rearrangement was detected on ThinPrep cytology slides using the Ventana immunocytochemistry ALK-D5F3 system, which adopts two scoring systems for interpretation of the ICC results. The results were subsequently confirmed by reverse transcription polymerase chain reaction (RT-PCR) analysis and fluorescence in situ hybridization (FISH). RESULTS: Among the 121 ICC specimens, 16 that were considered ALK-positive by either scoring system were referred for PCR analysis. Among the ALK ICC-negative cases, 33 had correlated FISH ALK results. A total of 49 specimens that exhibited either a positive or negative ICC result with a correlated ALK status were analyzed statistically. ICC results showed a high concordance rate with the results of PCR/FISH analysis. The sensitivity and specificity of ALK ICC by the binary scoring algorithm were 68.75 and 96.97%, respectively. These values increased to 93.75 and 96.97%, respectively, when interpreted by the semiquantified interpretation system. CONCLUSIONS: ALK ICC analysis on ThinPrep slides is a reliable ALK testing method, and the semiquantified interpretation system on cytology specimens is recommended rather than the binary scoring algorithm on tissue specimens.

The gene mutational discrepancies between primary and paired metastatic colorectal carcinoma detected by next-generation sequencing.

PURPOSE: To better understand the gene mutational status and heterogeneity between primary and metastatic CRC (mCRC) using a sensitive sequencing method. METHODS: The mutational status of EGFR, KRAS, NRAS, PIK3CA, ERBB2, BRAF, KIT, and PDGFRA was analyzed in 65 patients, with 147 samples of primary and paired live or lung metastatic CRC, using next-generation sequencing (NGS), quantitative RT-PCR (qPCR), and Sanger sequencing. RESULTS: Fifteen cases (15/22, 68.2%) of lung mCRC and thirteen cases (13/20, 65%) of liver mCRC harboured the same mutation profiles of KRAS, NRAS, or BRAF in the primary lesions. To all detected genes, 11 cases (11/22, 50%) of lung mCRC and 11 cases (11/20, 55%) of liver mCRC showed different mutational genes in the primary tumours. KRAS and BRAF mutations were more frequent in lung metastatic lesions (p = 0.004 and 0.003, respectively). The gene mutations in KRAS, NRAS, BRAF, and PIK3CA in the lung metastatic sites were more frequent than those in the liver metastatic sites (86.7 vs. 44%, respectively, p = 0.000). Some new mutations were not covered in the qPCR ranges but were detected by NGS. CONCLUSION: The study demonstrated that the discordance of gene mutational status between paired primary and metastatic tumours is rather high when detected by NGS. Evaluating the mutational status of both the primary and metastatic tumours should be considered in clinical mutation testing.

Comparison of 627 patients with right- and left-sided colon cancer in China: Differences in clinicopathology, recurrence, and survival.

OBJECTIVE: Recent studies have reported increased mortality for right-sided colon cancers; however, the results are conflicting for different stage tumors. We examined the differences in clinicopathology between right- and left-sided colon cancers and the relationships between colon cancer location (right- and left-side) and 5-year disease-free survival (DFS) and overall survival (OS). METHODS: We identified patients from 2005 to 2008 with stage II/III colon cancer who underwent surgery for curative intent. We explored the impact of the tumor location on the postoperative DFS and OS using univariate and multivariate analyses. RESULTS: Of 627 patients, 50.6% (317/627) had right-sided colon cancer. These patients were more likely to have weight loss, second primary tumor, elevated preoperative carbohydrate antigen 19-9 (CA19-9), increased incidence of non-adenocarcinoma, more poorly differentiated tumors, vascular invasion, defective mismatch repair, and a lighter smoking history (P < 0.05). Right-sided colon cancer had a higher recurrence incidence compared with left-sided cancer (30.6% vs. 23.2%, P = 0.037), particularly with multiple metastatic sites in the first recurrence (17.5% vs. 5.6%, P = 0.020). Kaplan-Meier survival curves demonstrated a significant difference in the 5-year DFS rate between right- and left-sided cancers across all stages (68.1% vs. 75.2%, P = 0.043). However, there was no significant difference in the 5-year OS rate between the two groups (73.8% vs. 79.0%, P = 0.103). Subgroup analysis demonstrated that patients with left-sided colon cancer had a significantly better 5-year DFS and OS rates compared with those with right-sided disease at stage III (64.3% vs. 46.8%, P = 0.002; 69.5% vs. 53.5%, P = 0.006, respectively); there were no significant differences in the 5-year DFS and OS rates at stage II (85.2% vs. 85.9%, P = 0.819; 89.8% vs. 88.5%, P = 0.803, respectively). Adjusted Cox regression analysis showed no significant differences in the 5-year OS and DFS rates for stage II [hazard ratio (HR) = 1.203, 95% confidence interval (CI): 0.605-2.391, P = 0.598; HR = 0.980, 95% CI: 0.542-1.774, P = 0.948, respectively] or all stages combined (HR = 0.867, 95% CI: 0.613-1.227, P = 0.421; HR = 0.832, 95% CI: 0.606-1.142, P = 0.255, respectively). However, stage III left-sided cancer had higher 5-year OS and DFS rates (HR = 0.626, 95% CI: 0.414-0.948, P = 0.027; HR = 0.630, 95% CI: 0.428-0.926, P = 0.019, respectively). CONCLUSION: We found that right- and left-sided colon cancers had significantly different clinicopathological characteristics. Right-sided colon cancer had a higher incidence of recurrence than left-sided disease. Patients with stage III right-sided colon cancer had a worse prognosis compared with those with stage III left-sided colon cancer.

EGFR T790M ctDNA testing platforms and their role as companion diagnostics: Correlation with clinical outcomes to EGFR-TKIs.

Somatic mutation in the epidermal growth factor receptor (EGFR) predict clinical response to EGFR tyrosine kinase inhibitors in non-small cell lung cancer (NSCLC) and is a promising target for personalised medicine. EGFR mutations have prognostic value. Initially patients respond well to tyrosine kinase inhibitors but finally they would develop resistance and about 50% of this resistance can be attributed to the emergence of EGFR resistant mutation, T790M. This necessitates the need for genetic testing for clinical management of patients. Molecular testing has become the standard of care in patients with NSCLCs based on the recommendations of standard guidelines. Though there are several platforms for EGFR mutation detection, highly sensitive platforms for clinical applicability as companion diagnostics for ctDNA based testing are emerging. Due to the dynamic changes in the T790M mutation during tyrosine kinase inhibitor (TKI) treatment, real-time monitoring of these genetic alterations is mandate for planning treatment strategies. With the advent of third generation TKIs that potentially target T790M, improvement in clinical outcome is documented in patients with NSCLCs. Managing these outcomes with appropriate companion diagnostics using ctDNA in early detection of these genetic alterations will improve patient care.

Association between BRAFV600E mutation and the clinicopathological features of solitary papillary thyroid microcarcinoma.

The B-Raf proto-oncogene serine/threonine kinase (BRAF)V600E mutation is an important oncogene in the development of papillary thyroid carcinoma (PTC) and has been identified as a risk factor for poor prognosis in patients with PTC. However, whether the BRAFV600E mutation is a prognostic marker in patients with solitary papillary thyroid microcarcinoma (sPTMC) has not yet been established. The present study aimed to identify the association between BRAFV600E mutation and the clinicopathological features of patients with sPTMC. A total of 108 patients with sPTMC who underwent surgery at the Cancer Institute and Hospital of the Chinese Academy of Medical Sciences between December 2010 and December 2012 were analyzed retrospectively. Exon 15 of the BRAF gene was amplified using the polymerase chain reaction and direct sequencing was performed to detect the BRAFV600E mutation. Statistical analysis was subsequently performed using SPSS software (version 16.0). The association between BRAFV600E mutation and clinicopathological features of sPTMC was tested with the χ2 test or Fisher's exact test, as appropriate. There were 27 males and 81 females in the cohort, who were aged between 22 and 66 years old, with an average age of 42 years. The BRAFV600E mutation was found in 59 out of 108 (54.6%) patients with sPTMC. The presence of the BRAFV600E mutation was demonstrated to be significantly associated with extrathyroidal extension (P=0.019), advanced Tumor-Node-Metastasis stage (P=0.007) and the presence of autoimmune thyroiditis (P=0.010). The BRAFV600E mutation was not significantly associated with gender, anatomic location or subtype of sPTMC (P>0.05). In addition, the BRAFV600E mutation indicated poor prognosis in patients with sPTMC. These results suggest that the BRAFV600E mutation is a risk factor for poor prognosis in patients with sPTMC. This knowledge will aid in the risk stratification and post-operative management of patients with sPTMC.

Correlation between the clinicopathological features and prognosis in patients with extranodal natural killer/T cell lymphoma.

OBJECTIVE: To investigate the correlation between the clinicopathological features and prognosis in patients with extranodal natural killer (NK)/T-cell lymphoma (ENKTCL). METHODS: One hundred and four patients diagnosed with ENKTCL at the Department of Pathology, Cancer Hospital, Chinese Academy of Medical Sciences, Beijing, China from November 1991 to September 2011 were included in the study. The clinicopathological features and their correlations with disease prognosis were evaluated in these patients. RESULTS: The number of effective follow-up cases was 56 (53.8%) by the end of last follow-up in October 2015. Univariate survival analysis showed that granzyme B, perforin, and Bcl-2 expression was significantly associated with a poor prognosis in ENKTCL (P = 0.033, 0.004, and 0.034, respectively), whereas platelet-derived growth factor receptor-alpha (PDGFRA) expression was significantly associated with a better prognosis (P = 0.034). Ki-67 overexpression (≥50%) was significantly associated with a poor prognosis (P = 0.017). Different treatment approaches were also associated with prognosis (P = 0.014); specifically, the efficacies of combination treatments including chemotherapy and radiotherapy, and autologous hematopoietic stem cell transplantation were significantly better than those involving radiotherapy and chemotherapy alone. Patient gender, age, tumor location, staging, the presence of B symptoms, pretreatment lactate dehydrogenase levels, and ß2-microglobulin levels were not associated with the prognosis of ENKTCL (P > 0.05). However, multivariate analyses showed that the treatment approach and all the immune markers were not independent prognostic factors for ENKTCL. CONCLUSION: Granzyme B, perforin, and Bcl-2 expression and Ki-67 overexpression (≥50%) might be adverse prognostic factors for ENKTCL, whereas PDGFRA-positivity suggested a better disease prognosis. In addition, different treatment approaches might be closely related to patient prognosis.

Prognostic Value of Lymph Node Ratio in Patients Receiving Combined Surgical Resection for Gastric Cancer Liver Metastasis: Results from Two National Centers in China.

The purpose of this study was to evaluate the prognostic value of lymph node ratio (LNR) in patients with gastric cancer liver metastasis (GCLM) who received combined surgical resection. A retrospective analysis of 46 patients from two hospitals was conducted. Patients were dichotomized into two groups (high LNR and low LNR) by the median value of LNR. The overall survival (OS) and recurrence-free survival (RFS) were analyzed by the Kaplan-Meier method with the log-rank test. The Cox proportional hazard model was used to carry out the subsequent multivariate analyses. And the relationship between LNR and clinicopathological characteristics was assessed. The cut-off value defining elevated LNR was 0.347. With a median follow-up of 67.5 months, the median OS and RFS of the patients were 17 and 9.5 months, respectively. Six patients survived for >5 years after surgery. Patients with higher LNR had significantly shorter OS and RFS than those with lower LNR. In the multivariate analyses, higher LNR and multiple liver metastatic tumors were identified as the independent prognostic factors for both OS and RFS. Elevated LNR was significantly associated with advanced pN stage (P <0.001), larger primary tumor size (P = 0.046), the presence of microvascular invasion (P = 0.008), and neoadjuvant chemotherapy (P = 0.004). LNR may be prognostic indicator for patients with GCLM treated by synchronous surgical resection. Patients with lower LNR and single liver metastasis may gain more survival benefits from the surgical resection. Further prospective studies with reasonable study design are warranted.

Hypermethylation of the 16q23.1 tumor suppressor gene ADAMTS18 in clear cell renal cell carcinoma.

To identify tumor suppressor genes (TSGs) silenced by hypermethylation and discover new epigenetic biomarkers for early cancer detection. ADAMTS18, located at 16q23.1, has been reported to be a critical TSG in multiple primary tumors; however, this has not yet been verified in clear cell renal cell carcinoma (ccRCC). We explored epigenetic alterations in this gene in ccRCC and analyzed possible clinicopathological associations. We examined ADAMTS18 gene expression and methylation by semi-quantitative reverse transcription PCR (RT-PCR) and methylation-specific polymerase chain reaction (MSP) in 5 ccRCC-derived cell lines before and after treatment with 5-aza-2'-deoxycytidine (5-AzaC). MSP was further performed for 101 ccRCC primary tumors and 20 adjacent normal tissues. Some cell lines and specimens were examined by subsequent bisulfite genomic sequencing (BGS) and real-time PCR. Further, we analyzed the relationship between the ADAMTS18 gene methylation and clinicopathological features, including short-term disease-free survival (DFS), in patients with ccRCC. ADAMTS18 down-regulation and hypermethylation were detected in the ccRCC-derived cell lines using RT-PCR and MSP. Treatment with 5-AzaC reversed the hypermethylation of the ADAMTS18 gene and restored its expression. Hypermethylation was further detected in 44 of 101 (43.6%) primary tumors and 3 of 20 (15.0%) adjacent normal tissues. However, a significant difference between both groups was observed (p = 0.02). BGS analysis and real-time PCR were subsequently performed to confirm the results of RT-PCR and MSP. Furthermore, the methylation status of ADAMTS18 was not significantly associated with gender, age, location, tumor diameter, pathological stage, nuclear grade or short-term DFS in patients with ccRCC (p > 0.05). The ADAMTS18 gene is often down-regulated by hypermethylation in ccRCC-derived cell lines and primary tumors, indicating its critical role as a TSG in ccRCC. We conclude that ADAMTS18 gene hypermethylation may be involved in the tumorigenesis of ccRCC and may serve as a novel biomarker for this disease.

[Immunophenotypes and gene mutations in colorectal precancerous lesions and adenocarcinoma].

OBJECTIVE: To analyze immunophenotypes and gene mutations of colorectal precancerous lesions and adenocarcinoma, and to compare the difference of carcinogenetic mechanisms between the two precancerous lesions. METHODS: Fifty-three cases of colorectal serrated lesions including 30 hyperplastic polyps, 20 sessile serrated adenomas (SSA) and 3 mixed polyps were collected from January 2006 to June 2012.Forty-five cases of traditional adenomas and 50 cases of colorectal adenocarcinomas were also recruited. Thirty hyperplastic polyps, 20 cases of SSA, 3 mixed polyps and 45 traditional adenomas were investigated by immunohistochemistry for the expression of DNA mismatch repair (MMR) proteins (MLH1, MSH2 and MSH6) and DNA methyltransferase MGMT. Mutations of KRAS, BRAF and PIK3CA genes in 10 cases of SSAs, 10 traditional adenomas, 1 mixed polyps and 50 colorectal adenocarcinomas were analyzed by PCR followed by direct Sanger sequencing. RESULTS: (1) Only 3 cases of hyperplastic polyps lost MLH1 expression, and none of SSAs or traditional adenomas showed loss of MLH1. The negative expression rates of MSH2, MSH6 and MGMT in hyperplastic polyps and SSA were significantly higher than those of traditional adenomas. (2) KRAS mutation was found in 5/10 cases of SSAs, 5/10 traditional adenomas and 1/1 mixed polyps. (3) Colorectal adenocarcinomas harbored the mutations of KRAS (48%, 24/50), BRAF (6%, 3/50) and PIK3CA (4%, 2/50). CONCLUSIONS: Immunophenotypic and gene mutation profiles are different between colorectal serrated lesion and traditional adenoma. Alterations of MMR and MGMT expression play important roles in the pathogenesis of "serrated neoplasm". KRAS mutation is a significant genetic change in the early phase of colorectal carcinogenesis.

Promoter methylation of tumor suppressor genes in esophageal squamous cell carcinoma.

Esophageal squamous cell carcinoma (ESCC) is a prevalent and fatal cancer in China and other Asian countries. Epigenetic silencing of key tumor suppressor genes (TSGs) is critical to ESCC initiation and progression. Recently, many novel TSGs silenced by promoter methylation have been identified in ESCC, and these genes further serve as potential tumor markers for high-risk group stratification, early detection, and prognosis prediction. This review summarizes recent discoveries on aberrant promoter methylation of TSGs in ESCC, providing better understanding of the role of disrupted epigenetic regulation in tumorigenesis and insight into diagnostic and prognostic biomarkers for this malignancy.

[Detection of KRAS, BRAF, PIK3CA and EGFR gene mutations in colorectal carcinoma].

OBJECTIVE: To investigate the mutation frequencies of KRAS, BRAF, PIK3CA and EGFR genes that were effective on the targeted therapies in colorectal carcinoma. METHODS: The tissue specimens from 331 colorectal cancer patients were collected and subject to KRAS, BRAF, PIK3CA and EGFR mutation analysis. Paraffin-embedded tissue samples were obtained and macrodissection was performed to enrich the tumor cells for DNA extraction when necessary. PCR-based direct DNA sequencing was used to investigate the codons 12 and 13 in exon 2 of KRAS gene, exons 11 and 15 of BRAF gene, exons 9 and 20 of PIK3CA gene and exons 18-21 of EGFR gene. RESULTS: Activating mutations were detected in KRAS (44.1%, 137/311), BRAF (5.8%, 9/156), PIK3CA (2.6%, 4/156) and EGFR (1.3%, 2/156) in the study cohort of colorectal carcinoma cases. Among KRAS gene mutations, 81.0% (111/137) occurred in codon 12, with p.G12D as the most common variant (45.3%, 62/137); 19.0% (26/137) occurred in codon 13, with 38G > A (G13D) as the most common variant (17.5%, 24/137). CONCLUSIONS: The KRAS mutation frequency is the highest among the four genes (KRAS, BRAF, PIK3CA and EGFT) tested in colorectal carcinoma. The presence of these gene mutations may provide therapeutic information for targeted therapy. Mutation analyses of BRAF and PIK3CA in addition to KRAS should be a part of the standard diagnostic algorithm for colorectal carcinoma patients.