An Na Seo

BRAF, PIK3CA, and HER2 Oncogenic Alterations According to KRAS Mutation Status in Advanced Colorectal Cancers with Distant Metastasis

Background Anti-EGFR antibody–based treatment is an important therapeutic strategy for advanced colorectal cancer (CRC); despite this, several mutations—including KRAS, BRAF, and PIK3CA mutations, and HER2 amplification—are associated with the mechanisms underlying the development of resistance to anti-EGFR therapy. The aim of our study was to investigate the frequencies and clinical implications of these genetic alterations in advanced CRC. Methods KRAS, BRAF, and PIK3CA mutations were determined by Cobas real-time polymerase chain reaction (PCR) in 191 advanced CRC patients with distant metastasis. Microsatellite instability (MSI) status was determined by a fragmentation assay and HER2 amplification was assessed by silver in situ hybridization. In addition, KRAS mutations were investigated by the Sanger sequencing method in 97 of 191 CRC cases. Results Mutations in KRAS, BRAF, and PIK3CA were found in 104 (54.5%), 6 (3.1%), and 25 (13.1%) cases of advanced CRC, respectively. MSI-high status and HER2 amplification were observed in 3 (1.6%) and 16 (8.4%) cases, respectively. PIK3CA mutations were more frequently found in KRAS mutant type (18.3%) than KRAS wild type (6.9%) (P = 0.020). In contrast, HER2 amplifications and BRAF mutations were associated with KRAS wild type with borderline significance (P = 0.052 and 0.094, respectively). In combined analyses with KRAS, BRAF and HER2 status, BRAF mutations or HER2 amplifications were associated with the worst prognosis in the wild type KRAS group (P = 0.004). When comparing the efficacy of detection methods, the results of real time PCR analysis revealed 56 of 97 (57.7%) CRC cases with KRAS mutations, whereas Sanger sequencing revealed 49 cases (50.5%). Conclusions KRAS mutations were found in 54.5% of advanced CRC patients. Our results support that subgrouping using PIK3CA and BRAF mutation or HER2 amplification status, in addition to KRAS mutation status, is helpful for managing advanced CRC patients.

HER3 protein expression in relation to HER2 positivity in patients with primary colorectal cancer: clinical relevance and prognostic value

The clinical and prognostic significance of HER3 expression and its relation to HER2 status in primary colorectal cancer (pCRC) were investigated. We retrospectively analysed 365 consecutive cases of pCRC that had been previously evaluated for HER2 status and included their 143 matched lymph node metastases. Immunohistochemistry (IHC) was performed to assess HER3 expression using tissue array methods. Of 364 eligible patients, HER3 overexpression was detected in 251 cases (69xa0%) (IHC 2+, nu2009=u2009186 and IHC 3+, nu2009=u200965). HER3 overexpression was inversely correlated with histologic grade (pu2009=u20090.006), tumour size (pu2009<u20090.001), tumour depth (pu2009<u20090.001), TNM stage (pu2009=u20090.002), lymphatic invasion (pu2009=u20090.004), lymph node metastasis (pu2009=u20090.013) and distant metastasis (pu2009=u20090.039). Moreover, it positively correlated with both HER2 overexpression (pu2009=u20090.007) and HER2 gene amplification (pu2009=u20090.006). Although HER3 overexpression was associated with longer survival in univariate analysis (pu2009=u20090.026), it was not an independent prognostic factor in multivariate analysis (pu2009=u20090.359). Moreover, co-alteration of HER3 and HER2 was associated with neither survival nor any clinicopathologic parameter except tumour location in the rectum. Although not an independent prognostic factor for overall survival, HER3 overexpression was associated with several favourable prognostic clinicopathologic parameters. Additionally, HER3 overexpression strongly correlated with HER2 positivity in this cohort of patients.

Immunohistochemical classification of primary and secondary glioblastomas.

Background Glioblastomas may develop de novo (primary glioblastomas, P-GBLs) or through progression from lower-grade astrocytomas (secondary glioblastomas, S-GBLs). The aim of this study was to compare the immunohistochemical classification of glioblastomas with clinically determined P-GBLs and S-GBLs to identify the best combination of antibodies for immunohistochemical classification. Methods We evaluated the immunohistochemical expression of epidermal growth factor receptor (EGFR), p53, and isocitrate dehydrogenase 1 (IDH-1) in 150 glioblastoma cases. Results According to clinical history, the glioblastomas analyzed in this study consisted of 146 P-GBLs and 4 S-GBLs. Immunohistochemical expression of EGFR, p53, and IDH-1 was observed in 62.6%, 49.3%, and 11.1%, respectively. Immunohistochemical profiles of EGFR(+)/p53(-), IDH-1(-)/EGFR(+)/p53(-), and EGFR(-)/p53(+) were noted in 41.3%, 40.2%, and 28.7%, respectively. Expression of IDH-1 and EGFR(-)/p53(+) was positively correlated with young age. The typical immunohistochemical features of S-GBLs comprised IDH-1(+)/EGFR(-)/p53(+), and were noted in 3.6% of clinically P-GBLs. The combination of IDH-1(-) or EGFR(+) was the best set of immunohistochemical stains for identifying P-GBLs, whereas the combination of IDH-1(+) and EGFR(-) was best for identifying S-GBLs. Conclusions We recommend a combination of IDH-1 and EGFR for immunohistochemical classification of glioblastomas. We expect our results to be useful for determining treatment strategies for glioblastoma patients.

Performance Characteristics of Nested Polymerase Chain Reaction vs Real-Time Polymerase Chain Reaction Methods for Detecting Mycobacterium tuberculosis Complex in Paraffin-Embedded Human Tissues

OBJECTIVESnNucleic acid amplification tests on formalin-fixed, paraffin-embedded (FFPE) tissue specimens enable Mycobacterium tuberculosis complex (MTB) detection and rapid tuberculosis diagnosis in the absence of microbiologic culture tests. We aimed to evaluate the efficacy of different polymerase chain reaction (PCR) methods for detecting Mycobacterium species in FFPE tissues.nnnMETHODSnWe examined 110 FFPE specimens (56 nonmycobacterial cases, 32 MTB, and 22 nontuberculous mycobacteria [NTM] determined by acid-fast bacilli [AFB] culture) to assess five PCR methods: nested PCR (N-PCR) (Seeplex MTB Nested ACE Detection; Seegene, Seoul, South Korea), an in-house real-time PCR (RT-PCR) method, and three commercial RT-PCR methods (AccuPower MTB RT-PCR [Bioneer, Seoul, Korea], artus M tuberculosis TM PCR [Qiagen, Hilden, Germany], and AdvanSure tuberculosis/NTM RT-PCR [LG Life Sciences, Seoul, Korea]).nnnRESULTSnThe results of N-PCR, in-house RT-PCR, and AdvanSure RT-PCR correlated well with AFB culture results (concordance rates, 94.3%, 87.5%, and 89.5%, respectively). The sensitivity of N-PCR (87.5%) was higher than that of the RT-PCR methods, although these differences were not statistically significant between N-PCR and the in-house and AdvanSure RT-PCR methods (68.8% and 80.0%, respectively). All the PCR methods had high specificities, ranging from 98.2% to 100%. Only two NTM cases were detected by AdvanSure RT-PCR, implying a very low sensitivity.nnnCONCLUSIONSnWell-designed RT-PCR and N-PCR can effectively identify MTB in FFPE specimens.

Clinical and prognostic value of MET gene copy number gain and chromosome 7 polysomy in primary colorectal cancer patients

We aimed to explore the clinical and prognostic influence of numeric alterations of MET gene copy number (GCN) and chromosome 7 (CEP7) CN in colorectal cancer (CRC) patients. MET GCN and CEP7 CN were investigated in tissue arrayed tumors from 170 CRC patients using silver in situ hybridization (SISH). MET GCN gain was defined as ≥4xa0copies of MET, and CEP7 polysomy was prespecified as ≥3xa0copies of CEP7. Additionally, MET messenger RNA (mRNA) transcription was evaluated using mRNA ISH and compared with MET GCN. MET GCN gain was observed in 14.7xa0% (25/170), which correlated with advanced stage (Pu2009=u20090.037), presence of distant metastasis (Pu2009=u20090.006), and short overall survival (OS) (Pu2009=u20090.009). In contrast, CEP7 polysomy was found in 6.5xa0% (11/170), which was related to tumor location in the left colonxa0(Pu2009=u20090.027) and poor OS (Pu2009=u20090.029). MET GCN positively correlated with CEP7 CN (Ru2009=u20090.659, Pu2009<u20090.001) and mRNA transcription (Ru2009=u20090.239, Pu2009=u20090.002). Of note, MET GCN gain and CEP7 polysomy were also associated with poor OS (Pu2009=u20090.016 and Pu2009<u20090.001, respectively) in stage II/III CRC patients (nu2009=u2009123). In multivariate analysis, CEP7 polysomy was an independent prognostic factor for poor OS in all patients (Pu2009=u20090.009; hazard ratio [HR], 2.220; 95xa0% confidence interval [CI], 1.233–3.997) and in stage II/III CRC patients (Pu2009<u20090.001; HR, 20.781; 95xa0% CI, 4.600–93.882). MET GCN gain and CEP7 polysomy could predict a poor outcome in CRC patients, especially CEP7 polysomy has the most powerful prognostic impact in stage II/III CRC patients.

Clinicopathologic and molecular pathology of collecting duct carcinoma and related renal cell carcinomas

Collecting duct carcinoma (CDC) and related tumors [ie, renal medullary carcinoma (RMC)] are rare types of highly aggressive renal cell carcinomas (RCC) with poor prognosis. Because of the rarity and diagnostic uncertainty of them, their molecular pathology and significance have not yet been fully elucidated. CDC, RMC, fumarate hydratase–deficient RCC (including hereditary leiomyomatosis and RCC-associated RCC HLRCC-RCC), and recently reported anaplastic lymphoma kinase (ALK)-rearrangement RCC have significant morphologic overlaps, but they are separately distinct entities having different molecular pathway and clinical settings. CDC is more likely to occur in middle to old age population with immunoreactivity for PAX8 and integrase interactor-1 proteins (INI-1). Various chromosomal and genomic alterations have been reported with inconsistent results. In contrast, RMC is more likely to occur in younger patients with sickle cell trait. In RMC, loss of INI-1 expression and OCT3/4 expression are distinguished compared with other RCCs. Finally, ALK-rearrangement RCC seems to have 2 different clinical settings, one with sickle cell trait (VCL-ALK fusion) and the other without (other fusions such as TPM3-ALK, EML4-ALK, and STRN-ALK fusions). Interestingly, VCL-ALK fusion was found in pediatric patients with sickle cell trait, whereas other fusions were detected in adolescent or adult without sickle cell trait. Taken together, CDC and related tumors such as RMC, fumarate hydratase–deficient RCC (including hereditary leiomyomatosis and RCC-associated RCC), and ALK-rearrangement RCC are the distinct entities and their recognition is important for the development of future personalized therapeutic options. This review updates the clinicopathologic features of these tumors with overlapping morphology and outcome.

Clinical influence of cancer stem cells on residual disease after preoperative chemoradiotherapy for rectal cancer

We evaluated the clinical influence of cancer stem cells (CSCs) on residual disease after preoperative chemoradiotherapy (CRT) in patients with rectal cancer. The surgical specimens of 145 patients with residual rectal cancer after preoperative CRT were assessed. To identify CSCs, immunohistochemistry was performed using their surrogate makers (CD44 and aldehyde dehydrogenase 1 [ALDH1]) in full section tissues. Of the 145 cases, ALDH1 and CD44 positivity was found in 80.0xa0% (nu2009=u2009116) and 47.6xa0% (nu2009=u200969), respectively; ALDH1 positivity showed weakly positive correlation with CD44 (rsu2009=u20090.269, Pu2009=u20090.002). ALDH1 and CD44 positivity was related to lower tumor regression grade (TRG) (Pu2009=u20090.009 and 0.003, respectively). Additionally, ALDH1 positivity was associated with positive circumferential resection margin (Pu2009=u20090.019). However, ALDH1 and CD44 positivity showed no relationship with KRAS or BRAF mutation. In univariate analysis, ALDH1 positivity was associated with short recurrence-free survival (RFS) (Pu2009=u20090.005) and rectal cancer-specific survival (RCSS) (Pu2009=u20090.043), but not CD44 positivity (RFS, Pu2009=u20090.725; RCSS, Pu2009=u20090.280). In multivariate analysis, ALDH1 positivity was an independent prognostic factor for poor RFS (Pu2009=u20090.039; hazard ratiou2009=u20092.997; 95xa0% confidence intervalu2009=u20091.059–8.478), but not RCSS (Pu2009=u20090.571). The expression of ALDH1 assessment independently predicts RFS in patients with residual disease after CRT. These results suggest that targeting CSCs could be an effective therapeutic approach to rectal cancer patients receiving preoperative CRT.

Clinical significance of fibroblast growth factor receptor 2 expression in patients with residual rectal cancer after preoperative chemoradiotherapy: relationship with KRAS or BRAF mutations and MSI status.

This study was designed to determine the prognostic impact and clinical significance of FGFR2 in residual disease after preoperative chemoradiotherapy (CRT) in patients with rectal cancer. The surgical specimens of 145 patients with residual rectal cancer after preoperative CRT were analyzed. To evaluate FGFR2 expression, immunohistochemistry was performed on whole section tissues. KRAS exon 2 (codon 12 and 13), BRAF V600E mutational status, and microsatellite instability (MSI) were determined using polymerase chain reactions. Of the eligible 141 patients, FGFR2 over-expression was observed in 75.9xa0% (nu2009=u2009107) and was correlated with perineural invasion (Pu2009=u20090.005) and inferior tumor regression grading (TRG) (Pu2009=u20090.009). However, FGFR2 expression had no relationship with KRAS and BRAF mutation results or with MSI results. On univariate analysis, FGFR2 over-expression was significantly associated with worse rectal cancer-specific survival (RCSS) (Pu2009=u20090.005) and disease-free survival (DFS) (Pu2009=u20090.035). However, multivariate analysis revealed that FGFR2 over-expression was not independently associated with RCSS and DFS (all Pu2009>u20090.05). Although FGFR2 over-expression did not independently influence patient outcome, FGFR2 over-expression was associated with worse prognosis and inferior TRG. Our data may aid in understanding the therapeutic approaches targeting FGFR2 in patients with residual rectal cancer after preoperative CRT.

Congenital Primary Cutaneous Anaplastic Large-Cell Lymphoma: A Case Report

Primary cutaneous anaplastic large-cell lymphoma (C-ALCL) is the second most common type of primary cutaneous T-cell lymphoma. The median age of onset of C-ALCL is 60 years. Presented here is a case of congenital CD30-positive (CD30(+)) primary C-ALCL in a 10-day-old neonate who presented with a large erythematous indurative plaque in the right postauricular area. A systemic workup of the patient excluded other potential causes. The neonate was treated with wide excision, but chemotherapy or radiation therapy was not administered, as the patients parents did not consent to such treatment. The patient has been monitored for 30 months after excision and there has been no disease recurrence. C-ALCL rarely occurs in children, and to the best of our knowledge, this is the first reported case of a neonate with congenital primary C-ALCL.

HER2 status in patients with residual rectal cancer after preoperative chemoradiotherapy: the relationship with molecular results and clinicopathologic features

The specific role of human epidermal growth factor receptor-2 (HER2) status in rectal cancers remains unclear. This study therefore aimed to explore clinicopathologic and molecular characteristics, and prognostic value of HER2-positivity in residual mid- and/or low-rectal cancers after preoperative chemoradiotherapy (CRT). Surgical specimens from 145 patients with residual rectal cancer after preoperative CRT between January 2006 and January 2011 were used to evaluate HER2 status. HER2 protein expression and gene amplification were determined using immunohistochemistry (IHC) and silver in situ hybridization (SISH) on whole tissue sections, respectively. Polymerase chain reaction was used to analyze molecular characteristics, including microsatellite instability (MSI) and mutations in KRAS exon 2 (codon 12 and 13) and BRAF V600E mutation. Of 139 eligible patients, 8 (5.8%) had HER2 overexpression (IHC 2+ and 3+) that was not associated with clinicopathologic characteristics and patient survival, except positive circumferential resection margin (CRM) (Pu2009=u20090.012). SISH was performed on 24 patient samples with IHC 1+ (nu2009=u200916), 2+ (nu2009=u20096), and 3+ (nu2009=u20092). HER2 amplification was identified in 3 patients (2.2%); however, this was also associated with positive CRM (Pu2009=u20090.009) but not survival (all Pu2009>u20090.05). Moreover, HER2 overexpression and amplification had no relationship with KRAS or BRAF mutations, and MSI status (all Pu2009>u20090.05). HER2 positivity was found in a minority of rectal cancer patients and was not significantly associated with clinicopathologic and molecular characteristics. Our findings can be helpful in understanding the clinicopathologic bases of HER2 status in rectal cancers.