Comparison of an amplicon-based large panel next generation sequencing (NGS) assay with conventional testing methods for MET and HER2 amplification in lung and breast cancers

The frequency of MET and HER2 amplification being detected by next generation sequencing (NGS) is increasing due to NGS being increasingly adopted for molecular profiling of cancers. However, the accuracy of NGS in detecting these gene amplifications remains uncertain due to conflicting reports in the scientific literature. We studied the accuracy of an amplicon-based large panel NGS assay in detecting MET and HER2 amplification in lung and breast cancers, respectively, by comparing it against conventional testing methods. Amongst 48 lung cancers, four of five cancers that were MET amplified on fluorescence in situ hybridisation (FISH) were classified as amplified on NGS while 42 of the remaining 43 non-amplified cancers were classified as non-amplified on NGS, giving a sensitivity of 80%, specificity of 97.7% and overall concordance of 95.8%. Of the 46 breast cancers tested, only six of the nine cancers that were HER2-positive on immunohistochemistry (IHC)/FISH were HER2-positive on NGS, while all the remaining HER2-negative cases were negative on NGS, giving a sensitivity of 66.7%, specificity of 100% and overall concordance of 93.5%. All the false-negative cases had low level gene amplification (MET:CEP7 or HER2:CEP17 FISH ratio of <3). The low sensitivity for HER2 amplification may be confounded by the small sample size and disproportionate number of cases with low level amplification. In summary, the NGS assay has good concordance with conventional testing methods but may be less sensitive in detecting low level gene amplification.

Cord blood-derived Vδ2+ and Vδ2- T cells acquire differential cell state compositions upon in vitro expansion

Human cord blood-derived γδ T cells (CBγδ) display a highly diverse TCRγδ repertoire and have a unique subtype composition different from fetal or adult peripheral blood counterparts. We expanded CBγδ in vitro using an irradiated Epstein-Barr virus-transformed feeder cell-based modified rapid expansion protocol (REP). Single-cell RNA sequencing tracked progressive differentiation of naïve CBγδ into cells expressing neoantigen-reactive tumor-infiltrating lymphocyte as well as tissue-resident memory precursor-like and antigen-presenting cell-like gene signatures. TCRγδ clonal tracing revealed a bias toward cytotoxic effector differentiation in a much larger proportion of Vδ2- clones compared to Vδ2+ clones, resulting in the former being more cytotoxic at the population level. These clonotype-specific differentiation dynamics were not restricted to REP and were recapitulated upon secondary nonviral antigen stimulations. Thus, our data showed intrinsic cellular differences between major subtypes of human γδ T cells already in operation at early postnatal stage and highlighted key areas of consideration in optimizing cell manufacturing processes.

Prevalence and psychosocial impact of acne vulgaris among high school and university students in Sarawak, Malaysia

BACKGROUND

Acne vulgaris is a common skin condition that affects adolescents and young adults. Its psychosocial impact can be significant. The primary objective of this study was to determine the prevalence of acne vulgaris and its psychosocial impact among high school and university students in Kuching, Sarawak. In addition, the clinical characteristics of acne and its potential predisposing factors were assessed.

METHODS

This cross-sectional study was conducted among high school and university students in Kuching, Sarawak. A team of dermatology-trained doctors examined a representative sample of high school and university students aged 16 to 25 years to identify acne vulgaris. The Dermatology Life Quality Index (DLQI) was used to assess the psychosocial impact of acne on affected individuals. The Global Acne Grading System (GAGS) was used to determine the severity of acne. Demographic data and clinical characteristics of acne were recorded.

RESULTS

A total of 582 students aged 16 to 25 years were recruited. The overall prevalence of acne vulgaris was 75.8% (n=441). The prevalence of acne was highest (85.5%) in the age group of 16-18 years. There was a significantly higher tendency for male students to have moderate to severe acne (p=0.010). A significantly higher proportion of female students had impaired quality of life (p<0.001) compared to male students. In comparison to male students, the mean DLQI scores were significantly higher in female students in the domains of 'Work and school' and 'Personal relationship' (p<0.05). There were 41 students who had a very large impact on the quality of life with a DLQI score of 11-20 and 34 (82.9%) of them had mild acne. There was a significantly higher proportion of students who had frequent insomnia in the group of students with acne compared to those without acne (11.6% vs. 4.3%, p=0.011). There was no significant association of acne vulgaris with dietary intakes, such as chocolates, sweets, potato chips, yoghurt, milk, fried chicken, ice cream, nuts and carbonated drinks (p>0.05). Of the 441 students with acne, 247 (56%) had not sought any medical attention.

CONCLUSION

Acne vulgaris impacts the quality of life similarly to psoriasis, atopic eczema, and chronic urticaria. In mild acne cases, the quality of life may be significantly affected. Therefore, acne education is required in high schools and colleges to ensure that students understand their disease and are aware of available treatments.

Correlating SS18-SSX immunohistochemistry (IHC) with SS18 fluorescent in situ hybridization (FISH) in synovial sarcomas: a study of 36 cases

The recently introduced, highly sensitive and specific SS18-SSX immunohistochemistry (IHC) is an attractive alternative to SS18 fluorescence in situ hybridization (FISH) testing in synovial sarcoma (SS). However, little is known about how SS18-SSX IHC correlates with SS18 FISH. We correlated the SS18 FISH results of SS from 36 patients with SS18-SSX IHC. Twenty-six tumours had a classic break-apart FISH pattern (1 fused, 1 red and 1 green signal) and all stained positive for the IHC. Ten had an atypical (non-classic) FISH pattern of which 5 stained positive for the IHC. Four of these (including two with novel atypical SS18 FISH patterns) were confirmed to harbour the SS18-SSX fusion on targeted RNA sequencing, while one had classic features of a biphasic SS. The remaining 5 tumours stained negative for the IHC. One had a TPM3-NTRK1 fusion, and one had no fusion, while the remaining three had insufficient tissue/RNA for sequencing. The sensitivity of the IHC was 91% (after excluding the 2 cases with confirmed absence of SS18-SSX fusion). Twenty histologic mimics of SS also stained negative for the IHC (100% specificity). Our study shows that the SS18-SSX IHC is more specific than SS18 FISH in diagnosing SS, especially in cases with atypical FISH patterns. It correlates well with RNA sequencing result and has the potential to replace SS18 FISH testing. A positive IHC result supports the diagnosis of SS, while a tumour with atypical FISH pattern and negative IHC result should undergo further molecular testing.

Individualized Molecular Profiling for Allocation to Clinical Trials Singapore Study-An Asian Tertiary Cancer Center Experience

PURPOSE

Precision oncology has transformed the management of advanced cancers through implementation of advanced molecular profiling technologies to identify increasingly defined subsets of patients and match them to appropriate therapy. We report outcomes of a prospective molecular profiling study in a high-volume Asian tertiary cancer center.

PATIENTS AND METHODS

Patients with advanced cancer were enrolled onto a prospective protocol for genomic profiling, the Individualized Molecular Profiling for Allocation to Clinical Trials Singapore study, at the National Cancer Center Singapore. Primary objective was to identify molecular biomarkers in patient's tumors for allocation to clinical trials. The study commenced in February 2012 and is ongoing, with the results of all patients who underwent multiplex next-generation sequencing (NGS) testing until December 2018 presented here. The results were discussed at a molecular tumor board where recommendations for allocation to biomarker-directed trials or targeted therapies were made.

RESULTS

One thousand fifteen patients were enrolled with a median age of 58 years (range 20-83 years). Most common tumor types were lung adenocarcinoma (26%), colorectal cancer (15%), and breast cancer (12%). A total of 1,064 NGS assays were performed, on fresh tumor tissue for 369 (35%) and archival tumor tissue for 687 (65%) assays. TP53 (39%) alterations were most common, followed by EGFR (21%), KRAS (14%), and PIK3CA (10%). Of 405 NGS assays with potentially actionable alterations, 111 (27%) were allocated to a clinical trial after molecular tumor board and 20 (4.9%) were enrolled on a molecularly matched clinical trial. Gene fusions were detected in 23 of 311 (7%) patients tested, including rare fusions in new tumor types and known fusions in rare tumors.

CONCLUSION

Individualized Molecular Profiling for Allocation to Clinical Trials Singapore demonstrates the feasibility of a prospective broad molecular profiling program in an Asian tertiary cancer center, with the ability to develop and adapt to a dynamic landscape of precision oncology.

Knowledge, attitude, practice and perception on sunscreen and skin cancer among doctors and pharmacists

INTRODUCTION

Excessive ultraviolet light (UV) can cause premature skin aging and potentially skin cancer. Currently there is a lack of awareness among health care professionals and the public on sun protection. The objectives of this study were to determine knowledge on sunscreen and skin cancer among health care professionals, to evaluate the knowledge, attitude, practice and perception of doctors and pharmacists toward the usage of sunscreen as protection against UV radiation.

MATERIALS AND METHODS

This is a cross-sectional study conducted among doctors and pharmacists in Hospital Sultanah Nora Ismail, Batu Pahat, Johor, Malaysia. Questionnaires were used in this study.

RESULTS

A total of 384 participants completed the questionnaires. The participants consisted of 323 doctors (84.1%) and 61 pharmacists (15.9%). The age group of the participants ranged between 25 till 55 years old. Ninety doctors (27.9%) and thirty-one pharmacists (51.0%) reported used sunscreen daily (p<0.001). This finding showed that there was a deficit in the practice of sun protection. Pharmacists scored a higher knowledge score of median 12 (IQR=3.0) while the doctors scored 11 (IQR=2.0). This study showed a significant association between ethnicity and skin cancer knowledge (p<0.05).

CONCLUSION

This study demonstrated a lack of knowledge of sunscreen and skin cancer prevention among health care practitioners. This finding supports better medical education program on this topic.

Implementation of cytogenomic microarray with plasma cell enrichment enables better abnormality detection and risk stratification in patients with plasma cell neoplasia than conventional cytogenetics and fluorescence in situ hybridization

The detection of chromosomal abnormalities is important in the diagnosis, prognosis and disease monitoring in plasma cell neoplasia (PCN). However, the gold standard diagnostic techniques of conventional cytogenetics (CC) and fluorescence in situ hybridization (FISH) are hampered by culture difficulties and probe availability. Cytogenomic microarray (CMA), however, is able to surmount such limitations and generate a comprehensive genomic profile with the implementation of plasma cell (PC) enrichment. In this study, we examined 89 bone marrow specimens with CC and FISH without PC enrichment, 35 of which were examined with CMA after PC enrichment. Results revealed that after PC enrichment, CMA was able to detect chromosomal abnormalities in 34 of 35 specimens tested (97.1%), compared to 21 and 32 specimens (60% and 91.4%, respectively) achieved by CC and FISH, respectively, which were similar to the abnormality detection rates among all 89 specimens (59.5% by CC and 92.1% by FISH). In addition, as the only technique capable of detecting copy neutral loss of heterozygosity (CN-LOH) and chromothripsis, CMA appears to be the most powerful tool in risk stratification as it successfully re-stratified 9 (25.7%) and 12 (34.3%) specimens from standard risk (determined by CC and FISH, respectively) to high risk. Based on the encouraging data presented by our study and others, we conclude that implementation of CMA with PC enrichment is of great value in routine clinical workup in achieving a more complete genetic profile of patients with PCN.

A Case of Severe Falciparum Malaria in a Returned Traveler

Primary care providers should be alert to travel-related infections. Around 10-40% of returning travelers from all destinations and 15-70% of travelers from tropical settings experience ill health, either overseas or upon returning home.¹ A systematic approach concentrating on possible infections should be undertaken based on the patient's travel location, immunization history, presence of malaria chemoprophylaxis at the destination, other potential exposures, incubation period, and clinical presentation.^2-3 The World Health Organization (WHO) website is constantly being updated on specific travel-related infections and recent geographical outbreaks. In this paper, we report a case of severe falciparum malaria in a returned traveler.

Molecular Characterization and Clinical Outcomes in RET-Rearranged NSCLC

INTRODUCTION

RET rearrangements are an emerging targetable oncogenic fusion driver in NSCLC. However, the natural history of disease and activity of different classes of systemic therapy remain to be defined. Furthermore, molecular testing for RET is not yet routine, and the optimal method of testing is unclear. We present a comparative analysis of molecular profiling with fluorescence in situ hybridization (FISH) or next-generation sequencing (NGS) and treatment outcomes.

METHODS

This study was a retrospective analysis of patients treated at the National Cancer Centre Singapore. Baseline demographics and treatment outcomes were collected.

RESULTS

A total of 64 patients were included, with a median age of 62 years (range: 25-85), 56% were women, 77% were of Chinese ethnicity, 95% had adenocarcinoma, and 69% were never smokers. RET rearrangement was detected by FISH in 30 of 34 patients (88%), NGS in 40 of 43 patients (93%), and with discordant results in seven of 13 patients (54%) tested with both methods. Of 61 patients with stage IIIB/IV or recurrent disease, prevalence of central nervous system metastases was 31% and 92% received palliative systemic therapy. Overall survival was prolonged in patients treated with a selective RET tyrosine kinase inhibitor versus untreated patients (median 49.3 versus 15.3 mo; hazard ratio [HR]: 0.16, 95% confidence interval [CI]: 0.06-0.40, p < 0.001). However, it was not different in patients treated with immunotherapy versus untreated patients (median 37.7 versus 49.3 mo; HR: 1.30, 95% CI: 0.53-3.19, p = 0.53). Overall survival was also prolonged in patients with CCDC6-RET fusion versus those with KIF5B-RET fusion (median 113.5 versus 37.7 mo; HR: 0.12, 95% CI: 0.04-0.38, p = 0.009).

CONCLUSIONS

In RET-rearranged NSCLC, selective RET tyrosine kinase inhibitor therapy is associated with improved survival outcomes, especially in patients with CCDC6-RET fusion. However, immunotherapy has poor efficacy. NGS and FISH testing methods may also result in substantial discordance.

Dilemma in the management of methanol poisoning at a district hospital in Malaysia

There are increasing reports of methanol poisoning (MP) incidence worldwide. In Malaysia, the largest first methanol poisoning was reported in Selangor in 2013 with a total of 41 patients and cluster of cases been reported from the country since then. Often MP involved adulterated alcohol containing more than the legal permissible concentration of methanol. Methanol is rapidly absorbed and metabolised into formic acid which causes variable symptoms of the central nervous system such as blindness, seizure, coma and gastrointestinal disturbances. Mortality could reach up to 83% as reported using the coma state, pH and pCO2 level in the worst-case scenario.

Metastatic alveolar rhabdomyosarcoma on the fine-needle aspiration cytology of cervical lymph node in an elderly patient, with FISH confirmation: A case report

INTRODUCTION

Alveolar rhabdomyosarcoma (RMS) usually occurs in adolescents and young adults, and most frequently arises in the extremities.

CASE REPORT

We present a rare case of metastatic alveolar RMS from a nasal primary to cervical lymph nodes (LNs) in an elderly patient, diagnosed on the fine-needle aspiration (FNA) biopsy. Smears showed malignant round cells featuring focal rhabdoid appearance, with rhabdomyoblastic differentiation further supported by immunocytochemical stains. Diagnosis of alveolar RMS was confirmed by fluorescence in situ hybridization (FISH) identifying FOXO1 gene involvement with dual colour break-apart probes at locus 13q14.

DISCUSSION

The differential diagnosis for a small round blue cell tumour in the elderly generally includes metastatic small cell carcinoma, lymphoma, malignant melanoma, RMS, desmoplastic small round cell tumour and Ewing's sarcoma/primitive neuroectodermal tumour. Subtle morphological analysis and expression pattern of immunostaining for skeletal muscle differentiation led to the diagnosis of RMS. Cytogenetic testing on the FOXO1 gene rearrangement helps definite subtyping of alveolar RMS.

Lack of Targetable FGFR2 Fusions in Endemic Fluke-Associated Cholangiocarcinoma

PURPOSE

Cholangiocarcinoma (CCA) remains a disease with poor prognosis and limited therapeutic options. Identification of driver genetic alterations may lead to the discovery of more effective targeted therapies. CCAs harboring FGFR2 fusions have recently demonstrated promising responses to FGFR inhibitors, highlighting their potential relevance as predictive biomarkers. CCA incidence is high in the northeast of Thailand and its neighboring countries because of chronic infection with the liver fluke Opisthorchis viverrini (Ov). However, there are currently no available data on the prevalence of FGFR alterations in fluke-associated CCA in endemic countries.

MATERIALS AND METHODS

In this study, we performed anchored multiplex polymerase chain reaction target enrichment RNA sequencing of FGFR1-3, validated by fluorescence in situ hybridization and Sanger sequencing, in 121 Ov-associated and 95 non-Ov-associated CCA tumors.

RESULTS

Compared with non-fluke-associated CCA (11/95; 11.6%), FGFR2 fusions were significantly less common in fluke-associated CCA (1/121; 0.8%; P = .0006). All FGFR fusions were detected exclusively in intrahepatic CCAs and were mutually exclusive with KRAS/ERBB2/BRAF/FGFR mutations, pointing to their potential roles as oncogenic drivers.

CONCLUSION

FGFR2 fusions are rare in fluke-associated CCA, underscoring how distinct etiologies may affect molecular landscapes in tumors and highlighting the need to discover other actionable genomic alterations in endemic fluke-associated CCA.

Facial segmental haemangioma with PHACE Syndrome successfully treated with oral propranolol

PHACE syndrome describes the association of large segmental haemangioma with extracutaneous features (posterior fossa anomalies, arterial, cardiac, eye and endocrine anomalies). We report a case of segmental facial infantile haemangioma with PHACE syndrome treated successfully with oral propranolol without neurological sequelae.

Chromosomal microarray analysis is superior in identifying cryptic aberrations in patients with acute lymphoblastic leukemia at diagnosis/relapse as a single assay

INTRODUCTION

Conventional cytogenetics (CC) is important in diagnosis, therapy, monitoring of post-transplant bone marrow, and prognosis assessment of acute lymphoblastic leukemia (ALL). However, due to the nature of ALL, CC often encounters difficulties of complex karyotype, poor chromosome morphology, low mitotic index, or normal cells dividing only. In contrast, chromosomal microarray analysis (CMA) showed a specificity >99% and a sensitivity of 100% in chronic lymphocytic leukemia (CLL) patients. Here, we report our experience with CMA on adult ALL patients.

METHODS

Thirty-three bone marrow/blood samples from ALL patients (aged 18-79 years, median 44) at diagnosis/relapse, analyzed by CC and/or fluorescence in situ hybridization (FISH), were recruited. Chromosomal microarray analysis results were compared with CC. Fluorescence in situ hybridization analysis, if available, was applied when there was a discrepancy.

RESULTS

Copy-neutral loss-of-heterozygosity (CN-LOH) was found in 8 cases (24.2%). Only CN-LOH at 9p was recurrent (3 cases, 9.1%). Copy number alterations (CNAs) were detected in 6 of 9 cases (66.7%) with normal karyotypes, in 3 of 5 cases (60.0%) with sole "balanced" translocations, and in 18 of 19 cases (94.7%) with complex karyotypes. Common CNAs involved CDKN2A/2B (30.3%), IKZF1 (27.3%), PAX5 (9.1%), RB1 (9.1%), BTG1 (6.7%), and ETV6 (6.7%), which regulate cell cycle, B lymphopoiesis, or act as tumor suppressors in ALL. Copy number alteration detection rate by CMA was 81.8% (27 of 33 cases) as compared to 57.6% (19 of 33 cases) by CC.

CONCLUSION

Incorporation of CMA as a routine clinical test at the time of diagnosis/relapse, in conjunction with CC and/or FISH, is highly recommended.

Clonal MET Amplification as a Determinant of Tyrosine Kinase Inhibitor Resistance in Epidermal Growth Factor Receptor-Mutant Non-Small-Cell Lung Cancer

PURPOSE

Mesenchymal epithelial transition factor ( MET) activation has been implicated as an oncogenic driver in epidermal growth factor receptor ( EGFR)-mutant non-small-cell lung cancer (NSCLC) and can mediate primary and secondary resistance to EGFR tyrosine kinase inhibitors (TKI). High copy number thresholds have been suggested to enrich for response to MET inhibitors. We examined the clinical relevance of MET copy number gain (CNG) in the setting of treatment-naive metastatic EGFR-mutant-positive NSCLC.

PATIENTS AND METHODS

MET fluorescence in situ hybridization was performed in 200 consecutive patients identified as metastatic treatment-naïve EGFR-mutant-positive. We defined MET-high as CNG greater than or equal to 5, with an additional criterion of MET/centromeric portion of chromosome 7 ratiο greater than or equal to 2 for amplification. Time-to-treatment failure (TTF) to EGFR TKI in patients identified as MET-high and -low was estimated by Kaplan-Meier method and compared using log-rank test. Multiregion single-nucleotide polymorphism array analysis was performed on 13 early-stage resected EGFR-mutant-positive NSCLC across 59 sectors to investigate intratumoral heterogeneity of MET CNG.

RESULTS

Fifty-two (26%) of 200 patients in the metastatic cohort were MET-high at diagnosis; 46 (23%) had polysomy and six (3%) had amplification. Median TTF was 12.2 months (95% CI, 5.7 to 22.6 months) versus 13.1 months (95% CI, 10.6 to 15.0 months) for MET-high and -low, respectively ( P = .566), with no significant difference in response rate regardless of copy number thresholds. Loss of MET was observed in three of six patients identified as MET-high who underwent postprogression biopsies, which is consistent with marked intratumoral heterogeneity in MET CNG observed in early-stage tumors. Suboptimal response (TTF, 1.0 to 6.4 months) to EGFR TKI was observed in patients with coexisting MET amplification (five [3.2%] of 154).

CONCLUSION

Although up to 26% of TKI-naïve EGFR-mutant-positive NSCLC harbor high MET CNG by fluorescence in situ hybridization, this did not significantly affect response to TKI, except in patients identified as MET-amplified. Our data underscore the limitations of adopting arbitrary copy number thresholds and the need for cross-assay validation to define therapeutically tractable MET pathway dysregulation in EGFR-mutant-positive NSCLC.

Ex Vivo Expansion of CD34+ CD90+ CD49f+ Hematopoietic Stem and Progenitor Cells from Non-Enriched Umbilical Cord Blood with Azole Compounds

Umbilical cord blood (UCB) transplants in adults have slower hematopoietic recovery compared to bone marrow (BM) or peripheral blood (PB) stem cells mainly due to low number of total nucleated cells and hematopoietic stem and progenitor cells (HSPC). As such in this study, we aimed to perform ex vivo expansion of UCB HSPC from non-enriched mononucleated cells (MNC) using novel azole-based small molecules. Freshly-thawed UCB-MNC were cultured in expansion medium supplemented with small molecules and basal cytokine cocktail. The effects of the expansion protocol were measured based on in vitro and in vivo assays. The proprietary library of >50 small molecules were developed using structure-activity-relationship studies of SB203580, a known p38-MAPK inhibitor. A particular analog, C7, resulted in 1,554.1 ± 27.8-fold increase of absolute viable CD45⁺ CD34⁺ CD38^- CD45RA^- progenitors which was at least 3.7-fold higher than control cultures (p < .001). In depth phenotypic analysis revealed >600-fold expansion of CD34⁺ /CD90⁺ /CD49f⁺ rare HSPCs coupled with significant (p < .01) increase of functional colonies from C7 treated cells. Transplantation of C7 expanded UCB grafts to immunodeficient mice resulted in significantly (p < .001) higher engraftment of human CD45⁺ and CD45⁺ CD34⁺ cells in the PB and BM by day 21 compared to non-expanded and cytokine expanded grafts. The C7 expanded grafts maintained long-term human multilineage chimerism in the BM of primary recipients with sustained human CD45 cell engraftment in secondary recipients. In conclusion, a small molecule, C7, could allow for clinical development of expanded UCB grafts without pre-culture stem cell enrichment that maintains in vitro and in vivo functionality. Stem Cells Translational Medicine 2018;7:376-393.

Concordance of anaplastic lymphoma kinase (ALK) gene rearrangements between circulating tumor cells and tumor in non-small cell lung cancer

Anaplastic lymphoma kinase (ALK) gene rearrangement in non-small cell lung cancer (NSCLC) is routinely evaluated by fluorescent in-situ hybridization (FISH) testing on biopsy tissues. Testing can be challenging however, when suitable tissue samples are unavailable. We examined the relevance of circulating tumor cells (CTC) as a surrogate for biopsy-based FISH testing. We assessed paired tumor and CTC samples from patients with ALK rearranged lung cancer (n = 14), ALK-negative lung cancer (n = 12), and healthy controls (n = 5) to derive discriminant CTC counts, and to compare ALK rearrangement patterns. Blood samples were enriched for CTCs to be used for ALK FISH testing. ALK-positive CTCs counts were higher in ALK-positive NSCLC patients (3–15 cells/1.88 mL of blood) compared with ALK-negative NSCLC patients and healthy donors (0–2 cells/1.88 mL of blood). The latter range was validated as the ‘false positive’ cutoff for ALK FISH testing of CTCs. ALK FISH signal patterns observed on tumor biopsies were recapitulated in CTCs in all cases. Sequential CTC counts in an index case of lung cancer with no evaluable tumor tissue treated with crizotinib showed six, three and eleven ALK-positive CTCs per 1.88 mL blood at baseline, partial response and post-progression time points, respectively. Furthermore, ALK FISH rearrangement suggestive of gene copy number increase was observed in CTCs following progression. Recapitulation of ALK rearrangement patterns in the tumor on CTCs, suggested that CTCs might be used to complement tissue-based ALK testing in NSCLC to guide ALK-targeted therapy when suitable tissue biopsy samples are unavailable for testing.

Role of fluorescence in situ hybridization in diagnosing cholangiocarcinoma in indeterminate biliary strictures

BACKGROUND AND AIM

Brush cytology, the conventional method to diagnose cholangiocarcinoma, has been plagued by low diagnostic sensitivity and false-negative results. This paper aims to study the clinical utility of fluorescence in situ hybridization (FISH) in enhancing identification of malignant biliary strictures.

METHODS

Brush cytologic specimens collected from endoscopic retrograde cholangiopancreatography for biliary strictures in a tertiary hospital in Singapore from March 2013 to July 2015 were examined by FISH technique using UroVysion probe set in this study.

RESULTS

Thirty patients were chosen with five patients having multiple FISH performed due to indeterminate results. The diagnoses for biliary strictures were 13 (43.3%) cholangiocarcinomas, seven (23.3%) pancreatic cancers, seven (23.3%) benign biliary strictures, and three (10%) primary sclerosing cholangitis. Conventional brush cytology had sensitivity of 53.8% with specificity of 82.4%. FISH had sensitivity of 30.8% with specificity of 100%. When FISH results were interpreted in cases with negative or atypical brush cytology, two patients had positive FISH results and cholangiocarcinomas. Based on this pilot study, FISH increased sensitivity of brush cytology in detection of cholangiocarcinoma from 53.8% to 69.2% while preserving specificity of 82.4%.

CONCLUSION

Compared with conventional cytology with low sensitivity, FISH may help to increase sensitivity on top of brush cytology while maintaining high specificity.

The Development of Emergency Medicine in South Korea: Academic Productivity in Highly Cited Journals

Introduction

The purpose of this study was to examine the number of publications by South Korean emergency physicians in highly cited journals and the increase in their numbers. It also sought to assess the impact factors of such publications.

Methods

The present study was a retrospective quantitative literature review of the publications by South Korean emergency physicians from 1996 to 2011 in the category of “emergency medicine” in the science edition of Journal Citation Reports 2011. We analysed the total number of articles published by South Korean emergency physicians and their impact factors.

Results

Between 1996 and 2011, the number of South Korean board-certified emergency physicians increased from 51 to 958, and 230 articles were published in 14 highly cited journals. The total impact factor (IF) of the original articles published during that period was 227.86, and the mean IF was 1.93. More than 10 articles had been published annually in the past 5 years in highly cited journals and there were over 400 South Korean board-certified emergency physicians.

Conclusions

Emergency medicine in South Korea started about 20 years ago, but academic productivity, indicated by at least ten articles annually in highly cited journals, was only achieved in the last five years. The mean IF of these articles was similar to that in other highly productive countries. (Hong Kong j.emerg.med. 2014;21:205-212)

Whole-Genome and Epigenomic Landscapes of Etiologically Distinct Subtypes of Cholangiocarcinoma

Cholangiocarcinoma (CCA) is a hepatobiliary malignancy exhibiting high incidence in countries with endemic liver-fluke infection. We analyzed 489 CCAs from 10 countries, combining whole-genome (71 cases), targeted/exome, copy-number, gene expression, and DNA methylation information. Integrative clustering defined 4 CCA clusters-fluke-positive CCAs (clusters 1/2) are enriched in ERBB2 amplifications and TP53 mutations; conversely, fluke-negative CCAs (clusters 3/4) exhibit high copy-number alterations and PD-1/PD-L2 expression, or epigenetic mutations (IDH1/2, BAP1) and FGFR/PRKA-related gene rearrangements. Whole-genome analysis highlighted FGFR2 3' untranslated region deletion as a mechanism of FGFR2 upregulation. Integration of noncoding promoter mutations with protein-DNA binding profiles demonstrates pervasive modulation of H3K27me3-associated sites in CCA. Clusters 1 and 4 exhibit distinct DNA hypermethylation patterns targeting either CpG islands or shores-mutation signature and subclonality analysis suggests that these reflect different mutational pathways. Our results exemplify how genetics, epigenetics, and environmental carcinogens can interplay across different geographies to generate distinct molecular subtypes of cancer.Significance: Integrated whole-genome and epigenomic analysis of CCA on an international scale identifies new CCA driver genes, noncoding promoter mutations, and structural variants. CCA molecular landscapes differ radically by etiology, underscoring how distinct cancer subtypes in the same organ may arise through different extrinsic and intrinsic carcinogenic processes. Cancer Discov; 7(10); 1116-35. ©2017 AACR.This article is highlighted in the In This Issue feature, p. 1047.

Fluorescence In Situ Hybridization on Tissue Sections

Formalin-fixed paraffin-embedded (FFPE) tissues are typically the specimens available for FISH analysis of solid tissues, particularly of tumor specimens. Occasionally, tissue cores constructed as tissue microarrays from several patients are presented for simultaneous evaluation. FFPE sections can also be prepared from cell blocks derived from cell suspensions. The interphase fluorescence in situ hybridization assay employs specific nucleic acid sequences (probes) that target complementary sequences of interest to detect gains or losses of genes/gene loci or a fusion gene within the tissue. In this chapter, we describe the protocols utilized in our laboratory and include slide deparaffinization, pretreatment, protease treatment, hybridization, washing, and counterstaining. This protocol can be applied to all of the earlier FFPE preparations. In general, the assay takes 3 consecutive days to complete, although a more rapid assay can be performed.

Abstract 5008: Elucidating HER2 molecular heterogeneity of circulating tumor cells among breast cancer patients

Background: HER2-positive tumors are often associated with poor prognosis, chemo-resistances and some patients eventually develop refractory disease during HER2 targeted therapy. While different mechanisms of trastuzumab resistance are being identified in recent years, contribution of confounding factors such as inherent genomic heterogeneity, equivocal HER2 amplifications and presence of chromosome 17 polysomy has been less understood thus far. In this pilot study, we aim to examine HER2 heterogeneity in CTCs obtained from breast cancer patients in the Asian population setting.

Methods: CTCs were enriched from blood samples using a label-free spiral microfluidics-based ClearCell® FX system. A total of 26 samples were collected from patients diagnosed with HER2 positive (17/26) and HER2 negative (9/26) breast cancer. The enriched CTCs were analyzed using conventional diagnostic modalities (fluorescence in-situ hybridisation (FISH) and immunocytochemistry) to examine HER2 status. Concordance rate between CTCs and matched primary tumor was evaluated.

Results: HER2-positive CTCs were successfully identified in 14 out of 17 HER2+ patients (82.4%); HER2 gene amplification and chromosome 17 polysomy were observed in 10(58.8%) and 13(76.5%) patients respectively. HER2+ CTC counts ranged from 2 to 30 cells from 7.5ml blood (median: 4 HER2+ CTCs/7.5ml). HER2 amplification was not observed in any of the 9 patients with HER2-negative tumors, though 5 out of 9 patients (55.6%) were identified with CTCs harbouring gain in chromosome 17 (median: 2 HER2+ CTCs/7.5ml). A “false positive” cut-off of more than 2 cells/7.5ml blood were established using receiver operating characteristic (ROC) curve analysis and a concordance rate of approximately 70% between paired tumor tissue and CTC among the 26 patients. Immunofluorescence labelling of CTCs with cytokeratin, CD45 and HER2 antibodies further revealed heterogeneity in HER2 expression on CTCs.

Conclusion: CTCs capture the heterogeneity of breast cancer, and could potentially overcome limitations of tissue biopsy which are site specific. HER2- patients, as confirmed by tissue biopsy, with HER2+ CTCs pose interesting questions while determining treatment regime.

Citation Format: Man Chun Leong, Tse Hui Lim, Chye Ling Tan, Yong Wei Chua, Elaine Hsuen Lim, Kiley Wei Jen Loh, Guek Eng Lee, Rebecca Dent, Raymond Chee Hui Ng, Andrew Wu, Wan-Teck Lim, Alvin Soon-Tiong Lim, Yoon-Sim Yap. Elucidating HER2 molecular heterogeneity of circulating tumor cells among breast cancer patients. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 5008.

Effect of Ganciclovir on the Hydrolytic Degradation of Poly(lactide-co-glycolide) Microspheres

Ganciclovir (GCV)-loaded poly(lactide-co-glycolide) (PLGA) microspheres, 125 ± 11 μm in diameter, are produced using the emulsification/solvent evaporation technique. The release rate of the drug is studied for 20 weeks in a phosphate-buffered solution of pH 7 at 37°C. The release of the drug shows a triphasic release pattern, i.e., an initial burst, a diffusive phase, and a second burst. The initial burst occurs within the first 2 days of immersion. After the burst, the release is by diffusion for up to 13 weeks, followed by another burst release, which signals the onset of bulk degradation of the PLGA polymer. The presence of GCV molecules decreases the hydrolytic rate of PLGA degradation. Gel permeation chromatography (GPC), differential scanning calorimetry (DSC), field emission scanning electron microscopy (FESEM), and ultraviolet (UV) spectroscopy are used to assess the hydrolytic degradation and drug release rate of the microspheres.

Implications of the Updated 2013 American Society of Clinical Oncology/College of American Pathologists Guideline Recommendations on Human Epidermal Growth Factor Receptor 2 Gene Testing Using Immunohistochemistry and Fluorescence In Situ Hybridization for Breast Cancer

Context

Human epidermal growth factor receptor 2 (HER2/neu) amplification is used as a predictive marker for trastuzumab treatment in breast cancer. Both immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) testing algorithms have been based on the 2007 American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP) guidelines. In late 2013, the guidelines were updated with new scoring criteria.

Objective

—To assess the impact of the revised ASCO/CAP recommendations on both IHC and FISH results by using the dual-color HER2/neu and centromeric FISH probes.

Design

Retrospective analysis of 590 invasive carcinomas with concurrent IHC and dual-color HER2/neu and centromeric 17 (CEP17) FISH results, based on 2007 ASCO/CAP guidelines, was conducted from July 2011 to June 2013. With the revised guidelines, patients were recategorized and concordance rates between the 2 assays were recalculated.

Results

—Overall concordance rates for FISH and IHC decreased from 94.9% to 93.8% with reclassification. Negative FISH cases decreased from 79.1% to 69.3%. However, equivocal FISH cases were significantly increased from 0.7% to 9.5%, leading to more retesting. Both positive IHC and FISH cases were also noted to be increased, leading to more patients being eligible for trastuzumab treatment, especially those patients with concurrent HER2/neu and CEP17 polysomy. Approximately 1% of patients with initial FISH negative results were reclassified as having positive results when both the ratios and average copy number of HER2/neu were considered under the revised guidelines.

Conclusions

The revised 2013 ASCO/CAP guidelines can potentially lead to more patients being eligible for trastuzumab therapy but additional retesting is to be expected owing to an increased number of equivocal FISH cases.

Effectiveness of chest compression feedback during cardiopulmonary resuscitation in lateral tilted and semirecumbent positions: a randomised controlled simulation study

Feedback devices have been shown to improve the quality of chest compression during cardiopulmonary resuscitation for patients in the supine position, but no studies have reported the effects of feedback devices on chest compression when the chest is tilted. Basic life support-trained providers were randomly assigned to administer chest compressions to a manikin in the supine, 30° left lateral tilt and 30° semirecumbent positions, with or without the aid of a feedback device incorporated into a smartphone. Thirty-six participants were studied. The feedback device did not affect the quality of chest compressions in the supine position, but improved aspects of performance in the tilted positions. In the lateral tilted position, the median (IQR [range]) chest compression rate was 99 (99-100 [96-117]) compressions.min(-1) with and 115 (95-128 [77-164]) compressions.min(-1) without feedback (p = 0.05), and the proportion of compressions of correct depth was 55 (0-96 [0-100])% with and 1 (0-30 [0-100])% without feedback (p = 0.03). In the semirecumbent position, the proportion of compressions of correct depth was 21 (0-87 [0-100])% with and 1 (0-26 [0-100])% without feedback (p = 0.05). Female participants applied chest compressions at a more accurate rate using the feedback device in the lateral tilted position but were unable to increase the chest compression depth, whereas male participants were able to increase the force of chest compression using the feedback device in the lateral tilted and semirecumbent positions. We conclude that a feedback device improves the application of chest compressions during simulated cardiopulmonary resuscitation when the chest is tilted.

Effects of cilostazol on the pharmacokinetics of carvedilol after oral and intravenous administration in rats

This study was designed to investigate the effects of cilostazol on the pharmacokinetics of carvedilol following oral or intravenous administration of carvedilol in rats. Clinically carvedilol and cilostazol can be prescribed for treatment of cardiovascular diseases. Carvedilol and cilostazol are all substrates of CYP2C9 enzymes. Carvedilol was administered orally or intravenously without or with oral administration of cilostazol to rats. The effects of cilostazol on cytochrome P450 (CYP) 2C9 activity and P-gp activity were also evaluated. Cilostazol inhibited CYP2C9 activity in a concentration-dependent manner with 50% inhibitory concentration (IC(50)) of 8.7 μM. Compared with the control group, the area under the plasma concentration-time curve (AUC) of carvedilol was significantly (P < 0.05) increased by 38.0%. The peak concentration (C(max)) was significantly (P < 0.05) increased by 49.2% in the presence of cilostazol after oral administration of carvedilol. Consequently, the relative bioavailability (R.B.) of carvedilol was increased by 1.15 - 1.38-fold, and the absolute bioavailability (A.B.) of carvedilol in the presence of cilostazol was significantly (P < 0.05) higher than that of the control. After intravenous administration, the AUC of carvedilol was significantly (P < 0.05) increased by 19.2% compared to that in the control by cilostazol. These results suggest that cilostazol effectively inhibited the metabolism of carvedilol. The increased oral bioavailability of carvedilol might be due to the inhibition of CYP2C9-mediated metabolism of carvedilol in the liver by cilostazol.

Amplification of 1q21 and other abnormalities in multiple myeloma patients from a tertiary hospital in singapore

Much effort has been made to stratify multiple myeloma patients for targeted therapy. However, responses have been varied and improved patient stratifications are needed. Forty-five diagnostic samples from multiple myeloma patients (median age 65 years) were stratified cytogenetically as 15 having non-hyperdiploidy, 20 having hyperdiploidy and 10 having a normal karyotype. Fluorescence in situ hybridization (FISH) assays with FGFR3/IGH, CCND1/IGH, IGH/MAF, RB1 and TP53 probes on bone marrow samples showed that IGH rearrangements were the most common abnormality in the non-hyperdiploid group but these were also found among hyperdiploid patients and patients with normal cytogenetics. Of these, FGFR3/IGH rearrangements were most frequent. Deletion of RB1/monosomy 13 was the most common genetic abnormality across the three groups and was significantly higher among non-hyperdiploid compared to hyperdiploid patients. On the other hand, the study recorded a low incidence of TP53 deletion/monosomy 17. The FGFR3/IGH fusion was frequently seen with RB1 deletion/monosomy 13. FISH with 1p36/1q21 and 6q21/15q22 probes showed that amplification of 15q22 was seen in all of the hyperdiploid patients while amplification of 1q21, Amp(1q21), characterized non-hyperdiploid patients. In contrast, deletions of 1p36 and 6q21 were very rare events. Amp(1q21), FGFR3/IGH fusion, RB1 deletion/monosomy 13, and even TP53 deletion/monosomy 17 were seen in some hyperdiploid patients, suggesting that they have a less than favorable prognosis and require closer monitoring.

CpG Oligonucleotide and Interleukin 2 stimulation enables higher cytogenetic abnormality detection rates than 12-o-tetradecanolyphorbol-13-acetate in Asian patients with B-cell chronic lymphocytic leukemia (B-CLL)

The present study was designed to compare abnormality detection rates using DSP30 + IL2 and 12-O-Tetradecanoylphorbol-13-acetate (TPA) in Asian patients with B-CLL. Hematological specimens from 47 patients (29 newly diagnosed, 18 relapsed) were established as 72 h-DSP30 + IL2 and TPA cultures. Standard methods were employed to identify clonal aberrations by conventional cytogenetics (CC). The B-CLL fluorescence in situ hybridization (FISH) panel comprised ATM, CEP12, D13S25, and TP53 probes. DSP30 + IL2 cultures had a higher chromosomal abnormality detection rate (67 %) compared to TPA (44 %, p < 0.001). The mean number of analyzable metaphases and abnormal metaphases per slide was also higher (p < 0.005, p < 0.001, respectively). Culture success rate, percentage of complex karyotype, and percentage of non-clonal abnormal cell were not significantly different (p > 0.05). Thirteen cases with abnormalities were found exclusively in DSP30 + IL2 cultures compared to one found solely in TPA cultures. DSP30 + IL2 cultures were comparable to the FISH panel in detecting 11q-, +12 and 17p- but not 13q-. It also has a predilection for 11q- bearing leukemic cells compared to TPA. FISH had a higher abnormality detection rate (84.1 %) compared to CC (66.0 %) with borderline significance (p = 0.051), albeit limited by its coverage. In conclusion, DSP30 + IL2 showed a higher abnormality detection rate. However, FISH is indispensable to circumvent low mitotic indices and detect subtle abnormalities.

Novel genetic aberrations in breast phyllodes tumours: comparison between prognostically distinct groups

Phyllodes tumours of the breast are uncommon fibroepithelial neoplasms which pose management challenges due to difficulties in accurate prediction of clinical behaviour, as histological assessment has its limitations. Molecular studies have improved the understanding of these rare tumours but such findings are scant. We aimed to investigate genetic aberrations in phyllodes tumours stratified according to clinical behaviour, to identify potential genes contributing to disease progression. Twenty phyllodes tumours were separated into prognostically distinct categories depending on whether they had recurred/metastasized within the follow-up period. DNA extracted from FFPE materials was subjected to Affymetrix OncoScan™ FFPE Express molecular inversion probe microarray platform for analysis of copy number changes and mutational status. Results were cross validated with Sanger sequencing, FISH and immunohistochemistry. A higher number of chromosomal aberrations were observed in cases which recurred/metastasized, with median events of 19 compared to 3.5 in cases which did not recur/metastasize. High-level amplification and homozygous deletions were detected exclusively in the former group. Regions of high-level amplification included MDM4 (1q32.1), RAF1 (3p25), EGFR (7p12) and PDZD2 (5p13.3). EGFR amplification was confirmed on FISH and accompanied by intense EGFR immunostaining. Regions of homozygous deletion included CDKN2A (9p21) and MACROD2 (20p12.1). Homozygous deletion of 9p21 which involved CDKN2A was accompanied by loss of protein expression. No mutations were identified in all samples. These findings provide insights into identifying target genes and pathways exploited by phyllodes tumours, which would aid future development of individualised therapy.

Comparison of foveal-sparing with foveal-involving photodynamic therapy for myopic choroidal neovascularization

PURPOSE

To evaluate the visual outcomes of choroidal neovascularization (CNV) secondary to pathological myopia in eyes treated with photodynamic therapy (PDT), and to determine the effect of lesion location and foveal involvement on visual prognosis.

METHODS

Interventional case series of 24 consecutive patients with myopic CNV treated with PDT. The main outcome measure was final LogMAR visual acuity (VA).

RESULTS

Of 24 eyes, the CNV lesion was subfoveal in 11 and extrafoveal in 13. Overall, the mean LogMAR VA at 24 months was 0.72. Extrafoveal CNV lesions achieved significantly better final VA compared with subfoveal CNV (LogMAR 0.45 vs 1.05, P=0.012). Eyes with extrafoveal CNV lesions were subdivided into foveal-sparing PDT (where the PDT laser spot did not involve the foveal center) and foveal-involved PDT (where the PDT laser covered the fovea). At all time points, the group with foveal-sparing PDT had significantly better VA compared with the foveal-involved group. The final LogMAR VA for the foveal-sparing PDT group was 0.26 compared with 1.00 for the foveal-involved PDT group (P=0.003). At 24 months, 77.8% of foveal-sparing PDT cases achieved VA of ≥ 20/40, compared with 25% of foveal-involved PDT cases and 9.1% of subfoveal CNV lesions (P=0.006).

CONCLUSION

For patients with myopic CNV, foveal-sparing PDT results in significantly better long-term visual outcomes compared with those with foveal-involved PDT. Foveal-sparing PDT may be of value for treatment of myopic CNV patients who are not suitable for treatment with anti-vascular endothelial growth factor injections.

Cytogenetic and molecular aberrations of multiple myeloma patients: a single-center study in Singapore

BACKGROUND

Much is known about the cytogenetic lesions that characterize multiple myeloma (MM) patients from the USA, Europe, and East Asia. However, little has been published about the disease among Southeast Asians. The aim of this study was to determine the chromosomal abnormalities of MM patients in our Singapore population.

METHODS

Forty-five newly-diagnosed, morphologically confirmed patients comprising 18 males and 27 females, aged 46 - 84 years (median 65 years) were investigated by karyotyping and fluorescence in situ hybridization (FISH). FISH employing standard panel probes and 1p36/1q21 and 6q21/15q22 probes was performed on diagnostic bone marrow samples.

RESULTS

Thirty-four cases (75.6%) had karyotypic abnormalities. Including FISH, a total detection rate of 91.1% was attained. Numerical and complex structural aberrations were common to both hyperdiploid and non-hyperdiploid patients. Numerical gains of several recurring chromosomes were frequent among hyperdiploid patients while structural rearrangements of several chromosomes including 8q24.1 and 14q32 characterized non-hyperdiploid patients. With FISH, immunoglobulin heavy chain (IGH) gene rearrangements, especially fibroblast growth factor receptor 3 (FGFR3)/IGH and RB1 deletion/monosomy 13 were the most common abnormalities (43.4%). Amplification 1q21 was 10 times more frequent (42.5%) than del(1p36) and del(6q21).

CONCLUSIONS

We have successfully reported the comprehensive cytogenetic profiling of a cohort of newly-diagnosed myeloma patients in our population. This study indicates that the genetic and cytogenetic abnormalities, and their frequencies, in our study group are generally similar to other populations.

The stability of markers in dried-blood spots for recommended newborn screening disorders in the United States

OBJECTIVE

We aimed to measure separately the contributions of heat and humidity to changes in levels of 34 markers of inborn disorders in dried-blood-spot (DBS) samples.

DESIGN AND METHODS

We stored paired sets of DBSs at 37°C for predetermined intervals in low-humidity and high-humidity environments. Marker levels of all samples in each complete sample set were measured in a single analytic run.

RESULTS

During the 30 ± 5 day studies, galactose-1-phosphate uridyltransferase and biotinidase lost almost 65% of initial activities in low-humidity storage; most of the degradation in 27 other markers was attributable to adverse effects of high-humidity storage; seven markers in DBSs stored at high humidity lost more than 90% of initial levels by the end of the study and 4 of the 7 lost more than 50% of initial levels within the first week of storage.

CONCLUSIONS

Minimizing both humidity and temperature in DBS transportation and storage environments is essential to maintaining sample integrity.

Biomechanical disc culture system: feasibility study using rat intervertebral discs

A small-scale biomechanical disc culture system was designed to stimulate intervertebral disc (IVD) 'motion segment' in culture environment with load-controlled compression and combined load (compression+shear). After 7 days of diurnal mechanical loading, cell viability of discs stimulated with static compression load (0.25 MPa) and static combined load (compression (0.25 MPa)+shear (1.5N)) were similar (>90 per cent) to unloaded controls. Mechanically stimulated discs showed decrease in static/dynamic moduli, early stress relaxation, and loss of disc height after 7 days of diurnal loading. Histological data of discs indicated load-induced transformations that were not apparent in controls. The feasibility of studying the mechanobiology of intact IVD as a motion segment was demonstrated. Media conditioning (improve tissue stability in long-term culture) and application of biochemical gene expression assays (differential tissue response to types of mechanical stimulation) are proposed as future improvements. The study suggests that the limitations in studying mechanobiology of IVD pathology in vitro can be overcome and it is possible to understand the physiologically relevant mechanism of IVD pathology.

Gefitinib, cisplatin, and concurrent radiotherapy for locally advanced head and neck cancer: EGFR FISH, protein expression, and mutational status are not predictive biomarkers

BACKGROUND

Gefitinib was demonstrated to be synergistic with cisplatin and radiotherapy (RT) in in vitro studies. Biomarkers predictive of response to gefitinib in squamous cell head and neck cancer is still lacking.

METHODS

Thirty-one patients with locally advanced and easily accessible primary tumor sites for biopsies were recruited. Gefitinib was started 3 weeks before the start of cisplatin/concurrent radiotherapy (CTRT) and continued during the CTRT phase and thereafter for 4 months as consolidation phase. Two baselines and a repeat tumor sample were taken after 2 weeks of gefitinib alone to study its impact on tumor gene expression. Epidermal growth factor receptor (EGFR) protein expression, FISH and mutational status, and matrix metallopeptidase 11 (MMP11) protein expression were correlated with response and survival outcome.

RESULTS

The overall response rate to gefitinib alone was 9.7%. The survival outcome is as follows: median disease free 1.3 years, median survival time 2.4 years, 3-year disease free 42.9%, and 3-year overall survival 48.4%. EGFR FISH, protein expression, and mutational status did not predict for response nor survival outcome of patients. Although MMP11 overexpression did not predict for response, it predicted significantly for a poorer survival outcome.

CONCLUSIONS

Gefitinib can be combined safely with cisplatin/RT. More studies are needed to uncover predictive biomarkers of benefit to gefitinib.

Optimising the management of choroidal neovascularisation in Asian patients: consensus on treatment recommendations for anti-VEGF therapy

In Asian countries, age-related macular degeneration (AMD), specifically wet AMD or choroidal neovascularisation (CNV), is an important cause of blindness and visual handicap. Vascular endothelial growth factors (VEGF) play an integral role in the development of CNV and thus provide an important therapeutic target. Current treatment paradigms for neovascular AMD recognise the place of photodynamic therapy (PDT) in the management of this condition. However, combination therapy targeting different pathways to produce a synergistic effect may result in improved visual outcomes and reduced duration of treatment. Anti-VEGF therapy has greatly improved treatment outcomes in patients with CNV, and a growing body of evidence supports the role of these agents as monotherapy or in combination with PDT. In particular, anti-VEGF may be a first-line treatment option in certain types of subfoveal myopic CNV as well as for classic and occult juxtafoveal and subfoveal CNV. The implementation of evidence-based medicine into current clinical practice is paramount to improving patient care. The authors, who are also members of the Singapore Medical Retina Advisory Board, outline the consensus points and recommended treatment algorithms based on currently available knowledge to provide a structured management approach to the treatment of Asian patients with CNV.

HER2/neu revisited: quality and interpretive issues

BACKGROUND

Immunohistochemistry (IHC) and fluorescence in situ hybridisation (FISH) are the only tests currently approved by the US Food and Drug Administration for classifying which patients will benefit from trastuzumab therapy. The accuracy of these two testing methods can be adversely affected by a variety of pre-analytical, analytical and post-analytical factors. According to the latest published recommendations of the panel of the Joint Committee of the American Society of Clinical Oncology and College of American Pathologists for HER2/neu testing, laboratories performing IHC and FISH for HER2/neu status in breast cancer are now required to have a high concordance of at least 95% between IHC and FISH, significantly higher than that in the published literature.

AIM

To perform a retrospective analysis of the concordance of IHC and FISH analysis for HER2/neu at Singapore General Hospital and review potential causes of disparity between these two methods.

METHOD

A retrospective review of a total of 106 invasive ductal carcinomas evaluated for HER2/neu at the Department of Pathology, Singapore General Hospital between 2007 and 2008 were included in the study. The initial HER2/neu immunostained slides were reviewed independently without knowledge of FISH results, and concordance between IHC and FISH was determined.

RESULTS

Concordance between IHC and FISH assay was excellent and within the published range (104/106=98.1%). The discordant cases represent a well-recognised subset of genetic heterogeneity in HER2/neu, which is known to contribute to positive IHC and negative FISH tests.