Detailed DNA methylation characterisation of phyllodes tumours identifies a signature of malignancy and distinguishes phyllodes from metaplastic breast carcinoma

Phyllodes tumours (PTs) are rare fibroepithelial lesions of the breast that are classified as benign, borderline, or malignant. As little is known about the molecular underpinnings of PTs, current diagnosis relies on histological examination. However, accurate classification is often difficult, particularly for distinguishing borderline from malignant PTs. Furthermore, PTs can be misdiagnosed as other tumour types with shared histological features, such as fibroadenoma and metaplastic breast cancers. As DNA methylation is a recognised hallmark of many cancers, we hypothesised that DNA methylation could provide novel biomarkers for diagnosis and tumour stratification in PTs, whilst also allowing insight into the molecular aetiology of this otherwise understudied tumour. We generated whole-genome methylation data using the Illumina EPIC microarray in a novel PT cohort (n = 33) and curated methylation microarray data from published datasets including PTs and other potentially histopathologically similar tumours (total n = 817 samples). Analyses revealed that PTs have a unique methylome compared to normal breast tissue and to potentially histopathologically similar tumours (metaplastic breast cancer, fibroadenoma and sarcomas), with PT-specific methylation changes enriched in gene sets involved in KRAS signalling and epithelial-mesenchymal transition. Next, we identified 53 differentially methylated regions (DMRs) (false discovery rate < 0.05) that specifically delineated malignant from non-malignant PTs. The top DMR in both discovery and validation cohorts was hypermethylation at the HSD17B8 CpG island promoter. Matched PT single-cell expression data showed that HSD17B8 had minimal expression in fibroblast (putative tumour) cells. Finally, we created a methylation classifier to distinguish PTs from metaplastic breast cancer samples, where we revealed a likely misdiagnosis for two TCGA metaplastic breast cancer samples. In conclusion, DNA methylation alterations are associated with PT histopathology and hold the potential to improve our understanding of PT molecular aetiology, diagnostics, and risk stratification. © 2024 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Looking beyond workforce parity: addressing gender inequity in pathology

While women pathologists have made up over one-third of pathologists in the Australian workforce for over 15 years and at least 50% since 2019, they are under-represented in senior leadership roles, scientific publications, grant recipients, editorial boards, key presentations, and professional awards. This is not unique to pathology and is seen in the broader medical and academic community. Barriers to gender equity and equality in pathology, medicine and academia include gender stereotypes, gender-based discrimination, structural and organisational barriers as well as broader social and cultural barriers. A diverse leadership reflective of the whole professional body and the broader community is important for optimal health outcomes. It is the responsibility and moral duty of individuals and organisations to address any gender disparities, inequities, and inequalities by monitoring, identifying, and acting on gender biases and systemic barriers that hinder appropriate levels of representation by women.

The subsurface lesion in erosive tooth wear

OBJECTIVES

This study compared the surface change on natural and polished enamel exposed to a joint mechanical and chemical wear regimen.

METHODS

Human enamel samples were randomly assigned to natural (n = 30) or polished (n = 30) groups, subjected to erosion (n = 10, 0.3% citric acid, 5 min), abrasion (n = 10, 30 s), or a combination (n = 10). Wear in the form of step height was measured with a non-contact profilometer, and surface changes were inspected with SEM on selected sections. Data was normalised and underwent repeated measures MANOVA, accounting for substrate and erosive challenge as independent variables, with Bonferroni correction for significant post hoc interactions.

RESULTS

After four cycles, polished samples had mean step heights of 3.08 (0.40) μm after erosion and 4.08 (0.37) μm after erosion/abrasion. For natural samples, these measurements were 1.52 (0.22) μm and 3.62 (0.39) μm, respectively. Natural surfaces displayed less wear than polished surfaces under erosion-only conditions (p<0.0001), but the difference disappeared with added abrasion. SEM revealed a shallow subsurface layer for polished surfaces and natural ones undergoing only erosion. However, natural surfaces exposed to both erosion and abrasion showed deeper subsurface changes up to 50 µm.

CONCLUSION

Natural enamel, when exposed to erosion alone, showed less wear and minimal subsurface alterations. But with added abrasion, natural enamel surfaces saw increased wear and notable subsurface changes compared to polished ones.

CLINICAL SIGNIFICANCE

The pronounced subsurface lesions observed on eroded/abraded natural enamel surfaces highlight how combined wear challenges may accelerate tooth tissue loss.

MCP-1 expression in breast cancer and its association with distant relapse

BACKGROUND

Distant relapse of breast cancer complicates management of the disease and accounts for 90% of breast cancer-related deaths. Monocyte chemoattractant protein-1 (MCP-1) has critical roles in breast cancer progression and is widely accepted as a pro-metastatic chemokine.

METHODS

This study explored MCP-1 expression in the primary tumour of 251 breast cancer patients. A simplified 'histoscore' was used to determine if each tumour had high or low expression of MCP-1. Patient breast cancers were retrospectively staged based on available patient data. p < 0.05 was used to determine significance and changes in hazard ratios between models were considered.

RESULTS

Low MCP-1 expression in the primary tumour was associated with breast cancer-related death with distant relapse in ER- breast cancers (p < 0.01); however, this was likely a result of most low MCP-1-expressing ER- breast cancers being Stage III or Stage IV, with high MCP-1 expression in the primary tumour significantly correlated with Stage I breast cancers (p < 0.05). Expression of MCP-1 in the primary ER- tumours varied across Stage I, II, III and IV and we highlighted a switch in MCP-1 expression from high in Stage I ER- cancers to low in Stage IV ER- cancers.

CONCLUSION

This study has emphasised a critical need for further investigation into MCP-1's role in breast cancer progression and improved characterisation of MCP-1 in breast cancers, particularly in light of the development of anti-MCP-1, anti-metastatic therapies.

Xanthogranulomatous inflammation and spindle cell proliferation in response to silicone breast implant leakage

This case study highlights the rare complications of silicone breast implants, as well as the diagnostic limitations of imaging. The patient initially presented with leakage of bilateral breast implants as discovered by a positron emission tomography (PET)-computerized tomography (CT) scan performed as part of a workup for small bowel Langerhans cell sarcoma metastases. The imaging results of the PET-CT scan revealed increased activity bilaterally with an enhancing, irregular, heterogeneously enhancing mass in the right breast. Given the clinical suspicion for breast implant-associated anaplastic large cell lymphoma, further investigation including surgical excision was undertaken. What initially was a concern for a serious complication of long-standing breast implants, fortuitously turned out to be a benign but exuberant xanthogranulomatous inflammatory reactive process. We hope that our report will add to the literature of this rare phenomenon and highlight it as a differential diagnosis of a mass in association with breast implants.

The early wear susceptibility of cementum, enamel and dentine in vitro

OBJECTIVES

To assess the differential early wear susceptibility of cementum, enamel and dentine at a micron level.

METHODS

Whole human molar buccal surfaces incorporating natural enamel and cementum (n = 20) confirmed by imaging (digital microscopy: Keyence, VHX-7000 Milton Keynes, UK), were mounted, scanned (profilometry: XYRIS 4000, Taicaan, Southampton, UK), and allocated to receive erosion (citric acid, pH 2.7, 30 min (n = 10)) or erosion/abrasion challenges (3 cycles of (citric acid, pH 2.7, 10 min, 60 300 g linear abrasion strokes), n=10). Samples were polished and the experiment repeated on polished enamel, and polished coronal and radicular dentine within the same tooth. Profilometric wear data were obtained using superimposition: GeoMagic (3Dsystems, Darmstadt, Germany) and subtraction: MountainsMap (DigitalSurf, Besancon, France). Data were normal. A general linear model was used to assess differences between groups and substrates.

RESULTS

The mean step height (SD) for natural enamel was 8.82 μm (2.53) for erosion and 11.48 μm (2.95) for erosion/abrasion. For natural cementum, the mean step height was 6.00 μm (2.29) for erosion and 4.67 μm (1.58) for erosion/abrasion. Dentine step heights ranged from 7.20 μm (1.53) for erosion and 9.79 μm (1.01) for erosion/abrasion with no statistical differences in dentine wear. Natural cementum surfaces had the lowest wear (p<0.001). Dentine had significantly less wear than natural enamel (p<0.02).

CONCLUSIONS

Cementum surfaces demonstrated the most wear resistance, followed by dentine under erosion dominant conditions in this in vitro study. Further in-vivo investigations are needed to confirm the intraoral stability of cementum.

CLINICAL SIGNIFICANCE

Cementum may be the least susceptible of dental substrates to wear and dentine does not wear at a faster rate than enamel under erosive conditions. This adds to our knowledge on the development of non-carious cervical lesions and questions whether wear rates will accelerate once dentine is exposed.

Reporting of Surgically Removed Lymph Nodes for Breast Tumors: Recommendations From the International Collaboration on Cancer Reporting

CONTEXT.—

The International Collaboration on Cancer Reporting (ICCR), supported by major pathology and cancer organizations, aims at the standardization of evidence-based pathology reporting of different types of cancers, with the inclusion of all parameters deemed to be relevant for best patient care and future data collection. Lymph node metastasis is one of the most important prognostic factors in breast cancer.

OBJECTIVE.—

To produce a histopathology reporting guide by a panel of recognized experts from the fields of pathology and surgery with elements deemed to be core (required) and noncore (recommended) to report when assessing regional lymph nodes of patients with breast cancer.

DATA SOURCES.—

Published literature, previous guidelines/recommendations, and current cancer staging principles were the basis of the data set drafted by the expert panel. This was discussed in a series of teleconferences and email communications. The draft data set was then made available for public consultation through the ICCR Web site. After this consultation and ICCR ratification, the data set was finalized.

CONCLUSIONS.—

The ICCR has published a data set for the reporting of surgically removed lymph nodes (including sentinel lymph node biopsy, axillary lymph node dissection, targeted axillary surgery, and lymph node sampling specimens) for breast tumors. This is part of a series of 4 ICCR breast cancer-related data sets. It includes 10 core elements along with 2 noncore elements. This should allow for synoptic reporting, which is more precise, uniform, and complete than nonsynoptic reporting, and leads to improved patient outcomes.

A Systematic Review of the Factors Associated with Post-Traumatic Growth in Parents Following Admission of Their Child to the Intensive Care Unit

This systematic review aims to identify the demographic, clinical and psychological factors associated with post-traumatic growth (PTG) in parents following their child's admission to the intensive care unit (ICU). Papers published up to September 2021 were identified following a search of electronic databases (PubMed, Medline, Web of Science, PsycINFO, CINAHL, PTSDpubs and EMBASE). Studies were included if they involved a sample of parents whose children were previously admitted to ICU and reported correlational data. 1777 papers were reviewed. Fourteen studies were eligible for inclusion; four were deemed to be of good methodological quality, two were poor, and the remaining eight studies were fair. Factors associated with PTG were identified. Mothers, and parents of older children, experienced greater PTG. Parents who perceived their child's illness as more severe had greater PTG. Strong associations were uncovered between PTG and post-traumatic stress, psychological well-being and coping. PTG is commonly experienced by this population. Psychological factors are more commonly associated with PTG in comparison with demographic and clinical factors, suggesting that parents' subjective ICU experience may be greater associated with PTG than the objective reality.

Temporal profiling of the breast tumour microenvironment reveals collagen XII as a driver of metastasis

The tumour stroma, and in particular the extracellular matrix (ECM), is a salient feature of solid tumours that plays a crucial role in shaping their progression. Many desmoplastic tumours including breast cancer involve the significant accumulation of type I collagen. However, recently it has become clear that the precise distribution and organisation of matrix molecules such as collagen I is equally as important in the tumour as their abundance. Cancer-associated fibroblasts (CAFs) coexist within breast cancer tissues and play both pro- and anti-tumourigenic roles through remodelling the ECM. Here, using temporal proteomic profiling of decellularized tumours, we interrogate the evolving matrisome during breast cancer progression. We identify 4 key matrisomal clusters, and pinpoint collagen type XII as a critical component that regulates collagen type I organisation. Through combining our proteomics with single-cell transcriptomics, and genetic manipulation models, we show how CAF-secreted collagen XII alters collagen I organisation to create a pro-invasive microenvironment supporting metastatic dissemination. Finally, we show in patient cohorts that collagen XII may represent an indicator of breast cancer patients at high risk of metastatic relapse.

The distribution and organisation of matrix molecules in the tumour stroma help shape solid tumour progression. Here they perform temporal proteomic profiling of the matrisome during breast cancer progression and show that collagen XII secreted from CAFs provides a pro-invasive microenvironment.

Pathologist initiated reflex BRAF mutation testing in metastatic melanoma: experience at a specialist melanoma treatment centre

Testing for BRAF mutations in metastatic melanoma is pivotal to identifying patients suitable for targeted therapy and influences treatment decisions regarding single agent versus combination immunotherapy. Knowledge of BRAF V600E immunohistochemistry (IHC) results can streamline decisions during initial oncology consultations, prior to DNA-based test results. In the absence of formal guidelines that require pathologist initiated ('reflex') BRAF mutation testing, our institution developed a local protocol to perform BRAF V600E IHC on specimens from all stage III/IV melanoma patients when the status is otherwise unknown. This study was designed to evaluate the application of this protocol in a tertiary referral pathology department. A total of 408 stage III/IV melanoma patients had tissue specimens accessioned between 1 January and 31 March in three consecutive years (from 2019 to 2021), reported by 32 individual pathologists. The BRAF mutation status was established by pathologists in 87% (352/408) of cases. When a prior BRAF mutation status was previously known, as confirmed in linked electronic records (202/408), this status had been communicated by the clinician on the pathology request form in 1% of cases (3/202). Pathologists performed BRAF V600E IHC in 153 cases (74% of cases where the status was unknown, 153/206) and testing was duplicated in 5% of cases (20/408). Reflex BRAF IHC testing was omitted in 26% of cases (53/206), often on specimens with small volume disease (cytology specimens or sentinel node biopsies) despite adequate tissue for testing. Incorporating BRAF IHC testing within routine diagnostic protocols of stage III/IV melanoma was both feasible and successful in most cases. Communication of a patient's BRAF mutation status via the pathology request form will likely improve implementation of pathologist initiated BRAF mutation testing and may result in a reduction of duplicate tests. To improve pathologist reflex testing rates, we advocate for the use of an algorithmic approach to pathologist initiated BRAF mutation testing utilising both IHC and DNA-based methodologies for stage III/IV melanoma patients.

Activin-A, Growth Differentiation Factor-11 and Transforming Growth Factor-β as predictive biomarkers for platinum chemotherapy in advanced non-small cell lung cancer

BACKGROUND

Despite advances in immunotherapy and targeted therapy, platinum-based chemotherapy remains crucial for many patients with advanced non-small cell lung cancer (NSCLC). Resistance to platinum chemotherapy is common, and predictive biomarkers are needed to tailor treatment to patients likely to respond. In vitro evidence implicates the transforming growth factor-β (TGF-β) superfamily ligands activin-A and growth differentiation factor 11 (GDF-11) in innate platinum resistance. We performed a validation study to assess their utility as predictive biomarkers of platinum chemotherapy response in advanced NSCLC.

PATIENTS AND METHODS

Our study included 123 adult patients with advanced NSCLC without a driver mutation treated with platinum chemotherapy. 98 patients were from a retrospective cohort and 25 from a prospective cohort. We performed immunohistochemistry staining for Activin-A, GDF-11 and TGF-β on tumour samples for each patient and analysed IHC expression with objective radiological response and overall survival.

RESULTS

The overall median survival was 14.8 months. We performed statistical analysis around a cytoplasmic score of 8/18 for Activin-A and GDF-11 based on previously published work, and 110/30 for TGF-β based on a calculated cutpoint for significance. No survival difference was detected between these groups for Activin-A (p=0.35), GDF-11 (p=0.57) or TGF-β (p=0.34). There was no association between rates of progressive disease and high Activin-A expression (p=0.43), high GDF-11 expression (p=1.0) or high TGF-β expression p=0.89).

CONCLUSION

Within the confines of our study, Activin-A, GDF-11 and TGF-β expression was not a predictor of objective radiological response to chemotherapy or overall survival.

Diagnosis and management of phyllodes tumours for the surgeon: An algorithm

A Phyllodes Tumour (PT) is an uncommon fibroepithelial lesion, with three histological grades - benign, borderline and malignant. PTs cause significant challenges in diagnosis, management and prognostication. Recent publications have clarified the definitions and prognostication of PTs. Contemporary data currently challenge international guidelines on PT management. We performed an in-depth literature review to develop a best-practice management algorithm for PTs. Diagnostic recommendations are that neither current imaging techniques, nor fine-needle biopsies, can reliably diagnose a PT. Core needle biopsy is the optimal diagnostic technique. Indeterminate or suspicious lesions are recommended to undergo an excisional biopsy due to the inherently heterogeneous nature of PTs. Management guidelines are that benign PTs should be completely excised, although an involved margin is acceptable in select situations. Borderline PTs should have a clear margin on excision due to their higher risk of recurrence, as well as the potential for a recurrence to progress to a malignant PT. In malignant PTs, a margin of 3 mm is acceptable as there is no reduction in recurrence risk if margins are >3 mm. Routine axillary surgery is not indicated in PTs, with axillary surgery only indicated in a histologically-confirmed positive axilla. Adjuvant treatment recommendations are that borderline and malignant PTs should be discussed at MDT, with radiotherapy considered in both. Chemotherapy should be discussed in malignant PT patients. In summary, we have developed an up-to-date simple algorithm to guide the surgeon's management of patients diagnosed with PTs and reduce excessive surgery.

The interplay of saliva, erosion and attrition on enamel and dentine

Purpose

This investigation aimed to compare the protective role of saliva against erosion and attrition challenges.

Method

Polished enamel and dentine samples (n = 160) were prepared and randomly assigned to either the saliva or saliva-free group (n = 40 enamel and n = 40 dentine/group). Within each subgroup, they were allocated to four subgroups: negative control (deionized water exposure 10 min), erosion (0.3% citric acid 10 min), attrition (120 S of 300 g force), or combined erosion/attrition (0.3% citric acid 10 min then 120 S of 300 g force). Experimental cycles were repeated three times. Data analysis was performed using SPSS.

Results

The mean and standard deviation (SD) of step heights produced by the attrition and erosion/attrition groups in enamel in the saliva-free group were 5.6 µm (2.4) and 13.4 µm (2.8), respectively, while they were 2.4 µm (3.8) and 12.9 µm (3.5) in the saliva group, with no significant difference between the saliva and saliva-free groups. For dentine, the corresponding step heights were 25.2 µm (5.5) and 35.9 µm (7.9) for the saliva-free group, but 21.8 µm (5.3) and 27.3 µm (6.4) for the saliva group (p < 0.001).

Conclusion

There was a trend that saliva decreased wear, but this was only statistically significant for erosion/attrition dentine wear.

Updates in the molecular pathology of non-small cell lung cancer

An understanding of the molecular pathology of non-small cell lung cancer (NSCLC) is important for pathologists as molecular characterization is now required for treatment decisions in advanced stage disease. While assessment for EGFR mutations, ALK and ROS1 fusions, and in some countries BRAF mutations, is now standard practice, other oncogenic mutations are also emerging that may impact routine clinical practice including alterations involving KRAS, NTRK, RET, MET and HER2. In addition, molecular pathology alterations of NSCLC are associated with responses to immune checkpoint therapy and are being increasingly investigated. Finally, specific molecular pathological alterations define some rarer subtypes of NSCLC such as salivary gland tumours, NUT carcinoma and SMARCA4-deficient undifferentiated tumour, and an understanding of the molecular pathology is important for their accurate diagnosis. In this review, the molecular pathology of NSCLC is discussed with a focus on clinically relevant molecular alterations.

Programmed death ligand-1 (PD-L1) as a predictive marker for immunotherapy in solid tumours: a guide to immunohistochemistry implementation and interpretation

Immunotherapy with checkpoint inhibitors is well established as an effective treatment for non-small cell lung cancer and melanoma. The list of approved indications for treatment with PD-1/PD-L1 checkpoint inhibitors is growing rapidly as clinical trials continue to show their efficacy in patients with a wide range of solid tumours. Clinical trials have used a variety of PD-L1 immunohistochemical assays to evaluate PD-L1 expression on tumour cells, immune cells or both as a potential biomarker to predict response to immunotherapy. Requests to pathologists for PD-L1 testing to guide choice of therapy are rapidly becoming commonplace. Thus, pathologists need to be aware of the different PD-L1 assays, methods of evaluation in different tumour types and the impact of the results on therapeutic decisions. This review discusses the key practical issues relating to the implementation of PD-L1 testing for solid tumours in a pathology laboratory, including evidence for PD-L1 testing, different assay types, the potential interchangeability of PD-L1 antibody clones and staining platforms, scoring criteria for PD-L1, validation, quality assurance, and pitfalls in PD-L1 assessment. This review also explores PD-L1 IHC in solid tumours including non-small cell lung carcinoma, head and neck carcinoma, triple negative breast carcinoma, melanoma, renal cell carcinoma, urothelial carcinoma, gastric and gastroesophageal carcinoma, colorectal carcinoma, hepatocellular carcinoma, and endometrial carcinoma. The review aims to provide pathologists with a practical guide to the implementation and interpretation of PD-L1 testing by immunohistochemistry.

Squamous metaplasia of lactiferous ducts (SMOLD): an under-recognised entity

Breast abscesses are a common surgical problem, typically occurring secondary to lactation mastitis. Recurrent subareolar abscesses are rarely reported and may be poorly recognised as a presentation of squamous metaplasia of lactiferous ducts, known eponymously as 'Zuska's disease'. Other synonyms include subareolar breast abscess and lactiferous or mammary fistulas. Recognition of this painful entity is crucial for optimal outcomes since typical breast abscess management of recurrent aspiration or incision and drainage can lead to recurrence and chronic complications, such as fistula formation.

A case of an asymptomatic sacrococcygeal teratoma diagnosed in adulthood

Sacrococcygeal teratomas are rare congenital tumours that are even more uncommon when present in adulthood. They are derived from residual stem cells in the presacral space that differentiate into clusters of somatic cell. We present the diagnosis, management and post-operative follow-up in a 37-year-old gentleman referred to our department with an incidental finding of a lobulated presacral cystic mass on computed tomography imaging. Magnetic resonance imaging and fluorodeoxyglucose (FDG)-positron emission tomography (PET) scans were performed to further characterize the lesion. The decision was then made for surgical excision and the specimen along with the coccyx was retrieved en-bloc via a trans-sacral surgical approach. Histopathology of the mass uncovered the presence of squamous, respiratory and prostatic epithelium consistent with the diagnosis of a sacrococcygeal teratoma.

Stromal cell diversity associated with immune evasion in human triple-negative breast cancer

The tumour stroma regulates nearly all stages of carcinogenesis. Stromal heterogeneity in human triple-negative breast cancers (TNBCs) remains poorly understood, limiting the development of stromal-targeted therapies. Single-cell RNA sequencing of five TNBCs revealed two cancer-associated fibroblast (CAF) and two perivascular-like (PVL) subpopulations. CAFs clustered into two states: the first with features of myofibroblasts and the second characterised by high expression of growth factors and immunomodulatory molecules. PVL cells clustered into two states consistent with a differentiated and immature phenotype. We showed that these stromal states have distinct morphologies, spatial relationships and functional properties in regulating the extracellular matrix. Using cell signalling predictions, we provide evidence that stromal-immune crosstalk acts via a diverse array of immunoregulatory molecules. Importantly, the investigation of gene signatures from inflammatory-CAFs and differentiated-PVL cells in independent TNBC patient cohorts revealed strong associations with cytotoxic T-cell dysfunction and exclusion, respectively. Such insights present promising candidates to further investigate for new therapeutic strategies in the treatment of TNBCs.

A multiplanet system of super-Earths orbiting the brightest red dwarf star GJ 887

The closet exoplanets to the Sun provide opportunities for detailed characterization of planets outside the Solar System. We report the discovery, using radial velocity measurements, of a compact multiplanet system of super-Earth exoplanets orbiting the nearby red dwarf star GJ 887. The two planets have orbital periods of 9.3 and 21.8 days. Assuming an Earth-like albedo, the equilibrium temperature of the 21.8-day planet is ~350 kelvin. The planets are interior to, but close to the inner edge of, the liquid-water habitable zone. We also detect an unconfirmed signal with a period of ~50 days, which could correspond to a third super-Earth in a more temperate orbit. Our observations show that GJ 887 has photometric variability below 500 parts per million, which is unusually quiet for a red dwarf.

Proteogenomic analysis of Inhibitor of Differentiation 4 (ID4) in basal-like breast cancer

BACKGROUND

Basal-like breast cancer (BLBC) is a poorly characterised, heterogeneous disease. Patients are diagnosed with aggressive, high-grade tumours and often relapse with chemotherapy resistance. Detailed understanding of the molecular underpinnings of this disease is essential to the development of personalised therapeutic strategies. Inhibitor of differentiation 4 (ID4) is a helix-loop-helix transcriptional regulator required for mammary gland development. ID4 is overexpressed in a subset of BLBC patients, associating with a stem-like poor prognosis phenotype, and is necessary for the growth of cell line models of BLBC through unknown mechanisms.

METHODS

Here, we have defined unique molecular insights into the function of ID4 in BLBC and the related disease high-grade serous ovarian cancer (HGSOC), by combining RIME proteomic analysis, ChIP-seq mapping of genomic binding sites and RNA-seq.

RESULTS

These studies reveal novel interactions with DNA damage response proteins, in particular, mediator of DNA damage checkpoint protein 1 (MDC1). Through MDC1, ID4 interacts with other DNA repair proteins (γH2AX and BRCA1) at fragile chromatin sites. ID4 does not affect transcription at these sites, instead binding to chromatin following DNA damage. Analysis of clinical samples demonstrates that ID4 is amplified and overexpressed at a higher frequency in BRCA1-mutant BLBC compared with sporadic BLBC, providing genetic evidence for an interaction between ID4 and DNA damage repair deficiency.

CONCLUSIONS

These data link the interactions of ID4 with MDC1 to DNA damage repair in the aetiology of BLBC and HGSOC.

Activin as a biomarker for platinum resistance in non-small cell lung cancer

e21737

Background: Lung cancer is the leading cause of cancer death in Australia with 13,000 new cases per year. Although targeted therapy and immunotherapy have drastically changed the treatment landscape, the majority of patients will receive platinum-based chemotherapy for which the response rate is approximately 30% (Reck et al, 2016). An immunohistochemistry-based, predictive biomarker would be beneficial for patients and help avoid toxicity for patients unlikely to respond. Marini et al (2018) identified 3 biomarkers associated with in-vitro platinum resistance – activin A, growth differentiation factor-11 and transforming growth factor-b – which were investigated in a real-world retrospective cohort to determine their relation to objective radiological response and overall survival. Methods: We identified 101 patients with advanced non-small cell lung cancer who received platinum chemotherapy at 2 cancer centres between 2014-2015. Archival formalin-fixed paraffin embedded tissue samples were stained with activin A. Slides were manually scored by 2 independent clinicians using the multiplicative quickscore method (Detre et al, 1995). Kaplan Meier analysis for overall survival, a Cox-proportional hazards model for confounding variables and a chi-square analysis was performed to analyse the relationship between high immunohistochemistry scores (greater or less than 6) and radiological response. Results: We performed statistical analysis around the median cytoplasmic score (6). The overall median survival was 15.3 months. No significant difference in survival was detected between the two populations (p value = 0.97). The immunohistochemistry score was also not associated with rates of partial response (p value = 0.98) or progressive disease (p value 0.22). Conclusions: Despite an association with lower progression-free survival in a retrospective cohort in a previous study, high expression of activin does not appear to be a useful biomarker for platinum response in the setting of non-small cell lung cancer. Further research into associated antibodies including GDF-11 and TGF-b is in progress.

Tooth wear and aging

BACKGROUND

In an ageing population, tooth wear is likely to increase. It is increasing in prevalence in the younger population and a greater number of patients are retaining their teeth into old age.

METHODS

This paper is a narrative review of the clinical presentation, the epidemiology and the restorative intervention for erosive tooth wear. The dilemmas in managing this common condition with the aging dentition in mind are described. The paper discusses evidence-based prevention methods and highlights how preventive intervention may be preferable over extensive restorative care and high maintenance needs. Patient wishes, expectations and commitment to treatment and maintenance require consideration during clinical decision making.

CONCLUSION

Successful management of erosive tooth wear in an ageing population depends on effective diagnosis, preventive intervention and holistic advice regarding restorative intervention.

Abstract P5-07-03: Small molecule inhibition of smoothened in triple negative breast cancer-associated fibroblasts depletes cancer stem cells and sensitizes to cytotoxic chemotherapy in mice and humans

The cellular and molecular basis of stromal cell recruitment, activation and crosstalk in carcinomas is poorly understood, limiting the development of targeted anti-stromal therapies.

In mouse models of triple negative breast cancer (TNBC), we use single cell genomics to show that Hh ligand produced by neoplastic cells reprograms cancer-associated fibroblast (CAF) gene expression, driving tumor growth and metastasis. Hh-activated CAFs upregulated expression of FGF5 and deposition of fibrillar collagen, leading to FGFR and FAK activation in adjacent neoplastic cells and the acquisition of a stem-like, drug-resistant phenotype.

Treatment with smoothened inhibitors (SMOi) reversed these phenotypes. Stromal treatment of TNBC patient-derived xenograft (PDX) models with SMOi downregulated the expression of cancer stem cell markers and sensitized tumors to docetaxel, leading to markedly improved survival and reduced metastatic burden.

In the phase I clinical trial EDALINE, 3 patients with metastatic TNBC derived clinical benefit from combination therapy with the SMOi Sonedigib and docetaxel chemotherapy, with one patient experiencing a complete radiological response. Responders also exhibited high baseline FGFR activation and ECM deposition, suggesting a mechanism of action consistent with findings from the animal models.

These studies identify Hh signaling to CAFs as a novel mediator of cancer stem cell plasticity and drug resistance and an exciting new therapeutic target in TNBC.

Citation Format: Swarbrick A, Cazet A, Hui M, O'Toole S, Lim E, Martin M. Small molecule inhibition of smoothened in triple negative breast cancer-associated fibroblasts depletes cancer stem cells and sensitizes to cytotoxic chemotherapy in mice and humans [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-07-03.

Abstract P3-08-03: Dissecting the heterogeneity of metaplastic breast cancer: A morphological, immunohistochemical and genomic analysis of a large cohort

Although rare, Metaplastic Breast Carcinomas (MBC) account for significant global breast cancer mortality. This subgroup is extremely heterogeneous and by definition exhibits metaplastic change to squamous and/or mesenchymal elements, including but not limited to spindle, squamous, chondroid, osseous and rhabdomyoid elements. The WHO working group recognizes that the current classification is inadequate and in the interim, has suggested a purely descriptive classification. The mixed epithelial-mesenchymal morphology has led to speculation that MBC represent 'stem cell tumours'; in support of this, MBC have been shown to have a CD44+/CD24-/low phenotype. Clinically, patients present with tumours that are larger (higher stage), have increased likelihood of distant metastases at presentation and overall, have a reduced 5-year survival rate compared to Invasive Carcinoma-NST. Hence, this is a unique subtype with poor outcome but without a robust classification or understanding of the biology to aid clinical management. We present a detailed morphological, immunohistochemical and genomic analysis of a large series of MBC (n=347), as amassed through the Asia-Pacific MBC consortium. We consider our morphological dissection using the WHO subtyping guidelines and show that an increasing number of phenotypes in a mixed MBC (classified as WHO_1) significantly associates with a poor prognosis. Immunohistochemical analysis showed that a pure spindle (WHO_5) is significantly less likely to express vimentin, CK5/6, CK14, and CK19 than a mixed WHO_1 with spindle features. Similarly, a WHO_1 with chondroid features is less likely to express EGFR than WHO_1 with chondroid features and rhabdoid or osseous differentiation. Across the cohort, positivity for the AE1/3 antibody and a lack of EGFR expression both significantly associate with a better outcome. We report no significant association between patient age at diagnosis and breast cancer specific survival, nor between age and specific WHO MBC subtypes. We report a significant association between WHO_1 types and increasing tumour grade, and also between tumour size and grade, with tumour size being a highly significant prognostic indicator in this cohort. Our exome sequencing confirms a significant enrichment for TP53 and PTEN mutations in MBC, and intriguingly for concurrent mutations of TP53, PTEN and PIK3CA. A novel enrichment for NF1 mutations is also presented. In summary, we provide a thorough assessment of a large cohort of MBC, including morphology, survival, IHC and exome sequencing, and present our analysis contextualized by the WHO guidelines, extending the existing knowledge base of this rare tumour type.

Citation Format: McCart Reed AE, Kalaw E, Nones K, Bettington M, Lim M, Bennett J, Johnstone K, Kutasovic JR, Kazakoff S, Xu QC, Saunus JM, Reid LE, Black D, Niland C, Ferguson K, Gresshoff I, Raghavendra A, Liu JC, Kalinowski L, Reid AS, Davidson M, Pearson JV, Yamaguchi R, Harris G, Tse G, Papadimos D, Pathmanathan R, Pathmanathan N, Tan PH, Fox S, O'Toole S, Waddell N, Simpson PT, Lakhani SR. Dissecting the heterogeneity of metaplastic breast cancer: A morphological, immunohistochemical and genomic analysis of a large cohort [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-08-03.

Abstract GS1-01: Landscape of the breast tumour microenvironment at single-cell resolution

Breast cancers are a complex 'ecosystem' of diverse cell types, whose heterotypic interactions play central roles in defining the aetiology of disease and its response to therapy. The next generation of therapies will likely be based upon an integrated understanding of the malignant, microenvironmental and immune states that define the tumour and inform treatment response. However, our poor understanding of the tumour microenvironment (TME) of breast cancers has limited the development and implementation of new drugs that target stromal and immune cells.

Single cell genomics (SCG) is a remarkable new platform to examine the compositional, gene expression and other parameters of thousands of cells, rapidly and at scale. We have used a multi-dimensional SCG approach to characterise the TME in a unique cohort of early and metastatic breast cancers with rich clinico-pathological annotation. We have conducted single cell RNA-Sequencing on more than 125,000 cells collected from 22 patients.

Malignant cells showed remarkable intra-tumoural heterogeneity for canonical breast cancer features, such as intrinsic subtype, hormone receptor expression and activity, drug targets, drug resistance signatures and transcriptional drivers.

Cancer Associated Fibroblasts (CAFs), which are classically studied as a single cell type, were heterogeneous across primary and metastatic sites. Interestingly we identified a myofibroblast-like subset and an inflammatory-mediator subset and propose multi-faceted roles in regulating malignancy and tumour immunity. Distinct transcription factor networks regulated these polarised states.

We applied a new method known as CITE-Seq to measure cell surface immune markers and checkpoint proteins simultaneous to RNA-Sequencing. We resolve the tumour-immune milieu with high precision and generate new transcriptional signatures of breast tumour-infiltrating leukocytes.

To track lymphocyte clonal dynamics through space and time, we developed a novel method known as RAGE-Seq to permit simultaneous full length lymphocyte receptor- and RNA-sequencing at single cell resolution. We observe clonal expansion and trafficking of CD4+ and CD8+ T lymphocytes between the lymph nodes, blood and tumor of patients. In comparison, B cells were polyclonal, suggesting an absence of antigen-dependent clonal expansion.

This data provides by far the most extensive insights into the cellular landscape of breast cancer and will reveal new biomarkers and opportunities for stromal- and immune-based therapy.

Citation Format: Swarbrick A, Wu SZ, Roden D, Al-Eryani G, O'Toole S, Lim E. Landscape of the breast tumour microenvironment at single-cell resolution [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr GS1-01.

Abstract OT1-01-03: The WinPro study: A window of opportunity study of endocrine therapy with and without prometrium in postmenopausal women with early stage hormone receptor-positive breast cancer

Background

There is bidirectional interplay between PR and ER in human breast cancers (Lim et al, Endo Rel Can 2016). There is evidence for a reprogramming of ER chromatin binding sites with 470 genes differentially regulated by dual treatment with estrogen plus progestogen compared to estrogen alone in breast cancer cell lines (Mohammed et al, Nature 2015). Functionally, there was an additive anti-cancer effect with the addition of natural progesterone to endocrine therapy in preclinical breast cancer models.

Trial Design

This is a phase II multi-site, randomised, open-label, three-arm, study in 200 postmenopausal women with early-stage ER+, PR+, HER2-negative breast cancer. Eligible patients will be randomised 1:1:1 to receive 14 days of intervention with either letrozole 2.5mg PO daily (arm 1), letrozole 2.5mg + prometrium 300mg PO daily (arm 2) or tamoxifen 20mg + prometrium 300mg PO daily (arm 3), between diagnosis of breast cancer and definite surgery.

Australian Clinical Trials Registry: ACTRN1261800092813

Eligibility Criteria

Inclusion Criteria

a) Histologically confirmed ER+ and PR+ breast cancers (≥10% positive staining cells)

b) HER2/CEP17 ratio of &lt;2 and mean HER2 copy number &lt;6 (ASCO CAP 2013 guidelines)

c) Tumour size ≥1cm on ultrasound and/or mammogram

d) Aged ≥18 years

Exclusion Criteria

a) Currently on hormone therapies (HRT and OCP)

b) Locally advanced/inoperable and inflammatory breast cancer

c) Clinical evidence of metastatic disease

d) Received other preoperative systemic therapies

e) Nut allergy (prometrium contains peanut oil)

f) Prior history of uterine cancer, deep vein thrombosis, pulmonary embolism or clotting disorder

g) Women who are pregnant/breast feeding

Specific Aims

a) Primary Endpoint

The geometric mean suppression of the centrally assessed proliferation marker Ki67, after two weeks of intervention, compared with baseline. This will be obtained by comparing the mean difference in Ki67 staining between pre and post-treated samples in each intervention arm.

b) Secondary Endpoint

Safety and tolerability of combination therapy (NCI-CTCAE v4.0)

c) Translational Endpoints

1. Define a gene set as a predictive biomarker for a reduction in Ki67

2. Evaluate changes in the apoptotic markers Bcl-2 and Caspase 3 in the tumors following intervention

3. Evaluate changes in ER, PR, AR, FoxA1, Cyclin D1 protein and mRNA expression in the tumors following intervention

Statistical Methods

The IMPACT study reported a geometric mean reduction in Ki67 after 2 weeks of preoperative tamoxifen of 59.5% and anastrazole of 76% (Dowsett et al, JNCI 2007). This allows estimation of power to detect differences between Arm 1 and either Arm 2 or Arm 3 with a p-value of 0.025. For the third possible comparison of Arm 2 vs Arm 3, there is no prior evidence, therefore this as a purely exploratory comparison. With a total trial recruitment of 200 and allowing 4% dropouts, this would give 80% power to detect an improvement in Ki67 suppression from 76% in the letrozole alone control arm to 92% in either experimental arm.

Accrual

Present: 5 (1 site open)

Target: 200 (8 sites total)

Contact Information

Elgene Lim, MBBS, FRACP, PhD. e.lim@garvan.com.au

Citation Format: Carson E, Segara D, Parker A, O'Toole S, Coates A, Mann B, Lindeman G, Tilley W, Lim E. The WinPro study: A window of opportunity study of endocrine therapy with and without prometrium in postmenopausal women with early stage hormone receptor-positive breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr OT1-01-03.

A systematic review and meta-analysis revealing realistic outcomes following paediatric torsion of testes

INTRODUCTION

Reported testicular loss rates following paediatric testicular torsion often reflect the surgical decision-making process, rather than long-term survival of the testes.

OBJECTIVES

We aim to perform systematic analysis and meta-analysis to investigate testicular salvage rates and to assess predictors of long-term viability.

STUDY DESIGN

Systematic review according to PRISMA guidelines was performed to investigate immediate and long-term (>12 months) testicular loss rates following torsion in the paediatric population. Literature search and study inclusion were performed by two investigators. A study quality score was derived and attributed to each study. Predictors of testicular loss were described. Proportions meta-analysis was performed with random effects modelling, and testing for heterogeneity.

RESULTS

Twelve studies were includedm, 6 reporting early orchidectomy rates, and 6 reporting long-term outcomes. Study quality was generally low.

DISCUSSION

The mean early testicular loss rate was 39%, whereas meta-analysis revealed late loss to approach 50%. Predictors of outcomes include prehospital symptom duration, location of presentation, transfer to a tertiary centre, social affluence and use of ultrasound prior to diagnosis or transfer.

CONCLUSIONS

This study has shown a considerable late testicular loss rate, which must be relayed to families even after testicular salvage. Delay in time to presentation is consistently found to predict poor outcomes.

Optimise not compromise: The importance of a multidisciplinary breast cancer patient pathway in the era of oncoplastic and reconstructive surgery

Modern breast cancer care is a complex multidisciplinary undertaking in which the integrated function of multiple constituent parts is critical, and where changes to one therapeutic component may profoundly influence the delivery and outcomes of another. Oncoplastic and reconstructive breast surgery has evolved in the era of longer survival rates for women with breast cancer and aims to enhance oncological and cosmetic outcomes. However, concurrently there has been an expansion in the indications for post-mastectomy radiation therapy (Abdulkarim et al., 2011; Early Breast Cancer Trialists' Collaborative Group (EBCTCG), 2014; Poortmans et al., 2015; Wang et al., 2011), the recognition of several biologically distinct breast cancer subtypes (Perou et al., 2000; Sørlie et al., 2001, 2003; Cheang et al., 2008, 2009; Sotiriou et al., 2003; Millar et al., 2011; Blows et al., 2010; Schnitt, 2010; Haque et al., 2012; Dai et al., 2015) and the development of recommendations for prophylactic surgery for high-risk women, including BRCA-mutation carriers (James et al., 2006; Domchek et al., 2010). Primary systemic therapy is increasingly utilised yet has varying efficacy depending on tumour biology (Cortazar et al., 2014). In this paper we review the evidence which informs the multidisciplinary team opinion in the era of oncoplastic and reconstructive breast surgery. We aim to describe an optimal multidisciplinary approach which balances competing risks of multimodal therapies to optimise oncological and cosmetic outcomes.

Targeting stromal remodeling and cancer stem cell plasticity overcomes chemoresistance in triple negative breast cancer

The cellular and molecular basis of stromal cell recruitment, activation and crosstalk in carcinomas is poorly understood, limiting the development of targeted anti-stromal therapies. In mouse models of triple negative breast cancer (TNBC), Hedgehog ligand produced by neoplastic cells reprograms cancer-associated fibroblasts (CAFs) to provide a supportive niche for the acquisition of a chemo-resistant, cancer stem cell (CSC) phenotype via FGF5 expression and production of fibrillar collagen. Stromal treatment of patient-derived xenografts with smoothened inhibitors (SMOi) downregulates CSC markers expression and sensitizes tumors to docetaxel, leading to markedly improved survival and reduced metastatic burden. In the phase I clinical trial EDALINE, 3 of 12 patients with metastatic TNBC derived clinical benefit from combination therapy with the SMOi Sonidegib and docetaxel chemotherapy, with one patient experiencing a complete response. These studies identify Hedgehog signaling to CAFs as a novel mediator of CSC plasticity and an exciting new therapeutic target in TNBC.

Targeting stromal remodeling and cancer stem cell plasticity overcomes chemoresistance in triple negative breast cancer

The cellular and molecular basis of stromal cell recruitment, activation and crosstalk in carcinomas is poorly understood, limiting the development of targeted anti-stromal therapies. In mouse models of triple negative breast cancer (TNBC), Hedgehog ligand produced by neoplastic cells reprograms cancer-associated fibroblasts (CAFs) to provide a supportive niche for the acquisition of a chemo-resistant, cancer stem cell (CSC) phenotype via FGF5 expression and production of fibrillar collagen. Stromal treatment of patient-derived xenografts with smoothened inhibitors (SMOi) downregulates CSC markers expression and sensitizes tumors to docetaxel, leading to markedly improved survival and reduced metastatic burden. In the phase I clinical trial EDALINE, 3 of 12 patients with metastatic TNBC derived clinical benefit from combination therapy with the SMOi Sonidegib and docetaxel chemotherapy, with one patient experiencing a complete response. These studies identify Hedgehog signaling to CAFs as a novel mediator of CSC plasticity and an exciting new therapeutic target in TNBC.

Stromal cell recruitment, activation and crosstalk with cancer cells is poorly understood. Here, the authors demonstrate that cancer cell-derived Hedgehog ligand  triggers stromal remodeling that in turn induces a cancer-stem-cell like, drug-resistant phenotype of nearby cancer cells while treatment with smoothened inhibitors reverses these phenotypes.

Randomised Controlled Clinical Trial Investigating The Impact of Implementation Planning on Behaviour Related to The Diet

There is a perceived gap between dietary advice given by health practitioners and adherence to the advice by patients. We investigated whether a behaviour change technique (implementation-planning) was more effective than standard-of-care diet advice at reducing dietary acid intake using quantitative erosive tooth wear progression as an objective clinical outcome. This study was a randomised controlled, double-blind, single-centre clinical trial in the UK. Participants (n = 60) with high dietary acid intake (≥2 daily), were recruited and randomly assigned (1:1) to receive either implementation-planning or standard-of-care diet advice in a single clinical session. Questionnaires and impressions were taken at baseline and 6 months later. Dental casts were scanned using laser profilometry and superimposed using surface-matching software. Data were analysed per protocol and intention-to-treat using independent t-tests and Mann-Whitney tests. The intervention group reduced their dietary acid intake between meals to 1 intake per day compared to 2 intakes per day for the controls and demonstrated reduced dental hard tissue volume loss (-0.00 mm³ (SD = 0.01)) compared to controls (-0.07 mm³ (SD 0.17)), p = 0.049. This paper supports the use of implementation planning in clinical practice and presents a non-invasive method of intervention assessment in behaviour change. Larger trials are needed to confirm the generalisability of results.

Tumor PIK3CA Genotype and Prognosis in Early-Stage Breast Cancer: A Pooled Analysis of Individual Patient Data

Purpose Phosphatidylinositol-4, 5-bisphosphate 3-kinase catalytic subunit alpha ( PIK3CA) mutations are frequently observed in primary breast cancer. We evaluated their prognostic relevance by performing a pooled analysis of individual patient data. Patients and Methods Associations between PIK3CA status and clinicopathologic characteristics were tested by applying Cox regression models adjusted for age, tumor size, nodes, grade, estrogen receptor (ER) status, human epidermal growth factor receptor 2 (HER2) status, treatment, and study. Invasive disease-free survival (IDFS) was the primary end point; distant disease-free survival (DDFS) and overall survival (OS) were also assessed, overall and by breast cancer subtypes. Results Data from 10,319 patients from 19 studies were included (median OS follow-up, 6.9 years); 1,787 patients (17%) received chemotherapy, 4,036 (39%) received endocrine monotherapy, 3,583 (35%) received both, and 913 (9%) received none or their treatment was unknown. PIK3CA mutations occurred in 32% of patients, with significant associations with ER positivity, increasing age, lower grade, and smaller size (all P < .001). Prevalence of PIK3CA mutations was 18%, 22%, and 37% in the ER-negative/HER2-negative, HER2-positive, and ER-positive/HER2-negative subtypes, respectively. In univariable analysis, PIK3CA mutations were associated with better IDFS (HR, 0.77; 95% CI, 0.71 to 0.84; P < .001), with evidence for a stronger effect in the first years of follow-up (0 to 5 years: HR, 0.73; 95% CI, 0.66 to 0.81; P < .001; 5 to 10 years: HR, 0.82; 95% CI, 0.68 to 0.99; P = .037); > 10 years: (HR, 1.15; 95% CI, 0.84 to 1.58; P = .38; P heterogeneity = .02). In multivariable analysis, PIK3CA genotype remained significant for improved IDFS ( P = .043), but not for the DDFS and OS end points. Conclusion In this large pooled analysis, PIK3CA mutations were significantly associated with a better IDFS, DDFS, and OS, but had a lesser prognostic effect after adjustment for other prognostic factors.

Analysis of clinically relevant somatic mutations in high-risk head and neck cutaneous squamous cell carcinoma

Cutaneous squamous cell carcinoma is the second most prevalent malignancy, most frequently occurring in the head and neck (head and neck cutaneous squamous cell carcinoma). Treatment of locally advanced or metastatic disease is associated with functional morbidity and disfigurement. Underlying genetic mechanisms are poorly understood. Targeted sequencing of 48 clinically relevant genes was performed on DNA extracted from formalin-fixed and paraffin-embedded high-risk primary head and neck cutaneous squamous cell carcinomas that remained non-metastatic at minimum follow-up of 24 months. Associations of somatic mutations with clinicopathologic characteristics were evaluated and compared with those described in the literature for metastatic disease. Alterations in 44 cancer-associated genes were identified. TP53 was mutated in 100% of cases; APC, ATM, ERBB4, GNAQ, KIT, RB1 and ABL1 were altered in 60% of cases. FGFR2 mutations (40%) were exclusively seen in patients with perineural invasion. MLH1 mutations were exclusively seen in the two younger patients (<45 years). Lower incidences of NOTCH1 mutations were observed compared with that described in metastatic head and neck cutaneous squamous cell carcinoma in the literature. Somatic mutations susceptible to EGFR inhibitors, and other small molecular targeted therapeutics were seen in 60% of cases. This study provides insights into somatic mutations in non-metastatic, high-risk head and neck cutaneous squamous cell carcinoma and identifies potential therapeutic targets. Alterations in FGFR2 and NOTCH1 may have roles in local and distant disease progression.

Shorter anogenital and anoscrotal distances correlate with the severity of hypospadias: A prospective study

INTRODUCTION

Anogenital distance (AGD) is a recognised marker of in utero androgen action.

OBJECTIVE

This study aimed to evaluate the relationship between severity of hypospadias and AGD.

STUDY DESIGN

Boys undergoing hypospadias repair in a single tertiary centre between May 2012 and February 16 were included in the study. Anogenital distance was measured from the centre of the anus to the base of the penis, and anoscrotal distance (ASD) from the centre of the anus to the junction between the smooth perineal skin and scrotal skin. Trained paediatric urologists made all measurements using digital callipers.

RESULTS

Fifty-nine boys with hypospadias and 31 age-matched controls undergoing circumcision (median age 1.37 years, range 1.01-1.96) had AGD and ASD measured under anaesthetic. The patients were divided into two groups, according to hypospadias severity: group 1 - distal penile/subcoronal/glandular (n = 40); and group 2 - perineal/penoscrotal/midshaft (n = 19). The median AGD for controls was 74.0 mm (range 53.2-87.8) and for hypospadias it was 72.3 mm (range 50.7-90.0) (P = 0.816). The median ASD for controls was 42.3 mm (range 31.0-56.1) and for hypospadias it was 39.4 mm (range 20.7-77.0) (P = 0.224). Considering severity of hypospadias, the median AGD for group 1 and group 2 was 73.7 mm (range 50.7-90.0) and 63.3 mm (range 53.6-77.0), respectively (P < 0.001). The median ASD was also higher in group 1, at 41.3 mm (range 20.7-65.0), compared to 35.2 mm (range 23.5-77.0) in group 2 (P = 0.119) (Summary Fig.).

DISCUSSION

This study showed that more severe forms of hypospadias are associated with shorter AGD and ASD. These findings agree with two previous studies that identified reduced AGD in boys with hypospadias. However, these studies did not investigate an association with severity of hypospadias. As hypospadias is multifactorial, only a small proportion of cases are thought to be associated with impaired in utero androgen exposure. The shorter AGD in boys with severe hypospadias compared with mild hypospadias would indicate that AGD is a marker of the severity of androgen production. This may also suggest that less severe forms of hypospadias have a different aetiology involving a later stage of development, and that they are not the result of reduced androgen exposure in the male programming window between the 8-14 weeks gestation.

CONCLUSION

This study identified that boys with more severe hypospadias are more likely to have a shorter AGD and ASD than boys with mild hypospadias. This may indicate that there is a more profound impairment of in utero androgen action in severe hypospadias.

EGFR-Co-Mutated Advanced NSCLC and Response to EGFR Tyrosine Kinase Inhibitors

OBJECTIVES

The evolution of EGFR tyrosine kinase inhibitors (TKIs) has changed the landscape of disease for a subset of patients with NSCLC. Most patients with an EGFR mutation respond to these drugs; however, a proportion show limited or no tumor response. We explored the impact of co-mutation (double or multiple mutation), compared with a single mutation, of the EGFR gene on response to TKIs in a series of patients with metastatic NSCLC.

METHODS

We retrospectively analyzed the mutation profiles of nonsquamous NSCLC tested at Royal Prince Alfred Hospital between 2012 and 2015 by MassArray using the OncoCarta v1.0 panel. Patients with metastatic disease whose tumors had sensitizing EGFR mutation(s) were included. The primary end point was progression-free survival (PFS). We used the Kaplan-Meier method for PFS and overall survival; the log rank test was used to compare groups with and without co-mutation. Multivariable analysis was done for PFS; response rate was assessed using chi-square and logistic regression analysis.

RESULTS

A total of 62 patients were included, and of these, eight (12.9%) had a co-mutation. The median PFS and overall survival times were 11.5 and 26.3 months, respectively. Patients with EGFR co-mutation had a significantly shorter median PFS than those with a single mutation (5.7 months versus 12.3 months, p = 0.02). The response rate to TKIs was significantly worse in those with co-mutation compared with in those without co-mutation (38% versus 89%, p < 0.001).

CONCLUSIONS

Taking into account the small number of patients in this study, PFS in patients with EGFR co-mutation appeared significantly shorter, and response rate significantly lower, than in patients with a single mutation. Data from multipanel testing may identify subgroups of patients who are likely to respond poorly to standard treatment. Clarification of these subgroups may improve patient care.

"I don't like talking about it because that's not who I am": Challenges children face during epilepsy-related family communication

OBJECTIVES

Childhood epilepsy not only significantly impacts a child's social relationships and psychosocial wellbeing, but it can also cause disruptions in family relations. Children living with epilepsy often rely on parental figures for guidance in relation to their condition. A paucity of research has examined the challenges for children when communicating about epilepsy with parental figures. This qualitative study explored the challenges faced by children when talking about epilepsy with their parent(s).

METHODS

Semi-structured interviews were conducted with 29 children (aged 6-16 years) living with epilepsy. Participants were recruited from a neurology department of a major pediatric hospital and from a national epilepsy association. Interviews were transcribed verbatim and thematically analyzed.

RESULTS

Findings revealed four themes: communication impeding normalcy, parental overprotection, parental reactions to epilepsy-related communication, and restriction of activities as a consequence of epilepsy-related communication.

DISCUSSION

The study highlights the need for a greater understanding of parent-child dialogue surrounding epilepsy and where challenges lie for children in conversing about their condition. Parents and health care professionals play a pivotal role in facilitating an environment where children feel comfortable talking about epilepsy. This information will be instrumental in the development of a communication-based intervention for families living with epilepsy.