Pancreatic carcinogenesis

Pancreatic cancer is an almost universally lethal disease. Research over the last two decades has shown that pancreatic cancer is fundamentally a genetic disease, caused by inherited germline and acquired somatic mutations in cancer-associated genes. Multiple alterations in genes that are important in pancreatic cancer progression have been identified, including tumor suppressor genes, oncogenes, and genome maintenance genes. Furthermore, the identification of noninvasive precursor lesions of pancreatic adenocarcinoma has led to the formulation of a multi-step progression model of pancreatic cancer and the subsequent identification of early and late genetic alterations culminating in invasive cancer. In addition, an increased understanding of the molecular basis of the disease has facilitated the identification of new drug targets enabling rational drug design. The elucidation of genetic alterations in combination with the development of high-throughput sensitive techniques should lead to the discovery of effective biomarkers for early detection of this malignancy. This review focuses mainly on the current knowledge about the molecular insights of the pathogenesis of pancreatic ductal adenocarcinoma.

The diagnosis and management of pre-invasive breast disease: pathology of atypical lobular hyperplasia and lobular carcinoma in situ

The term lobular neoplasia refers to a spectrum of lesions featuring atypical lobular hyperplasia and lobular carcinoma in situ (LCIS). The histopathological characteristics of these lesions are well documented. What is less well understood is the management implications of a patient diagnosed with LCIS; treatment regimes vary and are somewhat controversial. LCIS is now considered a risk factor and a non-obligate precursor for the subsequent development of invasive cancer.

Somatic POLE exonuclease domain mutations are early events in sporadic endometrial and colorectal carcinogenesis, determining driver mutational landscape, clonal neoantigen burden and immune response

Genomic instability, which is a hallmark of cancer, is generally thought to occur in the middle to late stages of tumourigenesis, following the acquisition of permissive molecular aberrations such as TP53 mutation or whole genome doubling. Tumours with somatic POLE exonuclease domain mutations are notable for their extreme genomic instability (their mutation burden is among the highest in human cancer), distinct mutational signature, lymphocytic infiltrate, and excellent prognosis. To what extent these characteristics are determined by the timing of POLE mutations in oncogenesis is unknown. Here, we have shown that pathogenic POLE mutations are detectable in non-malignant precursors of endometrial and colorectal cancer. Using genome and exome sequencing, we found that multiple driver mutations in POLE-mutant cancers show the characteristic POLE mutational signature, including those in genes conventionally regarded as initiators of tumourigenesis. In POLE-mutant cancers, the proportion of monoclonal predicted neoantigens was similar to that in other cancers, but the absolute number was much greater. We also found that the prominent CD8+ T-cell infiltrate present in POLE-mutant cancers was evident in their precursor lesions. Collectively, these data indicate that somatic POLE mutations are early, quite possibly initiating, events in the endometrial and colorectal cancers in which they occur. The resulting early onset of genomic instability may account for the striking immune response and excellent prognosis of these tumours, as well as their early presentation. © 2018 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

Upregulation and redistribution of integrin alpha6beta4 expression occurs at an early stage in pancreatic adenocarcinoma progression

Pancreatic adenocarcinomas are highly invasive cancers for reasons that are currently unclear. Here we sought to determine if the proinvasive integrin alpha6beta4 may be related to pancreatic adenocarcinoma tumor progression. Expression of integrin alpha6beta4 was analyzed via immunohistochemistry for the beta4 subunit in normal pancreas, pancreatic intraepithelial neoplasia (PanIN) lesions, pancreatic adenocarcinomas and chronic pancreatitis. In normal pancreatic ducts, integrin alpha6beta4 was noted only at the cell's basal interface with the basement membrane. In pancreatic adenocarcinomas, 92% (104/113) demonstrated overexpression of integrin alpha6beta4 and altered localization to the cytoplasm and membranous regions. This pattern of expression was observed in all PanIN lesions as early as PanIN-1A, and was evident in lesions that were juxtapositioned to normal epithelium. In contrast, 93% (13/14) of chronic pancreatitis samples resembled the staining pattern of normal pancreas. When cancer was present in areas of chronic pancreatitis, this altered expression of alpha6beta4 integrin identified the cancer. We conclude that integrin alpha6beta4 is expressed only on the basal surface of ductal cells in normal pancreas and chronic pancreatitis. During pancreatic adenocarcinoma progression, the alpha6beta4 integrin is dramatically overexpressed and displays altered localization at the earliest stages of PanIN, thus representing an early event in pancreatic adenocarcinoma progression.

Laryngeal precursor lesions: Interrater and intrarater reliability of histopathological assessment

OBJECTIVE

The World Health Organization classification (WHOC) 2017 of low-grade versus high-grade laryngeal dysplasia recently replaced the previous WHOC 2005 of mild, moderate, and severe dysplasia and carcinoma in situ. Our objectives were to compare the interrater agreement of the WHOC 2017 with that of the WHOC 2005 and to test the intra-rater agreement of the WHOC 2005.

METHODS

Two expert head and neck pathologists rated 211 tissue samples that were initially diagnosed with laryngeal precursor lesions. The samples were rated twice according to the WHOC 2005 and once according to the WHOC 2017; estimates of interrater and intrarater agreements were calculated with kappa statistics.

RESULTS

The crude intrarater agreements using the WHOC 2005 were 0.93 for rater 1 and 0.62 for rater 2. The corresponding unweighted kappa values were 0.90 (95% confidence interval [CI], 0.86-0.95) for rater 1 and 0.43 (95% CI, 0.35-0.54) for rater 2, whereas the standard linear weighted kappa values were 0.93 (95% CI, 0.90-0.97) for rater 1 and 0.60 (95% CI, 0.53-0.69) for rater 2. The crude interrater agreement for the WHOC 2005 was 0.57, with a corresponding unweighted kappa value 0.38 (95% CI, 0.31-0.48) and a standard linear weighted kappa value 0.52 (95% CI, 0.42-0.60). The crude interrater agreement for the WHOC 2017 was 0.83, with a corresponding unweighted kappa value 0.45 (95% CI, 0.31-0.59) and a standard linear weighted kappa value 0.46 (95% CI, 0.30-0.60).

CONCLUSION

Our results indicate difficulties in providing reliable diagnosis of laryngeal precursor lesions, even with experienced head and neck pathologists and the application of a newly revised classification system.

LEVEL OF EVIDENCE

4. Laryngoscope, 128:2375-2379, 2018.

miRNA profiling of biliary intraepithelial neoplasia reveals stepwise tumorigenesis in distal cholangiocarcinoma via the miR-451a/ATF2 axis

Distal cholangiocarcinoma (dCCA) is a biliary tract cancer with a dismal prognosis and is often preceded by biliary intraepithelial neoplasia (BilIN), representing the most common biliary non-invasive precursor lesion. BilIN are histologically well defined but have not so far been characterised systematically at the molecular level. The aim of this study was to determine miRNA-regulated genes in cholangiocarcinogenesis via BilIN. We used a clinicopathologically well-characterised cohort of 12 dCCA patients. Matched samples of non-neoplastic biliary epithelia, BilIN and invasive tumour epithelia of each patient were isolated from formalin-fixed paraffin-embedded tissue sections by laser microdissection. The resulting 36 samples were subjected to total RNA extraction and the expression of 798 miRNAs was assessed using the Nanostring® technology. Candidate miRNAs were validated by RT-qPCR and functionally investigated following lentiviral overexpression in dCCA-derived cell lines. Potential direct miRNA target genes were identified by microarray and prediction algorithms and were confirmed by luciferase assay. We identified 49 deregulated miRNAs comparing non-neoplastic and tumour tissue. Clustering of these miRNAs corresponded to the three stages of cholangiocarcinogenesis, supporting the concept of BilIN as a tumour precursor. Two downregulated miRNAs, i.e. miR-451a (-10.9-fold down) and miR-144-3p (-6.3-fold down), stood out by relative decrease. Functional analyses of these candidates revealed a migration inhibitory effect in dCCA cell lines. Activating transcription factor 2 (ATF2) and A disintegrin and metalloproteinase domain-containing protein 10 (ADAM10) were identified as direct miR-451a target genes. Specific ATF2 inhibition by pooled siRNAs reproduced the inhibitory impact of miR-451a on cancer cell migration. Thus, our data support the concept of BilIN as a direct precursor of invasive dCCA at the molecular level. In addition, we identified miR-451a and miR-144-3p as putative tumour suppressors attenuating cell migration by inhibiting ATF2 in the process of dCCA tumorigenesis. © The Authors. The Journal of Pathology published by John Wiley & Sons, Ltd. on behalf of The Pathological Society of Great Britain and Ireland.

Oncogenic BRAF and KRAS mutations in endosalpingiosis

Endosalpingiosis, a microscopic lesion composed of ectopic Fallopian tube epithelium, frequently involves the peritoneum and lymph nodes in patients with ovarian serous borderline tumour or low-grade serous carcinoma, but its pathogenic significance remains unclear. Using laser-capture microdissection and droplet digital PCR, we investigated whether endosalpingiosis harbours the driver mutations in BRAF and KRAS that characterise ovarian low-grade serous neoplasms. Somatic mutations were detected in 14 (33%) of 43 endosalpingiotic lesions analysed. Of 21 women with endosalpingiosis associated with a synchronous or metachronous ovarian low-grade serous tumour, mutations were identified in endosalpingiotic lesions from 11 (52%) women, with most cases (10/11, 91%) demonstrating identical mutations in both tumour and endosalpingiosis. In contrast, of 13 cases of endosalpingiosis not associated with an ovarian tumour, only one harboured a KRAS mutation. The proliferative activity as assessed by Ki-67 immunohistochemistry was lower in endosalpingiosis than in low-grade serous tumours, and endosalpingiosis with either a BRAF or KRAS mutation had a significantly lower Ki-67 index than those without. Ectopic expression of KRAS^G12V in Fallopian tube epithelial cells led to ERK phosphorylation, p21 induction, growth arrest and cellular senescence. In conclusion, we demonstrate that endosalpingiosis represents an interesting example of cancer driver mutations in deceptively normal-appearing cells, which may be prone to neoplastic transformation upon bypass of endogenous oncosuppressive mechanisms. © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Early Diagnosis of Oral Cancer and Lesions in Fanconi Anemia Patients: A Prospective and Longitudinal Study Using Saliva and Plasma

Fanconi anemia (FA) patients display an exacerbated risk of oral squamous cell carcinoma (OSCC) and oral potentially malignant lesions (OPMLs) at early ages. As patients have defects in their DNA repair mechanisms, standard-of-care treatments for OSCC such as radiotherapy and chemotherapy, give rise to severe toxicities. New methods for early diagnosis are urgently needed to allow for treatment in early disease stages and achieve better clinical outcomes. We conducted a prospective, longitudinal study wherein liquid biopsies from sixteen patients with no clinical diagnoses of OPML and/or OSCC were analyzed for the presence of mutations in cancer genes. The DNA from saliva and plasma were sequentially collected and deep-sequenced, and the clinical evaluation followed over a median time of approximately 2 years. In 9/16 FA patients, we detected mutations in cancer genes (mainly TP53) with minor allele frequencies (MAF) of down to 0.07%. Importantly, all patients that had mutations and clinical follow-up data after mutation detection (n = 6) developed oral precursor lesions or OSCC. The lead-time between mutation detection and tumor diagnosis ranged from 23 to 630 days. Strikingly, FA patients without mutations displayed a significantly lower risk of developing precursor lesions or OSCCs. Therefore, our diagnostic approach could help to stratify FA patients into risk groups, which would allow for closer surveillance for OSCCs or precursor lesions.

Survival Outcomes of Pancreatic Intraepithelial Neoplasm (PanIN) versus Intraductal Papillary Mucinous Neoplasm (IPMN) Associated Pancreatic Adenocarcinoma

Pancreatic intraepithelial neoplasms (PanINs) and intraductal papillary mucinous neoplasms (IPMNs) are common pancreatic adenocarcinoma precursor lesions. However, data regarding their respective associations with survival rate and prognosis are lacking. We retrospectively evaluated 72 pancreatic adenocarcinoma tumor resection patients at the University of Kansas Hospital between August 2009 and March 2019. Patients were divided into one of two groups, PanIN or IPMN, based on the results of the surgical pathology report. We compared baseline characteristics, overall survival (OS), and progression free survival (PFS) between the two groups, as well as OS and PFS based on local or distant tumor recurrence for both groups combined. 52 patients had PanINs and 20 patients had IPMNs. Patients who had an IPMN precursor lesion had better median PFS and OS when compared to patients with PanIN precursor lesions. However, the location of tumor recurrence (local or distant) did not show a statistically significant difference in OS.

National Cancer Institute Think-Tank Meeting Report on Proteomic Cartography and Biomarkers at the Single-Cell Level: Interrogation of Premalignant Lesions

A Think-Tank Meeting was convened by the National Cancer Institute (NCI) to solicit experts' opinion on the development and application of multiomic single-cell analyses, and especially single-cell proteomics, to improve the development of a new generation of biomarkers for cancer risk, early detection, diagnosis, and prognosis as well as to discuss the discovery of new targets for prevention and therapy. It is anticipated that such markers and targets will be based on cellular, subcellular, molecular, and functional aberrations within the lesion and within individual cells. Single-cell proteomic data will be essential for the establishment of new tools with searchable and scalable features that include spatial and temporal cartographies of premalignant and malignant lesions. Challenges and potential solutions that were discussed included (i) The best way/s to analyze single-cells from fresh and preserved tissue; (ii) Detection and analysis of secreted molecules and from single cells, especially from a tissue slice; (iii) Detection of new, previously undocumented cell type/s in the premalignant and early stage cancer tissue microenvironment; (iv) Multiomic integration of data to support and inform proteomic measurements; (v) Subcellular organelles-identifying abnormal structure, function, distribution, and location within individual premalignant and malignant cells; (vi) How to improve the dynamic range of single-cell proteomic measurements for discovery of differentially expressed proteins and their post-translational modifications (PTM); (vii) The depth of coverage measured concurrently using single-cell techniques; (viii) Quantitation - absolute or semiquantitative? (ix) Single methodology or multiplexed combinations? (x) Application of analytical methods for identification of biologically significant subsets; (xi) Data visualization of N-dimensional data sets; (xii) How to construct intercellular signaling networks in individual cells within premalignant tumor microenvironments (TME); (xiii) Associations between intrinsic cellular processes and extrinsic stimuli; (xiv) How to predict cellular responses to stress-inducing stimuli; (xv) Identification of new markers for prediction of progression from precursor, benign, and localized lesions to invasive cancer, based on spatial and temporal changes within individual cells; (xvi) Identification of new targets for immunoprevention or immunotherapy-identification of neoantigens and surfactome of individual cells within a lesion.

Endometriosis - insights into a multifaceted entity

Firstly described at the end of nineteenth century, endometriosis remains an enigmatic disease, from etio-pathogenesis to specific markers of diagnosis and its ability to associate with malignancies. Our review has been designed from a historical perspective and steps up to an updated understanding of the disease, facilitated by relatively recent molecular and genetic progresses. Although the histopathological diagnosis is relatively simple, the therapy is difficult or ineffective. Experimental models have been extremely useful as they reproduce the human disease and allow the testing of different potential modulators or treatment options. Due to molecular resemblance to carcinogenesis, applications of anti-cancer agents are currently under scrutiny. The desired goal of an efficient therapy against symptomatic disease, along with associated infertility and malignancies, needs a deeper insight into the complex mechanisms involved in endometriosis initiation, development, and progres-sion. Current trends in genomic and proteomic approaches are useful for a more accurate classification and for the identification of new therapeutic targets.

Neovascular age-related macular degeneration without drusen in the fellow eye: clinical spectrum and therapeutic outcome

Purpose

To investigate the clinical characteristics and therapeutic outcome of patients with neovascular age-related macular degeneration (nAMD) in 1 eye, without drusen in the fellow eye.

Patients and methods

Medical records of 381 patients were analyzed to identify the cases. The main outcomes included Early Treatment Diabetic Retinopathy Study (ETDRS) best-corrected visual acuity (BCVA) and change in central retinal thickness (CRT). These parameters were reviewed at baseline, first follow-up visit, and after 6, 12, and 24 months.

Results

Out of 381 patients, 29 cases (8%) were included (of whom 3 had polypoidal choroidal vasculopathy [PCV]) who were treated with anti-vascular endothelial growth factor (anti-VEGF) therapy which was supplemented by photodynamic therapy (PDT) in the PCV patients. Overall, no statistically significant change in mean BCVA was observed during follow-up. BCVA improved or remained stable (defined as a gain in BCVA, a stable BCVA, or a loss of <5 ETDRS letters) in 22 patients (76%), and 7 patients (23%) had lost ≥5 ETDRS letters at final follow-up. A gain of ≥15 ETDRS letters at final follow-up was seen in 5 patients (17%). Mean CRT had decreased significantly with 99 µm (P<0.001) at 24 months after the initial visit.

Conclusion

There is a clinical spectrum of nAMD that is not associated with drusen in the fellow eye. Patients with nAMD without drusen in the fellow eye respond to anti-VEGF treatment and, in cases of PCV, to supplemental PDT. The pathophysiology of this spectrum of nAMD may be different from drusen-associated age-related macular degeneration.

On Naevi and Melanomas: Two Sides of the Same Coin?

Benign naevi are closely linked to melanoma, as risk factors, simulators, or sites of melanoma formation. There is a heavy genetic overlap between the two lesions, a shared environmental influence of ultraviolet radiation, and many similar cellular features, yet naevi remain locally situated while melanomas spread from their primary site and may progress systemically to distal organs. Untangling the overlapping contributors and predictors of naevi and melanoma is an ongoing area of research and should eventually lead to more personalized prevention and treatment strategies, through the development of melanoma risk stratification tools and early detection of evolving melanomas. This will be achieved through a range of complementary strategies: risk-adjusted primary prevention counseling; the use of lesion imaging technologies such as sequential 3D total body photography and consumer-performed lesion imaging; artificial intelligence deep phenotyping and clinical assistance; a better understanding of genetic drivers of malignancy, risk variants, clinical genetics, and polygenic effects; and the interplay between genetics, phenotype and the environment.

Pathological survey of precursor lesions in cholangiocarcinoma

BACKGROUND

To clarify the pathological significance of two precursors (high-grade biliary intraepithelial neoplasm [BilIN] and intraductal papillary neoplasm of bile duct [IPNB]) in cholangiocarcinomas (CCAs).

METHODS

Ninety-one cases of CCA (47 distal CCAs [dCCAs], 31 perihilar CCAs [pCCAs] and 13 intrahepatic CCAs of large duct type [LD-iCCAs]) were examined for their association with precursors. Neoplastic intraepithelial lesions without underlying infiltrating carcinoma in the surrounding mucosa of CCAs were considered to reflect high-grade BilIN. High-grade BilIN and IPNB were subdivided into gastric, biliary, intestinal and oncocytic subtypes, while CCAs were subdivided into gastrobiliary, intestinal and oncocytic subtypes. The postoperative overall survival (OS) was examined.

RESULTS

Fifty-four and 8 of 91 CCAs were associated with high-grade BilIN and IPNB, respectively, while these precursors were unidentifiable in the remaining CCAs. A majority of CCAs were of the gastrobiliary subtype, while the intestinal subtype was occasionally detected, and the oncocytic subtype was rare. CCAs with high-grade BilIN showed a similar postoperative OS to CCAs without precursors, while CCAs with IPNB showed a favorable postoperative OS compared to CCAs without precursors.

CONCLUSIONS

CCAs were frequently associated with precursors; high-grade BilIN may be a major precursor and IPNB a minor one. CCAs with IPNB showed a favorable postoperative OS compared to CCAs with high-grade BilIN.

Embryonal Origin of MTSCC of Kidney May Explain its Morphological Heterogeneity: Diagnostic Impact of Genetic Analysis

BACKGROUND/AIM

Previous genetic and morphologic characterisation of mucinous tubular and spindle cell carcinoma (MTSCC) have yielded controversial results. The aim of this study was to explain the phenotypic heterogeneity of MTSCC diagnosed by genetic means.

MATERIALS AND METHODS

We analyzed 7 MTSCC by array CGH and microsatellite allelotyping and by histology for morphological variation. We worked-up two entire kidneys with MTSCC to find microscopic alterations.

RESULTS

We confirmed the diagnosis of MTSCC by detecting copy number changes at chromosomes 1, 4, 6, 8, 13, 14, 15, 18 and 22. We detected 13 small, microscopic precursor lesions in the two kidneys and found similar histological structures in precursor lesions and MTSCC.

CONCLUSION

MTSCC develops from embryonal rest-like lesions of impaired differentiation which may explain its morphological variations. Until diagnosis of a "malignant" MTSCC" is not confirmed by genetic means, it should not be called carcinoma.

Cytomorphologic and molecular analyses of fallopian tube fimbrial brushings for diagnosis of serous tubal intraepithelial carcinoma

BACKGROUND

The paradigm shift localizing the origin of ovarian high-grade serous carcinoma (HGSC) to the fallopian tube underscores the rationale for meticulous microscopic examination of salpingectomy specimens. The precursor, termed "serous tubal intraepithelial carcinoma," is often a focal lesion, which poses difficulties for histologic diagnosis.

METHODS

The authors describe a method to examine exfoliated epithelial cells from fallopian tube fimbria by gentle brushing, thereby enabling thorough sampling of the mucosal surface. Fimbrial brushings were collected from 20 fresh salpingectomy specimens from 15 patients, including 5 who had pathologically confirmed ovarian HGSC. Samples taken only from tubes that were grossly negative for tumor were processed for Papanicolaou staining, p53 immunocytochemistry, and tumor protein 53 (TP53) mutation analysis.

RESULTS

Cells with malignant cytomorphologic features were identified only in tubal brushings from patients with ovarian HGSC. In all cases, atypical/malignant cells on cytology corresponded to lesions with similar morphology and immunostaining pattern in permanent sections, demonstrating the sensitivity of the technique while providing reassurance that specimen integrity was not disrupted by the procedure. Targeted next-generation sequencing confirmed the presence of TP53 mutations in fimbrial brushings from HGSC, but not in benign samples, and demonstrated concordance with the immunostaining pattern. Identical mutations were observed in matched lesions microdissected from formalin-fixed tissue sections.

CONCLUSIONS

The described technique enables cytologic evaluation of the fallopian tube fimbria for a diagnosis of serous tubal intraepithelial carcinoma, serving as a complement to histology while offering distinct advantages with respect to the procurement of cellular material for ancillary testing and research.

Infantile hemangioma precursor lesions on day of life 1: A Mayo Clinic retrospective case series

BACKGROUND

Infantile hemangiomas (IHs), the most prevalent vascular tumors in infancy, are generally understood to be absent at birth, appearing in the initial weeks of life during their proliferative stage. While the classic presentation is recognizable, the precursor lesion of IHs may be misinterpreted as other entities, including vascular malformations.

METHODS

A retrospective, single-center study was conducted, examining neonates with photographed IH precursor lesions on day of life (DOL) 1 and matured classical IHs. The study spanned from 2017 to 2023.

RESULTS

The case series is comprised of nine neonates all exhibiting precursor lesions on DOL 1. A comparative display of photographs featuring precursor lesions and classic IH is presented. Further tabulated information for each case includes IH locations, subsequent treatment modalities, and further diagnostic workup if necessary.

CONCLUSIONS

Improving recognition of precursor lesions increases diagnostic accuracy, decreasing unnecessary workup. This, in turn, allows dermatologists to confidently employ close follow-up management strategies. Additionally, in cases of extensive involvement, recognition of the precursor lesion allows for expedited investigation for syndromes such as PHACE (posterior fossa malformations, hemangioma, arterial anomalies, coarctation of the aorta/cardiac defects, and eye abnormalities) and LUMBAR (lower body IH, urogential anomalies, ulceration, myelopathy, bony deformities, anorectal malformations, arterial anomalies, and renal anomalies).

Differences in Ancestry and Presence of Gastric Precursor Lesions in Individuals With Young- and Average-Onset Gastric Cancer

BACKGROUND

There has been a paradoxical rise in young-onset gastric cancer (YOGC), defined as gastric cancer (GC) diagnosed before age 50. Precursor lesions may contribute to pathogenesis, though their role in progression to different histologic subtypes is unclear. The impact of self-reported race is also poorly characterized and may be unreliable as a proxy for genetic differences. We aimed to compare differences in histology and genetic ancestry between YOGC and average-onset gastric cancer (AOGC).

METHODS

This retrospective cohort included all patients with GC at Memorial Sloan Kettering (MSK) from January 2013 to March 2021. Data on demographics, tumor characteristics, and precursor lesions were collected. Genetic ancestry was inferred from MSK-Integrated Mutation Profiling of Actionable Cancer Targets panel.

RESULTS

Of 1685 individuals with GC, 290 had YOGC. Compared to AOGC, individuals with YOGC tended to be female, Hispanic, foreign-born, and feature diffuse-type histology. YOGC was less likely to have precursor lesions, including intestinal metaplasia (20% vs. 37%, p < 0.01) and dysplasia (4% vs. 14%, p < 0.01). Of 560 patients with ancestry data, 127 had YOGC. Admixed, East Asian, and South Asian ancestries were more likely to present with YOGC while Europeans presented with AOGC. Intestinal metaplasia was enriched among East Asians, maintained when stratifying by histology and GC onset.

CONCLUSIONS

We observed YOGC was more common in East and South Asians, and while YOGC may be less likely to develop in the setting of precursor lesions these high-risk states may also be enriched in East Asians. Future research is needed to understand drivers behind such differences and outcome disparities given these individuals may be less amenable to endoscopic interventions.

Evaluation of Retinal Sensitivity in Complete Retinal-Pigment-Epithelium and Outer Retinal Atrophy (cRORA) Lesions in Intermediate Age-Related Macular Degeneration (iAMD) by High-Resolution Microperimetry

Objective: Lesions characterized as complete retinal pigment epithelium and outer retinal atrophy (cRORA) are linked to the progression of intermediate age-related macular degeneration (iAMD). However, the extent of functional impairment of such precursor lesions remains uncertain. Methods: In this cross-sectional study, 4 participants (mean age ± standard deviation: 71.5 ± 2.1 years) underwent extensive multimodal imaging and psychophysical testing of cRORA lesions secondary to iAMD. Lesion-specific functional testing was performed using patient individualized testing grids with clinical conventional available (Stimulus size: 0.43°, ~125 µm) and experimental adaptive optics scanning light ophthalmoscope (AOSLO, stimulus size 0.07°, ~20 µm) based microperimetry (MP). One cRORA lesion site and one in-eye control region were tested per patient, respectively. Results: AOSLO imaging revealed an overall decrease in photoreceptor reflectivity, areas of hyporeflectivity over drusen, interspersed with hyperreflective foci, and disrupted photoreceptor mosaic in regions of cRORA. Localized retinal sensitivity assessment with clinical conventional MP yielded an average loss of -14.0 ± 3.3 dB at cRORA lesions compared to the in-eye control regions. In contrast, localized visual impairment assessed by high-resolution AOSLO-MP with smaller test stimuli (20 µm) revealed a sensitivity loss of -15.1 ± 5.1 dB at cRORA lesions (p < 0.01). Notably, also the area surrounding cRORA lesions can be impacted. Conclusions: We demonstrated that cRORA lesions are associated with severe localized functional impairment. cRORA precursor lesions may thus be considered as a surrogate outcome measure in future interventional iAMD trials.

Clinicopathological spectrums and prognosis of primary appendiceal adenocarcinoma, goblet cell adenocarcinoma, and low-grade appendiceal mucinous neoplasms

Primary appendiceal adenocarcinoma (APCA), goblet cell adenocarcinoma (GCA), and low/high-grade appendiceal mucinous neoplasms (LAMN/HAMN) are distinct entities with overlapping clinical presentation and histomorphology, leading to diagnostic challenges. We retrospectively reviewed our archived cases between 2010 and 2018 for diagnosis reappraisal and comparative analysis using updated terminology and modern parameters. A total of 87 cases (22 APCA, 40 GCA, and 25 LAMN pT≥3) were included. The entire cohort had 49 women and 38 men with a median age of 59.9 (range 26-88) years. There were no statistically significant differences in age and sex among the three groups. Clinically, patients with GCA were more likely to present with acute appendicitis (65%) and more likely to have appendectomy as initial surgery (68%). Both APCA and GCA were more likely to involve the proximal appendix while LAMN was more likely to involve the distal appendix (p<0.05). All APCAs were associated with mucosal precursor lesions, most commonly tubular, tubulovillous, or villous adenoma, flat LAMN/HAMN-pTis mucinous epithelium, or mixed, which correlated with distinct histomorphology, tumour differentiation, and stage. Although polypoid precursor lesions were rare in GCA, a significant proportion of GCA showed crypt atypia associated with neoplastic cells. Immunohistochemically, APCA had more frequent β-catenin nuclear positivity and loss of SATB2 expression (p<0.05). KRAS mutation was more common in APCA than in GCA (8/11 vs 1/7, p<0.01). We further validated the three-tiered grading system (G1, G2, G3) in GCA, which correlated well with tumour stage and patient survival. APCA had worse progression-free and disease-specific survivals than GCA and LAMN (pT≥3) with the latter being relatively indolent even when perforated with peritoneal spread. Our study is the first comprehensive comparison between all three appendiceal neoplasms. We also describe a spectrum of previously under-recognised crypt atypia in GCA, which should trigger a diligent search for GCA if present.

The Validation of a Precursor Lesion of Epithelial Ovarian Cancer in Fancd2-KO Mice

Ovarian cancer (OC) has the highest mortality rate of all gynaecological malignancies. The asymptomatic nature and limited understanding of early disease hamper research into early-stage OC. Therefore, there is an urgent need for models of early-stage OC to be characterised to improve the understanding of early neoplastic transformations. This study sought to validate a unique mouse model for early OC development. The homozygous Fanconi anaemia complementation group D2 knock-out mice (Fancd2^-/-) develop multiple ovarian tumour phenotypes in a sequential manner as they age. Using immunohistochemistry, our group previously identified purported initiating precursor cells, termed 'sex cords', that are hypothesised to progress into epithelial OC in this model. To validate this hypothesis, the sex cords, tubulostromal adenomas and equivalent controls were isolated using laser capture microdissection for downstream multiplexed gene expression analyses using the Genome Lab GeXP Genetic Analysis System. Principal component analysis and unbiased hierarchical clustering of the resultant expression data from approximately 90 OC-related genes determined that cells from the sex cords and late-stage tumours clustered together, confirming the identity of the precursor lesion in this model. This study, therefore, provides a novel model for the investigation of initiating neoplastic events that can accelerate progress in understanding early OC.

Non-coding RNAs in Precursor Lesions of Colorectal Cancer: Their Role in Cancer Initiation and Formation

Colorectal cancer (CRC) is one of the world's most common types of malignancy. The proliferation of precancerous lesions causes this type of cancer. Two distinct pathways for CRC carcinogenesis have been identified: the conventional adenoma-carcinoma pathway and the serrated neoplasia pathway. Recently, evidence has demonstrated the regulatory roles of noncoding RNAs (ncRNAs) in the initiation and progression of precancerous lesions, especially in the adenoma-carcinoma pathway and serrated neoplasia pathway. By expanding the science of molecular genetics and bioinformatics, several studies have identified dysregulated ncRNAs that function as oncogenes or tumor suppressors in cancer initiation and formation by diverse mechanisms via intracellular signaling pathways known to act on tumor cells. However, many of their roles are still unclear. This review summarizes the functions and mechanisms of ncRNAs (such as long non-coding RNAs, microRNAs, long intergenic non-coding RNAs, small interfering RNAs, and circRNAs) in the initiation and formation of precancerous lesions.

Artificial intelligence assisted cytological detection for early esophageal squamous epithelial lesions by using low-grade squamous intraepithelial lesion as diagnostic threshold

BACKGROUND

Manual cytological diagnosis for early esophageal squamous cell carcinoma (early ESCC) and high-grade intraepithelial neoplasia (HGIN) is unsatisfactory. Herein, we have introduced an artificial intelligence (AI)-assisted cytological diagnosis for such lesions.

METHODS

Low-grade squamous intraepithelial lesion or worse was set as the diagnostic threshold for AI-assisted diagnosis. The performance of AI-assisted diagnosis was evaluated and compared to that of manual diagnosis. Feasibility in large-scale screening was also assessed.

RESULTS

AI-assisted diagnosis for abnormal cells was superior to manual reading by presenting a higher efficiency for each slide (50.9 ± 0.8 s vs 236.8 ± 3.9 s, p = 1.52 × 10^-76 ) and a better interobserver agreement (93.27% [95% CI, 92.76%-93.74%] vs 65.29% [95% CI, 64.35%-66.22%], p = 1.03 × 10^-84 ). AI-assisted detection showed a higher diagnostic accuracy (96.89% [92.38%-98.57%] vs 72.54% [65.85%-78.35%], p = 1.42 × 10^-14 ), sensitivity (99.35% [95.92%-99.97%] vs 68.39% [60.36%-75.48%], p = 7.11 × 10^-15 ), and negative predictive value (NPV) (97.06% [82.95%-99.85%] vs 40.96% [30.46%-52.31%], p = 1.42 × 10^-14 ). Specificity and positive predictive value (PPV) were not significantly differed. AI-assisted diagnosis demonstrated a smaller proportion of participants of interest (3.73%, [79/2117] vs.12.84% [272/2117], p = 1.59 × 10^-58 ), a higher consistence between cytology and endoscopy (40.51% [32/79] vs. 12.13% [33/272], p = 1.54 × 10^- 8), specificity (97.74% [96.98%-98.32%] vs 88.52% [87.05%-89.84%], p = 3.19 × 10^-58 ), and PPV (40.51% [29.79%-52.15%] vs 12.13% [8.61%-16.75%], p = 1.54 × 10^-8 ) in community-based screening. Sensitivity and NPV were not significantly differed. AI-assisted diagnosis as primary screening significantly reduced average cost for detecting positive cases.

CONCLUSION

Our study provides a novel cytological method for detecting and screening early ESCC and HGIN.