Early Malignant Transformation Research Articles

Emerging strategies to investigate the biology of early cancer.

Early detection and intervention of cancer or precancerous lesions hold great promise to improve patient survival. However, the processes of cancer initiation and the normal-precancer-cancer progression within a non-cancerous tissue context remain poorly understood. This is, in part, due to the scarcity of early-stage clinical samples or suitable models to study early cancer. In this Review, we introduce clinical samples and model systems, such as autochthonous mice and organoid-derived or stem cell-derived models that allow longitudinal analysis of early cancer development. We also present the emerging techniques and computational tools that enhance our understanding of cancer initiation and early progression, including direct imaging, lineage tracing, single-cell and spatial multi-omics, and artificial intelligence models. Together, these models and techniques facilitate a more comprehensive understanding of the poorly characterized early malignant transformation cascade, holding great potential to unveil key drivers and early biomarkers for cancer development. Finally, we discuss how these new insights can potentially be translated into mechanism-based strategies for early cancer detection and prevention.

Immunohistochemical Glutamine Synthetase As a Surrogate Marker for Beta Catenin (Exon 3 Deletion) in a Rare Case of Hepatic Adenomatosis with Early Malignant Transformation to Well Differentiated Hepatocellular Carcinoma

Abstract Introduction/Objective Hepatic adenomatosis (HA) is a rare entity defined by ≥ 10 hepatocellular adenomas (HCAs). About half of HA cases are asymptomatic and incidentally found. Compared to individual HCAs, HA carries a higher risk of complications including: tumor rupture, bleeding, and an approximate 4.2% overall frequency of malignant transformation. Methods/Case Report A 29-year-old woman presented to the emergency department (ED) requesting a CT scan. She was seen by a gastroenterologist days prior to her ED visit for ongoing sharp rectal pain for 2-3 months. After a recent rectal exam, she was recommended to have a CT abdomen/pelvis to rule out a potential abscess. CT did not show a perianal or perirectal abscess but instead identified a 9.1 cm right hepatic lobe mass. A liver MRI showed a 6.4 x 8.5 cm mass with arterial enhancement. The patient had a prior history of OCP use. She underwent robotic wedge resection of liver segment 6 with cholecystectomy. Gross examination showed a 6 cm tumor with many smaller nodules ranging in size from 0.5-2.2 cm. Our case was submitted entirely for histologic examination. Microscopy demonstrated well differentiated hepatocellular carcinoma (WDHCC) confirmed with positive immunohistochemical (IHC) staining for HepPar1 and Arginase. Tumor cells showed mild patchy cytological atypia, occasional pseudoglands, and architectural atypia with “nodule in nodule growth.” There was reticulin loss in multiple areas and CD34 showed strong diffuse sinusoidal staining. Glypican 3, CRP, and HAA were negative. Low Ki-67, LFABP retention, and absent nuclear staining of beta catenin (BC) were noted. Glutamine synthetase (GS) was diffuse and homogeneous. The gallbladder was unremarkable. Results (if a Case Study enter NA) NA Conclusion This case emphasizes that, despite negative nuclear BC staining, diffuse homogenous staining of GS is a quality surrogate marker for BC mutations (ex. exon 3 deletions). Thorough gross, microscopic, and molecular examination in HA cases is essential for identifying transformation to WDHCC.

Genetic Links between Endometriosis and Endometriosis-Associated Ovarian Cancer-A Narrative Review (Endometriosis-Associated Cancer).

Endometriosis is a frequent, estrogen-dependent, chronic disease, characterized by the presence of endometrial glands and stroma outside of the uterine cavity. Although it is not considered a precursor of cancer, endometriosis is associated with ovarian cancer. In this review, we summarized the evidence that clear-cell and endometrioid ovarian carcinomas (endometriosis-associated ovarian carcinoma-EAOC) may arise in endometriosis. The most frequent genomic alterations in these carcinomas are mutations in the AT-rich interaction domain containing protein 1A (ARID1A) gene, a subunit of the SWI/SNF chromatin remodeling complex, and alterations in phosphatidylinositol 3-kinase (PI3K) which frequently coexist. Recent studies have also suggested the simultaneous role of the PTEN tumor-suppressor gene in the early malignant transformation of endometriosis and the contribution of deficient MMR (mismatch repair) protein status in the pathogenesis of EAOC. In addition to activating and inactivating mutations in cancer driver genes, the complex pathogenesis of EAOC involves multiple other mechanisms such as the modulation of cancer driver genes via the transcriptional and post-translational (miRNA) modulation of cancer driver genes and the interplay with the inflammatory tissue microenvironment. This knowledge is being translated into the clinical management of endometriosis and EAOC. This includes the identification of the new biomarkers predictive of the risk of endometriosis and cancer, and it will shape the precision oncology treatment of EAOC.

P.084 Early malignant transformation of intracranial epidermoid cysts: a case report and systematic review

Background: Intracranial epidermoid cysts (IEC) are benign congenital intracranial lesions that rarely undergo malignant transformation. We report a case of IEC evolving into squamous cell carcinoma (SCC) 1-year post-resection. Further, we conducted a systematic review on cases of early malignant transformations of IECs. Methods: MEDLINE, EMBASE, and Scopus were searched from inception until December 2023 for studies reporting malignant transformations of IECs within 2 years of diagnosis. Results: A 48-year-old female underwent surgical resection of a cerebellopontine angle (CPA) IEC in May 2022. She re-presented in July 2023 with headaches, nausea, vomiting, right facial weakness, and rapid cyst progression. Repeat surgical resection revealed a high-grade SCC. Our systematic review identified 19 (10 females, 9 males) additional IEC cases undergoing malignant transformation within 2 years. The mean age at presentation was 57.6 years, most common location was CPA (n=13, 68.4%) and mean time between IEC to malignant transformation was 10.6 months. Eighteen (94.7%) cases transformed to SCC, of which 2 had leptomeningeal carcinomatosis, and 1 transformed to glioblastoma. Conclusions: While malignant transformations of IECs are rare, regular postoperative follow-up is crucial for early malignancy detection and treatment initiation. Further study is warranted to evaluate factors contributing to accelerated malignant progression of IECs.

The Use of Salivary Levels of Matrix Metalloproteinases as an Adjuvant Method in the Early Diagnosis of Oral Squamous Cell Carcinoma: A Narrative Literature Review.

Oral squamous cell carcinoma (OSCC) is an aggressive malignancy with increased mortality, in which the early diagnosis is the most important step in increasing patients' survival rate. Extensive research has evaluated the role of saliva as a source of diagnostic biomarkers, among which matrix metalloproteinases (MMPs) have shown a valuable potential for detecting even early stages of OSCC. The aim of this review was to present recent clinical data regarding the significance of salivary MMPs in the detection of early malignant transformation of the oral mucosa. A narrative review was conducted on articles published in PubMed, Cochrane Library, Web of Science, EBSCO and SciELO databases, using specific terms. Our search revealed that MMP-1, MMP-2, MMP-3, MMP-8, MMP-9, MMP-10, MMP-12 and MMP-13 had significantly higher levels in saliva from patients with OSCC compared to controls. However, the strength of evidence is limited, as most information regarding their use as adjuvant diagnostic tools for OSCC comes from studies with a low number of participants, variable methodologies for saliva sampling and diagnostic assays, and insufficient adjustment for all covariates. MMP-1, MMP-3 and MMP-9 were considered the most promising candidates for salivary diagnosis of OSCC, but larger studies are needed in order to validate their clinical application.

Malignant Transformation of Giant Cell Tumour of Bone: A Review of Literature and the Experience of a Referral Centre

Giant cell tumour of bone (GCTB) is a benign, locally aggressive primary bone neoplasm that represents 5% of all bone tumours. The principal treatment approach is surgery. Although generally GCTB is considered only a locally aggressive disease, it can metastasise, and lung metastases occur in 1–9% of patients. To date, only the use of denosumab has been approved as medical treatment for GCTB. Even more rarely, GCTB undergoes sarcomatous transformation into a malignant tumour (4% of all GCTB), but history of this malignant transformation is unclear and unpredictable. Considering the rarity of the event, the data in the literature are few. In this review, we summarise published data of GCTB malignant transformation and we analyse three cases of malignant transformation of GCTB, evaluating histopathology, genetics, and radiological aspects. Despite the rarity of this event, we conclude that a strict follow up is recommended to detect early malignant transformation.

Integration of metabolites from meta-analysis with transcriptome reveals enhanced SPHK1 in PDAC with a background of pancreatitis

BackgroundPathophysiology of transformation of inflammatory lesions in chronic pancreatitis (CP) to pancreatic ductal adenocarcinoma (PDAC) is not clear.MethodsWe conducted a systematic review, meta-analysis of circulating metabolites, integrated this data with transcriptome analysis of human pancreatic tissues and validated using immunohistochemistry. Our aim was to establish biomarker signatures for early malignant transformation in patients with underlying CP and identify therapeutic targets.ResultsAnalysis of 19 studies revealed AUC of 0.86 (95% CI 0.81-0.91, P < 0.0001) for all the altered metabolites (n = 88). Among them, lipids showed higher differentiating efficacy between PDAC and CP; P-value (< 0.0001). Pathway enrichment analysis identified sphingomyelin metabolism (impact value-0.29, FDR of 0.45) and TCA cycle (impact value-0.18, FDR of 0.06) to be prominent pathways in differentiating PDAC from CP. Mapping circulating metabolites to corresponding genes revealed 517 altered genes. Integration of these genes with transcriptome data of CP and PDAC with a background of CP (PDAC-CP) identified three upregulated genes; PIGC, PPIB, PKM and three downregulated genes; AZGP1, EGLN1, GNMT. Comparison of CP to PDAC-CP and PDAC-CP to PDAC identified upregulation of SPHK1, a known oncogene.ConclusionsOur analysis suggests plausible role for SPHK1 in development of pancreatic adenocarcinoma in long standing CP patients. SPHK1 could be further explored as diagnostic and potential therapeutic target.

Hepatic Adenomas in Patients 60 and Older Are Enriched for HNF1A Inactivation and Malignant Transformation.

Hepatic adenomas occur most commonly in women between the ages of 20 and 40 years, but rarely they occur in older aged persons, including those 60 years of age or older. This group of adenomas, however, has not been systemically examined. Twenty-six hepatic adenomas in persons 60 years of age or older were studied, along with a control group of 50 hepatic adenomas in persons aged 30 to 39. Hepatic adenomas in persons 60 or more years of age were found in 21 women and 5 men, while the control group had 44 women and 6 men. Subtyping the adenomas in persons 60 years or older showed the following results: 18 HNF1A-inactivated adenomas (69%), 4 inflammatory adenomas (15%), and 4 unclassified adenomas (15%). In contrast, the control group showed a significantly different pattern (P=0.003), with a greater percentage of inflammatory adenomas (28, 56%), fewer HNF1A-inactivated adenomas (8, 16%), and more unclassified adenomas (14, 28%). Atypia and malignant transformation within the hepatic adenomas was studied next. Of the hepatic adenomas in persons age 60 or greater, 3 (12%) showed atypical histologic features, and 6 (23%) had a malignant transformation. In contrast, for hepatic adenomas in the control group, only 4 (8%) adenomas showed atypical histologic features, and 3 (6%) had undergone malignant transformation. In addition, the hepatic adenomas that were atypical or showed early malignant transformation were less likely to have beta-catenin activation in patients over 60 (2/9 cases) compared with those between 30 and 39 years (5/7 cases). Myxoid change and heavy lipofuscin deposition were also more common in adenomas in older aged persons. In conclusion, hepatic adenomas in persons 60 years of age or older are enriched for HNF1A-inactivated adenomas and have a higher frequency of malignant transformation. Malignant transformation, however, is less likely to develop through activation of the beta-catenin pathway.

Correlation of Soluble CD44 Expression in Saliva and CD44 Protein in Oral Leukoplakia Tissues.

Simple SummaryOne way to facilitate the detection of early malignant transformation processes in oral potentially malignant disorders, including oral leukoplakia, involves the parallel evaluation of tissue and saliva biomarkers, as such indicators may elucidate both protein CD44 expression in leukoplakia tissue and its soluble form and total protein detection in saliva. We concluded that the OncAlert® Oral Cancer Rapid test is a non-invasive and simple but only screening method which can complement clinical diagnostics methods in daily clinical practice when considering oral leukoplakia, most importantly, in order to obtain information about the potential for early malignancy.The aim of this study was to determine whether and how pan-CD44 protein expression in leukoplakia tissues correlates with positive SolCD44 test presence and their role in oral leukoplakia. SolCD44 and total protein expression in saliva were determined using an OncAlert® Oral Cancer Rapid test. Comparison of paired associations of total protein, SolCD44, mean number of CD44 expressed epithelial layers in leukoplakia tissue, and macrophages below the basement membrane between control group and patients with leukoplakia showed statistically significant results (p < 0.0001). It is shown that the total protein indicates low or elevated risk of possible malignant transformation processes in leukoplakia. Statistically significant differences between higher total protein level and clinical forms of oral leukoplakia (p < 0.0001), as well as CD44-labeled epithelial cell layer decrease (p < 0.0001), were found. This possibly points to the onset of the stemness loss in leukoplakia tissue. CD9 antigen expression in the exosomes of the oral epithelium explained the intercellular flow of SolCD44 and other fluids in the leukoplakia area. We conclude that the OncAlert® Oral Cancer Rapid test is a valuable screening method in daily clinical practice, in terms of complementing clinical diagnostics methods and to assess the potential for early malignancy.

Loss of the Base Excision Repair Gene Apex1 Leads to Dysfunctional Adult Hematopoietic Stem and Progenitor Cells

Postnatal hematopoietic stem (and progenitor) cells (HS(P)Cs) are especially vulnerable to oxidative stress, leading to early hematopoietic senescence and/or malignant transformation. Elevated intracellular reactive oxygen species (ROS) can, among others, oxidize nucleotides, and thus can result in genotoxicity and mutagenesis if left unrepaired. Oxidized bases, as well as other spontaneous single base modifications, are recognized and repaired by the base excision repair (BER) pathway. Hence, the BER pathway is crucial to maintain genome integrity. In contrast to other DNA repair pathways however, the role of BER in maintaining HSPC functionality remains enigmatic, chiefly because knockout (KO) of BER genes is in many cases embryonic lethal.BER is a complex multi-step repair process. After initial removal and excision of the damaged base, the apurinic/apyrimidinic (AP) site is processed by the AP endonuclease (APEX1) enzyme. At this point, the BER pathway branches into 2 sub-pathways, namely the short-patch (SP-BER; wherein DNA polymerase beta (Polβ), Ligase III (Lig3) together with X-ray repair cross-complementing protein 1 (Xrcc1) are active) and the long-patch BER (LP-BER; wherein Lig1, Flap Structure-Specific Endonuclease 1 (Fen1), and sometimes Polβ are active) for the repair synthesis and the gap filling steps.In this study we wished to address the role of BER in adult hematopoiesis. Therefore, we used CRISPR-Cas9 to KO different BER genes in adult bone marrow (BM) HS(P)Cs, including two genes common to the BER (sub-)pathway(s) (Apex1 and Polβ) as well as one gene in the SP-BER (Xrcc1) and one gene in the LP-BER (Lig1) pathway. The effect thereof was evaluated on HS(P)C repopulation in vivo as well as on HS(P)C expansion during long-term in vitro culture (using the culture medium described by Wilkinson et al., Nature 2019). All CRISPR-Cas9 experiments were validated using a second sgRNA targeting the selected BER genes.Lig1-KO caused in vivo HSPC dysfunction: at 20 weeks post-transplantation, significantly less Lig1 KO cells were observed in the committed progenitor (HPC) and lineage committed (Lin +) BM compartments. By contrast, KO of Xrcc1 had only minor effects on HS(P)C repopulation, but we observed increased HSC expansion and myeloid biased differentiation in some recipient mice, which might correspond to clonal hematopoiesis and is consistent with the finding of XRCC1 loss-of-function mutation in myelodysplastic patients (Joshi et al, Ann Hematol 2016). Knockout of Polβ did not affect hematopoiesis in vivo or in vitro. The most severe phenotype was observed when we knocked out Apex1, as Apex1-KO HS(P)Cs failed to repopulate irradiated recipient mice. Already after 2 weeks, significantly less Apex1 deficient cells were detected in the different blood lineages and nearly no CRISPR-Cas9 KO cells could be detected from 4 weeks onwards. This was confirmed in vitro, where reduced expansion of Apex1 KO BM cells was observed.APEX1 has two major functional activities, namely its nuclease activity, involved in BER, and its redox activity (also called Ref-1 function) important in reducing oxidized transcription factors and therefore implicated in transcriptional regulation. However, little is known regarding the nuclease and Ref-1 function(s) in primary adult hematopoietic cells. We therefore cultured BM HS(P)Cs for 1 week in the continuous presence of 2 distinct chemicals blocking the APEX1 nucleases, or 2 different chemicals inhibiting specifically the Ref-1 function. We demonstrated that both APEX1 functions are essential for hematopoiesis, even if the 2 functions appear to support the survival, expansion and maintenance of HS(P)Cs through different mechanisms. While the Ref-1 function was essential for proliferation (as both Ref-1 inhibitors cause cell cycle arrest) of all the lineages (including the Lin + cells), both inhibitors of the nuclease function affected more the expansion/survival of the less committed HS(P)Cs without leading to any cell cycle arrest.In conclusion, this study demonstrates for the first time the important role of BER genes in adult hematopoiesis, often deregulated in cancer, including hematopoietic malignancies. We observed a particularly severe phenotype upon loss of Apex1 in adult HSPCs, and ongoing studies (such as RNA sequencing analysis) should provide novel insights in underlying mechanisms of APEX1 deficiencies in HS(P)Cs. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

MYCN-induced nucleolar stress drives an early senescence-like transcriptional program in hTERT-immortalized RPE cells

MYCN is an oncogenic driver in neural crest-derived neuroblastoma and medulloblastoma. To better understand the early effects of MYCN activation in a neural-crest lineage context, we profiled the transcriptome of immortalized human retina pigment epithelial cells with inducible MYCN activation. Gene signatures associated with elevated MYC/MYCN activity were induced after 24 h of MYCN activation, which attenuated but sustained at later time points. Unexpectedly, MYCN activation was accompanied by reduced cell growth. Gene set enrichment analysis revealed a senescence-like signature with strong induction of p53 and p21 but in the absence of canonical hallmarks of senescence such as β-galactosidase positivity, suggesting incomplete cell fate commitment. When scrutinizing the putative drivers of this growth attenuation, differential gene expression analysis identified several regulators of nucleolar stress. This process was also reflected by phenotypic correlates such as cytoplasmic granule accrual and nucleolar coalescence. Hence, we propose that the induction of MYCN congests the translational machinery, causing nucleolar stress and driving cells into a transient pre-senescent state. Our findings shed new light on the early events induced by MYCN activation and may help unravelling which factors are required for cells to tolerate unscheduled MYCN overexpression during early malignant transformation.

Pleomorphic adenoma: the great mimicker of malignancy.

Pleomorphic adenoma (PA) is the most common salivary gland neoplasm, and its diagnosis is straightforward in the majority of cases. However, not infrequently, PA shows unusual and uncommon histological features that can be confused with those of malignancy. The difficulties in diagnosing PA arise from its ability to mimic invasion, show atypical or metaplastic cytomorphology, and show morphological features that overlap with those of established salivary gland carcinomas. In addition, recognising early malignant transformation to carcinoma ex-pleomorphic adenoma continues to be a frequent challenge. This review describes the diagnostic pitfalls of PA, and offers a systematic approach to avoid them by combining classic histopathology with novel immunohistochemical and molecular tests.

The role of multi-parametric magnetic resonance imaging (MRI) in early prediction of malignant transformation of low-grade Gliomas (A Systematic review)

Introduction: Low-grade gliomas is the most common primary brain tumour, although the presentation may take up to two decades, there is high tendency of early malignant transformation which raise a growing concern. Multi-parametric MRI studies have the potential for predicting the early malignant transformation. Methods: A comprehensive electronic search of various databases was conducted together with forward tracking of the reference list to retrieve relevant qualitative primary studies. Moreover, hand search for journal that was not available electronically was also conducted. Through assessment of the relevant studies was ensured and the included studies were carefully selected. The relevant data was extracted by data extraction form recommended by Cochrane collaborations. Results: The search yielded 1158 which was narrowed down to eight (8) studies that satisfied the inclusion criteria. These studies are assessing the role of different MRI parameters in predicting the early malignant transformation of Low-grade gliomas. The risk of bias and the applicability concern of the included studies are low. Conclusion: Based on the findings of this review; Multi-parametric MRI studies have the potential of predicting the early malignant transformation of low-grade gliomas. There is need for high quality large scale, prospective studies on the role of multi-parametric MRI studies in early prediction of malignant transformation of LGGs and meta-analysis of these studies is highly recommended.

Lichenoid proliferative leukoplakia, lichenoid lesions with evolution to proliferative leukoplakia or a continuum of the same precancerous condition? A revised hypothesis.

Multiple white plaques of the oral mucosa are usually associated with potentially malignant disorders such as oral lichen planus, oral lichenoid lesions and proliferative verrucous leukoplakia. Previous studies in the current literaturedescribe a potential clinical overlap in these entities. The aim of this study is to review clinicopathological and evolutive features of these Oral Potentially Malignant Disorders highlighting the dynamic changes of diagnoses. It was previously hypothesized that a subset of patients with oral lichen planus or oral lichenoid diagnosis, could develop multiple white plaques during the natural history of the disease, fulfillingdiagnostic criteria for proliferative verrucous leukoplakia. Consequently, these entities could, under certain conditions, obey a continuum of the same precancerous condition in the context of the field cancerization theory, increasing the risk of malignant transformation. Nevertheless,there is limited scientific evidence concerning this issue. Further studies are needed to understand the biological and evolutive features of the link between these oral potentially malignant disorders. Regardless of its diagnosis, these patients with multifocal white lesions must be carefully monitored to detect early malignant transformation.

Abstract LB-081: A nuclear cAMP microdomain functions as a tumor suppressor in melanoma

Abstract Cyclic AMP (cAMP), a ubiquitous second messenger, has a broad impact on cellular processes such as proliferation, differentiation, apoptosis, migration, and gene expression. It has been widely linked to melanomagenesis; however, studies often report contradictory functions for cAMP (e.g., cancer promotion, but also tumor suppression and therapy resistance). Thus, a huge conundrum exists in the field of cAMP signaling and melanoma – one that might be explained by examining cAMP at the level of microdomains. In mammalian cells, two classes of adenylyl cyclases synthesize cAMP: the transmembrane adenylyl cyclases (tmACs) and the soluble adenylyl cyclase (sAC). Unlike tmACs, which are tethered to the plasma membrane, sAC is expressed throughout the cell and within organelles (e.g., nucleus and mitochondria). Thus, sAC and tmACs define distinct sources that generate cAMP in spatially separated cell regions, further restricted by the cAMP catabolizing enzymes phosphodiesterases (PDEs). Since cAMP signaling cascades can be evoked and restricted to small compartments, it is imperative that we interrogate all available cAMP microdomains to truly unravel their role in melanoma. To address this question, we have created a panel of virally-encoded, doxycycline-inducible sAC cDNAs, targeted to specific cellular compartments, i.e. nucleus, cytoplasm or mitochondria. We infected a melanoma sAC knock-out cell line with these cDNAs and have established single clone cell lines where sAC activity can be rapidly restored, only in a specific microdomain, at near pharmacologic time scales. Utilizing these model cell lines, we showed that only the nuclear sAC-dependent cAMP microdomain inhibits melanoma growth, both in vitro and in mice. Neither mitochondrial, nor cytoplasmic sAC cAMP microdomains affected tumor cell growth. Using ATACseq and RNAseq, we discovered that the nuclear cAMP microdomain leads to specific changes in chromatin landscape and a unique gene expression profile, distinct from the canonical MC1R/cAMP-dependent gene expression profile, that encompasses a range of genes with both established and potentially new roles in melanomagenesis. Immunohistochemical analysis of melanoma patient biopsies revealed that sAC localization in melanocytes is not static; while sAC is mostly cytoplasmic in benign melanocytes, it becomes nuclear as melanocytes undergo early malignant transformation (in situ disease and radial growth phase) but is lost from the nucleus upon transition to vertical growth phase. These data suggest that nuclear sAC expression is an early tumor suppressive pathway that is lost in melanoma cells capable of dermal invasion. Thus the pattern of cellular localization of sAC during different stages of melanoma may be a prognostic marker. Taken together, our findings support a novel tumor suppressor pathway that relies on the expression of sAC in specific cellular microdomains. Citation Format: Marek M. Drozdz, Jenny Wang, Michael Reilly, Elsbeth Kane, Kelsey Aguirre, Ashley Doane, Jedd D. Wolchok, Olivier Elemento, Garrett Desman, Taha Merghoub, Elena Piskounova, Jonathan Zippin. A nuclear cAMP microdomain functions as a tumor suppressor in melanoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr LB-081.

Intracapsular Carcinoma ex Pleomorphic Adenoma

This is the case of a 37-year-old female patient presenting with a 10-year history of a gradually enlarging right infra-auricular mass. A parotidectomy was performed. The surgical pathology specimen consisted of an 18 cm diameter encapsulated nodular mass with a homogenous, cream-tan solid surface. Microscopic section showed an encapsulated neoplasm with abundant chondromyxoid stroma and tubular epithelial elements characteristic of a pleomorphic adenoma. (Figure 1) Randomly scattered within the tumor were foci of haphazard and complex glands. (Figure 2) These glands exhibited nuclear pleomorphism, luminal necrosis, and mitoses compatible with an adenocarcinomatous proliferation. (Figure 3) Based on these features, the case was signed out as an intracapsular carcinoma ex pleomorphic adenoma.&#x0D; &#x0D; Carcinoma ex pleomorphic adenoma is a carcinoma arising from a pre-existing pleomorphic adenoma. The antecedent benign tumor may either be a long-standing one, often with a history measured in decades, or characterized by a protracted history of excisions and multiple recurrences.1,2 The carcinoma on the other hand is either epithelial or myoepithelial in derivation. By morphologic sub-type, the most commonly reported carcinoma arising in a pleomorphic adenoma is a salivary duct carcinoma or an adenocarcinoma that is not otherwise specified (NOS).1,3 Residual pleomorphic adenoma tissue is identifiable either in its typical morphology, a chondromyxoid stroma, or a hyalinized sclerotic nodule.1&#x0D; &#x0D; Aside from the type of carcinoma arising from the pleomorphic adenoma, another parameter that has to be reported is the extent of involvement by the carcinomatous component. A carcinoma that is entirely limited to within the parent tumor that is still enclosed by a complete capsule is termed an “intracapsular” or “non-invasive” carcinoma ex pleomorphic adenoma.1,2 Once the carcinoma breaches the capsule and infiltrates the surrounding tissue, then it is considered invasive. If the invasion is less than 4 – 6 mm beyond the capsular border, the tumor is termed “minimally invasive”. Carcinomatous elements that extend beyond this threshold is termed “widely invasive”.1 This threshold is greater than the previous threshold of 1.5 mm recommended in an earlier edition of the WHO classification although the present edition does state that this threshold is preliminary and requires further validation.1,2,4 It has to be pointed out though that quantifying invasion may not always be possible in tumors that have positive margins, those that are intrinsically unencapsulated such as minor salivary gland tumors, and those with complex multinodular growth patterns such as in recurrent pleomorphic adenoma.1 This difficulty has to be stated in the report and what conditions preclude quantifying the degree of invasion.&#x0D; &#x0D; Non-invasive carcinoma ex pleomorphic adenoma has quite a good outcome with very low reported rates of recurrence or regional metastasis. In a review of thirty cases and a report of an additional three cases, only one case showed recurrence or metastasis.3 This favorable outcome certainly contrasts with that of the widely invasive type where metastasis is reported to occur in up to 70% of cases.1 Another review of ten cases showed one case developing metastasis, and recommended that non-invasive cases should thus still be followed up closely after primary treatment because regional or distant metastasis can occur.2 &#x0D; &#x0D; To the best of our knowledge, there are no published local data on the incidence of early malignant transformation of pleomorphic adenomas in the Filipino population. Hence, we take this opportunity to report this case. Awareness of the entity and prudent liberal sampling of these tumors may help address this gap.

Texture analysis on conventional MRI images accurately predicts early malignant transformation of low-grade gliomas.

Texture analysis performed on MRI images can provide additional quantitative information that is invisible to human assessment. This study aimed to evaluate the feasibility of texture analysis on preoperative conventional MRI images in predicting early malignant transformation from low- to high-grade glioma and compare its utility to histogram analysis alone. A total of 68 patients with low-grade glioma (LGG) were included in this study, 15 of which showed malignant transformation. Patients were randomly divided into training (60%) and testing (40%) sets. Texture analyses were performed to obtain the most discriminant factor (MDF) values for both training and testing data. Receiver operating characteristic (ROC) curve analyses were performed on MDF values and 9 histogram parameters in the training data to obtain cutoff values for determining the correct rates of discrimination between two groups in the testing data. The ROC analyses on MDF values resulted in an area under the curve (AUC) of 0.90 (sensitivity 85%, specificity 84%) for T2w FLAIR, 0.92 (86%, 94%) for ADC, 0.96 (97%, 84%) for T1w, and 0.82 (78%, 75%) for T1w + Gd and correctly discriminated between the two groups in 93%, 100%, 93%, and 92% of cases in testing data, respectively. In the astrocytoma subgroup, AUCs were 0.92 (88%, 83%) for T2w FLAIR and 0.90 (92%, 74%) for T1w + Gd and correctly discriminated two groups in 100% and 92% of cases. The MDF outperformed all 9 of the histogram parameters. Texture analysis on conventional preoperative MRI images can accurately predict early malignant transformation of LGGs, which may guide therapeutic planning. • Texture analysis performed on MRI images can provide additional quantitative information that is invisible to human assessment. • Texture analysis based on conventional preoperative MR images can accurately predict early malignant transformation from low- to high-grade glioma. • Texture analysis is a clinically feasible technique that may provide an alternative and effective way of determining the likelihood of early malignant transformation and help guide therapeutic decisions.

Abstract 3304: The mutation landscape of cancers serves as a record of early malignant transformation

Abstract How the cell lineage influences a tissue's susceptibility to malignant transformation is a fundamental question in cancer biology, which has been barely addressed in cancer genomics thus far. Cell properties are encoded in the cell type-specific chromatin structure and we previously demonstrated that the cell-of-origin (COO) chromatin organization is a key determinant of the landscape of somatic mutations, which accumulated over lifetime serving as a memory of the historical cell lineage (Polak et al, Nature , 2015). We now show that this principle is generalizable to common tumor types and offers insights into the molecular events of cancer initiation. We extended our work to 2,641 genomes from 30 cancer types and epigenetic modifications from 98 normal tissues. In 25 cancer types, the tumor originated from a cell type that was its direct cellular counterpart or a close proxy; in only two, there was no match or a close proxy; and in the remaining three (esophageal, pancreatic ductal and biliary adenocarcinoma) the best matched cell type suggested metaplasia to stomack mucosa like tissue.The cellular context of breast tumor formation was investigated in more detail, showing that the COO, and not the gene inactivation event, determines the subtype. Basal-like tumors appeared to arise from luminal progenitor cells, while all other subtypes arose from mature luminal cells. Furthermore, irrespective of the inactivation mechanism (pathogenic germline, somatic truncating or epigenetic silencing event), all BRCA1/2- and RAD51C-altered basal-like tumors best matched to luminal progenitors while BRCA1/2- and CHEK2 -mutated luminal A/B subtypes best matched mature luminal cells. Finally, we observed that tumor type-specific driver genes reside in genomic regions that are defined by a highly active chromatin environment in their COOs. This highlights their essential role in cell type differentiation and implies the acquisition of somatic mutations early, when the chromatin architecture still reflected the COO. Taken together, our findings shed light on the crucial role of the COO in shaping the mutational landscape and tumor evolution. Citation Format: Paz Polak, Rosa Karlic, Kirsten Kubler, William D. Foulkes, Gad Getz. The mutation landscape of cancers serves as a record of early malignant transformation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3304.

Serum glycine dehydrogenase is associated with increased risk of lung cancer and promotes malignant transformation by regulating DNA methyltransferases expression.

Identification of novel risk factors that are critical to the initiation of lung cancer will be key for its prevention. Recently, it has been reported that glycine dehydrogenase (GLDC) can drive the formation of lung cancer initiating cells. However, there have been no perspective studies on the association between circulating GLDC and lung cancer until now. To identify whether serum GLDC is a risk factor for lung cancer, the present study conducted a nested case‑control study within a Chinese cohort. Using ELISAs, serum GLDC was measured in 300case subjects, who were subsequently diagnosed with lung cancer during follow‑up, and in 600 matched healthy controls. The results revealed that serum GLDC was associated with increased lung cancer risk [odds ratio=1.48; 95% confidence intervals (1.01‑2.04)]. Spearman correlation was employed to analyze the associations between age, body mass index, years of smoking and the serum concentration of GLDC. It was demonstrated that years of smoking was associated with serum GLDC (spearman's correlation, ρ=0.81) in patients with lung cancer. However, the association was attenuated in the serum of matched controls (ρ=0.48). In addition, overexpression of GLDC protein contributed to malignant transformation and inhibited microRNA (miR)‑29 family expression in normal human bronchial epithelial (NHBE) cells. Aberrant methylation of tumor suppressive gene (TSG) is an early event in the development of lung cancer, which is controlled by DNA methyltransferases (DNMTs). The present study demonstrated that GLDC promoted the expression of DNMT proteins; however, the miR‑29 family inhibited their expression in NHBE cells. Thus, it was concluded that elevated serum GLDC may increase lung cancer risk, and that smoking, GLDC, the miR‑29 family and DNMT signaling pathways may serve an important role in early malignant transformation during the development of lung cancer.

Comparison analysis of Baso Cellular Carcinoma and Spino Cellular Carcinoma - Protein Kinase D1, Wnt/β-catenin and Epithelial to Mesenchimal Transition (markers)

Understanding cancer biology is crucial to the successful diagnosis and application of personalized therapies. Skin carcinogenesis is a multi-step process. The first step is the development of potentially malignant disorders (PMDs) known as leukoplakia, erytroplakia, lichen planus, probably trough mutation in the proteins regulated cell cycle (p16INK4A, p21Waf1/Cip1/Sdi1, p27 kip1, Cyclin D1) and, second in p53 (TP53), Ras, hTert, EGFR, will reverse benign phenotype of late precancer lesions (PMDs) into benign cancer lesion. Third mutation probably in PI3K, PKD1 or E-cadherin, will increase malignant potential of SCCs, activating EMTransition, invasion and metastasis, e.g. aggressive phenotype. In BCC mutations of p53 are known to be late events (UV signature), whereas silencing of 14-3-3 takes place early in tumor progression, concomitant with increased activity of Snail. Early increased expression of PKD1 and down-regulation of c-myc mRNA are also events in pathogenesis of BCC. There is no data for detected mutations in PKD1 gene in both cancers, although the kinases is with high expression in BCC and lack of expression in SCC. There is no data concerning PKD1 expression in the PMDs leading to SCCs, nor to BCCs, such data were recently published concerning PKD1 expression in pancreatic oncogenesis. Curently adequate question is whether lack of PKD1 expression in SCCs, despite its PMDs origin, is a consequence of its spinous layer origin, or is a consequense of PKD1 gene mutations (downregulation). Identification of mutations as markers for early malignant transformation could be useful for early diagnosis and treatment of skin head and neck cancers.