Common Human Cancers Research Articles

Targeting fibroblast activation protein with chimeric antigen receptor macrophages

Under the rapid advancement of chimeric antigen receptor T cell (CAR-T) technology, CAR-macrophages (CAR-Ms) are also being developed currently in the pre-clinical stage and have been shown to inhibit tumor growth in several mouse tumor models. Fibroblast activation protein (FAP) is a type II transmembrane serine protease, which is expressed in stromal fibroblasts of over 90 % of common human epithelial cancers and is upregulated in fibrotic diseases of the liver, lung and colon, etc. In this study, we firstly constructed FAP-CAR macrophages to target FAP+ cells through in vitro phagocytosis assays. In subsequent in vivo assays, we discovered that FAP-CAR-ΔZETA bone marrow-derived macrophages (BMDMs) rather than FAP-CAR BMDMs, exhibited a pronounced anti-tumor effect in mouse subcutaneous MC38 colon cancer model. In addition, FAP-CAR and FAP-CAR-ΔZETA BMDMs therapy could effectively improve CCl4-induced liver fibrosis in mice. Collectively CAR-Ms targeting FAP demonstrated great therapeutic potential in cancer and liver fibrosis therapy.

In Silico Prediction of Carcinogenic Mechanisms Induced by Mixture of Toxic Substances from E-Waste Dust

Humans are constantly exposed to low doses of various metals and organic compounds in electronic waste (e-waste) recycling areas. Although these substances individually have been identified as environmental carcinogens that influence the onset and progression of tumors, their combined effect on human cancers has not been sufficiently investigated. For this reason, the goal of the current analysis is to evaluate the possible molecular mechanisms between exposure to a mixture of As, Cd, Cr, Hg, Pb, Sb, DBDE, DBDPE, and TBBPA from e-waste and the onset and progression of common human cancers via in silico toxicogenomic tools. The CTD, GeneMANIA, ToppGene Suite portal, and TIMER2 online server were utilized as the primary data-mining tools. Eleven genes that were linked to different types of cancer were found to be shared by most of the substances under investigation. Notably, co-expression (58.91%) was the most common interaction among these genes. The examined mixture's primary molecular route linked to human cancers was found to be the interleukin 4 and interleukin 13 signaling pathway, which was further connected to the macrophage infiltration. These results underline the critical need for the future research that focus on examining the 11 particular genes as well as the mechanism involving IL4/IL13-mediated macrophage infiltration, to address this environmental health hazard and the development of targeted tumor prevention and control policies for populations exposed to the toxic substance from e-waste recycling process.

Basal Cell Carcinoma of the External Auditory Canal and Conchal Bowl

Basal cell carcinoma (BCC) is the most common cancer in humans, and is the most common cutaneous malignancy in the United States. It affects close to 4 million people per year, or one in five Americans. BCC typically arise in sun-exposed areas of the body, due to damage caused by UV light. Although sunlight exposure is the most predictive risk factor for BCC, it can also occur by other methods, giving rise to BCCs that are not in sun-exposed areas of the skin. This case report describes a BCC located in the conchal bowl with extension into the external auditory canal (EAC), a site that is rare for BCC to occur. We are presenting this case to raise awareness of the fact that BCCs could occur anywhere on the body, and dermatologists as well as other clinicians should be observant in their total-body examinations. In addition, we are emphasizing the fact that treating BCC often is a multi-disciplinary effort, and interdisciplinary communication between dermatologic and surgical teams is key to successfully excise BCC in atypical areas.

Genomic analyses identify 15 susceptibility loci and reveal HDAC2, SOX2-OT, and IGF2BP2 in a naturally-occurring canine model of gastric cancer.

Gastric cancer (GC) is the fifth most common human cancer worldwide, but the genetic etiology is largely unknown. We performed a Bayesian genome-wide association study and selection analyses in a naturally-occurring canine model of GC, the Belgian Tervuren and Sheepdog breeds, to elucidate underlying genetic risk factors. We identified 15 loci with over 90% predictive accuracy for the GC phenotype. Variant filtering revealed germline putative regulatory variants for the EPAS1 (HIF2A) and PTEN genes and a coding variant in CD101. Although closely related to Tervuren and Sheepdogs, Belgian Malinois rarely develop GC. Across-breed analyses uncovered protective haplotypes under selection in Malinois at SOX2-OT and IGF2BP2. Among Tervuren and Sheepdogs, HDAC2 putative regulatory variants were present at comparatively high frequency and were associated with GC. Here, we describe a complex genetic architecture governing GC in a dog model, including genes such as PDZRN3, that have not been associated with human GC.

Micro RNA Dysregulation in Keratinocyte Carcinomas: Clinical Evidence, Functional Impact, and Future Directions.

The keratinocyte carcinomas, basal cell carcinoma (BCC), and cutaneous squamous cell carcinoma (cSCC), are the most common cancers in humans. Recently, an increasing body of literature has investigated the role of miRNAs in keratinocyte carcinoma pathogenesis, progression and their use as therapeutic agents and targets, or biomarkers. However, there is very little consistency in the literature regarding the identity of and/or role of individual miRNAs in cSCC (and to a lesser extent BCC) biology. miRNA analyses that combine clinical evidence with experimental elucidation of targets and functional impact provide far more compelling evidence than studies purely based on clinical findings or bioinformatic analyses. In this study, we review the clinical evidence associated with miRNA dysregulation in KCs, assessing the quality of validation evidence provided, identify gaps, and provide recommendations for future studies based on relevant studies that investigated miRNA levels in human cSCC and BCC. Furthermore, we demonstrate how miRNAs contribute to the regulation of a diverse network of cellular functions, and that large-scale changes in tumor cell biology can be attributed to miRNA dysregulation. We highlight the need for further studies investigating the role of miRNAs as communicators between different cell types in the tumor microenvironment. Finally, we explore the clinical benefits of miRNAs as biomarkers of keratinocyte carcinoma prognosis and treatment.

Effectiveness of Virtual Reality in the Management of Anxiety and Pain Peri-Treatment for Breast Cancer: A Systematic Review and Meta-Analysis.

Breast cancer is the second most common cancer in humans. Its therapy procedures such as breast biopsy can cause anxiety and persistent pain in patients. Virtual reality (VR) has been applied to promote comfort in various populations. However, the effectiveness of VR in relieving pain and anxiety in patients undergoing breast cancer treatment is unclear. This study was designed to examine the effect of VR on anxiety and pain in people undergoing treatment for breast cancer. PubMed, Cochrane, Embase, Scopus, Web of Science, and MEDLINE databases were searched for studies involving VR, pain, and anxiety in patients with breast cancer published up to March 2022. The Cochrane Handbook for Systems quality evaluation standard 6.3.0 was followed to assess risk of bias in the identified studies, with the results reported in line with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Subsequently, a meta-analysis of the included data was conducted using RevMan 5.3 software. Six randomized controlled trials and one quasi-experimental study were included. The strength of the evidence ranged from moderate to high. Although VR was found to ameliorate anxiety in patients with breast cancer, only three studies showed statistically significant changes. All of the included studies reported statistically significant improvement in pain levels. In addition, two of the studies reported cybersickness symptoms as a common side effect of VR. VR has an important role to play in alleviating pain in patients with breast cancer. However, evidence demonstrating VR's importance in alleviating anxiety symptoms in this population is insufficient. Studies conducted with larger sample sizes and high-quality research methodologies will be necessary to clarify this issue. Clinical nurses should address the potential side effects of VR.

Retrospective study of postoperative survival of keratinocyte-derived skin cancer patients at the end of life.

Basal and squamous cell carcinoma (BCC, SCC), collectively referred to as keratinocyte-derived skin cancer (KC), are the most common human cancers worldwide. Surgery is the treatment of choice, but may represent overtreatment in the very elderly. This study aims to address this issue by investigating the life expectancy of patients over 80 years after surgery. A single-center, retrospective study was performed to include surgically treated KC patients at the Department of Dermatology and Venereology of the University Hospital in St. Pölten, Austria, between 01.01.2011 and 31.12.2017, who were 80 years or older. Data on individual survival (cut-off April 30, 2020), date and cause of death were retrieved from the Austrian national demographic database at Statistics Austria (Vienna). 940 patients (450 female, 490 male, 639 BCCs, 301 SCCs) were included with 307 being alive at the cut-off date. Median postoperative survival was 57 months (95% CI, 54-63months). With a median postoperative survival of almost 5years, surgery remains a valid treatment option for KC at the end of life. However, 77 of the treated patients died within a year after surgery and preoperative assessment might have helped to avoid overtreatment in some of these cases.

The prognostic value of immune escape-related genes in lung adenocarcinoma.

Lung cancer is one of the most common cancers in humans, and lung adenocarcinoma (LUAD) has become the most common histological type of lung cancer. Immune escape promotes progression of LUAD from the early to metastatic late stages and is one of the main obstacles to improving clinical outcomes for immunotherapy targeting immune detection points. Our study aims to explore the immune escape related genes that are abnormally expressed in lung adenocarcinoma, providing assistance in predicting the prognosis of lung adenocarcinoma and targeted. RNA data and related clinical details of patients with LUAD were obtained from The Cancer Genome Atlas (TCGA) database. Through weighted gene coexpression network analysis (WGCNA), 3112 key genes were screened and intersected with 182 immune escape genes obtained from a previous study to identify the immune escape-related genes (IERGs). The role of IERGs in LUAD was systematically explored through gene ontology (GO) and Kyoto Encyclopedia of Genes and Genome (KEGG) analyses, which were used to enrich the relevant pathways of IERGs. The least absolute shrinkage and selection operator (LASSO) algorithm and multivariate Cox regression analysis were used to identify the key prognostic genes, and a prognostic risk model was constructed. Estimation of Stromal and Immune Cells in Malignant Tumor Tissues Using Expression Data (ESTIMATE) and microenvironment cell populations (MCP) counter methods (which can accurately assess the amount of eight immune cell populations and two stromal cell groups) were used to analyze the tumor immune status of the high and low risk subgroups. The protein expression level of the differentially expressed genes in lung cancer samples was determined by using the Human Protein Atlas (HPA) database. A nomogram was constructed, and the prognostic risk model was verified via the Gene Expression Omnibus (GEO) datasets GSE72094 and GSE30219. Twenty differentially expressed IERGs were obtained. GO analysis of these 20 IERGs revealed that they were mainly associated with the regulation of immune system processes, immune responses, and interferon-γ enrichment in mediating signaling pathways and apoptotic signaling pathways; meanwhile, KEGG analysis revealed that IERGs were associated with necroptosis, antigen processing and presentation, programmed cell death ligand 1 (PD-L1) expression and programmed cell death 1 (PD-1) pathway in tumors, cytokine-cytokine receptor interactions, T helper cell 1 (Th1) and Th2 differentiation, and tumor necrosis factor signaling pathways. Using LASSO and Cox regression analysis, we constructed a four-gene model that could predict the prognosis of patients with LUAD, and the model was validated with a validation cohort. The immunohistochemical results of the HPA database showed that AHSA1 and CEP55 had low expression in normal lung tissue but high expression in lung cancer tissue. We constructed an IERG-based model for predicting the prognosis of LUAD. Among the genes identified, CEP55 and AHSA1 may be potential prognostic and therapeutic targets, and reducing their expression may represent a novel approach in the treatment of LUAD.

Gene expression landscape of cutaneous squamous cell carcinoma progression.

Cutaneous squamous cell carcinomas (cSCCs) are the second most common human cancer and have been characterized by RNA sequencing (RNA-Seq); however, the transferability of findings from individual studies may be limited by small sample sizes and diverse analysis protocols. To define the transcriptome landscape at different stages in the progression of normal skin to cSCC via a meta-analysis of publicly available RNA-Seq samples. Whole-transcriptome data from 73 clinically normal skin samples, 46 actinic keratoses (AK) samples, 16 in situ SCC samples, 13 keratoacanthoma (KA) samples and 147 cSCC samples [including 30 samples from immunocompromised patients and 8 from individuals with recessive dystrophic epidermolysis bullosa (RDEB)] were uniformly processed to harmonize gene expression. Differential expression, fusion detection and cell-type deconvolution analyses were performed. Individual RNA-Seq studies of cSCC demonstrated study-specific clustering and varied widely in their differential gene expression detection. Following batch correction, we defined a consensus set of differentially expressed genes (DEGs), including those altered in the preinvasive stages of cSCC development, and used single-cell RNA-Seq data to demonstrate that DEGs are often - but not always - expressed by tumour-specific keratinocytes (TSKs). Analysis of the cellular composition of cSCC, KA and RDEB-cSCC identified an increase in differentiated keratinocytes in KA, while RDEB-cSCC contained the most TSKs. Compared with cSCC arising in immunocompetent individuals, cSCC samples from immunosuppressed patients demonstrated fewer memory B cells and CD8+ T cells. A comprehensive and unbiased search for fusion transcripts in cSCC and intermediate disease stages identified few candidates that recurred in >1% of all specimens, suggesting that most cSCC are not driven by oncogenic gene fusions. Finally, using Genotype-Tissue Expression (GTEx) data, we distilled a novel 300-gene signature of chronic sun exposure that affirms greater cumulative ultraviolet (UV) exposure in later stages of cSCC development. Our results define the gene expression landscape of cSCC progression, characterize cell subpopulation heterogeneity in cSCC subtypes that contribute to their distinct clinical phenotypes, demonstrate that gene fusions are not a common cause of cSCC and identify UV-responsive genes associated with cSCC development.

Office-based management of non-muscle invasive bladder cancer (NMIBC): a position paper on current state of the art and future perspectives.

To the Editor, Bladder cancer is one of the most common cancers in humans, representing the 7th and 17th type of neoplasm in both genders. Its incidence and mortality are quite heterogeneous in different countries and are due to different risk factors, quality and prevalence of healthcare and the possibility of early diagnosis and treatment of the tumor and its potential recurrences. [...].

Pluronic F-127-coated ZnO nanoparticles as superior photosensitizers for effective bladder cancer photodynamic therapy: In-vitro evaluation

Bladder cancer is the most prevalent malignancy of the urinary system and ranks among the top ten most common cancers in humans. Photodynamic therapy (PDT) demonstrates significant promise in cancer treatment due to its high selectivity and minimal side effects. Zinc oxide nanoparticles (ZnO NPs) exhibit substantial potential in various biomedical applications, including cancer therapy. This study systematically investigates the potential of bare and Pluronic F-127-coated ZnO NPs as photosensitizers (PSs) for effective photodynamic therapy against the RT4 bladder cancer cell line, marking the first such exploration. Transmission electron microscopy (TEM) micrographs reveal the formation of a Pluronic F-127 coating layer with thickness ranging from approximately 3 nm–7 nm on the particle surface. The Pluronic coating process significantly enhances the cytotoxicity of ZnO NPs under dark conditions and during photodynamic therapy on the RT4 bladder cancer cell line. Additionally, the impact of PDT using bare and coated ZnO NPs is further evaluated through a 3D spheroid assay, which better replicates the real tumor environment for photodynamic therapy. Hoechst and rhodamine assays confirm the induction of apoptosis, characterized by nuclear condensation and disruption of mitochondrial membrane potential in the cells. This study advances the potential of ZnO NPs in bladder cancer photodynamic therapy and highlights the importance of Pluronic F-127 coatings, paving the way for more effective and targeted cancer treatments.

Dermoscopic features of pigmented basal cell carcinoma according to size.

Basal cell carcinoma (BCC), the most common skin cancer in humans, requires early detection. Dermoscopy enhances diagnostic accuracy through a noninvasive approach. Pigmented BCC (pBCC) is characterized by distinctive dermoscopic features, including the presence of pigmented globules or nests. While dermoscopic features of large pBCC (size >6 mm) have been extensively studied, limited data are available on small pBCC (size ≤6 mm) and its relationship with tumor progression. Dermoscopic images of histologically proven pBCCs were collected between 2014 and 2022 at Hualien Tzu Chi Hospital. Each image was analyzed for patterns of pigmentation, vasculature, and epidermal and dermal structures. Statistical analysis was performed to compare the differences according to the size and the trend during tumor progression. In total, 135 pBCCs (48 small and 87 large) were included. Pigment structures were present in all cases. Short fine telangiectasia and small erosions constituted over 85% of the cases, showing no significant distinction between small and large pBCCs, nor any specific pattern correlating with tumor enlargement. The number of arborizing vessels, ulcerations, and shiny white structures showed an increasing trend associated with size progression. Arborizing vessels appeared when tumor size exceeded 6 mm. This study provides a dynamic interpretation of the dermoscopic features of pBCC according to size enlargement. Short fine telangiectasia and small erosions are highly important features for the early diagnosis of small pBCCs. Arborizing vessels, ulceration, and shiny white structures are more frequent in large pBCCs, and they increase in association with tumor progression.

A combined opposite targeting of p110δ PI3K and RhoA abrogates skin cancer

Malignant melanoma is the most aggressive and deadly skin cancer with an increasing incidence worldwide whereas SCC is the second most common non-melanoma human skin cancer with limited treatment options. Here we show that the development and metastasis of melanoma and SCC cancers can be blocked by a combined opposite targeting of RhoA and p110δ PI3K. We found that a targeted induction of RhoA activity into tumours by deletion of p190RhoGAP-a potent inhibitor of RhoA GTPase-in tumour cells together with adoptive macrophages transfer from δD910A/D910A mice in mice bearing tumours with active RhoA abrogated growth progression of melanoma and SCC tumours. Τhe efficacy of this combined treatment is the same in tumours lacking activating mutations in BRAF and in tumours harbouring the most frequent BRAF(V600E) mutation. Furthermore, the efficiency of this combined treatment is associated with decreased ATX expression in tumour cells and tumour stroma bypassing a positive feedback expression of ATX induced by direct ATX pharmacological inactivation. Together, our findings highlight the importance of targeting cancer cells and macrophages for skin cancer therapy, emerge a reverse link between ATX and RhoA and illustrate the benefit of p110δ PI3K inhibition as a combinatorial regimen for the treatment of skin cancers.

Gene expression changes of isocitrate dehydrogenase 1 and isocitrate dehydrogenase 2 affect carcinogenesis and survival probability

Isocitrate dehydrogenase (IDH) is an essential metabolic enzyme in the regulation of cellular metabolism. IDH gene encodes three protein isoforms, IDH1, IDH2, and IDH3, and the expression level of isoforms is altered in human cancer types. Examining the gene expression level of IDH is a therapeutic advantage that could help find a new target to use in cancer metabolism. The present study aimed to explore the gene expression level of IDH1 and IDH2 isoforms in the ten common human cancers using bioinformatic tools. In addition, the effect of gene expression changes on IDH1 and IDH2 on carcinogenesis and survival probability was examined in publicly available data deposited in the TCGA database. The results showed that the expression of IDH isoforms showed tissue-specific differences. IDH1 expression increased in esophageal and lung squamous cell carcinoma and lung and stomach adenocarcinoma tumors. Bladder urothelial, breast urothelial, and lung squamous cell carcinoma, colon, and lung adenocarcinoma displayed a significant upregulation of IDH2 expression. There was a direct relationship between the expression of IDH isoforms and the progression of various cancer types. High IDH1 expression led to decreased survival probability in esophageal carcinoma, lung, and stomach adenocarcinoma. Elevated IDH2 expression level led to decreased survival probability in bladder urothelial, breast urothelial, and lung squamous cell carcinoma and colon adenocarcinoma. In conclusion, all data showed that IDH1 could be a biomarker for esophageal carcinoma, lung and stomach adenocarcinoma, and IDH2 for bladder urothelial, breast urothelial, and lung squamous cell carcinoma, and colon adenocarcinoma.

DOK1 facilitates the advancement of ccRCC.

Background: Renal cell carcinoma (RCC) is one of the most common human cancers. Clear cell renal cell carcinoma (ccRCC) is a major subtype of RCC. However, the molecular mechanisms underlying ccRCC oncogenesis require further investigation. Docking protein 1 (DOK1) is a putative tumor suppressor gene; however, its role in ccRCC remains unclear. Methods: Bioinformatic analysis was used to illustrate the poor prognosis associated with DOK1 expression and its role in tumor development in ccRCC in patients. qPCR (quantitative polymerase chain reaction) and western blotting assays were used to validate DOK1 expression in ccRCC cells. In vitro experiments were performed to further elucidate the biological role of DOK1 in ccRCC. Results: DOK1 was overexpressed in ccRCC tissues and cells at both mRNA and protein levels. High DOK1 expression closely correlated with poor survival in patients with ccRCC. DOK1 expression significantly accelerated ccRCC proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT). Through PI3K (phosphatidylin-ositol-3-kinase)/AKT (protein kinase B)/GSK3β (glycogen synthase kinase 3 beta) signaling, DOK1 may control the progression of ccRCC. Conclusion: DOK1 has the potential to serve as a valuable biomarker and target for treatment in ccRCC through its regulation of PI3K/AKT/GSK3β signaling to promote ccRCC progression.

The Role of the AT-Rich Interaction Domain 1A Gene (ARID1A) in Human Carcinogenesis.

The switch/sucrose non-fermentable (SWI/SNF) (SWI/SNF) complex uses energy from ATP hydrolysis to mobilise nucleosomes on chromatin. Components of SWI/SNF are mutated in 20% of all human cancers, of which mutations in AT-rich binding domain protein 1A (ARID1A) are the most common. ARID1A is mutated in nearly half of ovarian clear cell carcinoma and around one-third of endometrial and ovarian carcinomas of the endometrioid type. This review will examine in detail the molecular functions of ARID1A, including its role in cell cycle control, enhancer regulation, and the prevention of telomerase activity. ARID1A has key roles in the maintenance of genomic integrity, including DNA double-stranded break repair, DNA decatenation, integrity of the cohesin complex, and reduction in replication stress, and is also involved in mismatch repair. The role of ARID1A loss in the pathogenesis of some of the most common human cancers is discussed, with a particular emphasis on gynaecological cancers. Finally, several promising synthetic lethal strategies, which exploit the specific vulnerabilities of ARID1A-deficient cancer cells, are briefly mentioned.

Orexins and Prostate Cancer: State of the Art and Potential Experimental and Therapeutic Perspectives.

Prostate cancer (PCa) is the second most common cancer in humans. Peptides have recently been used as targeted therapeutics in cancers, due to their extensive multi-functional applications. Two hypothalamic peptides, orexins A (OXA) and B (OXB) and their specific receptors, orexin receptor 1 (OX1R) and 2 (OX2R), orchestrate several biological processes in the central nervous system and peripheral organs. However, in addition to their role in physiological responses, orexins are involved in numerous inflammatory and/or neoplastic pathologies. The presence and expression of orexins in different cancer models, including prostate cancer, and their role in inducing pro- or anti-apoptotic responses in tumor cell lines, suggest that the orexinergic system might have potential therapeutic action or function as a diagnostic marker in PCa. In addition to the traditional animal models for studying human PCa, the canine model might also serve as an additional tool, due to its clinical similarities with human prostate cancer.

The Importance of Basal Cell Carcinoma Risk Stratification and Potential Future Pathways.

Basal cell carcinoma (BCC) is the most common human cancer. Although there are surgical and topical treatments available, surgery remains the mainstay of treatment, leading to higher costs. What is needed is an accurate risk assessment of BCC so that treatments can be planned in a patient-centered manner. In this study, we will review the literature about guidelines for the management of BCC and analyze the potential indicators of high-risk BCC. Using this risk assessment approach, we will propose pathways that will be able to optimize treatments more efficiently. This paper presents a perspective from a skin cancer expert and clinic involved in the treatment of both simple and complex cases of BCC. It addresses the key challenges associated with accurate risk stratification prior to any treatment or procedure. Different immunohistochemical and angiogenic markers for high-risk BCC were reviewed in this study. The expression of interleukin-6, vascular endothelial growth factor, and mast cells within BCC correlates with its aggressiveness. Other immunohistochemical markers, such as Cyclin D1 and Bcl-2, also play a significant role-Cyclin D1 is higher in the aggressive BCC, while Bcl-2 is lower in the aggressive BCC, compared to the nonaggressive variants. Based on our research, we will conclude that using immunohistochemical and angiogenic markers for risk assessment and stratification of BCC can help optimize treatment, ensuring that surgical procedures are used only when necessary.

Case Report of Lower Eyelid Basal Cell Carcinoma

Basal cell carcinoma is the most common skin cancer in humans and is frequently found in the periocular region. It is the mostcommon type of eyelid cancer, generally characterized by slow growth with rare metastasis and has an excellent prognosis withcurrent surgical techniques. This is a case report of left lower eyelid basal cell carcinoma for which surgical excision with eyelid reconstruction was performed. Histopathological examination of resected mass was consistent with nodulo-ulcerative basal cell carcinoma.Early diagnosis and management of suspicious lesions is important to ensure the clinical result.

PROSPECTIVE POSTMORTEM ASSESSMENT OF THE INCIDENCE OF MAMMARY NEOPLASIA IN CHIMPANZEES (PAN TROGLODYTES).

When evaluating the last 25 yr of morbidity and mortality from adult chimpanzees managed within the Association of Zoo and Aquarium Chimpanzee Species Survival Plan® for North American zoos, only two female chimpanzees were diagnosed with mammary neoplasia: one incidentally antemortem and one with a terminal metastatic neoplasia. When comparing this observation of prevalence of mammary neoplasia to humans, a substantial disparity is apparent. Mammary neoplasia is the second most common cancer in adult female humans, with a lifetime risk of 1:8 in the United States. The reason for the disparity between humans and chimpanzees, as closely related species, is unknown. The true prevalence in chimpanzees may be higher than currently noted, because routine examination of mammary tissue in chimpanzees is generally less complete than for other tissues postmortem, and antemortem assessment is generally limited to mammary palpation. This study was performed on intact, bilateral mammary glands harvested at postmortem examination of adult female chimpanzees (n = 7) from six institutions. With mammography, complete histopathologic sectioning, and genetic evaluation, the risk of mammary neoplasia was evaluated more thoroughly than during a typical postmortem exam in zoo populations during 2017-2019. No chimpanzees in the study were diagnosed with mammary neoplasia. Overall, this study supports the previous impression that chimpanzees do not develop mammary neoplasia at a similar rate as humans, even when comparable diagnostic modalities for evaluation are used.