RESUMEN
Introduction: Early relapse and development of metastatic disease are some of the primary reasons for the poor prognosis of patients with head and neck squamous cell carcinoma (HNSCC). HNSCC is a heterogeneous disease which may develop in large premalignant fields of genetically altered cells. Yet knowing which individuals will progress and develop clinically significant cancers during their lifetimes remains one of the most important challenges of reducing HNSCC morbidity and mortality. To further elucidate the molecular mechanisms, we performed a focused analysis of the genome and immune microenvironment from multiple, matched normal squamous tissue, premalignant lesions, as well as primary and recurrent tumors from seven patients with p16-negative HNSCC. Methods: We performed targeted panel Next Generation Sequencing (161 genes) to analyze somatic variants from sequentially collected, matched formalin-fixed paraffin-embedded tissue (normal, premalignant, HNSCC) from two patients. These samples plus samples from five additional patients were analyzed with the Nanostring PanCancer Immune Panel. In addition, we performed shallow whole genome sequencing (0.5x coverage on average) on samples from three of these patients. Patients were, apart from one case, primarily treated with curative-intent surgery, and received subsequent adjuvant treatment, if indicated. Results: The most frequently mutated genes were TP53 and NOTCH1. Other mutated genes included NOTCH3 and CDKN2A, among others. A significant number of mutations were private to dysplasia and invasive carcinoma, respectively, however, almost 20% were shared between them. Increasing genomic instability was observed when comparing histologically normal squamous mucosa with higher levels of dysplasia. High-grade dysplasia showed similarly rearranged genomes as invasive carcinoma. Pathways related to interferon alpha and gamma response were upregulated even in moderate dysplastic lesions with increasing expression in higher grades of dysplasia and carcinoma. SPINK5, a known tumor suppressor gene in HNSCC, was already downregulated in low-grade dysplastic lesions, indicating an early deactivation in the evolution of the disease. Conclusion: Genomic alterations as well as aberrant immune gene expression can be observed early in the evolution of tumors of the upper aerodigestive tract, highlighting the potential for targeting early mechanisms of disease progression.
RESUMEN
OBJECTIVES: About 17% of patients with human papillomavirus (HPV)-positive head and neck squamous cell carcinoma (HNSCC), which is mainly comprised of oropharyngeal SCC (OPSCC), will experience disease recurrence, which is often considered incurable when manifested at a metastatic and/or recurrent stage. We conducted a critical qualitative systematic review. Our objectives were to provide an overview of the molecular landscape of recurrent/metastatic HPV-positive HNSCC as well as novel molecular biomarkers. DESIGN: A literature review was conducted to identify studies reporting on the molecular characteristics of recurrent/metastatic HPV-positive HNSCC, novel molecular biomarkers and treatment options. The reviews of abstracts, full articles, and revision of the included studies, followed by data extraction and quality assessment were performed by three independent assessors. All primary literature, such as retrospective, prospective, and clinical trials as well as basic research studies were considered, and the final search was conducted at the end of February 2023. The level of evidence was rated using the guidelines published by the Oxford Centre for Evidence-based Medicine and quality was assessed using the Newcastle-Ottawa Scale criteria. RESULTS AND CONCLUSIONS: The literature search resulted in the identification of 1991 articles. A total of 181 full articles were screened, and 66 articles were included in this analysis. Several studies reported that recurrent/metastatic HPV-positive HNSCC had higher rates of TP53 mutation and were genomically similar to HPV-negative HNSCC. The detection of circulating tumour tissue-modified HPV DNA (ctHPVDNA) as a specific biomarker has shown promising results for monitoring treatment response and recurrence in the subset of HPV-positive HNSCC. In addition, evidence for targeted therapy in recurrent/metastatic HPV-positive HNSCC has emerged, including agents that inhibit overexpressed EGFR. Studies of combination immunotherapy are also underway. Our review outlines the latest evidence on the distinct molecular profiles of recurrent/metastatic HPV-positive HNSCC as well as the clinical potential of ctHPVDNA testing in routine practice. More controlled and longitudinal studies are needed to identify additional molecular targets and to assess the performance and benefits of novel molecular biomarkers in clinical practice.
Asunto(s)
Neoplasias de Cabeza y Cuello , Recurrencia Local de Neoplasia , Infecciones por Papillomavirus , Carcinoma de Células Escamosas de Cabeza y Cuello , Humanos , Recurrencia Local de Neoplasia/virología , Recurrencia Local de Neoplasia/genética , Carcinoma de Células Escamosas de Cabeza y Cuello/virología , Carcinoma de Células Escamosas de Cabeza y Cuello/terapia , Carcinoma de Células Escamosas de Cabeza y Cuello/genética , Infecciones por Papillomavirus/virología , Infecciones por Papillomavirus/complicaciones , Neoplasias de Cabeza y Cuello/virología , Neoplasias de Cabeza y Cuello/patología , Neoplasias de Cabeza y Cuello/terapia , Neoplasias de Cabeza y Cuello/genética , Biomarcadores de Tumor/genética , Papillomaviridae/genéticaRESUMEN
High-risk endometrial cancer has poor prognosis and is increasing in incidence. However, understanding of the molecular mechanisms which drive this disease is limited. We used genetically engineered mouse models (GEMM) to determine the functional consequences of missense and loss of function mutations in Fbxw7, Pten and Tp53, which collectively occur in nearly 90% of high-risk endometrial cancers. We show that Trp53 deletion and missense mutation cause different phenotypes, with the latter a substantially stronger driver of endometrial carcinogenesis. We also show that Fbxw7 missense mutation does not cause endometrial neoplasia on its own, but potently accelerates carcinogenesis caused by Pten loss or Trp53 missense mutation. By transcriptomic analysis, we identify LEF1 signalling as upregulated in Fbxw7/FBXW7-mutant mouse and human endometrial cancers, and in human isogenic cell lines carrying FBXW7 mutation, and validate LEF1 and the additional Wnt pathway effector TCF7L2 as novel FBXW7 substrates. Our study provides new insights into the biology of high-risk endometrial cancer and suggests that targeting LEF1 may be worthy of investigation in this treatment-resistant cancer subgroup.
Asunto(s)
Carcinogénesis , Neoplasias Endometriales , Femenino , Humanos , Ratones , Animales , Proteína 7 que Contiene Repeticiones F-Box-WD/genética , Proteína 7 que Contiene Repeticiones F-Box-WD/metabolismo , Carcinogénesis/genética , Neoplasias Endometriales/genética , Neoplasias Endometriales/metabolismo , Mutación , Mutación MissenseRESUMEN
BACKGROUND: Head and neck squamous cell carcinoma remains a substantial burden to global health. Despite evolving therapies, 5-year survival is <50% and unlike in other cancers, reliable molecular biomarkers to guide treatment do not exist. METHODS: We performed targeted panel next-generation sequencing to analyse somatic variants from primary and recurrent tumour tissue, corresponding resection margins and cell-free DNA from intra-operatively collected plasma samples from eight patients with human papillomavirus-negative head and neck squamous cell carcinoma. Patients were primarily treated with curative-intent surgery and received subsequent adjuvant treatment. RESULTS: The most frequently mutated gene was TP53. Other mutated genes included NOTCH1, NF1 and CDKN2A among others. A total of 20.8% of variants were shared between primary tumour and resection margin. Out of all the variants detected, 37.5% were shared between cell-free DNA and primary tumour, whereas 12.5% were commonly found in cell-free DNA, primary tumour and resection margin. Mutational profiling was able to distinguish between a locoregional recurrence and a second primary tumour by identifying a different TP53 mutation in the primary tumour compared to the recurrent tumour in addition to private FBXW7 and CTNNB1 mutations. We also identified identical TP53 and PIK3CA mutations in another primary tumour and corresponding recurrence. CONCLUSION: Molecular profiling of cell-free DNA and resection margins has potential applications in clinical practice to guide future treatment decisions.
Asunto(s)
Alphapapillomavirus , Carcinoma de Células Escamosas , Ácidos Nucleicos Libres de Células , Neoplasias de Cabeza y Cuello , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/patología , Carcinoma de Células Escamosas/cirugía , Neoplasias de Cabeza y Cuello/genética , Neoplasias de Cabeza y Cuello/cirugía , Humanos , Márgenes de Escisión , Mutación , Recurrencia Local de Neoplasia/genética , Carcinoma de Células Escamosas de Cabeza y Cuello/genética , Carcinoma de Células Escamosas de Cabeza y Cuello/cirugíaRESUMEN
BACKGROUND: Head and neck squamous cell carcinoma (HNSCC) remain a substantial burden to global health. Cell-free circulating tumour DNA (ctDNA) is an emerging biomarker but has not been studied sufficiently in HNSCC. METHODS: We conducted a single-centre prospective cohort study to investigate ctDNA in patients with p16-negative HNSCC who received curative-intent primary surgical treatment. Whole-exome sequencing was performed on formalin-fixed paraffin-embedded (FFPE) tumour tissue. We utilised RaDaRTM, a highly sensitive personalised assay using deep sequencing for tumour-specific variants, to analyse serial pre- and post-operative plasma samples for evidence of minimal residual disease and recurrence. RESULTS: In 17 patients analysed, personalised panels were designed to detect 34 to 52 somatic variants. Data show ctDNA detection in baseline samples taken prior to surgery in 17 of 17 patients. In post-surgery samples, ctDNA could be detected at levels as low as 0.0006% variant allele frequency. In all cases with clinical recurrence to date, ctDNA was detected prior to progression, with lead times ranging from 108 to 253 days. CONCLUSIONS: This study illustrates the potential of ctDNA as a biomarker for detecting minimal residual disease and recurrence in HNSCC and demonstrates the feasibility of personalised ctDNA assays for the detection of disease prior to clinical recurrence.
Asunto(s)
ADN Tumoral Circulante , Neoplasias de Cabeza y Cuello , Biomarcadores de Tumor/genética , ADN Tumoral Circulante/genética , Neoplasias de Cabeza y Cuello/diagnóstico , Neoplasias de Cabeza y Cuello/genética , Neoplasias de Cabeza y Cuello/cirugía , Humanos , Biopsia Líquida , Neoplasia Residual/genética , Estudios Prospectivos , Carcinoma de Células Escamosas de Cabeza y Cuello/genética , Carcinoma de Células Escamosas de Cabeza y Cuello/cirugíaRESUMEN
BACKGROUND: In-office biopsies (IOB) using local anaesthetic for laryngopharyngeal tumours has become an increasingly popular approach since the advent of distal chip endoscopes. Although a wide range of studies advocate use in clinical practice, the widespread application of the procedure is hampered by concerns regarding diagnostic accuracy. OBJECTIVE: To assess the diagnostic accuracy of IOB performed via flexible endoscopy. In addition, to analyse modifiable factors that may affect diagnostic accuracy of IOB. DESIGN: A systematic review following the PRISMA guidelines was conducted. PubMed, EMBASE, the Cochrane Library, Web of Science and CINAHL were used in the literature database search. Quality assessment of included studies was perfomed using the Newcastle-Ottawa Scale. RESULTS: A total of 875 studies were identified, 16 of which were included into the systematic review; 1572 successful biopsies were performed using flexible endoscopy; 1283 cases were accurately diagnosed in the outpatient setting (81.6%) and 289 samples did not provide an accurate diagnosis (18.4%). The median sensitivity of IOB was 73%, and the specificity was 96.7%. Analysis of variable factors did not show any significant differences in method of approach, size of equipment (forceps) and additional lighting system or learning curve. CONCLUSION: IOB are a viable tool for diagnostic workup of laryngopharyngeal tumours. Clinicians should be wary of reported limitations of IOB when benign or pre-malignant diagnoses are made. In cases suspicious of malignancy, confirmatory investigation should be conducted.
Asunto(s)
Biopsia/métodos , Neoplasias Laríngeas/diagnóstico , Neoplasias Faríngeas/diagnóstico , Humanos , Pacientes AmbulatoriosRESUMEN
An 85-year-old man suffering from oropharyngeal dysphagia due to a pharyngeal pouch and cricopharyngeal spasm underwent endoscopic stapling of the pouch under general anaesthesia. During the procedure, an iatrogenic perforation of the oesophagus was noticed. After considering several options, 5 mL of Tisseel tissue glue was used to seal the perforation intraoperatively. The patient was started on intravenous co-amoxiclav, kept nil by mouth and fed via a nasogastric tube. After 4 days of observation mediastinal collection and any leakage was ruled out with a gastrografin contrast swallow procedure. At this point he was considered safe for oral intake.
Asunto(s)
Trastornos de Deglución/cirugía , Perforación del Esófago/diagnóstico , Adhesivos Tisulares/administración & dosificación , Divertículo de Zenker/cirugía , Anciano de 80 o más Años , Trastornos de Deglución/complicaciones , Diagnóstico Diferencial , Perforación del Esófago/cirugía , Esofagoscopía/efectos adversos , Humanos , Enfermedad Iatrogénica , Periodo Intraoperatorio , Masculino , Divertículo de Zenker/complicacionesRESUMEN
Inverted papilloma is a rare and benign tumour. It affects the nasal cavity and paranasal sinuses, has a high rate of recurrence and is associated with malignant transformation. Only few cases of a poorly differentiated carcinoma arising from inverted papilloma have been reported, none of which in the nasopharynx. We report a case of a 37-year-old female, who presented originally in 2012 with inverted papilloma of the nasal septum which was surgically resected. Nasopharyngeal biopsy from 2014 was reported as carcinoma in situ and treated with local endoscopic resection. Three years later she presented with a solitary lesion of the right Eustachian tube opening, confirmed as invasive poorly differentiated carcinoma. Imaging revealed T4 N2b M0 malignancy with skull base and prevertebral space invasion, likely extension into right temporal lobe and malignant adenopathy. Although rare, malignant transformation of inverted papilloma in unusual places should be considered during workup and monitoring of patients.
RESUMEN
BACKGROUND: Parotidectomy is often performed as an inpatient procedure largely due to drain insertion; however, outpatient parotidectomy has increasingly become an attractive alternative for its shorter hospital stays and greater efficiency in cost-effectiveness. OBJECTIVE OF REVIEW: To assess the safety and feasibility of outpatient (or same-day discharge) parotidectomy compared with inpatient parotidectomy. TYPE OF REVIEW: Systematic review of the literature and meta-analysis, in accordance with the PRISMA guidelines. METHODS: Pubmed/Medline, Embase, CINAHL, Google Scholar, Web of Science, The Cochrane Library, Cochrane Central Register of Controlled Trials (CENTRAL) were searched for articles published in English between 01/01/1990 and 05/10/2019. The Newcastle-Ottawa Scale was used for quality assessment and Review Manager 5.3 for meta-analyses. MAIN OUTCOME MEASURES: Primary outcomes assessed were postoperative complications including bleeding/haematoma, surgical site infection, seroma and facial weakness. Secondary outcome was readmission rate. RESULTS: Out of 445 studies identified, 6 were selected for systematic review. The overall quality of evidence was moderate. A total of 3664 patients were included (1646 in the outpatient group and 2018 in the inpatient group). Comparing the outpatient with inpatient cohorts, there were lower complications in outpatient groups though not statistically significant for haematoma (OR = 0.45; 95% CI = 0.11-1.92; P = .28), surgical site infection (OR = 0.88; 95% CI = 0.46-1.69; P = .70), seroma (0.79; 95% CI = 0.21-3.03; P = .74), facial nerve weakness (OR 0.39; 95% CI = 0.14-1.08; P = .07) and hospital readmission (OR 0.58; 95% CI = 0.33-1.04; P = .07). CONCLUSIONS: Outpatient parotidectomy appears to be safe and compares favourably to inpatient procedure in postoperative complication and readmission rates.
Asunto(s)
Procedimientos Quirúrgicos Ambulatorios , Hospitalización , Enfermedades de las Parótidas/cirugía , HumanosRESUMEN
OBJECTIVES/HYPOTHESIS: Indication for postoperative radiotherapy in patients with locally circumscribed tumors (pT1-pT2) and a single ipsilateral lymph node metastasis (pN1) is debatable. The aim of this study was to evaluate the oncological long-term outcome of patients with pT1-pT2 pN1 squamous cell carcinoma (SCC) of the oral cavity, the oropharynx, and the hypopharynx without extracapsular spread (ECS) after a margin-negative surgical resection, who either received or did not receive postoperative (chemo)radiotherapy. STUDY DESIGN: Retrospective case series. METHODS: The oncological outcome of patients with pT1-pT2 pN1 SCC without ECS was evaluated retrospectively. All patients underwent primary tumor resection that included transoral laser microsurgery and neck dissection at an academic tertiary referral center. RESULTS: Of 65 identified patients treated between 1986 and 2015 (18 oral cavity, 30 oropharynx, 17 hypopharynx), 21 (32%) received postoperative radiotherapy, and 44 (68%) were treated by surgery alone. The group of patients receiving postoperative treatment showed a significantly superior 5-year disease-specific (94.4% vs. 73.2%, P = .029) and recurrence-free survival (85.2% vs. 43.2%, P = .002), as well as a higher local control rate (90.2% vs. 64.9%, P = .042). The overall survival was 71.4% vs. 62.6% (P = .53). The mean follow-up was 80.7 months. CONCLUSIONS: Patients with locally circumscribed carcinomas and a single ipsilateral ECS-negative lymph node metastasis seem to benefit from postoperative radiotherapy. LEVEL OF EVIDENCE: 4 Laryngoscope, 130:E530-E538, 2020.
Asunto(s)
Carcinoma de Células Escamosas/radioterapia , Carcinoma de Células Escamosas/cirugía , Neoplasias de Cabeza y Cuello/radioterapia , Neoplasias de Cabeza y Cuello/cirugía , Metástasis Linfática/patología , Carcinoma de Células Escamosas/patología , Femenino , Neoplasias de Cabeza y Cuello/patología , Humanos , Terapia por Láser , Masculino , Microcirugia , Persona de Mediana Edad , Disección del Cuello , Estadificación de Neoplasias , Cuidados Posoperatorios , Estudios RetrospectivosRESUMEN
In cancer, many genes are mutated by genome rearrangement, but our understanding of the functional consequences of this remains rudimentary. Here we report the F-box protein encoded by FBXL17 is disrupted in the region of the gene that encodes its substrate-binding leucine rich repeat (LRR) domain. Truncating Fbxl17 LRRs impaired its association with the other SCF holoenzyme subunits Skp1, Cul1 and Rbx1, and decreased ubiquitination activity. Loss of the LRRs also differentially affected Fbxl17 binding to its targets. Thus, genomic rearrangements in FBXL17 are likely to disrupt SCFFbxl17-regulated networks in cancer cells. To investigate the functional effect of these rearrangements, we performed a yeast two-hybrid screen to identify Fbxl17-interacting proteins. Among the 37 binding partners Uap1, an enzyme involved in O-GlcNAcylation of proteins was identified most frequently. We demonstrate that Fbxl17 binds to UAP1 directly and inhibits its phosphorylation, which we propose regulates UAP1 activity. Knockdown of Fbxl17 expression elevated O-GlcNAcylation in breast cancer cells, arguing for a functional role for Fbxl17 in this metabolic pathway.
Asunto(s)
Neoplasias de la Mama/genética , Proteínas F-Box/genética , Proteínas F-Box/metabolismo , Acetilglucosamina/metabolismo , Neoplasias de la Mama/enzimología , Neoplasias de la Mama/metabolismo , Línea Celular Tumoral , Roturas del ADN , Femenino , Células HEK293 , Humanos , Fosforilación , Procesamiento Proteico-Postraduccional , Eliminación de Secuencia , Ubiquitina-Proteína Ligasas/metabolismo , UbiquitinaciónAsunto(s)
Cánula , Terapia por Láser/métodos , Microcirugia/métodos , Cirugía Endoscópica por Orificios Naturales/métodos , Terapia por Inhalación de Oxígeno/instrumentación , Adulto , Anciano , Diseño de Equipo , Estudios de Seguimiento , Humanos , Periodo Intraoperatorio , Neoplasias Laríngeas/cirugía , Masculino , Persona de Mediana Edad , Boca , Estudios Retrospectivos , Resultado del Tratamiento , Adulto JovenRESUMEN
BACKGROUND: Cigarette smoking is a well-established risk factor for head and neck (HN) cancers. Use of electronic cigarettes (e-cigarettes) is gaining popularity, being advertised as benign alternatives to tobacco. A wide variety of potentially harmful chemical components with variable quantity have been identified in e-liquids and aerosols of e-cigarettes. However, use of e-cigarettes remains controversial due to conflicting evidence. OBJECTIVES: We aimed to assess the association between e-cigarettes and HN cancers. We conducted a systematic review to evaluate the literature for evidence on carcinogenic effects of e-cigarettes in the pathogenesis of HN cancers. TYPE OF REVIEW: Qualitative systematic review. SEARCH STRATEGY: A PubMed/MEDLINE, Cochrane, CINAHL Plus, Trip Medical Database and Web of Science search was done for studies on e-cigarettes and HN cancer. EVALUATION METHOD: Abstract review of all articles, full article revision of included studies, data extraction and quality assessment were performed by two independent assessors. RESULTS: The literature search resulted in the identification of 359 articles. Eighteen articles were selected for inclusion into the systematic review. The majority were laboratory-based studies, followed by several cohort and case studies, representing low-level evidence. A few reports suggested DNA damage following exposure to e-cigarettes potentially due to increased oxidative stress. Flavoured e-liquids appear to be more harmful. There is variable evidence from clinical studies. CONCLUSIONS: Our review outlines potential dangers associated with the use of e-cigarettes and their role in HN cancers. More longitudinal and controlled studies are needed to assess the possible link between e-cigarettes and HN cancers.
Asunto(s)
Sistemas Electrónicos de Liberación de Nicotina , Medición de Riesgo/métodos , Salud Global , Neoplasias de Cabeza y Cuello/epidemiología , Neoplasias de Cabeza y Cuello/etiología , Humanos , Incidencia , Factores de RiesgoRESUMEN
BACKGROUND: Red blood cell (RBC) antigen matching policies to prevent alloimmunization in females of childbearing potential (FCP) vary between centers. To inform transfusion centers responsible for making decisions about matching policies for FCPs, the causal stimulus of the antibodies implicated in severe hemolytic disease of the fetus and newborn (HDFN) must be determined. STUDY DESIGN AND METHODS: We conducted a multinational retrospective study of women with offspring affected by severe HDFN requiring neonatal exchange transfusion and/or intrauterine transfusion. Mothers treated at centers that provide extended antigen-negative RBCs (MATCH, five centers) and those that do not (NoMATCH, nine centers) were compared. RESULTS: A total of 293 mothers had at least one affected pregnancy: 179 at MATCH centers and 114 at NoMATCH centers. Most alloimmunization (83%) was attributed to previous pregnancy: 3% to transfusion (two cases at MATCH, six at NoMATCH centers) and 14% undetermined (both antecedent transfusion and pregnancy). Only 50 mothers had received transfusions; 13 had HDFN due to anti-K at MATCH and four at NoMATCH centers. Most (12/13, 92%) of the anti-K HDFN cases at MATCH centers had K+ paternal antigen status. Mothers at the MATCH centers do not appear to be protected from HDFN due to K, C, c, and E antibodies, although the low number of FCPs who received transfusions precluded drawing firm conclusions. CONCLUSION: The causal stimulus of antibodies that cause HDFN is predominantly from previous pregnancy. Although extended RBC matching for FCPs may impart some protection from allosensitization, we were unable to show a positive effect, possibly because matching policies are not uniform and there was a small number of mothers who previously received transfusions.
Asunto(s)
Antígenos de Grupos Sanguíneos/sangre , Tipificación y Pruebas Cruzadas Sanguíneas , Transfusión Fetomaterna , Isoanticuerpos/sangre , Adulto , Eritroblastosis Fetal/sangre , Eritroblastosis Fetal/epidemiología , Femenino , Transfusión Fetomaterna/sangre , Transfusión Fetomaterna/epidemiología , Humanos , Embarazo , Estudios RetrospectivosRESUMEN
We conducted a meta-analysis of three endometrial cancer genome-wide association studies (GWAS) and two follow-up phases totaling 7,737 endometrial cancer cases and 37,144 controls of European ancestry. Genome-wide imputation and meta-analysis identified five new risk loci of genome-wide significance at likely regulatory regions on chromosomes 13q22.1 (rs11841589, near KLF5), 6q22.31 (rs13328298, in LOC643623 and near HEY2 and NCOA7), 8q24.21 (rs4733613, telomeric to MYC), 15q15.1 (rs937213, in EIF2AK4, near BMF) and 14q32.33 (rs2498796, in AKT1, near SIVA1). We also found a second independent 8q24.21 signal (rs17232730). Functional studies of the 13q22.1 locus showed that rs9600103 (pairwise r(2) = 0.98 with rs11841589) is located in a region of active chromatin that interacts with the KLF5 promoter region. The rs9600103[T] allele that is protective in endometrial cancer suppressed gene expression in vitro, suggesting that regulation of the expression of KLF5, a gene linked to uterine development, is implicated in tumorigenesis. These findings provide enhanced insight into the genetic and biological basis of endometrial cancer.