RESUMEN
Lung cancer is the leading cause of cancer mortality rate worldwide, mainly because of the presence of metastatic disease at the time of diagnosis. Early detection of lung cancer improves prognosis, and towards this end, large screening trials in high-risk individuals have been conducted since the past century. Despite all efforts, the need for novel (complementary) lung cancer diagnostic and screening methods still exists. In this review, we focus on the assessment of lung cancer-related biomarkers in sputum in the past decennium. Besides cytology, mutation and microRNA analysis, special attention has been paid to DNA promoter hypermethylation, of which all available literature is summarised without time restriction. A model is proposed to aid in the distinction between diagnostic and risk markers. Research on the use of sputum for non-invasive detection of early-stage lung cancer has brought new insights and advanced molecular techniques. The sputum shows a promising potential for routine diagnostic and possibly screening purposes.
Asunto(s)
Biomarcadores de Tumor/análisis , Neoplasias Pulmonares/diagnóstico , Esputo/química , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/metabolismo , Metilación de ADN , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patología , Regiones Promotoras Genéticas , Esputo/metabolismoRESUMEN
SUMMARY: Free DNA is present in the serum of cancer patients in a higher concentration than that in non-cancer patients. Free DNA in sputum may originate from malignant or inflammatory diseases. The aim of the study was to examine the presence of free DNA in sputum and the relationship to lung cancer. The contribution of inflammatory cells was established as well. The amount of free and cellular DNA in sputum was determined using real-time beta-globin PCR in 28 lung cancer patients and 68 controls. Free DNA was present in sputum samples of the cancer patients and controls. We found no differences in DNA concentration in sputum of patients with and without lung cancer. For all patients combined the amount of free DNA was related to the amount of inflammation. Further, we found increased hypermethylation of RASSF1A in lung cancer patients compared to controls to show that tumour related DNA is present in sputum. In conclusion, free DNA can be detected in sputum of lung cancer patients. The amount of free DNA is related to the amount of inflammation, but not to the presence of lung cancer.
Asunto(s)
ADN de Neoplasias/metabolismo , Neoplasias Pulmonares/metabolismo , Enfermedad Pulmonar Obstructiva Crónica/metabolismo , Esputo/metabolismo , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , Distribución de Chi-Cuadrado , Metilación de ADN , Femenino , Genes ras , Humanos , Masculino , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa/métodos , Estadísticas no ParamétricasRESUMEN
OBJECTIVE: To determine in a screening population the human papillomavirus (HPV) status in those with cytological abnormalities and to evaluate the presence of high-risk (HR) HPV with a minimum of 5-year follow up. DESIGN: Retrospective examination of HPV status on prospectively collected and cytologically screened cervical smears. SETTING: Canisius-Wilhelmina Hospital in Nijmegen, The Netherlands. POPULATION: Three hundred and fifty-seven women aged 30-60 years, from the population screened. METHODS: Three hundred and fifty-seven women with borderline or higher cytological abnormalities were retrospectively examined for HPV with DNA microarray typing. Follow up was through the nationwide Dutch Pathology database (PALGA). MAIN OUTCOME MEASURES: For the cytological abnormalities, the CISOE-A classification was used. HPV was scored as negative or positive. In case of positive HPV polymerase chain reaction, the HPV genotype was determined. The occurrence of cervical intraepithelial neoplasia lesions of grade 3 or higher was considered as endpoint for follow up. RESULTS: The majority of the women with borderline cytology in this study were HPV negative (87%). Among the HPV-positive women in borderline cytology group, 74% had HR-HPV or probable high-risk types. The overall percentage of HR-HPV types increased with progressive cytological abnormalities. The cytological classifications of borderline dyskaryosis and moderate dyskaryosis contain all types of HPVs, e.g. low risk, HR and unknown risk. The samples with severe dyskaryosis or higher contain only HR types. The negative predictive value for HR-HPV typing in the group with borderline cytological abnormalities is more than 99%. CONCLUSIONS: In cervical screening with an interval of 5 years, HPV can be reliably used as triage point in cases of borderline cytological abnormalities.
