title: Night shift work and chronic lymphocytic leukemia in the MCC-Spain case-control study.
abstract: Chronic lymphocytic leukemia (CLL) has few known modifiable risk factors. Recently, circadian disruption has been proposed as a potential contributor to lymphoid neoplasms' etiology. Serum melatonin levels have been found to be significantly lower in CLL subjects compared with healthy controls, and also, CLL prognosis has been related to alterations in the circadian molecular signaling. We performed the first investigation of an association between night shift work and CLL in 321 incident CLL cases and 1728 population-based controls in five areas of Spain. Participants were interviewed face-to-face by trained interviewers to collect information on sociodemographic factors, familial, medical and occupational history, including work shifts and other lifestyle factors. We used logistic regression models adjusted for potential confounders to estimate odds ratios (OR) and 95% confidence intervals (CI). Seventy-nine cases (25%) and 339 controls (20%) had performed night work. Overall, working in night shifts was not associated with CLL (OR = 1.06; 95% CI = 0.78-1.45, compared with day work). However, long-term night shift (>20 years) was positively associated with CLL (OR(tertile 3 vs . day-work)  = 1.77; 95% = 1.14-2.74), although no linear trend was observed (P trend = 0.18). This association was observed among those with rotating (OR(tertile 3 vs . day-work)  = 2.29; 95% CI = 1.33-3.92; P trend = 0.07), but not permanent night shifts (OR(tertile 3 vs . day-work) = 1.16; 95% CI = 0.60-2.25; P trend = 0.86). The association between CLL and long-term rotating night shift warrants further investigation.
authors.affiliation: Unit of Infections and Cancer, Cancer Epidemiology Research Programme, IDIBELL, Catalan Institute of Oncology, Barcelona, Spain.|Department of Medicine, University of Barcelona, Barcelona, Spain.|Consortium for Biomedical Research in Epidemiology and Public Health (CIBER Epidemiología y Salud Pública, CIBERESP), Spain.
authors.forename: Laura
authors.initials: L
authors.lastname: Costas
authors.affiliation: Unit of Infections and Cancer, Cancer Epidemiology Research Programme, IDIBELL, Catalan Institute of Oncology, Barcelona, Spain.|Consortium for Biomedical Research in Epidemiology and Public Health (CIBER Epidemiología y Salud Pública, CIBERESP), Spain.
authors.forename: Yolanda
authors.initials: Y
authors.lastname: Benavente
authors.affiliation: Consortium for Biomedical Research in Epidemiology and Public Health (CIBER Epidemiología y Salud Pública, CIBERESP), Spain.|Department of Preventive Medicine and Public Health, University of Granada, Granada, Spain.|Instituto de Investigación Biosanitaria ibs, Granada, Complejo Hospitales Universitarios de Granada, Universidad de Granada, Granada, Spain.
authors.forename: Rocío
authors.initials: R
authors.lastname: Olmedo-Requena
authors.affiliation: Unit of Infections and Cancer, Cancer Epidemiology Research Programme, IDIBELL, Catalan Institute of Oncology, Barcelona, Spain.|Consortium for Biomedical Research in Epidemiology and Public Health (CIBER Epidemiología y Salud Pública, CIBERESP), Spain.
authors.forename: Delphine
authors.initials: D
authors.lastname: Casabonne
authors.affiliation: Unit of Infections and Cancer, Cancer Epidemiology Research Programme, IDIBELL, Catalan Institute of Oncology, Barcelona, Spain.|Prevention and Implementation Group, International Agency for Research on Cancer, Lyon, France.
authors.forename: Claudia
authors.initials: C
authors.lastname: Robles
authors.affiliation: Hematology, IDIBELL, Institut Català d' Oncologia, 08908, L' Hospitalet De Llobregat, Barcelona, Spain.
authors.forename: Eva-Maria
authors.initials: EM
authors.lastname: Gonzalez-Barca
authors.affiliation: Department of Pathology, Hospital Universitari de Bellvitge, 08908, L'Hospitalet De Llobregat, Barcelona, Spain.
authors.forename: Esmeralda
authors.initials: E
authors.lastname: de la Banda
authors.affiliation: Department of Pathology, Hospital Universitari de Bellvitge, 08908, L'Hospitalet De Llobregat, Barcelona, Spain.
authors.forename: Esther
authors.initials: E
authors.lastname: Alonso
authors.affiliation: Hematopathology Unit, Pathology Department, Hospital Clínic, University of Barcelona, Institute of Biomedical Research August Pi i Sunyer (IDIBAPS), Barcelona, 08036, Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: Aymerich
authors.affiliation: Consortium for Biomedical Research in Epidemiology and Public Health (CIBER Epidemiología y Salud Pública, CIBERESP), Spain.|Instituto Universitario de Oncología del Principado de Asturias (IUOPA), University of Oviedo, Spain.
authors.forename: Adonina
authors.initials: A
authors.lastname: Tardón
authors.affiliation: Consortium for Biomedical Research in Epidemiology and Public Health (CIBER Epidemiología y Salud Pública, CIBERESP), Spain.|Unitat d'Epidemiologia i Registre de Càncer de Girona (UERCG), Pla Director d'Oncologia, Institut Català d'Oncologia, Institut d'Investigació Biomèdica de Girona (IdIBGi), Universitat de Girona, Girona, Spain.
authors.forename: Rafael
authors.initials: R
authors.lastname: Marcos-Gragera
authors.affiliation: Department of Clinical Hematology, Hospital del Mar, Barcelona, 08003, Spain.|Grup de Recerca Aplicada en Neoplasies Hematològiques-PSMAR, Barcelona, Spain.
authors.forename: Eva
authors.initials: E
authors.lastname: Gimeno-Vázquez
authors.affiliation: Consortium for Biomedical Research in Epidemiology and Public Health (CIBER Epidemiología y Salud Pública, CIBERESP), Spain.|Instituto de Investigación Marqués de Valdecilla (IDIVAL), Universidad de Cantabria, Santander, Spain.
authors.forename: Inés
authors.initials: I
authors.lastname: Gómez-Acebo
authors.affiliation: ISGlobal, Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain.|Department of Epidemiology, Medical University of Vienna, Vienna, Austria.
authors.forename: Kyriaki
authors.initials: K
authors.lastname: Papantoniou
authors.affiliation: Consortium for Biomedical Research in Epidemiology and Public Health (CIBER Epidemiología y Salud Pública, CIBERESP), Spain.|ISGlobal, Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain.|Hospital del Mar Medical Research Institute (IMIM), Barcelona, Spain.|Universitat Pompeu Fabra (UPF), Barcelona, Spain.
authors.forename: Gemma
authors.initials: G
authors.lastname: Castaño-Vinyals
authors.affiliation: Consortium for Biomedical Research in Epidemiology and Public Health (CIBER Epidemiología y Salud Pública, CIBERESP), Spain.|Cancer and Environmental Epidemiology Unit, National Center for Epidemiology, Carlos III Institute of Health, Madrid, Spain.|Cancer Epidemiology Research Group, Oncology and Hematology Area, IIS Puerta de Hierro (IDIPHIM), Madrid, Spain.
authors.forename: Nuria
authors.initials: N
authors.lastname: Aragonés
authors.affiliation: Consortium for Biomedical Research in Epidemiology and Public Health (CIBER Epidemiología y Salud Pública, CIBERESP), Spain.|Cancer and Environmental Epidemiology Unit, National Center for Epidemiology, Carlos III Institute of Health, Madrid, Spain.|Cancer Epidemiology Research Group, Oncology and Hematology Area, IIS Puerta de Hierro (IDIPHIM), Madrid, Spain.
authors.forename: Marina
authors.initials: M
authors.lastname: Pollán
authors.affiliation: Consortium for Biomedical Research in Epidemiology and Public Health (CIBER Epidemiología y Salud Pública, CIBERESP), Spain.|ISGlobal, Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain.|Hospital del Mar Medical Research Institute (IMIM), Barcelona, Spain.|Universitat Pompeu Fabra (UPF), Barcelona, Spain.|National School of Public Health, Athens, Greece.
authors.forename: Manolis
authors.initials: M
authors.lastname: Kogevinas
authors.affiliation: Unit of Infections and Cancer, Cancer Epidemiology Research Programme, IDIBELL, Catalan Institute of Oncology, Barcelona, Spain.|Department of Medicine, University of Barcelona, Barcelona, Spain.|Consortium for Biomedical Research in Epidemiology and Public Health (CIBER Epidemiología y Salud Pública, CIBERESP), Spain.
authors.forename: Silvia
authors.initials: S
authors.lastname: de Sanjosé
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D002940:Circadian Rhythm; D005260:Female; D006801:Humans; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000453:epidemiology* / Q000209:etiology; D008297:Male; D008550:Melatonin / Q000097:blood; D016017:Odds Ratio; D012044:Regression Analysis; D012307:Risk Factors; D013030:Spain / Q000453:epidemiology; D011795:Surveys and Questionnaires; D014940:Work Schedule Tolerance; D055815:Young Adult
chemical_list: D008550:Melatonin
keywords: case-control study; chronic lymphocytic leukemia; night shift work