Diabetes mellitus, metformin and head and neck cancer.
Diabetes mellitus (DM (Diabetes Mellitus)) is directly associated with some cancers. However, studies on the association between diabetes mellitus and head and neck cancer (HNC (Head and Neck Cancer)) have rendered controversial results. The objective of this study was to evaluate the association between DM and HNC, as well as the impact of metformin use on the risk of HNC.



This case-control study was conducted within the framework of the Brazilian Head and Neck Genome Project in 2011-2014. The study included 1021 HNC cases with histologically confirmed squamous cell carcinoma of the head and neck admitted to five large hospitals in São Paulo state. A total of 1063 controls were selected in the same hospitals. Odds ratios (OR) and 95% confidence intervals (CI) were estimated using unconditional logistic regression.



Diabetic participants had a decreased risk of HNC (OR=0.68; 95% CI: 0.49-0.95) than non-diabetic participants, and this risk was further decreased among diabetic metformin users (OR=0.54; 95% CI: 0.29-0.99). Diabetic metformin users that were current smokers (OR=0.13; 95% CI: 0.04-0.44) or had an alcohol consumption of >40g/day (OR=0.31; 95% CI: 0.11-0.88) had lower risk of HNC than equivalent non-diabetic participants.



The risk of HNC was decreased among diabetic participants; metformin use may at least partially explain this inverse association.
Faculdade de Saude Publica, Departamento de Epidemiologia, Universidade de Sao Paulo, Av. Dr Arnaldo, 715, 01246-904 Sao Paulo, SP, Brazil; Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Nobels väg 12, SE-171 77 Stockholm, Sweden. Electronic address: rejane.figueiredo@usp.br.
Rejane Augusta de Oliveira
RA
Figueiredo
Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, PO Box 281, SE-171 77 Stockholm, Sweden; Department of Community Medicine, Faculty of Health Sciences, University of Tromsø, The Arctic University of Norway, Tromsø N-9037, Norway; Department of Research, Cancer Registry of Norway, PB 5313 Majorstuen, 0304 Oslo, Norway; Genetic Epidemiology Group, Folkhälsan Research Center, PB 63, FI-00014 University of Helsinki, Helsinki, Finland. Electronic address: elisabete.weiderpass.vainio@ki.se.
Elisabete
E
Weiderpass
Faculdade de Medicina de São José do Rio Preto, Departamento de Biologia Molecular, Av Brigadeiro Faria Lima n 5416, 15090000 São José do Rio Preto, SP, Brazil. Electronic address: etajara@hotmail.com.
Eloiza Helena
EH
Tajara
Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Nobels väg 12, SE-171 77 Stockholm, Sweden. Electronic address: peter.strom@ki.se.
Peter
P
Ström
Fundação PIO XII, Hospital de Câncer de Barretos, Av. Antenor Duarte Villela, 1331, 14784400 Barretos, SP, Brazil. Electronic address: alopescarvalho@uol.com.br.
André Lopes
AL
Carvalho
Hospital Heliópolis, Rua Cônego Xavier, 276, 04231-030 Sao Paulo, SP, Brazil. Electronic address: brasilino.heliopolis@gmail.com.
Marcos Brasilino
MB
de Carvalho
Faculdade de Medicina do ABC, Hospital de Ensino, Rua Silva Jardim, 470, 09715-090 Sao Bernardo do Campo, SP, Brazil. Electronic address: jossikanda@uol.com.br.
Jossi Ledo
JL
Kanda
Cirurgia de Cabeça e Pescoço (LIM 28), Faculdade de Medicina, Universidade de São Paulo, Av. Dr. Enéas de Carvalho Aguiar, 255, 8° andar, 05403900 São Paulo, SP, Brazil. Electronic address: ramccp@gmail.com.
Raquel Ajub
RA
Moyses
Faculdade de Saude Publica, Departamento de Epidemiologia, Universidade de Sao Paulo, Av. Dr Arnaldo, 715, 01246-904 Sao Paulo, SP, Brazil. Electronic address: wunsch@usp.br.
Victor
V
Wünsch-Filho
D000328:Adult; D003920:Diabetes Mellitus / Q000188:drug therapy*; D005260:Female; D006258:Head and Neck Neoplasms / Q000150:complications*; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use*; D008297:Male; D008687:Metformin / Q000627:therapeutic use*; D008875:Middle Aged
D007004:Hypoglycemic Agents; D008687:Metformin
Case-control studies; Diabetes mellitus; Head and neck cancer; Metformin