CARING (CAncer Risk and INsulin analoGues): the association of diabetes mellitus and cancer risk with focus on possible determinants - a systematic review and a meta-analysis.
BACKGROUND
Patients suffering from diabetes mellitus (DM) may experience an increased risk of cancer; however, it is not certain whether this effect is due to diabetes per se.


OBJECTIVE
To examine the association between DM and cancers by a systematic review and meta-analysis according to the PRISMA guidelines.


METHODS
The systematic literature search includes Medline at PubMed, Embase, Cinahl, Bibliotek.dk, Cochrane library, Web of Science and SveMed+ with the search terms: "Diabetes mellitus", "Neoplasms", and "Risk of cancer".


METHODS
The included studies compared the risk of cancer in diabetic patients versus non-diabetic patients. All types of observational study designs were included.


RESULTS
Diabetes patients were at a substantially increased risk of liver (RR=2.1), and pancreas (RR=2.2) cancer. Modestly elevated significant risks were also found for ovary (RR=1.2), breast (RR=1.1), cervix (RR=1.3), endometrial (RR=1.4), several digestive tract (RR=1.1-1.5), kidney (RR=1.4), and bladder cancer (RR=1.1). The findings were similar for men and women, and unrelated to study design. Meta-regression analyses showed limited effect modification of body mass index, and possible effect modification of age, gender, with some influence of study characteristics (population source, cancer- and diabetes ascertainment).


CONCLUSIONS
Publication bias seemed to be present. Only published data were used in the analyses.


CONCLUSIONS
The systematic review and meta-analysis confirm the previous results of increased cancer risk in diabetes and extend this to additional cancer sites. Physicians in contact with patients with diabetes should be aware that diabetes patients are at an increased risk of cancer.
Jakob
J
Starup-Linde
Oystein
O
Karlstad
Stine Aistrup
SA
Eriksen
Peter
P
Vestergaard
Heleen K
HK
Bronsveld
Frank
F
de Vries
Morten
M
Andersen
Anssi
A
Auvinen
Jari
J
Haukka
Vidar
V
Hjellvik
Marloes T
MT
Bazelier
Anthonius de
Ad
Boer
Kari
K
Furu
Department of Endocrinology and Internal Medicine (MEA), Aarhus University Hospital, Tage Hansens Gade 2, 8000 Aarhus C, Denmark. jakolind@rm.dk.
Marie L
ML
De Bruin
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D048909:Diabetes Complications / Q000453:epidemiology*; D003920:Diabetes Mellitus / Q000188:drug therapy; D006801:Humans; D007004:Hypoglycemic Agents / Q000009:adverse effects* / Q000627:therapeutic use; D007223:Infant; D007328:Insulin / Q000009:adverse effects* / Q000031:analogs & derivatives* / Q000627:therapeutic use; D008875:Middle Aged; D009369:Neoplasms / Q000453:epidemiology*; D017594:Publication Bias; D012044:Regression Analysis; D012306:Risk; D055815:Young Adult
D007004:Hypoglycemic Agents; D007328:Insulin