Thalassaemia and risk of cancer: a population-based cohort study.
BACKGROUND
Studies that have investigated the epidemiological relationship between thalassaemia and cancers are scarce. Therefore, we conducted a longitudinal nationwide cohort study to determine whether patients with thalassaemia are at an increased risk of cancer.


METHODS
We investigated the incidence and risk of cancer in 2655 patients diagnosed with thalassaemia between 1998 and 2010 by using data from the Taiwan Longitudinal Health Insurance Database. The comparison cohort comprised 10 620 people from the general population without thalassaemia. The follow-up period extended from the diagnostic date for thalassaemia to the date of a cancer diagnosis, censoring or 31 December 2011. We used Cox proportional hazard regression models to analyse the risks of cancer.


RESULTS
The incidences of cancer were 3.96 and 2.60/1000 person-years for the thalassaemia and comparison cohorts, respectively. The overall incidence of cancer was 52% higher in the thalassaemia cohort than in the comparison cohort, with an adjusted HR (aHR) of 1.54 (95% CI 1.15 to 2.07). Patients with thalassaemia had a considerably higher risk of haematological malignancy (aHR=5.32, 95% CI 2.18 to 13.0) and abdominal cancer (aHR=1.96, 95% CI 1.22 to 3.15) than did the comparison cohort. Furthermore, patients with thalassaemia with transfusion exhibited a 9.31-fold risk for developing haematological malignancy and a 9.12-fold risk for developing abdominal cancer compared with those who did not receive transfusion.


CONCLUSIONS
This nationwide retrospective cohort study indicates that patients with thalassaemia carried substantial risks of haematological malignancy and abdominal cancer compared with those of the general population.
Department of Internal Medicine, Taichung Hospital, Ministry of Health and Welfare, Taichung, Taiwan Department of Healthcare Administration, Central Taiwan University of Science and Technology, Taichung, Taiwan.
Wei-Sheng
WS
Chung
Department of Internal Medicine, Taichung Hospital, Ministry of Health and Welfare, Taichung, Taiwan.
Chun-Liang
CL
Lin
Management Office for Health Data, China Medical University Hospital, Taichung, Taiwan College of Medicine, China Medical University, Taichung, Taiwan.
Cheng-Li
CL
Lin
Graduate Institute of Clinical Medical Science and School of Medicine, College of Medicine, China Medical University, Taichung, Taiwan Department of Nuclear Medicine and PET Center, China Medical University Hospital, Taichung, Taiwan.
Chia-Hung
CH
Kao
D000008:Abdominal Neoplasms / Q000453:epidemiology; D000328:Adult; D016022:Case-Control Studies; D015897:Comorbidity; D005260:Female; D019337:Hematologic Neoplasms / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D007345:Insurance Claim Review; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009369:Neoplasms / Q000453:epidemiology*; D015995:Prevalence; D016016:Proportional Hazards Models; D018570:Risk Assessment; D012720:Severity of Illness Index; D013624:Taiwan / Q000453:epidemiology; D013789:Thalassemia / Q000453:epidemiology*; D055815:Young Adult
BIRTH DEFECTS; CANCER; CHRONIC DI; Cancer epidemiology; Cohort studies