ABO blood group and cancer
Introduction
Although the relation between ABO blood group and cancer was the subject of intensive research in the mid 1900’s, there has been renewed interest after the recent publication of reports establishing an association between ABO blood group and pancreatic cancer.1, 2 Simultaneously, a genome-wide association study (GWAS) identified pancreatic cancer susceptibility loci in the ABO gene.3 Given the lack of survival improvement during the past 30 years,4 these recent findings on the individual predisposition to pancreatic cancer might play an important role in screening planning and clinical practice.
In order to confirm these recent findings in a different population and different setting and to assess whether the association is limited to pancreatic cancer, we studied the distribution of ABO blood group in patients with various forms of cancer using data from the tumour registry of the European Institute of Oncology (IEO). We also performed a meta-analysis of all published reports on the association between ABO blood group and pancreatic cancer to summarise the current evidence.
Section snippets
Tumour registry data
This study is based on data from the IEO Tumour Registry, a database activated in March 2006 with the aim to collect and analyse data on all those consulting at IEO, at risk of developing or already presenting with a tumour. More details on data collection, data quality control procedures and activity of the IEO Tumour Registry have been published elsewhere.5
For the present study, in order to deal with the most reliable and complete data in the registry, we limited the analysis to patients with
Tumour registry data
Information on ABO blood type was available for 79% of all patients referred and treated for the first time at the IEO during 1999–2003. Overall, the ABO blood group distribution of the 15,359 cancer patients was similar to that of the Italian general population15 (P = 0.78): 6753 patients (44%) were blood group O, 6174 (40%) group A, 1782 (12%) group B and 650 (4%) group AB. The blood group distribution of patients with each form of cancer is reported in Table 1.
Pancreas was the only cancer site
Discussion
In the IEO Tumour Registry, exocrine pancreatic cancer was the only form of tumour that exhibited a significant difference in the proportion of patients with blood type O compared to other forms of cancer. Overall, O blood group was associated with a 47% risk reduction of exocrine pancreatic cancer. This association was not modified by established risk factors for pancreatic cancer, including age, medical history of diabetes and cigarette smoking, but the lack of significant interaction may be
Conflict of interest statement
None declared.
Acknowledgements
The authors would like to thank Marina Francesca Alfieri, Nadia Burzoni, Marco Martinetti, Laura Manghi, Bruno Montanari, Barbara Bazolli and Elena Albertazzi for their precious contribution to the IEO Tumour Registry.
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