Risks for hepatocellular carcinoma and non-Hodgkin lymphoma appeared greater among women who had undergone a blood transfusion more than 5 years earlier, according to results of a prospective study conducted in the United Kingdom.
Nucleic acid amplification testing for hepatitis C virus was introduced in the U.K. in 1999 as a blood screening tool. Since then, there have been no population-based data on whether people who underwent transfusions in 2000 or later were at increased risk for various cancers. Therefore, TienYu Owen Yang, MD, DPhil, epidemiologist at the Nuffield Department of Population Health at University of Oxford in the United Kingdom, and colleagues evaluated 1.3 million women (median age, 56 years; interquartile range, 52-60 years) from The Million Women Study.
Researchers used Cox regression models to show adjusted RRS of 11 site-specific cancers for women who had undergone a prior blood transfusion compared with women who had not. Women with cancer or precancerous conditions before or at the time of transfusion were excluded.
A total of 11,274 women underwent transfusion in 2000 or later, of whom 14.6% (n = 1,648) were diagnosed with cancer a mean 6.8 years after the blood transfusion. Women who underwent transfusion were older at baseline and more likely to smoke, drink less alcohol, have increased BMI and have come from the deprived tertile of the population.
Within the first 5 years posttransfusion, nine of 11 cancer site RRs were increased after adjusting for multiple comparisons (P < .05), which the researchers noted was most likely due to some of the patients presenting with preclinical cancer.
Overall, risks appeared lower if transfusion was performed more than 5 years ago.
The RRs that remained high after 5 or more years (mean, 8 years) after blood transfusion included for hepatocellular carcinoma (HCC; RR = 2.63; 95% CI, 1.45-4.78) and NHL (RR = 1.74; 95% CI, 1.21-2.51).
The transfusion-associated RRs attenuated to 13% for HCC and 7% for NHL after adjusting for smoking status, alcohol consumption and BMI.
The absolute risk for HCC was 0.16 (95% CI, 0.08-0.24) per 1,000 person-years 5 or more years posttransfusion compared with 0.07 (95% CI, 0.06-0.07) per 1,000 person-years among women who did not undergo transfusion.
The absolute risk for non-Hodgkin lymphoma was 0.4 (95% CI, 0.31-0.49) per 1,000 person-years 5 or more years post-transfusion compared with 0.28 (95% CI, 0.27-0.29) per 1,000 person-years among women who did not undergo transfusion.
The most common procedure associated with transfusion is a knee or hip replacement. Of the 11 women who developed HCC, six had surgery at the time of transfusion, including three hip/knee replacements. Of the 29 women who developed NHL, 16 had surgery at the time of the transfusion, 12 of which were hip/knee replacements.
When analyses were restricted to women who underwent knee/hip replacement surgery, researchers observed similar risks for HCC (RR = 2.1; 95% CI, 0.68-6.55) and NHL (RR = 2.14; 95% CI, 1.21-3.77).
“No other study has reported on cancer risk associated with 21st century blood transfusion,” the researchers wrote. “The long-term excess risks for liver cancer and of non-Hodgkin lymphoma warrants investigation of carcinogenic agents not currently screened for that are still being transmitted by transfusion.” – by Melinda Stevens
Disclosures: The researchers report no relevant financial disclosures.