Results presented at The International Liver CongressTM 2015 show that cancer rates in patients with the hepatitis C virus (HCV) were significantly increased compared to the non-HCV cohort. The researchers suggest an extrahepatic manifestation of HCV may be an increased risk of cancer.
Researchers aimed to describe the rates of all cancers in the cohort of HCV patients compared to the non-HCV population. Known cancer types associated with hepatitis C include non-Hodgkin lymphoma as well as renal, prostate, and liver cancers.
A retrospective study at Kaiser Permanente Southern California was conducted. The study authors recorded all cancer diagnoses in patients over 18 years of age with or without HCV from 2008 to 2012. Within the time frame of the study, 145,210 patient years were included in the HCV cohort, and 13,948,826 patient years were included in the non-HCV cohort.
In the HCV cohort, there were 2,213 cancer diagnoses (1,524 per 100,000) during the 5-year period, and 1,654 cancer diagnoses when liver cancer was excluded (1,139 per 100,000). In the non-HCV cohort, there were 84,419 cancer diagnoses (605 per 100,000) during the same 5-year period, and 83,795 (601 per 100,000) when liver cancer was excluded. When all cancers are considered, the rate is 2.5 times higher in the HCV cohort; when liver cancers are excluded, the rate is still almost 2 times higher.
Lisa Nyberg, MD, MPH, of Kaiser Permanente Southern California, explained, “The results suggest that cancer rates are increased in the cohort of hepatitis C patients vs the non–hepatitis C patients, both including and excluding liver cancers. These findings certainly point to the suggestion that hepatitis C may be associated with an increased risk of cancer. However, the findings must be interpreted with caution, as the study also showed that confounding factors such as alcohol abuse, tobacco, obesity, and diabetes modified the results.”
Laurent Castera, MD, PhD, Vice-Secretary, European Association for the Study of the Liver, commented, “These data add to the evidence bank linking hepatitis C with an increased risk of cancer and highlight that there is still a long way to go in order to fully understand this complex and devastating disease.” ■