Infection rates may be associated with cancer diagnosis

Increased rates of certain infections were found in patients in the years prior to being diagnosed with cancer, according to results from a study published in Cancer Immunology Research. 

Influenza, gastroenteritis, hepatitis, and pneumonia were associated with an eventual cancer diagnosis.

In this retrospective case-control study, the researchers used claims data following patients ≥30 years of age for 7 years. By the 7th year of the study, 2354 people were diagnosed with cancer and 48,395 people were not. Digestive and gastrointestinal, head and neck, and stomach cancers were the most commonly diagnosed. 

Patients who were diagnosed with cancer had higher rates of infections in the 6 years before being diagnosed. The biggest differences in annual infection prevalence rates was in the year prior to diagnosis, with an 18% higher rate for influenza, 46.1% for gastroenteritis, 232.1% for hepatitis, and 135.9% for pneumonia, compared with the control group.

“Cancer can develop in an inflammatory environment caused by infections, immunity disruption, exposure to chemical carcinogens, or chronic or genetic conditions,” said Shinako Inaida, PhD, a visiting researcher at the Graduate School of Medicine at Kyoto University in Japan, in a press release. “An individual’s immunity is thought to be a factor in the development of cancer, but additional research is needed to understand the relationship among precancerous immunity, infections, and cancer development. This information may contribute to efforts to prevent or detect cancer.”

Reference

Inaida S and Matsuno S. Previous infection positively correlates to the tumor incidence rate of patients with cancer. Cancer Immunol Res. 2020;doi:10.1158/2326-6066.CIR-19-0510.