Infections, viruses, and parasites cause 13% of all cancers diagnosed worldwide, leading to tumor formation. An international team of researchers analyzed global cancer data and found that bacteria, viruses, and parasites trigger millions of cancer cases each year, according to infohub.kz.
Most often, these pathogens lead to tumors of the stomach, cervix, and liver.
Contrary to popular belief, the main culprit is not the human papillomavirus (HPV) but the bacterium Helicobacter pylori. It accounts for more than a third of all infection-related cancer cases — about 810,000 diagnoses annually. This bacterium lives in the stomach, causing chronic inflammation and ulcers, which over time increases the risk of cancer.
HPV ranks second, causing about 690,000 cancer cases a year, mainly cervical cancer. Next are hepatitis B and C viruses, which damage liver cells and lead to cirrhosis and hepatocellular carcinoma.
The authors emphasize that most such tumors can be prevented. Antibiotic courses are successfully used against Helicobacter pylori, and effective vaccines against HPV and hepatitis B are available in many countries.