It is now well established and confirmed by scientific research. A share of cancers, estimated at more than ten percent, has a viral basis, driven by the action of viruses and bacteria that alter the DNA structure, according to evidence from the latest edition of the AACR Cancer Progress Report 2025, compiled by the American Association for Cancer Research (AACR). Some organs, more than others, would be exposed to this triggering factor, but science also seems to point to some strategies that can help limit the effects and assaults of microorganisms.
Selected Data
About 2.2 million tumor cases, representing roughly 13% of all newly diagnosed cancers each year worldwide, would have a bacterial or viral origin. Of these, approximately 90%, an exceptionally high share, would be attributable to the primary action of four microorganisms: Helicobacter pylori, linked to the development of various stomach cancers and non-Hodgkin lymphoma, estimated up to 810,000 new cases annually; the human papillomavirus (HPV), which drives cervical cancers as well as cancers of the oral cavity or anus and, in general, cancers of the genital organs, with around 360,000 new diagnoses per year; the hepatitis B virus (HBV) and hepatitis C virus (HCV), which are connected to several forms of liver cancer, with numbers near 156,000 diagnoses each year.
These important figures should draw attention and prompt deeper exploration of the triggering mechanisms and the developmental synergies activated by these bacteria, capable of modifying DNA, thus initiating the abnormal proliferation of cancer cells, and the subsequent cascading reactions: a weakened immune system under stress, elevated inflammation, a fundamental driver behind many cancers, and progression toward chronic disease.
On the other hand, there is a need to implement strategies and foster synergy for effective early diagnosis, aimed at curbing the trend in cancer development, while also improving the profiling of these pathogens to inhibit their action. Among the potential solutions proposed by science are the development of vaccines for additional tumor forms, modeled on the HPV and HBV vaccines, as well as new antibiotics for H. pylori infections and antivirals for HCV.
Characterizations
Researchers have also managed to identify a “who and which” — i.e., the specific bacteria responsible for particular oncologic diseases. For example, a pivotal role would be played by the Epstein–Barr virus (EBV), considered responsible for about 156,600 cases annually of Hodgkin lymphoma and certain non-Hodgkin lymphomas, as well as nasopharyngeal cancers; the herpesvirus type 8 (HHV-8), associated with the development of 42,000 cases of Kaposi sarcoma; the T-cell lymphotropic virus type 1 (HTLV-1), which would drive the onset of about 3,600 cases of adult T-cell leukemia and lymphomas each year; or the liver flukes Clonorchis sinensis and Opisthorchis viverrini, thought to underlie about 3,500 diagnoses of cholangiocarcinoma, a cancer of the bile ducts.
Practical and Clinical Strategies
Enhancing hygienic and sanitary standards, along with knowledge education, and therefore addressing the risk factors tied to different cancers, the decisive use of condoms as protection against sexually transmitted viruses. These are some of the preventive and containment measures for virally driven cancers caused by cancer-causing microorganisms in an increasingly viral landscape.
Among effective clinical tools, vaccinations are recommended when available and appropriate for age groups and risk factors, actively participating in screening campaigns, the first line of prevention and early diagnosis, and implementing proper strategies to treat infections from their onset to dampen the risk of tumor progression. Specifically, the AACR document suggests pathogen-targeted strategies, namely for:
- – Helicobacter pylori: a combination of antibiotics (predominantly amoxicillin and clarithromycin) paired with acid-suppressing medications, such as proton pump inhibitors or H2 receptor antagonists.
- – HBV: in prevention, vaccination is the main tool; in the event of infection, antiviral drugs slow viral replication, delay liver damage, and reduce the risk of liver cancer.
- – HCV: similarly, antiviral drugs—the gold standard of therapy—act with the same aims as HBV. They slow and reduce the onset and damage caused by infection, but do not eradicate it completely.
- – HPV: the vaccine remains the most effective preventive measure, widely offered starting around age 11, capable of covering nine of the twelve high-risk HPV types (HPV 6, 11, 16, 18, 31, 33, 45, 52, 58). Women are also advised to undergo regular screening (Pap tests and HPV tests), while for men there are currently no widely available specific tests, underscoring the importance of physician-guided monitoring and testing as prescribed.
Source
AACR Cancer Progress Report 2025. American Association for Cancer Research (AACR). Link: https://cancerprogressreport.aacr.org/progress/
Abbonati a Karla Miller
