Globally, about 15 to 20% of cancers are linked to infections.
Lesser incidence in developed world, as infection load is lower.
Infections are Fourth leading cause of cancer Mortality, worldwide.
How do infections lead to cancers?
1. DNA Damage & Genomic Instability: Onco-viruses directly impact the genes of infected cells, blasting their growth out of control.
2. Infected cells undergo Chronic inflammation, which alters their behavior into hyper-growth states.
3. Immunity compromising Infections Such as HIV reduces the body’s ability to fight other viral infections that lead to cancer.
Virus infections that lead to Cancers
Human Papilloma Virus (HPV) – Cervical, Genital, Anal and Oro-pharyngeal Cancers.
Epstein-Barr virus (EBV) – Naso pharynx, Hodgkin’s disease, non-Hodgkin’s lymphoma
Human herpes virus type (HHV-8) – Kaposi’s sarcoma
Human immunodeficiency virus (HIV) – Kaposi’s sarcoma, lymphoma
Human T-cell lympho trophic virus type I (HTLV-I) – Leukemia, Lymphoma
Bacterial infections leading to Cancers
Helicobacter pylori – Stomach cancer
Parasites that trigger Cancers
Schistosoma hematobium – Bladder
(Liver flukes) Opisthorchis viverrini & Clonorchis sinensis – Biliary tract
Infections contribute to considerable Cancer mortality, worldwide.
Globally, the most common causes of cancer death are lung, liver and stomach cancers.
80% liver cancers (2nd leading cancer mortality) are due to hepatitis B and C virus infections.
75% of all stomach cancers (3rd in cancer mortality) are due to Helicobacter Pylori infection.
99.97% cancer cervix is due to HPV.
Vaccines exist for few of these infections.
HPV vaccine recommended for all girls & boys between 9 and 13 years of age.
Hepatitis B vaccine is recommended for certain high-risk adults — such as
People with sexually transmitted infections,
intravenous drug users,
adults who are sexually active with multiple partners, and
health care workers at risk of exposure to infected blood or body fluids.
Avoid Risky behaviors
Follow Safe-sex practices
Avoid blood exposure, for instance, by not sharing needles.
Get regular Pap tests and possibly HPV tests.