Most common tumour caused by virus is ?
**Core Concept**
Human papillomavirus (HPV) is a significant oncogenic virus that causes various cancers, primarily affecting the epithelial cells. The virus has a tropism for cervical epithelial cells, leading to cervical cancer, which is the most common HPV-related malignancy.
**Why the Correct Answer is Right**
HPV infection leads to the integration of viral DNA into the host genome, resulting in the disruption of normal cellular functions. The E6 and E7 oncogenes of HPV are responsible for the inactivation of tumor suppressor proteins p53 and Rb, respectively. This allows for uncontrolled cell proliferation and contributes to the development of cervical cancer. The virus also induces the production of high-risk HPV types, such as HPV 16 and 18, which are associated with a higher risk of cervical cancer.
**Why Each Wrong Option is Incorrect**
**Option A:** Epstein-Barr virus (EBV) is associated with several malignancies, including Burkitt lymphoma, Hodgkin lymphoma, and nasopharyngeal carcinoma. However, it is not the most common tumor caused by a virus.
**Option B:** Hepatitis B virus (HBV) is a significant risk factor for hepatocellular carcinoma, but it is not the most common tumor caused by a virus.
**Option C:** Human immunodeficiency virus (HIV) is not a direct cause of cancer, although it increases the risk of various opportunistic infections and malignancies due to immunosuppression.
**Clinical Pearl / High-Yield Fact**
HPV vaccination is an effective preventive measure against cervical cancer, and it is recommended for individuals aged 9-26 years. The vaccine targets high-risk HPV types, such as HPV 16 and 18, which are responsible for the majority of cervical cancer cases.
**Correct Answer: C. Hepatitis B virus (HBV)**