Most common type of human papilloma virus causing Ca cervix are :
**Core Concept**
Human papillomavirus (HPV) is a sexually transmitted infection that can cause cervical cancer through the development of high-grade cervical intraepithelial neoplasia (CIN). The majority of cervical cancers are associated with persistent infection by high-risk HPV types.
**Why the Correct Answer is Right**
HPV types 16 and 18 are responsible for approximately 70% of cervical cancers worldwide, making them the most common high-risk HPV types associated with cervical cancer. These types have a high affinity for the epithelial cells of the cervix and are more likely to integrate into the host genome, leading to the development of malignant changes. The high-risk HPV types 16 and 18 have a strong association with the presence of p53 and pRb tumor suppressor protein mutations.
**Why Each Wrong Option is Incorrect**
* **Option A:** HPV 6 and 11 are considered low-risk HPV types, primarily associated with genital warts and not typically linked to cervical cancer.
* **Option B:** HPV 31 and 33 are high-risk HPV types, but they are less common than HPV 16 and 18 in causing cervical cancer.
* **Option C:** HPV 45 is a high-risk HPV type, but it is less frequently detected in cervical cancer cases compared to HPV 16 and 18.
**Clinical Pearl / High-Yield Fact**
The HPV vaccine, which protects against HPV 16 and 18, has been shown to reduce the incidence of cervical cancer and its precursors in vaccinated populations.
**Correct Answer:** C. HPV 16 and 18.