Process of carcinogenesis in carcinoma cervix begins at the –
**Core Concept**
The process of carcinogenesis in carcinoma cervix involves the transformation of normal cervical cells into malignant cells, primarily driven by human papillomavirus (HPV) infection. This complex process involves viral oncogene expression, cellular proliferation, and genetic instability. The cervical epithelium's unique anatomy and hormonal influences also play critical roles in carcinogenesis.
**Why the Correct Answer is Right**
The correct answer is **A. Squamous cells**. Carcinogenesis in carcinoma cervix typically begins in the squamous epithelial cells of the cervix. HPV infection leads to the integration of viral oncogenes (E6 and E7) into the host genome, which disrupts the normal cell cycle regulation, leading to uncontrolled cellular proliferation. The E6 protein binds to and inactivates the tumor suppressor p53, while the E7 protein binds to and inactivates the retinoblastoma protein (Rb), releasing the cell cycle from its normal brakes.
**Why Each Wrong Option is Incorrect**
* **Option B:** While glandular cells are also present in the cervix, they are less commonly involved in carcinogenesis compared to squamous cells.
* **Option C:** Columnar cells are the primary cell type in the endocervical canal, but they are not the primary site of carcinogenesis in carcinoma cervix.
* **Option D:** Stromal cells, including connective tissue and blood vessels, are not directly involved in the carcinogenic process.
**Clinical Pearl / High-Yield Fact**
HPV types 16 and 18 are responsible for approximately 70% of cervical cancer cases worldwide. Screening for high-risk HPV types is an essential component of cervical cancer prevention.
**Correct Answer: A. Squamous cells**