Cervical squamous intraepithelial neoplasia

Many women will find that when they are doing cervical cancer screening, some seminars write low-grade/high-grade squamous intraepithelial neoplasia. So what is the cause of this squamous intraepithelial neoplasia? How is it caused? Let’s talk about it today. I hope that the detailed introduction in this article can be helpful to everyone.

Cervical intraepithelial neoplasia (CIN) is a group of precancerous lesions closely related to cervical invasive cancer, which reflects the continuous process of cervical cancer development. Cervical intraepithelial neoplasia has two different outcomes. One is that the lesion often disappears naturally and rarely develops into invasive cancer; the other is that the lesion has the potential for disease progression and may develop into invasive cancer. Cervical intraepithelial neoplasia often occurs in women of appropriate age, while cervical cancer is common in women over 40 years old.

According to the degree of somatic cell atypia and the extent of epithelial cell invasion, cervical intestinal metaplasia is divided into three degrees (or grades): mild, moderate, and severe.

(1) Mild intestinal metaplasia (or grade I): The somatic cell atypia is mild, and the abnormal proliferation of somatic cells is limited to the lower 1/3 of the epidermis, while the middle and surface somatic cells are normal.

(2) Mild to moderate intestinal metaplasia (or grade II): There is significant atypia of somatic cells, and the abnormal proliferation of somatic cells is limited to the lower 2/3 of the epidermis without invading the surface.

(3) Moderate to severe intestinal metaplasia (or grade III): Somatic cell atypia is obvious and abnormal proliferation of somatic cells occupies more than 2/3 of the epithelial cells or reaches the cell layer.

Disease-related factors

SIL is associated with cervical cancer and human papillomavirus (HPV) infection, multiple sexual partners, smoking, early sexual intercourse (<16 years old), reproductive tract infections, low economic status, birth control pills and immune enhancers.

(1) HPV infection: Currently, there are more than 200 known types of HPV, more than 40 of which are related to reproductive system infections, of which 13-15 are closely related to the occurrence of SIL and uterine cancer. High-risk HPV infection has been found in nearly 90% of SILs and 99% of cervical cancer tissues, of which 70% are related to HPV16 and 18. High-risk HPV causes viral oncoproteins, among which E6 and E7 respectively function to target the tumor suppressor genes P53 and Rb of target cells for degradation or inactivation, thereby causing lesions through a series of molecular events. Getting the HPV protective vaccine can provide primary prevention for cervical cancer.

(2) Frequency of sexual intercourse and childbirth: Having multiple sexual partners, first sexual intercourse before the age of 16, early childbirth, and multiple births are associated with the occurrence of cervical cancer. Women who have sex with men who are at high risk for penile cancer, prostate cancer, or whose sexual partners have had cervical cancer are also very likely to develop cervical cancer.

(3) In addition, smoking can increase the risk of HPV infection, and barrier contraception has a certain protective effect