Cervical cancer is the most common gynecological malignancy. The high incidence age of in situ cancer is 30 to 35 years old, and that of invasive cancer is 45 to 55 years old; in recent years, there is a trend of its incidence becoming younger. The common application of cervical cytology screening in recent decades has enabled early detection and treatment of cervical cancer and precancerous lesions, and the incidence and mortality rate of cervical cancer have been significantly reduced. More than 90% of cervical cancers are associated with high-risk HPV infection. 2.Sexual behavior and number of births Multiple sexual partners, first sexual intercourse <16 years old, young age at first birth, multiple pregnancies and multiple births are closely related to the occurrence of cervical cancer. 3.Other biological factors Chlamydia trachomatis, herpes simplex virus type II, trichomonas and other pathogens play a synergistic role in the development of cervical cancer caused by high-risk HPV infection. 4.Other behavioral factors Smoking as a synergistic factor of HPV infection can increase the risk of cervical cancer. In addition, poor nutrition and poor hygiene can also influence the occurrence of the disease. Clinical manifestations of cervical cancer Early cervical cancer often has no obvious symptoms and signs, and the cervix may be smooth or difficult to distinguish from cervical columnar epithelial ectopic. Patients with cervical canal type are easily missed or misdiagnosed because of the normal appearance of the cervix. With the development of lesions, the following manifestations may occur: 1. Symptoms (1) Vaginal bleeding Mostly contact bleeding in the early stage; irregular vaginal bleeding in the middle and late stage. The amount of bleeding varies according to the size of the lesion and the invasion of the interstitial vessels, and may cause hemorrhage if the large vessels are invaded. Younger patients may also present with prolonged periods and increased menstrual flow; older patients often have irregular vaginal bleeding after menopause. The exophytic type usually presents with vaginal bleeding earlier and with more bleeding; the endophytic type presents with the symptoms later. (2) Vaginal discharge Most patients have vaginal discharge, which is white or bloody and may be thin like water or rice slop, or have fishy odor. In advanced stage, due to necrosis of cancer tissue and infection, there may be large amount of rice-soup-like or pus-like foul-smelling leucorrhea. (3) Late symptoms Depending on the extent of cancer involvement, different secondary symptoms may appear. Such as frequent urination, urgent urination, constipation, swelling and pain of lower limbs, etc.; if the cancer compresses or involves ureter, it may cause ureteral obstruction, hydronephrosis and uremia; in advanced stage, there may be systemic failure symptoms such as anemia and cachexia. 2.Signs Carcinoma in situ and micro-infiltrating carcinoma may have no obvious foci, and the cervical area may be smooth or only columnar epithelial ectopic. Different physical signs may appear with the development of the disease. Ectogenous cervical cancer can be seen as polyp-like or cauliflower-like superfluous organisms, often accompanied by infection, and the tumor is brittle and prone to bleeding; endogenous cervical cancer can be seen as cervical hypertrophy, hardness and cervical canal expansion; in advanced stage, the cancer tissue is necrotic and falls off, forming ulcers or cavities with bad odor. When the vaginal wall is involved, superfluous growth can be seen on the vaginal wall or the vaginal wall is hardened; when the parametrial tissues are involved, thickened, nodular, hard or frozen pelvic tissues can be found on double or triple examination. 3.Pathological types Three types of carcinoma are common: squamous carcinoma, adenocarcinoma and adenosquamous carcinoma. (1) Squamous carcinoma is classified into grade III according to histological differentiation. Grade I is highly differentiated squamous carcinoma, grade II is medium differentiated squamous carcinoma (non-keratinized large cell type), and grade III is low differentiated squamous carcinoma (small cell type), which is mostly undifferentiated small cells. (2) Adenocarcinoma accounts for 15% to 20% of cervical cancer. There are 2 main histological types. (1) Mucinous adenocarcinoma: the most common type, which originates from columnar mucus cells in the cervical duct. It can be divided into high, medium and low differentiated adenocarcinoma. (2) Malignant adenoma: also known as slightly deviated adenocarcinoma, it is a highly differentiated mucosal adenocarcinoma of the cervical duct. There are many cancerous glands with different sizes and variable morphology, and they protrude into the deep interstitial layer of the human cervix in a punctate manner, and the glandular epithelial cells are not heterogeneous. (3) Adenosquamous carcinoma accounts for 3% to 5% of cervical cancer. It is formed by the differentiation of reserve cells to both glandular cells and squamous cells. The cancer tissue contains both adenocarcinoma and squamous carcinoma components. 4.Metastasis is mainly direct spread and lymphatic metastasis, while hematogenous metastasis is less common. (1) Direct spread is the most common, in which the cancer tissue infiltrates locally and spreads to adjacent organs and tissues. It often involves the vaginal wall downward and rarely involves the cervical canal upward to the official cavity; the cancer foci spread to both sides and can involve the paracervical and paravaginal tissues to the pelvic wall; when the cancer foci press or invade the ureter, it can cause ureteral obstruction and hydronephrosis. In late stage, it may spread to the bladder or rectum, forming vesicovaginal fistula or rectovaginal fistula. (2) Lymphatic metastasis: local infiltration of cancer foci invades lymphatic vessels and forms tumor emboli, which enter local lymph nodes with lymphatic drainage and spread within lymphatic vessels. The primary group of lymphatic metastasis includes parametrium, paracervical, foramen ovale, internal iliac, external iliac, common iliac and presacral lymph nodes; the secondary group includes deep and superficial inguinal lymph nodes and para-aortic lymph nodes. (3) Hematogenous metastasis is less common, but in advanced stage, it may metastasize to lung, liver or bone.