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.
Etiology
The etiology may be related to the following factors.
1.Viral infection
High-risk HPV infection is the main risk factor for cervical cancer. 90% or more 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 pathogenesis 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
Early stage 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 due to normal appearance of the cervix. With the development of lesions, the following manifestations may appear.
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, thin like water or rice slop, or smells fishy. 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 presses or involves ureter, it may cause ureteral obstruction, hydronephrosis and uremia; in the late stage, there may be anemia, cachexia and other symptoms of systemic failure.
2.Signs
Carcinoma in situ and
Microinfiltrating carcinoma may have no obvious foci, and the cervical area may be smooth or only columnar epithelial ectopic. Different signs may appear with the development of the disease. Ectogenic 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 is characterized by hypertrophy, hardness and dilatation of the cervical canal; in the advanced stage, the cancer tissue is necrotic and falls off, forming ulcers or cavities with bad odor. When the vaginal wall is involved, superfluous growths can be seen on the vaginal wall or the vaginal wall becomes hard.
In case of parametrial tissue involvement, thickened, nodular, hard or frozen pelvic tissue can be found on double or triple examination.
3.Pathological types
Squamous carcinoma, adenocarcinoma and adenosquamous carcinoma are three common types.
(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 route
Direct spread and lymphatic metastasis are the main routes of 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 compress 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.
Examination
1.Cervical smear cytology examination
It is the main method of cervical cancer screening and should be taken in the transformation zone of the cervix.
2.Cervical iodine test
The normal cervical vaginal squamous epithelium is rich in glycogen, which appears brown or dark brown after staining with iodine solution. The non-staining area indicates that the epithelium lacks glycogen and may have lesions. Biopsy in the iodine non-staining area can improve the diagnosis rate.
3.Colposcopy
Cervical biopsy should be performed under colposcopic observation when the cervical scraping cytology is classified as Pap grade III or above and TBS classification as squamous intraepithelial neoplasia.
4.Cervical and cervical canal biopsy
It is a reliable basis to confirm the diagnosis of cervical cancer and cervical precancerous lesions. The tissue taken should include interstitial and adjacent normal tissues. If the cervical smear is positive, but the cervix is smooth or the cervical biopsy is negative, a small scraper should be used to scratch the cervical canal and the scrapings should be sent for pathological examination.
5.Cervical conization
It is suitable for those with multiple positive cervical scrapings and negative cervical biopsies; or those with cervical intraepithelial neoplasia on cervical biopsy and need to exclude infiltrating cancer. Cold knife excision, circumferential electrosurgery or condensing electrosurgery can be used.
Diagnosis
Diagnosis can be confirmed based on history, symptoms, gynecologic examination and/or colposcopy with cervical tissue biopsy.
Prognosis
Closely related to clinical stage and type of pathology. Those with lymph node metastasis have poor prognosis. Early cervical adenocarcinoma is prone to lymphatic metastasis and has a relatively poor prognosis. In conclusion, early treatment has a better prognosis.
Prevention
Popularize the knowledge of cancer prevention, carry out sexual health education, and promote late marriage and less childbirth.
2. Pay attention to high-risk factors and high-risk groups, and seek medical treatment promptly if there are abnormal symptoms.
3. Early detection and treatment of cervical intraepithelial neoplasia and interruption of cervical invasive cancer.
4.Sound and play the role of women’s cancer prevention and health care network, carry out cervical cancer screening, achieve early detection, early diagnosis and early treatment.
Differential diagnosis
Confirmation of diagnosis is mainly based on cervical biopsy. Attention should be paid to differentiate from various cervical lesions with similar clinical symptoms or signs. These include.
1. benign cervical lesions
cervical columnar epithelial ectoplasia, cervical polyps, cervical endometriosis and cervical tuberculous ulcers.
2. Benign cervical tumors
cervical submucosal leiomyoma, cervical canal leiomyoma, cervical papilloma, etc.
3.Malignant tumors of the cervix
Primary malignant melanoma, sarcoma and lymphoma, metastatic cancer, etc.
Treatment
Appropriate individualized treatment plan is formulated according to the clinical stage, patient’s age, fertility requirements, general condition, medical technology level and equipment conditions, etc. We adopt a comprehensive treatment plan based on surgery and radiotherapy, supplemented by chemotherapy.
1.Surgical treatment
Surgery is mainly used for early stage cervical cancer patients.
Commonly used surgical procedures include: total hysterectomy; subextensive total hysterectomy and pelvic lymph node dissection; extensive total hysterectomy and pelvic lymph node dissection; abdominal para-aortic lymphadenectomy or sampling. Young patients with normal ovaries may be preserved
Retention. For young patients requiring preservation of reproductive function, conical hysterectomy or radical hysterectomy is feasible in particularly early stages. Different procedures are used depending on the stage of the patient.
2.Radiation therapy
It is suitable for: (1) middle and late stage patients; (2) early stage patients whose systemic condition is not suitable for surgery; (3) preoperative radiotherapy for large cervical lesions; (4) adjuvant treatment for high-risk factors found in pathological examination after surgical treatment.
3.Chemotherapy
It is mainly used for patients with advanced stage or recurrent metastasis. In recent years, surgery combined with preoperative neoadjuvant chemotherapy (intravenous or arterial infusion chemotherapy) is also used to shrink tumor lesions and control subclinical metastasis, as well as to sensitize radiotherapy. Commonly used chemotherapeutic drugs include cisplatin, carboplatin, paclitaxel, bleomycin, isocyclophosphamide, fluorouracil, etc.