Squamous cell carcinoma of the uterine cervix is a malignant neoplasia formed from the cells of the squamous epithelium, acquiring various degrees of atypia. Disease may have a “mute” course. In clinically pronounced cases, it is manifested by bloody discharge, whites of various kinds, with a neglected oncoprocess – pain in the pelvic region, impaired bladder and rectum function. Pathology is diagnosed according to vaginal examination, PAP test, colposcopy, biopsy, determination of the level of the cancer marker SCC in the blood. Methods of treatment of squamous cell carcinoma – surgical interventions (cervical conization, trachelectomy, hysterectomy), chemoradiotherapy.
General information
Squamous cell carcinoma of the uterine cervix is a histological type of cervical cancer originating from the multilayer flat epithelium lining the vaginal part of the cervix. In the structure of invasive cervical cancer (CC), this histological type is diagnosed in 70-80% of cases, cervical adenocarcinoma occurs in 10-20%, low-grade cancer occurs in 10%, other malignant tumors of the cervix are less than 1%. The maximum incidence falls on women aged 40-60 years. A long period of “silent” course leads to the fact that over 35% of cases of squamous cell carcinoma of the uterine cervix are diagnosed already at an advanced stage, which has a negative impact on the prognosis and outcome of the disease. The development of a prevention strategy and the mass screening of the female population for cervical cancer are priority tasks of practical gynecology and oncology.
Causes
Unambiguous causes of squamous cell carcinoma of the uterine cervix have not been determined, however, at the present stage, the factors that trigger the process of malignancy of the multilayer squamous epithelium have been well studied. First of all, human papillomavirus (HPV) belongs to such factors, mainly types 16 and 18, less often types 31 and 33. In most cases, HPV-16 is identified in squamous cell carcinoma of the uterine cervix. Among other sexually transmitted viral agents, the role of oncogenes can be played by herpes simplex virus type II, cytomegalovirus, etc. Background processes in which squamous cell carcinoma of the uterine cervix may develop in the future are erosion, ectropion, cervical canal polyp, leukoplakia, cervicitis, etc.
In addition, other factors contribute to cellular degeneration: hormonal disorders, smoking, taking immunosuppressants (glucocorticosteroids, cytostatics), immunodeficiency. A certain negative role is played by traumatization of the cervix during multiple births, the installation of an IUD, surgical interventions: abortions, diagnostic curettage, diathermocoagulation and diathermoconization, etc. The risk group for the occurrence of squamous cell carcinoma of the uterine cervix includes women who have started their sexual life early, often change sexual partners, neglect barrier contraception methods, and have suffered STDs.
Classification
Within the histological type under consideration, squamous cell with keratinization and squamous cell without keratinization are distinguished. Microscopically, squamous keratinizing cervical cancer is characterized by the presence of signs of keratinization of cells – “cancer pearls” and keratogyalin granules. Epithelial cells are abnormally large, pleomorphic, with uneven contours. Mitotic figures are sparsely represented. There are no keratin “pearls” in the preparations of non-cancerous squamous cell carcinoma of the uterine cervix. Cancer cells are predominantly large, polygonal or oval in shape. Their high mitotic activity is noted. The degree of differentiation of the cervical cancer can be high, moderate or low.
Taking into account the direction of tumor growth, exophytic, endophytic and mixed forms of squamous cell carcinoma of the uterine cervix are distinguished. The ulcerative-infiltrative form is characteristic of the advanced stages of cervical cancer; it is usually formed during the decay and necrosis of an endophytically growing tumor.
In its development, CC goes through four clinical stages. There is also a zero or initial stage (intraepithelial cancer), in which only the cells of the integumentary epithelium are affected without invasion into the basal plate. The first stage is divided into two periods: microinvasive cancer with a depth of penetration into the stroma up to 3 mm (stage 1A) and invasive cancer with an invasion of more than 3 mm (stage 1B). A sign of the second stage is the spread of the tumor process to the body of the uterus. The third stage of cervical cancer is characterized by the germination of the tumor into the pelvis; with compression or obstruction of the ureter, hydronephrosis develops. During the fourth stage, there is an invasion into the rectum and sacrum, the collapse of the tumor, the appearance of distant metastases.
Symptoms
In the zero and 1A stages, clinical manifestations of cervical cancer are usually absent. During this period, the diagnosis of squamous cell carcinoma of the uterine cervix is possible during a routine examination by a gynecologist. In the future, as the invasion deepens and the expansive growth of the tumor, a characteristic pathological triad appears: white blood, bleeding and pain syndrome. Discharge from the genital tract can have a different character: be serous transparent or with an admixture of blood (in the form of “meat slops”). In case of infection or disintegration of the tumor node, the whites may acquire a cloudy, pus-like character and a fetid smell.
Bleeding from the genital tract in squamous cell carcinoma of the uterine cervix varies in intensity – from spotting to acyclic or menopausal bleeding. More often, bleeding has a contact origin and is provoked by gynecological examination, sexual intercourse, douching, straining during defecation.
Pain syndrome in squamous cell carcinoma of the uterine cervix can also have different severity and localization (in the lumbar region, sacrum, perineum). As a rule, it indicates the neglect of the oncoprocess, the germination of parametral fiber and the lesion of the lumbar, sacral or coccygeal nerve plexuses. When cancer germinates into neighboring organs, dysuric disorders, constipation, and the formation of genitourinary fistulas may occur. In the terminal stage, cancer intoxication and cachexia develop.
Diagnosis
Clinically, “mute” forms of squamous cell carcinoma of the uterine cervix can be detected during colposcopy or by the results of a cytological PAP smear. An important role in the diagnosis is played by a carefully collected gynecological history (the number of sexual partners, childbirth, abortions, STDs), as well as the detection of highly oncogenic HPV strains in the studied scraping by PCR.
When examined in mirrors, squamous cell carcinoma of the uterine cervix is determined in the form of papillomatous or polypoid overgrowth or ulcerative formation. Edophytic tumors deform the cervix, giving it a barrel shape. Upon contact, the neoplasm bleeds. To determine the stage of cancer and exclude metastases to the pelvic organs, a two-handed vaginal and vaginal-rectal examination is performed. In all cases of detection of a pathologically altered cervix, extended colposcopy, smear sampling for oncocytology, targeted biopsy and curettage of the cervical canal are mandatory. For morphological confirmation of the diagnosis, the biopsy and scraping are sent for histological examination.
The determination of the level of SCC (a marker of squamous cell carcinoma) in the blood serum has a certain informative value. Transvaginal ultrasound, CT or MRI of the pelvis, excretory urography, lung radiography, cystoscopy, and rectoromanoscopy serve as methods of clarifying diagnosis of squamous cell carcinoma of the uterine cervix, designed to assess the prevalence of neoplasia and help in choosing the optimal method of treatment for the patient.
Treatment
For squamous cell carcinoma of the uterine cervix, surgical, radiation, chemotherapeutic and combined treatment can be used. The choice of a particular method or their combinations is determined by the prevalence and morphological type of the tumor, as well as the age and reproductive plans of the patient.
At stages 0 – IA, conization or amputation of the cervix is performed in patients of childbearing age. At stages IB-II, the optimal volume of intervention is hysterectomy with the upper third of the vagina, sometimes neoadjuvant chemotherapy is required; in postmenopause, pangisterectomy is indicated – removal of the uterus with adnexectomy. In stages III–IV of squamous cell carcinoma of the uterine cervix, chemoradiotherapy (radiation treatment + cisplatin) is the standard, however, some authors admit the potential for surgical treatment. If the urinary tract is affected, ureteral stenting may be required.
In functionally inoperable cases caused by concomitant diseases, intracavitary radiation therapy is prescribed. In case of recurrent cervical cancer, pelvic exenteration, palliative chemoradiotherapy and symptomatic therapy are indicated.
Prognosis and prevention
At the end of treatment, dynamic monitoring of the patient is carried out quarterly for the first 2 years, and then every six months until the 5-year period. If squamous cell carcinoma of the uterine cervix is detected at the zero stage, then timely treatment gives a chance of almost 100% recovery. The percentage of relapse-free five–year survival in stage I cervical cancer is 85%, stage II – 75%, III – less than 40%. At the IV stage of the disease, we can only talk about prolonging life, but not healing. Cervical stump cancer develops in less than 5% of patients.
Prevention of squamous cell carcinoma of the uterine cervix consists in conducting mass and regular cytological screening of the female population, medical examination of women with background and precancerous diseases of the cervix. Smoking cessation, STD prevention and preventive vaccination against cervical cancer in adolescence play an important preventive role.