Gynecological Cancers

Cervix cancer is the fourth most commonly diagnosed cancer and the fourth leading cancer-related death in women worldwide. It is the most common cancer in developing and underdeveloped countries. Over 90% of cervix cancer is human papillomavirus (HPV) infection related, and HPV is detectable in >99% of cervix cancer, whereas >70% are caused by HPV-16 and HPV-18. Cervix cancer is categorized into three histological subtypes of squamous cell cancer, adenocarcinoma, and others. 70–80% of all cervix cancer cases are SCC, and the most common origin point is the transformation zone. Endometrial cancer is the most commonly diagnosed cancer in European countries and the USA. It represents 3.5% of all cancers and 2% of cancer-related deaths in the USA. It has shown a prominent increase in developed countries. Although its incidence is high, it is only the seventh most common cause of cancer-related mortality due to early diagnosis and treatment. Endometrial cancer is separated into two forms: estrogen-related endometrioid type I constitutes 70–80% of cases, whereas non-estrogen-related nonendometrioid type II with high grade, serous, or clear cell characteristics has an aggressive clinical course. Endometrial cancer risk factors include advancing age, endogenous estrogen, exogenous unopposed estrogen, family history, and tamoxifen. Patients with uterus-confined disease have a 5-year relative survival rate of 94.9%, and patients with regional involvement have 68.6% 5-year relative survival rate. Vaginal cancer is a rare cancer comprising 1–2% of all gynecological cancers. They are classified into primary and secondary vaginal cancers, and 70% of the primary vaginal cancers originating from vagina are detected in women over 60 years of age while secondary vaginal cancers originate from cervix and vulvar cancer metastases. Vaginal mucosa contains mucosal type stratified nonkeratinized squamous cells that are sensitive to hormones and show cyclic changes. Vulvar cancer is a rare tumor with an estimated 45,240 new cases and 17,427 deaths in 2020. The vulva consists of mons pubis, clitoris, labia majora, labia minora, vaginal vestibule, Bartholin’s glands, prepuce over clitoris, posterior fourchette, and perineal body. HPV infection, vulvar intraepithelial neoplasia (VIN), cigarette smoking, lichen sclerosus, and immunodeficiency syndromes are classically associated with the development of vulvar cancer. It has a bimodal age distribution affecting both young and elderly patients. Prognostic factors are LN metastases, tumor size, grade, tumor localization, LVSI, surgical margin, and age. The most common histological type is SCC comprising ≥80% of cases, whereas basal cell carcinoma, Merkel cell tumors, verrucous carcinoma, carcinoid, malignant melanoma, sarcoma, Paget’s disease, Bartholin’s gland adenocarcinomas, and adenoid cystic carcinomas are other histologies. Basic concepts that are crucial to understanding cervix, endometrial, vaginal, and vulvar cancer are reviewed in depth in this chapter.