Cervical Cancer

Cervical cancer is a cancer of the cervix, part of the female reproductive system. Your uterus ends in the cervix, which is connected to your vagina. Most commonly (up to 90 %), the cause is human papillomavirus infection (HPV), a sexually transmitted infection. In some people, when the body’s defense system does not eliminate the virus, the virus initiates a series of reactions resulting in the development of abnormal cells (cancer cells)in the cervix that can invade and spread. Cancer starts as small lesions inside the epithelium called cervical intraepithelial neoplasia that evolves very slowly into bigger lesions. It can present with abnormal vaginal bleeding, pelvic pain, pain during sex, etc. Due to the screening methods and HPV vaccination, many cases of cervical cancer can now be prevented. The precancerous lesion can be managed with cryosurgery or conization, whereas treatment for cervical cancer involves surgery, chemotherapy, or a combination of both. 

Cervical cancer is one of the most common cancers in women, and it is usually the result of an infection by the human papillomavirus or HPV. The cervix is also called the neck of the uterus, and the interior cavity of the cervix is called the cervical canal. It can be divided into two sections; the endocervix is closer to the uterus, not visible to the naked eye, lined by columnar epithelial cells that produce mucus. The ectocervix is continuous with the vagina and is lined by mature squamous epithelial cells. The junction of these two types is called the squamocolumnar junction and is the transformation zone, where sub columnar cells multiply and transform into immature squamous. HPV infection affects the division and maturation of cells in this zone and converts them into cancer cells. There are over a hundred different types of HPV, but only about 15 of them have been linked with cervical cancer, specifically HPV 16, responsible for more than half of all cervical cancers.

Following are the main types of cervical cancer:

1.       Squamous cell carcinoma: It is the most common type. Almost 90% of the cases are squamous cells. It develops in the thin, flat cells that line the outer part of the cervix, which is connected with the vagina.

2.       Adenocarcinoma: It is the less common type involving the column-shaped glandular cells lining the cervical canal.

Based on the invasion, cervical cancer is categorized into the following grades;

Grade 1: intraepithelial neoplasia, affects the lower one-third of the epithelium 

Grade 2: It affects two-thirds of the epithelium

Grade 3: It affects almost all of the epithelium 

Carcinoma in situ: It affects the entire thickness of the epithelium 

Invasive cervical cancer: the cancerous cells break through the basement membrane and into the cervical stroma then can spread to neighboring tissues like epithelial layers of the uterus and the vagina.

Having one or more of the following risk factors increase your chances of developing cervical cancer;

• Sexually active females who do not use condoms 
• Multiple sexual partners 
• Early sexual activity 
• Immunocompromised 
• Smoking 
• Family history
• Using birth control pills
• The tumor has occurred in women whose mothers have taken DES diethylstilbestrol during pregnancy.

• Cervical cancer is the third most common cancer in women globally. However, the prevalence varies between developed and developing countries, being more cases in developing countries, in which it is the second most common cause of cancer-related death among women.
• In the United States, the incidence of cervical cancer has been reduced due to the effective screening by pap smear test and HPV vaccination.

Following are some of the signs and symptoms of cervical cancer;

• The first sign is abnormal vaginal bleeding, especially after sexual intercourse 
• Other symptoms include vaginal discomfort 
• Vaginal discharge with an unpleasant odor 
• Pain while urinating or during intercourse 
• When cancer has spread beyond the pelvic wall, it can cause symptoms like pelvic pain, constipation, and bloody urine. 

Some other conditions may mimic the signs and symptoms of cervical cancer like;

• Cervical polyp
• Uterine malignancy
• Vaginal cancer
• Ectopic pregnancy 
• Cervical leiomyoma
• Pelvic inflammatory disease
• Cervicitis
• Endometrial carcinoma
• Choriocarcinoma
• Cervical TB
• Endometriosis
• Cervical papilloma
• Cervical erosion
• Complication of pregnancy
• Vaginitis

Sometimes the patients come with symptoms, while most of the time, diagnosis is usually made by Pap smear test, as symptoms appear late in the disease. Pap tests are amazingly good at detecting precancerous cells. Screening using pap tests is recommended every three years for females between 21 to 65 years of age. The screening, together with the HPV vaccine, has contributed significantly to the drop in cases of cervical cancer worldwide. During the pap test, some cells from the transformation zone are collected with a brush, and they are examined under a microscope for the presence of cancerous cells. If the pap test comes back positive for dysplasia, it may be followed by a colposcopy in which the cervix is visualized clearly, and a more focused biopsy can be taken.

Scans for staging: MRI scan and CT scan may also be advised later to determine the spread of cancer and stage.

Treatment depends upon the stage of cancer and consists of surgery, radiotherapy, or chemotherapy.

• For initial small lesions, Cryosurgery liquid nitrous oxide is used to kill abnormal cells. Cold knife conization, laser, or large loop excision of the transformation zone can also be performed. 
• In coning, a cone-shaped cancerous part of the cervix is removed. 
• For a much bigger lesion, the whole cervix is removed surgically, but the uterus remains there.
• For bigger lesions, the uterus and associated lymph nodes are surgically removed.
• For advanced cancers, radiation and chemotherapy may be done.

Prognosis depends on the stage at which the cancer is detected. Early diagnosis and prevention have a better outcome. 5-year survival rate for stage 1 cancer is 90%. While for stage 4, it is less than 30%.