Cervical Cancer :- Causes, Risk Factors, Signs & Symptoms, Diagnosis & Screening And Treatment

cervical cancer also known as cervical carcinoma is the third most common malignancy in women and it is a leading cause of death for women in developing countries in developed countries however cervical cancer is relatively uncommon due to the availability of screening programs cervical cancer is caused by persistent high-risk human papilloma virus infection which is a double-stranded dna virus of which there are more than 100 different types approximately 70 percent of the cervical cancers are squamous cell carcinomas while most of the remainder is adenocarcinoma the virus is transmitted via sexual intercourse and therefore it is more prevalent among the women of reproductive age before we begin our discussion on cervical cancer itself let's quickly recall some anatomy knowledge on the female reproductive system it consists of five major parts vagina which allows deposition of sperm during sexual intercourse cervix which continues proximally with the uterus the muscular organ that implants the fetus fallopian tubes which transports the sperms towards the ovaries and the ovaries which produce egg cells that contain the maternal half of the fetus out of these cervix is the part that connects the vagina and uterus in order to transport sperm cells anatomically and histologically the cervix is distinct from the uterus therefore it is considered as a separate anatomical structure the cervix is composed of two regions the ectocervix and the endocervical canal the ectocervix is the portion of the cervix that projects into the vagina it is lined by stratified squamous non-keratinized epithelium the opening in the ectocervix the external loss marks the transition from the ectocervix to the endocervical canal the endocervical canal or endocervix is the more proximal and inner part of the cervix it is lined by a mucus secreting simple columnar epithelium the endocervical canal ends and the uterine cavity begins at a narrowing called the internal loss when we examine through the vagina the ectocervix and endocervix look like this the cervix is approximately 2.5 centimeters in length the upper part of the cervix mostly consists of involuntary muscle whereas the lower part is mainly fibrous connective tissue the epithelium of the endocervix is columnar and is also ciliated in its upper two-thirds this changes to stratified squamous epithelium around the region of the external loss as you can see in this picture and the junction of these two types of epithelium is called the squamo columnar junction position of the squamo columnar junction varies throughout life the area between the original squamo columnar junction and the current squamo columnar junction is called the transformational zone and this is the site where cervical cancer develops as already mentioned cervical cancer is caused by human papilloma virus infection more than 100 different types of this virus have been identified these are classified as low-risk and high-risk types depending on their ability to cause cancer low-risk types hpv-6 and 11 cause benign warts whereas high-risk types hpv 16 18 31 33 and 45 cause cervical cancer in most individuals the infection is transient and no clinical consequences occur however in a minority of individuals the infection is persistent and there is a higher risk for cervical cancer risk factors for persistent infection include smoking immunosuppressive therapy and conditions that cause impaired immunity such as hiv infection when hpv infection persists in certain individuals it triggers an oncogenic process in the region of the transformational zone integration of viral dna into basal epithelial cells leads to immortalization and rapid cell proliferation this process is called cervical intraepithelial neoplasia and it is important to note that this is only the metaplastic state and not the cancerous state it may or may not progress into cancer in this image the leftmost side diagram shows a normal cervical epithelium three diagrams in the middle show different stages of sin in all of these stages the basement membrane is intact therefore sin is considered as a pre-cancerous state rather than a cancer the diagram in the right most side shows cervical cancer where the basement membrane is breached stage 1 sin indicates low-grade disease whereas stage 2 and 3 syn indicates high grade disease if the basement membrane is breached it is considered as cervical cancer signs and symptoms of cervical cancer may vary depending on the extent of invasion small volume microscopic lesions are often asymptomatic and detected incidentally most cervical cancers are friable vascular masses on the cervix and patients usually present with abnormal bleeding typically post-coital bleeding prolonged intermenstral bleeding and post-menopausal bleeding any woman with these symptoms should therefore undergo a pelvic examination in more advanced cases patient may also have the following symptoms abdominal pain urinary incontinence anemia and renal failure now let's discuss about the diagnosis of cervical cancer complete evaluation starts with pap testing positive results in pap tests should prompt colposcopy and biopsies including excisional procedures pap testing was originally introduced by papanicolae in this test a small brush is used to sample cells from the transformational zone and looked under the microscope after several preparations for more than 95 percent of women cervical cytology is normal testing for high-risk hpv increases the sensitivity of cervical screening therefore nowadays many countries screen for high-risk hpv first followed by cervical cytology colposcopy is the examination of the magnified cervix using a light source it is used for both diagnosis and treatment application of acetic acid and iodine solutions highlights abnormal areas as you can see in this picture because acetic acids gives a white color to the areas where there is higher rate of cell proliferation imaging tests can be used to assess the distance spread of the cancer mri of the abdomen can be taken to look for local spread and lymphadenopathy chest x-rays are taken to assess lung metastasis finally let's come to the treatment low-grade sin regresses spontaneously in up to 60 percent of cases therefore close follow-up with colposcopy and cytology is recommended for sin one by contrast high-grade sin requires treatment with excision or ablation this image shows a large loop excision of the transformational zone for cervical cancer surgery and radiotherapy are recommended depending on the stage of the cancer you