Understand the Cervical Cancer

The part of the cervix closest to the body is called the endocervix; it is mostly covered with glandular cells. The part next to the vagina is called the exocervix and is mostly covered with squamous cells. The part of the cervix where these 2 cell types meet, called the transformation zone, is where most cervical cancers start.

 

Typically, normal cervical cells gradually develop pre-cancerous changes that might turn into cancer.

 

The pre-cancerous changes may include:

 

  • Cervical intraepithelial neoplasia (CIN)
  • Squamous intraepithelial lesion (SIL)
  • Dysplasia

 

Preinvasive cancer (CIN III) is a common diagnosis in women 25–40 years of age and is etiologically related to persistent infection with human papillomavirus (HPV). Human papillomavirus is a necessary precursor to cervical cancer. Approximately 100 types of HPV have been identified to date, and of these, approximately 15 virus types are known to cause cervical cancer. Only certain subtypes of these viruses (eg HPV16/18) are responsible for approximately 70% of cervical cancers globally.

 

There are two main types of cervical cancers: squamous cell carcinoma and adenocarcinoma.

 

  • About 80% to 90% of cervical cancers are squamous cell carcinomas, which are composed of cells that resemble the flat, thin cells, covering the surface of the endocervix.
  • The remaining 10% to 20% of cervical cancers are adenocarcinomas. Cervical adenocarcinoma develops from the mucus-producing gland cells of the endocervix.
  • Less common are cervical cancers that have features of both squamous cell carcinomas and adenocarcinomas. These are called adenosquamous carcinomas or mixed carcinomas.

 

The most common signs of cervical cancer are metrorrhagia, postcoital spotting, and cervical ulceration. Bloody or purulent, odorous, nonpruritic discharge may appear after invasion. Bladder and rectal dysfunction or fistulas and pain are late symptoms.

 

Studies have found a number of factors that may increase the risk of cervical cancer; these factors may act together to further increase the risk.

 

The risk factors include:


  • HPV infection, which is the main risk factor for cervical cancer. Women who have had many sexual partners or who have had sexual intercourse with a man who has had many sexual partners have a greater risk of HPV infection.

  • Age: Most cases of cervical cancer occur in women between the ages of 20 and 50.
 
  • Family History: Women with sisters or mothers who have had cervical cancer are 2 to 3 more times more likely to develop the disease than those without relatives who have had cervical cancer.
 
  • Smoking cigarettes: Women with an HPV infection who smoke cigarettes are about twice as likely to get cervical cancer than women who do not smoke.
 
  • Having children at a young age: Women who had their first full-term pregnancy before the age of 17 are twice as likely to get cervical cancer later in life than are women who were 25 or older when they had their first full-term pregnancy.
 
  • Chlamydia: Some studies indicate a higher incidence of cervical cancer among women who have had chlamydia.
 

STAGING OF CERVICAL CANCER

 

Stage

Definition

Preinvasive Carcinoma

Stage 0

Carcinoma in situ

Invasive carcinoma

Stage 1

Carcinoma strictly confined to the cervix

  IA

Invasive cancer diagnosed only by microscopy

  • IA1 Measured invasion of stroma no greater than 3 mm in depth and no wider than 7 mm
  • IA2 Measured invasion of stroma greater than 3 mm in depth and no greater than 5 mm in depth and no wider than 7 mm

   IB

Clinical lesions confined to the cervix or preclinical lesions greater than 1A

  • IB1 Clinical lesions no greater than 4 cm
  • IB2 Clinical lesions greater than 4 cm

Stage II

Carcinoma extends beyond the cervix but has not extended to the pelvic wall.  The carcinoma involves the vagina but not as far as the lower third.

   IIA

No obvious parametrial involvement

   IIB

Obvious parametrial involvement

Stage III

Carcinoma has extended either to the lower third of the vagina or to the pelvic sidewall.  All cases of hydronephrosis.

   IIIA

Involvement of lower third of vagina.  No extension to pelvic sidewall.

   IIIB

Extension onto the pelvic wall and/or hydronephrosis or nonfunctioning kidney

Stage IV

Carcinoma extended beyond the true pelvis or clinically involving the mucosa of the bladder or rectum

   IVA

Spread of growth to adjacent organs

   IVB

Spread of growth to distant organs