Cervical Cytology

Cervical cancer: Epidemiology, aetiology, pathogenesis and main histological types

Epidemiology
Clinical presentation
Histological types of cervical cancer
Cervical cancer as a multi stage disease
Histological features of CIN and adenocarcinoma in situ
Risk factors for cervical cancer

 

Clinical presentation of invasive cervical cancer

The clinical  presentation and pattern of growth of  invasive cervical  cancer  is variable. The tumour  may be have a polypoid or papillomatous  appearance  or it may be flat or ulcerating. Initially most cancers spread locally- upward into the body of the uterus, downward into the vagina or laterally into the pelvic folds. Eventually the tumour may involve the bladder  or rectum and metastatic spread to the liver and other organs occurs. Involvement of the pelvic lymphnodes occurs early in the disease and is associated with a poor prognosis.

The cancers are  most commonly diagnosed in women aged 45-65 however they have been described in very young women and an age range of 20-85 has been recorded for these cancers. Women with invasive cervical cancer are often  asymptomatic in the early stage of the disease; they  may  present with post coital, intermenstrual, or post menopausal bleeding, back ache or haematuria when the tumour is at an advanced stage.

Radical hysterectomy surgical specimen from woman with invasive cervical cancer.The cervix is ulcerated and infiltrated by tumour .Biopsy confirmed invasive squamous carcinoma.

Staging invasive cervical cancer

  • Five clinical stages of carcinoma of the cervix have been described by the International Federation of Obstetrics and Gynaecology (FIGO). These are  shown in an abreviated form in the Table below.
  • Stage 0 and Stage 1 comprise  the preclinical stages of cervical carcinoma. It is at these stages that cervical screening and colposcopy  play an important role in diagnosis since women with Stage 0 or Stage 1 cancers are usually symptomless and the cancer is not detectable with the naked eye.
  • Stages 2,3,and 4  are usually associated with symptoms such as post menopausal bleeding and comprise the clinically invasive stage of the disease.  The FIGO staging system is used largely by clinicians for planning treatment.
  • A histological staging system, known as  the TNM system, is preferred by pathologists (see TNM classification of malignant tumour UICC sixth edition 2002).
Stage
FIGO: Description
0 Preinvasive carcinoma (CIN3 or carcinoma in situ)
I Cervical carcinoma confined to uterus (extension to corpus disregarded)
Ia Invasive carcinoma diagnosed only by microscopy
Ia1 Stromal invasion <3mm depth and <7mm horizontal spread
Ia2 Stromal invasion >3mmbut >5mm and  <7mm horizontal spread
IB Clinically visible lesion confined to cervix or microscopic lesion >1A2
IB1 Clinically visible lesion <4cm in greatest dimension
IB2 Clinically visible lesion >4cm in greatest dimension
II Tumour invades beyond uterus but not to pelvic wall or lower third of vagina
IIA Without parametrial invasion
IIB With parametrial invasion
III Tumour extends to pelvic wall and/or involves lower third of vagina and /or causes hydronephrosis or non functioning kidney
IIIA Tumour  involves lower third of vagina  but no extension to pelvic wall
IIIB Tumour extends to pelvic wall and /or causes hydronephosis or non functioning kidney
IVA Tumour invades mucosa of bladder or rectum and / or extends beyond true pelvis
IVB Distant metastasis

Treatment of an invasive cervical carinoma

  • The clinical staging of invasive cervical cancer is important as it determines  the patient’s treatment . Cancers detected at Stage 0 (the preinvasive  stage) require only local ablation of the cancerous epithelium, either by diathermy or laser.
  • Stage 1 cancers are usually treated by radical hysterectomy with or without preservation of the ovaries according to the patients age.

    However in women that have early stage cancer of the cervix, trachelectomy may be used as a fertility saving treatment. A radical trachelectomy is a surgical procedure; whereby the cervix , the upper part of the vagina, the parametrial tissue (tissue around the lower end of the uterus), and the pelvic lymph nodes are removed. The uterus (the womb) and the ovaries are not removed and so it is still possible to have children.  
    This is done in early cervical cancer; the aim being to preserve fertility. This treatment has been developed in recent years by gynaecological oncologists in specialist centres around the world. It is done vaginally and through small incisions in the abdomen using a laparoscope, (key hole surgery).
  • The standard treatments for advanced cervical cancer are radical hysterectomy and/or pelvic radiotherapy.

    More advanced cancers may require  radiotherapy and /or chemotherapy.  The clinical stage at time of diagnosis also affects the prognosis (chances of survival) for  the patient.

  • The outlook is very good for women with cancer diagnosed in its early stages (Stage 0 or Stage 1) but  is  poor for women diagnosed with advanced cancer. The prognosis for patients diagnosed at Stage 0 ie the preinvasive stage  is excellent with only a very small risk (<less than 1%) of recurrence.
  • There is some evidence that cervical cancers in younger women may be more aggressive that those that are diagnosed in women over the age of 40.

 

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