Cervical Cancer
- 2nd most common cancer in women after breast
- Mostly effects women over 35
- Risk factors – early onset of sexual intercourse, multiple sexual partners, smoking, multigravide
- Associated with HPV, particularly 16 and 18. E6 and E7 genes encode proteins which interact with p53 and Rb respectively
- Listed as an AIDS defining illness
- Progression from a premalignant (CIN) to malignant phase well recognised
- CIN develops on the transformation zone of the cervix
- Term dyskaryosis is used for cellular abnormality seen on cervical smear
- Smears are done every 3 years from the age of 25 until the age of 50. After 50 they are done every 5 years until the age of 65
- Smear test has a false negative rate of 20% and a false positive rate of 10%
- CIN1 – deeper 1/3 of cervical epithelium shows abnormal cytopasmic and numclear maturation
- CIN2 – Up to 2/3 of epithelium show abnormalities
- CIN3 – More that 2/3 is abnormal
- 35% of CIN3 lesions will progress to invasive carcinoma by 10 years
Clinical Presentation
- Common presenting symptom is abnormal vaginal bleeding or discharge
- Bleeding maybe intermenstrual or postcoital in premenopausal women and postmenopausal in older women
- Pain is uncommon
- Presentation of advance disease may be via renal failure following bilateral ureteric obstruction
- Cervix may be hard or ulcerated on examination
Colposcopy
- Refer for colposcopy if patient has had
- 3 borderline smears over the last 6 months
- 2 mild smear over the last 6 months
- 1 mild/moderate graded smear
- 3 borderline smears over the last 6 months
- Require to see squamocolumnar junction – look for grosse abnormalities
- Clean with normal saline
- Look with green light for blood vessels associated with malignancy
- Add diluted acetic acid, columnar cells become white. Look for whiteness in squamous cells. Look for any acid white area, how quickly it develops and how long it stays white are indicators of severity
Pathology
- 90% squamous cell carcinomas – may be large cell keratinizing, large cell non-keratinizing or small cell non-keratinizing
- 10% adenocarcinoma – not easily picked up by smear
- Rarely small cell (neuroendocrine type), similar to that of the bronchus, poor prognosis
Staging
- FIGO staging (international federation of gynaecology and obstetrics)
- Stage 1a Microinvasion – less than 5mm deep and 7mm wide
- Stage 1b Cervix only
- Stage 2 Upper 2/3 of vagina involved and parametrium but not to the side wall
- Stage 3 Spread to pelvic side wall
- Stage 4 Spread to bladder, rectum or outside pelvis
Surgery
- Treatment of choice is large loop excision of the transformation zone using an electric current – 7mm is required to be removed
- Early stage 1 disease may be treated with radical hysterectomy, preserving the ovaries and leaving the vagina supple.
- In patients wishing to retain their fertility a cone biopsy maybe preferable. This is rarely done today. Cone biopsy goes further into the cervix and can result in cervical incompentence
Radiotherapy
- Advanced disease may be treated with radiotherapy
- Radiotherapy is delivered via and intracavity dose in conjugation with external beam radiotherapy
Chemotherapy
- In late stage disease chemotherapy can be employed
- Current regimes include cisplatin alone or in combination with ifosfamide, mitomycin or bleomycin
- Response rates of 15-30% although usually only for a short duration
Prognosis
- Stage 1 carries an 80-90% 5 year survival
- Stage 3 has a 5 year survival of 30%
- Overall 5 year survival rate is 60%
- Recurrence is difficult to treat unless it follows surgery alone, if not it is often radiotherapy resistant