Cervical Cancer Flashcards
Cervical cancer
2nd most deadly cancer among women
10th most common cancer in women in SG
Prognosis: 5 yr survival
Incidence declined in developed countries —> public education, screening, treatment
Human Papilllomavirus (HPV)
Causative agent in more than 90% of cancers
Most common STI
Infected genital skin or mucosa
Most asymptomatic
HPV types
Mucosal (infect cells of surface layers that line organs and cavities, 25%)
- High risk —> types 16, 18, 31, 33, 45, 58 e.g. —> high grade pre-cancers in mucosal cells ; anogenital cancers
- Low risk —> types 6 and 11 —> genital warts (rarely become cancer)
Major capsid protein (L1)
protect viral DNA from degradation
Enable virus to bind to target cells
Basal layer cells exposed to HPV via micro abrasions (during sexual intercourse) ; heparin sulfate receptors
Viral DNA
Proteins E6 and E7 inhibit tumour suppressor genes p53 and pRB
Transformation zone (T-zone)
Area of changing cells (columnar to squamous)
Abnormal cells develop
In older women, T zone may be higher up
Around menopause, cervix shrinks due to reduced influence of estrogen and age ; T zone retreats further into canal
Risk factors
HPV infection
Early age of sexual activity
Multiple sexual partners
History of STIs
Male sexual partner with history of STIs or extramarital sexual activity
Male sexual partner with parter with prev cervical cancer
HPV type
HIV infection
Co infection with other STIs
High parity — multiple pregnancies
Young age at first birth
Cigarette smoking
Oral contraceptives > 5 yrs
Low risk grps
Never had sexual intercourse
Hysterectomy where cervix was removed — unless performed due to cervical CA
Signs and symptoms
Abnormal bleeding from vagina
Unusual discharge from vagina
Pain during sexual intercourse
Lower abdominal pain
Early cervical CA usually asymptomatic
Prevention and control
HPV vaccines —> recommended for all of reproductive age, best when vaccinated before becoming sexually active ; Cervarix: protect against type 16 and 18 ; Gardasil 9: protect against 90% of cancers ; does not substitute routine screening, not protect against all types
Education —> raise awareness (delay sexual initiation, reduction of high risk behaviours, negotiation skills) , STI prevention, smoking cessation
Abstinence
Being faithful
Correct and consistent use of Condoms
Detection (early)
Screening —> detect pre-cancer lesions ; progression from pre-cancer to cancer takes 10-15 yrs
Pap smear
Cells from cervix surface scraped and examined under microscope to detect abnormal cells and lesions
Recommended for 25-29 yrs who have never had sexual intercourse
Frequency: every 3 yrs who have
Reasons for not going: lack understanding, don’t think at risk, not necessary, too young, never heard before
HPV DNA testing
Detect presence of HPV
PCR
For 30yrs or older — in < 30 yrs, transient HPV and unnecessary colposcopy
Freq: every 5 yrs
More sensitive and cost effective
Visual inspection with acetic acid. (VIA)
Dilute soln of acetic acid applied on cervix surface —> abnormalities white in colour
Only 1 visit needed
Low sensitivity and specificity
Risks of screening
Stigma from diagnosis of STI
Worry and discomfort from additional treatment
Bleeding
Increased risk of pregnancy complications
Cervical CA treatment
Surgery
- Cryotherapy: destroy abnormal changes by freezing with very cold instrument
- Loop electrosurgical excision procedure (LEEP): hot wire
- Conization: scalpel
Radiotherapy
Chemotherapy
Palliative care
Comfort care
Provide relief from pain and suffering
Ageing popn, rise of NCD burden
Caregiver training
Financial counselling
Guidance for family complex decision making
Grief support
Multidisciplinary team: physician, nurse, allied health, spiritual supporter, care coordinator
HPV vaccination in national school based health prgms
Opted out —> daughters alr vaccinated ; prefer to bring them to vaccinate on own ; concerned about side effects
Concerns that by sending them to vaccinated, may give impression that they are given green light to engage in intercourse earlier
