Approach to Cervical cancer screening

Background of cervical cancer

Type Clinical features 
Pathogenesis of colon cancer 
  • Human papilloma virus (HPV) found in > 99% of cervical cancer 
  • HPV 16 and 18 found in > 70% of cervical cancers 
  • Persistent HPV infection 
    • Affects cervical transformation zone (area between squamous epithelium of ectocervix and glandular epithelium of endocervix)  
    • Can take up to 15 years in some cases 
    • Leads to metaplasia, dysplasia, and eventual carcinoma with invasion 
      • Squamous cell, adenocarcinoma, or others 
Risk factors 
  • HPV related 
    • History of vulvar or vaginal squamous intraepithelial neoplasia/cancer 
    • Immunosuppression 
    • Multiple sexual partners 
    • Onset sexual activity < age 21 
    • Personal history of sexually transmitted infections 
    • Sexual partner with known HPV infection 
  • Non-HPV related 
    • Cigarette smoking 
    • Low socioeconomic status 
    • Oral contraceptive use 
Types of cervical pathology 
  • NILM 
    • Negative for intraepithelial lesion or malignancy 
  • AGC 
    • Atypical glandular cells 
 
    • CIN 1 has mild dysplasia 
    • CIN 2 has moderate dysplasia 
    • CIN 3 racnges from severe dysplasia to carcinoma in-situ 
  • Atypical squamous cells of undetermined significance (ASC-US) 
    • Abnormal apearing cells without obvious squamous intraepithelial lesion 
  • Low grade squamous intrepithelial  lesions (LSIL) 
    • HPV associated lesions that could possibly regress over time 
    • Includes CIN 1 and p-16 negative CIN 2 
  • Atypical squamous cells cannot exclude HSIL (ASC-H) 
    • Cells with likely mixture of HSIL and cells mimicking HSIL 
  • High grade squamous intraepithelial lesion (HSIL) 
    • High risk HPV associated lesions that can progress to CIN or cancer 
    • Includes p-16 positive CIN 2 and CIN 3 
Classification 
  • LAST (Lower anogenital squamous terminology) 
    • Cytology & Histology 
      • LSIL, HSIL 
  • Bethesda classification system 
    • Cytology 
      • LSIL, HSIL 
    • Histology 
      • CIN 1, CIN 2, CIN 3 
 
(Next Lesson) Clinical presentation of cervical cancer
Back to Approach to Cervical cancer screening

No Comments

Comments are closed.