Primary/Secondary Cervical Cancer prevention Flashcards Preview

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Flashcards in Primary/Secondary Cervical Cancer prevention Deck (25)
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1
Q

General trend in HPV screening recommendations

A
  • initial screening at progressively later ages
  • introduce new technologies (test for high risk HPV types)
  • progressive lengthening of recommended baseline screening intervals
2
Q

2013 ACS recommendations for cervical cancer screening

A
  • Screen starting at age 21
  • Cytology every 3 years between ages of 21 and 29
  • Cytology with HPV co-test every 5 years between 30-65
  • stop cervical cytology at 65 if adequately screened and not had CIN 2 or CIN 3 lesions for previous 20 years
3
Q

Cytology screening

A
  • 2 main categories: slide-based and liquid-based

Slide-based: fix sample of cervical cells on slide and send to lab

liquid-based: immerse collection in small vial and send to lab

histology= gold standard against which cytology is measured. Sensitivity/specificity of liquid-based higher than slide-based

4
Q

Where do you collect your cervical cell sample

A

Need to include cells from both sides of squamo-columnar junction-

  • premalignant squamous lesions of cervix almost always originate at this junction, so sample must include both squamous and columnar cells to be interpreted
5
Q

normal apperance of cells on pap

A
  • stratified sq epithelium 8-12 cell layers thick
  • Superficial squamous cells have abundant cytoplasm with dark pyknotic nucleus
  • Endo-cervical– may appear in “honeycomb” array, with distinct cell membranes due to cytplasmic mucin
6
Q

HPV co-testing

A

use in women > 30 to assess for high risk HPV strains

7
Q

Main categories of cervical dysplasia

A

Patten (Histology: Mild dysplasia, moderate dysplasia, severe dysplasia, Carcinoma in situ

Richart (histology): CIN (grade I), CIN II, CIN III, CIN IV

Bethesda (cytology)

  • AGUS
  • ASC-US
  • ASC-H
  • LSIL (associated with CIN I)
  • HSIL (associated with CIN II-IV)
8
Q

ASC-US

A

Atypical squamous cells of undetermined dignificance

  • alterations in squamous cells to warrant close clinical attention but not abnormal enough to be LSIL or HSIL
9
Q

LSIL

A

cells with unequivocal evidence of HPV infection (perinuclear cytoplasmic clearing)–attributed to aggregation of virally derived proteins around nucleus
- may have markedly enlarged hyper-chromatic nuclei with an abnormal chromatin distribution, irregular nuclear contour, abundant cytoplasm

10
Q

HSIL

A

changes thought to represent presence of significant premalignant lesion. Higher nuclear to cytoplasmic ratio than LSIL

CINII– moderate dysplasia
CIN III- severe dysplasia and carcinoma in situ

11
Q

What is the chance of progression of SIL

A

about 25% of all grades of SIL progress to higher grade lesions; of these, about 10% progress to carcinoma in situ and 1% to invasive cancer

12
Q

Histology of cervix

A
  • basal cells cuboidal and they become progressively flattened as they reach surface with small nucleus. Superficial cells are collected during Pap
  • with CIN I-III, you lose that progression so that the cells look the same from bottom to top (high nuclear to cytoplasmic ratio)
13
Q

HPV association with cervical cancer

A
  • considered necessary but not sufficient precursor to msot cervical dysplasia/carcinoma
  • associated with most cases of invasive squamous cell carcinoma, LSIL, HSIL, endo-cervical adenocarcinoma
  • most common STD in America, with lifetime risk about 80% for sexually active individuals
  • about half of new infections in 15-24 year olds
  • In general population, prevalence is 15%
  • infection cleared most of the time in 1-3 years. Those present >1 year associated with increased risk of progression to cervical dysplasia
14
Q

HPV types

A
  • lots of types but GENERALLY

Low risk: 6, 11 (31, 33, 45)- responsible for about 90T of genital warts
High risk: 16, 18–responsible for about 70% cervical cancers

  • can use a HPV test screen for 13 of most common high risk types but can’t tell you specific strain
  • another test only for 16/18 (Cervista assay)
15
Q

Management of abnormal screening

A
  • depends on pt age, degree of abnormality on current screen, recent screening/treatemnt hx, and pregnancy status

RISK OF CIN III in next 5 yrs:
- 5%: refer for colposcopy

16
Q

Management of abnormal biopsy

A
  • depends on age, current screen, recent screening/treatment hx, pregnancy status
  • if therapy indicated treat entire transition zone: cryotherapy, laser ablation, excision
  • success rates as high as 95%
17
Q

Gardasil

A
  • HPV vaccine approved in 2006
  • quadrivalent: 6, 11, 16, 18 virus-like particle (subunit)
  • series of 3 doses at 0, 2, 6 months for women between 9 and 26
  • efficacy of 98.8% in trails of reduction of genital warts, CIN2, CIN3 and adenocarcinoma in situ among women naiive to 4 subtypes
18
Q

Cervarix

A
  • bivalent vaccine covers HPV 16/18
  • approved 2009
  • 3 doses (0, 2, 6 months)
19
Q

efficacy of HPV vaccine

A
  • quadrivalent better for disease related to HPV 6/11 but bivalent appears more effective preventing disease attributable to viral types not covered by vaccine (i.e. HPV 31 and 45)
  • goal to give all 3 doses prior to sexual activity
20
Q

Gardasil -9

A

9-valent vaccine recently approved adds protection against 31, 33, 45, 52, 48, hoping to prevent 90% of cervical cancer.

21
Q

Acceptance of vaccine

A
  • relatively good receptance among physicians
  • variable rates of parental acceptance; less likely in eclectic subgroups
  • CDC study: about 25% didn’t intend to vaccinate daughters in next 12 months
  • top 5 reasons parents wouldnt vaccinate in next 12 months– not needed, vaccine not recommended, vaccine safety concerns, lack of knowledge about vaccine/disease, daughter not sexually active
  • lower rates in boys
  • generally well accepted in young adults (college ages)–higher when cover HPV 6/11
22
Q

Predicted economic impact of vaccine

A

first positive peak for genital warts and second for CIN, third/final peak for cervical cancer reduction about 30 years into vaccination program

23
Q

HPV vaccine impact on men

A
  • helps reduce genital warts, anal/penile/OP cancers
  • about 25% squamous cell OP cancers assciated with HPV
  • possible risk reduction for penile/anile cancers
  • herd immunity– will decrease female disease
  • immunologic responses similar to women
  • CIP recommend vaccination for boys 9026 with quadrivalent vaccine
24
Q

Vaccine in developing world

A
  • burden of HPV_related dz larger than in developed world
  • cervical cancer single largest cause of years of life lost from cancer in developing world
  • Cost! very expensive- look at ways to reduce
  • hard to administer especially 3 separate times, esp with variable school attendance
  • prevalence rates for various types different, so various impact
  • governments likely to prioritize vaccinations for food, water, and airborne illnesses instead of cervical cancer
25
Q

HPV vaccination in HIV infected individuals

A
  • benefit being researched
  • potential difference in vaccination strategies with those born with HIV vs getting later in life.
  • Issues: point in HIV infection when vaccinated, preexisting exposure to HPV, viral load, CD4 count, potential role of highly active antiretroviral therapy
  • study in south africa showed promising results, equivalent immune responses regardless of HIV status, CD4 count viral load, and use of anti-retroviral therapy with no big impact on HIV dz measured by viral load or CD4 count