Persistent infection with high-risk human papillomavirus (HPV) is the necessary cause of almost all cervical cancers. HPV 16 and 18 cause about 70% of cases. Most HPV infections clear within 1–2 years; persistence allows precancerous change in the transformation zone (the squamocolumnar junction), which can progress to invasive cancer over many years — the window that screening exploits.
Cervical intraepithelial neoplasia (CIN) — dysplasia confined above the basement membrane, graded by how much of the epithelium is abnormal:
| Grade | Extent of abnormal cells | Current terminology | Usual course |
|---|
| CIN 1 | Lower one-third | LSIL (low-grade squamous intraepithelial lesion) | Usually regresses — observe |
| CIN 2 | Lower two-thirds | HSIL | Treated in most adults; may be observed in young clients who want future pregnancy |
| CIN 3 (includes carcinoma in situ) | Full thickness, basement membrane intact | HSIL | Treat — highest risk of progression |
- Koilocytes (squamous cells with a clear halo around a wrinkled nucleus) are the cytologic hallmark of HPV infection.
- Invasive cancer = abnormal cells breach the basement membrane. About 80% are squamous cell carcinoma; most of the rest are adenocarcinoma (harder to detect by cytology).
Risk factors (cofactors with HPV) — early first intercourse, multiple partners (or a partner with multiple partners), smoking, immunosuppression (HIV, transplant), long-term combined oral contraceptive use, high parity, chlamydia co-infection, lack of screening (the biggest factor in cancer deaths), in utero diethylstilbestrol exposure.
Prevention
- Primary: HPV vaccination before exposure. The 9-valent vaccine covers high-risk types 16, 18, 31, 33, 45, 52, 58 and low-risk types 6 and 11 (genital warts). It prevents infection; it does not treat existing infection or lesions.
- Secondary: screening and treatment of precancer.
CIN — no symptoms; found only by screening.
Invasive cervical cancer
- Early: postcoital (contact) bleeding, intermenstrual or postmenopausal bleeding, watery, blood-tinged, or foul-smelling vaginal discharge
- Advanced: pelvic, back, or leg pain; unilateral leg edema (lymphatic or venous obstruction); flank pain, reduced urine output (ureteral obstruction → hydronephrosis, kidney failure); hematuria or rectal bleeding; vaginal leakage of urine or stool (fistula); weight loss, fatigue
- Speculum exam: friable, ulcerated, or exophytic cervical lesion that bleeds on contact (erosion and redness alone are more typical of cervicitis)
Screening of average-risk people with a cervix
| Organization | Ages 21–24 | Ages 25–29 | Ages 30–65 | Stop |
|---|
| USPSTF (2018 final; a 2024 draft update adds self-collected HPV tests) | Cytology every 3 years from 21 | Cytology every 3 years | Primary high-risk HPV every 5 years, or co-testing every 5 years, or cytology every 3 years | After 65 with adequate prior negative screening and not otherwise high risk |
| ACS (2020, updated December 2025) | No screening | Primary HPV every 5 years from age 25 (co-testing or cytology acceptable if primary HPV unavailable) | Primary HPV every 5 years | After 65 with negative primary HPV tests or co-tests at 60 and 65 (or 3 consecutive negative cytology tests, the last at 65) |
- Self-collected vaginal HPV samples (FDA-approved options since 2024): ACS 2025 lists them as acceptable (clinician collection preferred) — a negative self-collected test is repeated in 3 years. Self-collection improves access for people who avoid pelvic exams.
- Screening does not stop after HPV vaccination; people with HIV or other immunosuppression, prior CIN 2+, or in utero DES exposure follow more intensive schedules. After total hysterectomy for benign disease with no history of CIN 2+, screening stops.
- Pap test preparation: schedule when not menstruating; avoid douching, intercourse, tampons, and vaginal medications for about 48 hours before.
Follow-up of abnormal results (ASCCP 2019 risk-based management)
- Management is based on the person's estimated risk of CIN 3+, using current result and history
- HPV 16 or 18 positive, HSIL, ASC-H, or AGC → colposcopy (magnified exam after applying acetic acid, with biopsy of abnormal areas; endocervical sampling as needed)
- Low-grade results with low risk (e.g., HPV-positive NILM or LSIL after a negative prior screen) → repeat HPV-based testing in 1 year
- CIN 1 on biopsy → observation with repeat HPV-based testing in 1 year
Staging of invasive cancer (FIGO 2018)
- Stage I: confined to the cervix — IA microscopic (invasion ≤ 5 mm); IB1 ≤ 2 cm, IB2 > 2 to ≤ 4 cm, IB3 > 4 cm
- Stage II: beyond the uterus but not to the lower third of the vagina or pelvic wall
- Stage III: lower third of vagina, pelvic wall, hydronephrosis, or pelvic/para-aortic lymph node involvement
- Stage IV: bladder or rectal mucosa, or distant metastasis
- Imaging (MRI pelvis, PET-CT), biopsy, CBC, kidney function; HIV testing is recommended for anyone with cervical cancer
CIN treatment
- CIN 1: observation (most regress)
- CIN 2 and CIN 3: excision — loop electrosurgical excision procedure (LEEP) or cold-knife conization — preferred because it provides a specimen for pathology; ablation (cryotherapy, laser, thermal ablation) only when the whole lesion and transformation zone are visible and cancer is not suspected
- Conization is also the fertility-preserving treatment for very early (IA1) cancer
- After treatment: HPV-based testing at 6 months, then continued surveillance for at least 25 years (even beyond 65)
- Sex partners do not need treatment for CIN — there is no treatment for HPV itself; condoms reduce (but do not eliminate) transmission
Invasive cancer
| Stage | Usual treatment |
|---|
| IA1 | Conization (fertility-sparing) or simple hysterectomy |
| IB1–IB2, selected IIA1 | Radical hysterectomy (uterus, parametria, upper vagina) with pelvic lymph node dissection; an open abdominal approach is preferred for radical hysterectomy because minimally invasive surgery was linked to worse survival. Radical trachelectomy (removal of cervix, uterus preserved) for selected clients wanting fertility |
| IB3 to IVA (locally advanced) | Concurrent chemoradiation — external beam radiation with weekly cisplatin (a radiosensitizer), followed by brachytherapy; immunotherapy (pembrolizumab) is added for stage III–IVA in US labeling |
| IVB / recurrent | Systemic therapy (platinum and paclitaxel, often with pembrolizumab and/or bevacizumab); palliative radiation |
Drug safety (see chemotherapy safety in cancer treatment)
- Cisplatin: nephrotoxicity (hydrate; monitor creatinine and output), ototoxicity, severe nausea, low magnesium and potassium, neuropathy, myelosuppression; hypersensitivity reactions
- Paclitaxel: hypersensitivity (premedicate), neuropathy, alopecia, neutropenia
- Bevacizumab: hypertension, proteinuria, bleeding, GI perforation and fistula, delayed wound healing
- Pembrolizumab: immune-related colitis, pneumonitis, hepatitis, thyroiditis — report new diarrhea, cough, or jaundice
- Tisotumab vedotin (recurrent disease): ocular toxicity — eye drops and eye exams per protocol
Listed in priority order.
- Bleeding — advanced tumors can hemorrhage: monitor vital signs, pad count, hemoglobin; report heavy bleeding (vaginal packing, transfusion, or emergency radiation may be needed)
- Kidney function — monitor urine output, creatinine, flank pain (ureteral obstruction; cisplatin nephrotoxicity); ensure hydration before and after cisplatin
- Infection and neutropenia during chemoradiation — follow neutropenic fever thresholds and precautions
- After radical hysterectomy
- Bladder dysfunction is the most common complication (autonomic nerve injury) — indwelling catheter or intermittent self-catheterization for days to weeks; measure post-void residuals after removal; teach timed voiding
- Watch for ureteral injury or fistula (watery vaginal discharge, flank pain, rising creatinine, clear fluid in a drain), VTE (early ambulation, prophylaxis), lymphocyst, and lower-limb lymphedema
- After LEEP or conization — monitor bleeding; expect watery brownish discharge (from the hemostatic paste) and mild cramps
- Radiation care — skin (gentle washing with lukewarm water, pat dry, no scented or alcohol-based products on the field, loose clothing), diarrhea (low-residue diet, fluids, antidiarrheals as ordered), cystitis (fluids, avoid bladder irritants); brachytherapy precautions (see gynecologic cancer treatment)
- Psychosocial and sexual health — body image, fear of recurrence, stigma related to HPV; offer counseling; discuss vaginal dilator use after pelvic radiation
- Health promotion — vaccinate eligible clients and household members, promote screening, smoking cessation
- HPV vaccine
- Routine at age 11–12 (can start at 9); catch-up through age 26; for adults 27–45, vaccination is a shared decision with the clinician
- Dose schedule (US, in force): first dose at 9–14 years → 2 doses (0 and 6–12 months); first dose at 15 or older → 3 doses (0, 1–2, and 6 months); immunocompromised, including HIV → 3 doses at any starting age
- Background: the WHO also permits a single-dose schedule, which many countries use. A January 2026 HHS change to a single US dose was stayed by a federal court in March 2026 and is under appeal — follow the current CDC schedule
- Not given during pregnancy (no pregnancy test needed; no action needed if given inadvertently); fainting can occur — observe seated for 15 minutes
- Vaccinated people still need screening
- Pap/HPV test: avoid intercourse, douching, tampons, and vaginal products for 48 hours before
- After LEEP or cone: light bleeding and dark discharge for up to a few weeks; no tampons, douching, or intercourse for about 4 weeks (or as instructed); report heavy bleeding (more than a menstrual period), large clots, fever, foul discharge, or severe pain; keep follow-up testing — recurrence is possible; excision slightly increases the risk of preterm birth in later pregnancies
- Stop smoking — smoking promotes HPV persistence and progression
- Condoms reduce but do not fully prevent HPV transmission
- After cancer treatment: follow-up visits (history, exam, and testing) every few months for the first years; report new bleeding, pelvic or leg pain, leg swelling, cough, weight loss
| Complication | Warning signs | Priority action |
|---|
| Hemorrhage (tumor or post-conization) | Heavy bleeding, tachycardia, hypotension | Pressure/packing per provider, IV access, transfusion |
| Ureteral obstruction → kidney failure | Flank pain, oliguria, rising creatinine | Notify provider; stent or nephrostomy |
| Vesicovaginal or rectovaginal fistula | Continuous leakage of urine or stool from the vagina | Skin protection, notify provider |
| Neutropenic fever | ≥ 38.3 °C (101 °F) once or ≥ 38.0 °C (100.4 °F) sustained over 1 hour with neutropenia (clients call at ≥ 38.0 °C) | Cultures, IV antibiotics within 1 hour |
| Radiation enteritis / proctitis / cystitis | Diarrhea, rectal bleeding, dysuria, hematuria | Symptom management; report bleeding |
| VTE after pelvic surgery | Leg swelling, dyspnea, chest pain | Emergency evaluation |
| Lymphedema | Leg heaviness and swelling | Early referral to lymphedema therapy |
| Cervical stenosis after conization | Amenorrhea with cramping, infertility | Dilation |
- Persistent high-risk HPV (16, 18) is the necessary cause of cervical cancer
- CIN 1 = lower third (LSIL, observe); CIN 3 = full thickness, basement membrane intact (HSIL, treat)
- Koilocytes = HPV cytopathic effect
- Screening: cytology every 3 years from 21 (USPSTF); primary HPV every 5 years — from 30 (USPSTF) or 25 (ACS); stop after 65 with adequate negative history
- Abnormal screen → colposcopy with biopsy; CIN 2/3 → LEEP or conization
- Postcoital bleeding is the classic early symptom of invasive cancer
- Early stage → radical hysterectomy with pelvic node dissection; locally advanced → chemoradiation with weekly cisplatin + brachytherapy
- Bladder dysfunction is the most common complication of radical hysterectomy
- Cisplatin: hydrate; watch kidneys, hearing, magnesium
- HPV vaccine prevents, does not treat; vaccinated people still need screening
- Sex partners of clients with CIN do not need treatment
- After LEEP: no tampons, douching, or intercourse until cleared; report heavy bleeding
Country Notes
United States
- Screening schedules differ between USPSTF and ACS (start at 21 with cytology vs. start at 25 with primary HPV); both accept primary HPV testing every 5 years, and self-collected HPV testing is now available.
- HPV vaccination is part of the adolescent immunization schedule. A 2026 HHS change to a single HPV dose was stayed by a federal court; the CDC schedule currently lists 2 or 3 doses by age at first dose.
Philippines
- The DOH encourages cervical cancer screening for women 30–65; methods in use include HPV DNA testing, visual inspection with acetic acid (VIA), and Pap smear. In 2025 the national Health Technology Assessment Council recommended high-risk HPV DNA testing every 5 years for women 30–65 (final recommendation forwarded to the DOH Secretary; consistent with the DOH 2023 Omnibus Health Guidelines for Adults). Screening coverage remains low in many regions.
- The DOH, with the Department of Education ("Bakuna Eskwela"), gives free HPV vaccine to Grade 4 girls in public schools using a 2-dose schedule.
- The National Integrated Cancer Control Act (RA 11215) supports cancer prevention, screening, and a cancer assistance fund.