Expert Consensus: PAX1/JAM3 Methylation Testing & Clinical Use

1Background & Significance

Burden: 150,700 new cervical cancer cases in China 2022 (rank #5 female cancers).
Gap: screening coverage 36.8% (2018–19) — far from 70% target 2030.
Role: WHO/IARC recognize methylation as an emerging screening method.

2Lab Workflow & QC Essentials

Sample

cervical exfoliated cells

MSP/qPCR

bisulfite + PCR

ΔCt 8.4/8.8

PAX1/JAM3 cut-offs

Lab: licensed gene-amplification lab; validate manufacturer performance claims.
Sample: standardized collection & storage; 2–3 ml cell suspension for DNA.
Conversion: bisulfite immediately; DNA ≤1 week at −20°C; Bis-DNA ≤3 days.
QC: negative/weak-positive controls per run; internal & reference channels.
Reagent: NMPA-approved kits; performance verification before use.

2–3 ml

cell suspension

200–1000 ng

DNA input

−20°C

storage

DNA

extraction check

Bis-DNA

immediate PCR

vortex

sample prep

Extraction: column vs magnetic bead; check purity/yield/integrity.
Efficiency: assess kit extraction efficiency before standardization.
Performance items: method agreement · LOD · anti-interference · cross-reactivity.
Re-test: establish repeat-testing procedure & data analysis flow.
QC targets: set target values & control limits with current standard procedure.
Controls: kit/third-party/self-made validated controls each run.

Strong recommendations

6 of 8

Recommendations

2 of 8

Consensus 2–5: establish procedures, performance verification, sampling rules, QC system (all strong); Oxford CEBM evidence grading.

3Consensus Statements

Novel non-invasive test: methylation is feasible for cervical cancer detection.

L2 · Strong

Lab standards: licensed lab, procedures & performance verification.

L1 · Strong

Sampling rules: standardized collection & preservation.

L2 · Strong

Approved reagents: NMPA-approved kits + performance validation + retesting QC.

L2 · Strong

QC system: ensure result accuracy.

L2 · Strong

Qualitative reporting: positive/negative with standardized report format.

L2 · Strong

Adjunct diagnosis: combine with HPV/cytology for management decisions.

L2 · Rec

Discrepancy handling: follow guidelines when methylation vs biopsy mismatch.

L2 · Rec

Report: qualitative ± per Clinical Gene Testing Report consensus — integrates into risk-based management.

4Clinical Management Flowcharts

Fig 1 · hrHPV untyped (4 branches)

① HPV+ & M+ → colposcopy.
② HPV+ & M− → genotype; cytology if unavailable (ASC-US+ → colposcopy; NILM → 1yr).
③ HPV− & M+ → colposcopy or 6–12mo re-test.
④ both− → routine.

Fig 2 · hrHPV typed (16/18 & others)

① 16/18+ & M+ → colposcopy.
② 16/18+ & M− → colposcopy (high risk).
③ 16/18− & M+ → colposcopy; other types per rules; other− → routine.

Methylation with cytology management flowchart

Fig 3 · Methylation + cytology (ASC-US+ / NILM)

ASC-US+ & M+ → colposcopy · M− & (SCC/adeno/HSIL/ASC-H/AGC/AIS) → colposcopy · M− & (LSIL/ASC-US) → 6–12mo re-test or colposcopy · NILM & M+ → colposcopy · NILM & M− → 1yr re-test or HPV.