Target trial emulation of benefits and harms of immediate versus delayed treatment of cervical intraepithelial neoplasia grade 2

Cervical intraepithelial neoplasia grade 2 (CIN 2) is an equivocal diagnosis of cervical precancer, without consensus of appropriate management. A target trial emulation investigated the effect of immediate (by 6 months) versus delayed (after 6 months or no) treatment of CIN 2. The analysis included 12 012 women with CIN 2 found on initial biopsy during routine cervical screening at Kaiser Permanente Northern California from 2017 to 2023. A total of 6074 women underwent immediate excision without interim surveillance by screening or colposcopy, while 5938 were managed by delayed treatment (continued surveillance regardless of subsequent excison timing, or excision ≥ 6 months after initial CIN 2). The outcomes were 3-year probability of potentially unnecessary excision (less severe than CIN 2) and 3-year risks for CIN 3+ or invasive cervical cancer. Immediate treatment was associated with a higher 3-year probability of <CIN 2 on excision compared with delayed treatment (36.8% versus 7.8%). The IPW-standardized 3-year risks for cervical cancer (0.39% versus 0.43%) and CIN 3+ (8.85% versus 10.31%) were similar under the two management strategies. The authors conclude that immediate treatment did not reduce 3-year cancer risk compared with delayed treatment after CIN 2. Delaying treatment avoided some potentially unnecessary excisions but women with CIN 2 with immediate or delayed care were still at risk for cancer and required monitoring.