Immediate treatment of cervical intraepithelial neoplasia grade 2 (CIN2) did not reduce the risk of cervical cancer over three years compared with delayed treatment, according to a target trial emulation study published in Annals of Internal Medicine.
The findings suggest that delaying treatment may avoid some potentially unnecessary excisional procedures without substantially altering short-term cancer risk, although ongoing monitoring remains essential regardless of management strategy.
CIN2 is considered an equivocal diagnosis of cervical precancer, with some lesions progressing while others regress spontaneously. As a result, the optimal management approach remains a subject of debate, particularly among younger women for whom excisional procedures may affect future reproductive outcomes.
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The study emulated a target trial comparing immediate treatment, defined as excision within six months of diagnosis without interim surveillance, with delayed treatment, defined as continued surveillance with screening or colposcopy regardless of subsequent excision timing, or excision performed six months or more after diagnosis.
The primary outcomes included the three-year probability of potentially unnecessary excision, defined as excision yielding findings less severe than CIN2, as well as the three-year risks of cervical intraepithelial neoplasia grade 3 or worse (CIN3+) and invasive cervical cancer.
Immediate treatment was associated with a substantially higher probability of potentially unnecessary excision than delayed treatment, with rates of 36.2% and 7.8%, respectively.
By contrast, three-year risks of invasive cervical cancer were similar between the two management approaches. The inverse probability weighting-standardised risk of cancer was 0.39% in the immediate treatment group and 0.43% in the delayed treatment group.Similarly, the standardised three-year risk of CIN3+ was 8.85% with immediate treatment and 10.31% with delayed treatment.
According to the investigators, immediate treatment was associated with a substantially higher probability of potentially unnecessary excision, while three-year risks of cervical cancer and CIN3+ were similar between the two management strategies.
However, the authors noted that women receiving either immediate or delayed care remained at risk of developing cervical cancer and therefore require ongoing surveillance and follow-up.
The researchers also acknowledged several limitations, including the observational nature of the study and the rarity of cervical cancer events.
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The authors concluded that immediate treatment did not reduce three-year cancer risk compared with delayed treatment after CIN2 diagnosis. Delaying treatment avoided some potentially unnecessary excisions, although women receiving either immediate or delayed care remained at risk of cervical cancer and required ongoing monitoring.
Paper: Benefits and Harms of Immediate Versus Delayed Treatment of Cervical Intraepithelial Neoplasia Grade 2: A Target Trial Emulation. Ann Intern Med. [Epub 23 June 2026]. Access online here.
