Spontaneous Regression of Cervical Intraepithelial Neoplasia 2: A Meta-analysis

Cervical intraepithelial neoplasia (CIN) is a precancerous condition that, if progresses, can cause cervical cancer. Less severe forms such as CIN1 regress spontaneously for most of the cases, but for high-grade CIN (CIN2 or CIN3), have higher potentials for progression.

Aim of the present study was to obtain reliable estimates of spontaneous regression and progression rates of CIN2.

Data were extracted from eligible studies identified after literature search in electronic databases, and meta-analyses were performed by pooling the regression and progression rates reported by these studies. Meta-regression analyses were performed for the identification of factors affecting regression rate.

Sixteen studies (1,481 patients; 14.86 months [95% CI 9.25-20.48] follow-up; 28.23 years [95% CI 25.07-31.39] age) were included in the meta-analysis. Overall regression rate in these conservatively observed patients was 42.66% (95% CI 35.41-49.91), but regression rate was higher in studies that recruited patients with CIN2 (50.85% [95% CI 36.11-65.60]) in comparison with those that recruited patients without discrimination of CIN2 with CIN3 (36.31% [95% CI 27.67-44.95]. Progression rate in CIN2 patients was 10.28% [95% CI 3.72-16.84]). Age was significantly negatively associated with regression rate (coefficient -1.72 [-3.53 to 0.10]; p = 0.061).

Spontaneous regression rate of CIN2 is considerably high, especially in younger years.