The patients’ characteristics
The clinicopathological characteristics of 453 AIS patients, including 153 underwent cervical conization(s) alone and 300 underwent cervical conization followed by hysterectomy, were summarized in Table 1. There were 97.93% of HPV positive and 67.39% of abnormal cytology, respectively. The transformation zone was type III in 60.88% of the patients and type I~II in 39.12% of the patients. The initial conization margin was positive in 19.65% of the patients. Pathologically, 145 patients were AIS only, 308 patients were cervical AIS coexisting with CIN. The mean age was 34.54±5.59 years in patients with cervical conization alone and 45.10±7.77 years in patients with hysterectomy respectively. The flowchart of the study design was show in Figure 1.
Residual disease and its related factors
In 153 patients undergoing cervical conization alone, 143 had negative margins and 10 had positive margins who received repeated conization. In addition, 300 underwent further hysterectomy after conization, of those, 79 had positive margins and 221 had negative margins of conization. Thus, the overall rate of residual diseases was 16.13% in 310 specimens of hysterectomy and repeated conization. The rate of residual disease was 50.56% (45/89) for positive margins and 2.26% (5/221) for negative margins, respectively, with a significantly difference (p=0.000). In specimens with positive margins, 45 cases had residual diseases including 31 AIS, 9 CIN 2/3, and 5 (5/89, 5.62%) invasive adenocarcinoma. In specimens with negative margins, 5 cases had residual diseases including 4 AIS, 1 CIN 1, and 0 (0/221, 0%) invasive adenocarcinoma. The difference in the residual invasive carcinoma rate between patients with positive and negative conization margins was statistically significant (5.62% vs 0%, p=0.000).
The risk factors influencing residual disease were further analyzed by univariate (Table 2) and multivariate analysis. The results showed that pre-operative cytology (p=0.012), conization method (p=0.011), cone length (p=0.008), and positive margin (p=0.000) were significantly associated with residual disease, but only conization margin was the independent factor influencing residual disease (OR=0.018, 95% CI 0.006-0.060).