Background: Treatment of cervical intraepithelial neoplasia grade 3 (CIN3) is one of the most unexplored issues of the monitoring of cervical cancer screening. We evaluated (1) the frequency of major patterns of diagnosis and treatment of CIN3 (ICD-O code 8070.2), (2) the determinants of hysterectomy as a first choice treatment, and (3) the determinants of invasive cervical squamous carcinoma (CSC) detection among CIN3 cases treated by hysterectomy.
Methods: A population-based, retrospective, descriptive (objective 1) and analytical (objectives 2 and 3) study was conducted by the Romagna Cancer Registry (Northern Italy). Included were 316 CIN3 patients (median age, 38.5 years; range, 21-80) registered between 1986 and 1993 and meeting one of the following eligibility criteria: histological diagnosis of CIN3 on biopsy with any subsequent treatment, histological diagnosis of CIN3 on conization, histological diagnosis of CIN3 on hysterectomy with previous negative/benign (< or = CIN2) biopsy or conization. Multivariate associations were evaluated by the multiple logistic regression.
Results: Of 316 patients, 264 (84%) were first diagnosed on biopsy, 39 (12%) on conization, and 13 (4%) on hysterectomy. Among the 264 patients diagnosed on biopsy, the first choice treatment was local destructive therapy for 16 (6%), conization for 155 (59%) and hysterectomy for 93 (35%). Age was the strongest uni/multivariate predictor of hysterectomy (the most frequent first choice treatment >40 years) followed by adequacy of biopsy (inverse association) and place of treatment (decreased probability for patients treated outside the area and in the private sector). Among the 93 CIN3 patients undergoing hysterectomy, 23 (25%) had a CSC diagnosed. Multivariate analysis showed that the probability of CSC detection was related to adequacy of biopsy (inverse association), year of registration, and biopsy-to-treatment interval (inverse association).
Conclusion: Hysterectomy was a common treatment for patients with CIN3 on biopsy. Only in a minority of hysterectomized patients was a CSC diagnosed. Difficulties and inefficiencies in the biopsy and assessment procedure were found to be important factors in the management and outcome of CIN3 patients.