Purpose: The objective of this study was to define the learning curve required to attain satisfactory oncologic outcomes of cervical cancer patients who were undergoing open or minimally invasive surgery for radical hysterectomy, and to analyze the correlation between the learning curve and tumor size.
Materials and methods: Cervical cancer patients (stage IA-IIA) who underwent open radical hysterectomy (n=280) or minimal invasive radical hysterectomy (n=282) were retrospectively reviewed. The learning curve was evaluated using cumulative sum of 5-year recurrence rates. Survival outcomes were analyzed based on the operation period ("learning period," P1 vs. "skilled period," P2), operation mode, and tumor size.
Results: The 5-year disease-free and overall survival rates between open and minimally invasive groups were 91.8% and 89.0% (p=0.098) and 96.1% and 97.2% (p=0.944), respectively. The number of surgeries for learning period was 30 and 60 in open and minimally invasive group, respectively. P2 had better 5-year disease-free survival than P1 after adjusting for risk factors (hazard ratio, 0.392; 95% confidence interval, 0.210 to 0.734; p=0.003). All patients with tumors < 2 cm had similar 5-year disease-free survival regardless of operation mode or learning curve. Minimally invasive group presented lower survival rates than open group when tumors ≥ 2 cm in P2. Preoperative conization improved disease-free survival in patients with tumors ≥ 2 cm, especially in minimally invasive group.
Conclusion: Minimally invasive radical hysterectomy required more cases than open group to achieve acceptable 5-year disease-free survival. When tumors ≥ 2 cm, the surgeon's proficiency affected survival outcomes in both groups.
Keywords: Learning curve; Minimally invasive surgical procedures; Uterine cervical neoplasms.