Maintained survival outcome after reducing lymphadenectomy rates and optimizing adjuvant treatment in endometrial cancer
Main controversies in endometrial cancer treatment include the role of lymphadenectomy and optimal adjuvant treatment. We assessed clinical outcome in a population-based endometrial cancer cohort in relation to changes in treatment management over two decades. All consenting endometrial cancer patients receiving primary treatment at Haukeland University Hospital from 2001 to 2019 were included (n = 1308). Clinicopathological variables were evaluated for year-to-year changes. Clinical outcome before and after discontinuing adjuvant radiotherapy and individualizing extent of lymphadenectomy was analyzed. The rate of lymphadenectomy was reduced from 78% in 2001-2012 to 53% in 2013-2019. The rate of patients with verified lymph node metastases was maintained (9% vs 8%, p = 0.58) and FIGO stage I patients who did not undergo lymphadenectomy had stable 3-year recurrence-free survival (88% vs 90%, p = 0.67). Adjuvant chemotherapy for completely resected FIGO stage III patients increased from 27% to 97% from 2001 to 2009 to 2010-2019, while adjuvant radiotherapy declined from 57% to 0% (p < 0.001). These patients had improved 5-year overall- and recurrence-free survival; 0.49 [95% CI: 0.37-0.65] in 2001-2009 compared to 0.61 [0.45-0.83] in 2010-2019, p = 0.04 and 0.51 [0.39-0.68] to 0.71 [0.60-0.85], p = 0.03, respectively. For stage I, II and IV, survival rates were unchanged. Our study demonstrates that preoperative stratification by imaging and histological assessments permits a reduction in lymphadenectomy to around 50%, and is achievable without an increase in recurrences at 3 years. In addition, our findings support that adjuvant chemotherapy alone performs equally to adjuvant radiotherapy with regard to survival, and is likely superior in advanced stage patients.