Systematic lymphadenectomy (LNE) in patients with advanced ovarian cancer and complete resection does not improve progression-free or overall survival (OS), and should be omitted, according to results of a new study.
“Upfront surgery aiming at macroscopic complete resection is the goal in patients with primary advanced ovarian cancer,” said Philipp Harter, MD, PhD, of the Kliniken Essen-Mitte in Germany, during his presentation of the LION study (abstract 5500) at the 2017 American Society of Clinical Oncology (ASCO) Annual Meeting. Previous studies have showed mixed results regarding LNE in patients with otherwise complete resection.
The LION trial randomized 650 patients with advanced epithelial ovarian cancer and macroscopic complete resection to either systematic pelvic and para-aortic LNE (323 patients in intention-to-treat cohort), or no LNE (324 patients in intention-to-treat cohort). Patients were well matched between the groups, with a median age of 60 years, primarily ECOG 0 performance status, and mostly grade 2/3 serous histology.
Lymph node metastases were detected in 55.7% of the LNE patients. The median number of resected lymph nodes in those patients was 57 (22 para-aortic, 35 pelvic). The LNE patients had a median of 1 hour more of surgical duration (P < .001) and significantly more blood loss during surgery (P < .001). They also required more transfusions, experienced more infections requiring antibiotics (P = .03), and experienced a higher rate of 60-day postoperative mortality (3.1% vs 0.9%; P = .049).
These differences, however, did not translate into any difference with regard to survival outcomes. The full cohort had a median progression-free survival of 25.5 months, and a median OS of 67.2 months, with a 5-year OS rate of 55.9%. The median OS in LNE patients was 65.5 months, compared with 69.2 months with no LNE, yielding a hazard ratio of 1.057 (95% CI, 0.833–1.341). Similarly, the median progression-free survival in both groups was the same, at 25.5 months, for an HR of 1.106 (95% CI, 0.915–1.338).
A quality-of-life analysis using the QLQ-C30 Global Health Status instrument found nearly identical results in the two groups.
“Our data indicate that systematic LNE of clinical negative lymph nodes in patients with advanced ovarian cancer and complete resection should be omitted,” Harter concluded.
Ritu Salani, MD, MBA, of the Ohio State University Wexner Medical Center, was the Discussant for the session, and she agreed that these data suggest omitting LNE is acceptable. “I always thought that the lymph nodes represented a sanctuary for ovarian cancer and this is why we removed them, and I think this actually debunks that theory,” she said, adding that doing so would likely have cost-effectiveness benefits as well.