No Survival Benefit with Node Dissection in Ovarian Ca

CHICAGO -- Lymph node dissection had no impact on survival among women with completely resected ovarian cancer and clinically negative nodes, a large randomized trial showed.

Following complete resection of cancer, median overall survival (OS) was 65. 5 months in patients who underwent lymphadenectomy and 69.2 months in those who did not. Regardless of whether patients had lymph node dissection, they lived about 2 years without disease progression.

Omitting lymph node dissection did not prove harmful even though more than half of the patients in the trial had subclinical retroperitoneal nodal metastases, Philipp Harter, MD, of Klinikum Essen-Mitte in Germany, reported at the American Society of Clinical Oncology annual meeting.

"Patients with complete resection during upfront surgery and treated in quality-assured centers have an excellent prognosis," said Harter. "Systematic pelvic and para-aortic lymph node evaluation in patients with clinically negative lymph nodes improves neither OS nor progression-free survival (PFS).

"Our data indicate that systematic lymph node evaluation of clinically negative lymph nodes in patients with advanced ovarian cancer and complete resection should be omitted," he stated.

Invited discussant Ritu Salani, MD, of the Ohio State University in Columbus, considered the trial the most impactful gynecologic oncology presentation at ASCO.

"We had always believed that removing lymph nodes, whether they were normal or not, that patients actually derived benefit. This study negated that concept" Salani told MedPage Today. "Patients had equal progression-free and overall survival, but what was really striking is that patients had more complications and a higher [60-day] mortality when lymph nodes were removed, without any benefit. This is really going to change clinical practice."

Surgery to achieve macroscopic complete resection is the major therapeutic goal in patients with primary advanced ovarian cancer. The role of pelvic/para-aortic lymphadenectomy after complete resection remained unresolved. A randomized trial showed significant improvement in PFS but not OS. A retrospective analysis of phase III trials suggested a potential OS benefit from removal of clinically negative nodes after macroscopic complete resection of the primary cancer.

In an attempt to reach a definitive conclusion, investigators in Europe and Asia conducted the randomized, phase III Lymphadenectomy in Ovarian Neoplasms (LION) trial that included eligibility criteria for participating centers, as well as patients. To qualify for a trial, centers had to submit 12 anonymous surgical and pathologic reports to demonstrate surgical proficiency, focusing on lymphadenectomy.

Eligible patients had FIGO IIB-IV ovarian cancer considered feasible for macroscopic complete resection, clinically and radiographically negative pelvic and para-aortic lymph nodes, no prior chemotherapy, and no prior lymph node dissection. All patients underwent surgery and were randomized to lymphadenectomy. All patients then received adjuvant chemotherapy.

The trial had a primary endpoint of OS, and key secondary endpoints included PFS, quality of life (QoL), and number of resected lymph nodes. The intention-to-treat analysis included 647 patients.

Almost all patients had surgery that went beyond bilateral salpingo-oophorectomy to include hysterectomy (>99%), omentectomy (99%), complete or partial peritonectomy (90%), gastrointestinal resection (>50%), and splenectomy (18%). Surgeons achieved macroscopically complete resection in more than 99% of cases, said Harter.

Patients randomized to lymphadenectomy had higher rates of several types of adverse events: infections requiring antibiotics (25.8% versus 18.6%, P=0.03), asymptomatic lymph cysts (4.4% versus 0.3%, P<0.001), symptomatic lymph cysts (3.1% versus 0%, P=0.001), repeat laparotomy (12.4% versus 6.5%, P=0.01), and 60-day mortality (3.1% versus 0.9%, P=0.049).

Overall, patients whose surgeons achieved macroscopic complete resection had a median PFS of 25.5 months and median OS of 67.2 months. Analysis of the primary endpoint showed no significant difference between groups, although omission of lymphadenectomy was associated with slightly better survival (69.2 versus 65.5 months). Median PFS was 25.5 months in both groups.

Harter emphasized that the lack of difference in OS and PFS occurred despite the fact that 56% of the patients in the lymphadenectomy arm had subclinical retroperitoneal nodal metastases that were identified and removed.

QoL did not differ between the treatment groups at any point in time, declining from baseline to hospital discharge and then recovering to a similar extent and along a similar graphical trajectory to the end of chemotherapy and 6 months afterward, when QoL surpassed baseline values in both groups.

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