Removing Lymph Nodes Does Not Improve Survival Outcomes of Advanced Ovarian Cancer Patients, Trial Shows

Women with advanced ovarian cancer who underwent a complete resection of their tumor and have normal lymph nodes do not have better survival outcomes if the lymph nodes surrounding the tumor are removed, and instead, have a higher incidence of complications after surgery, a randomized trial shows.

The study, “A Randomized Trial of Lymphadenectomy in Patients with Advanced Ovarian Neoplasms,” was published in The New England Journal of Medicine. 

One of the most important prognostic factors for ovarian cancer patients is the amount of tumor that remains after surgery, with patients who have no macroscopically visible tumor having better outcomes than those with visible tumor after surgery.

But patients often experience cancer spreading to their lymph nodes, and retrospective analyses suggest that removing the pelvic and paraaortic lymph nodes — those surrounding the aorta near the kidney area — may improve the survival outcomes of advanced ovarian cancer patients.

Aiming to confirm the findings, researchers at the Philipps University Marburg Medical Center, in collaboration with the German Research Foundation, conducted a prospective clinical trial in which 647 patients were randomly assigned lymph node removal — a procedure called lymphadenectomy — or no lymphadenectomy.

The LION trial (NCT00712218) enrolled patients with advanced cancer, including patients whose tumor had not spread outside the peritoneal cavity and those with metastasis only in the pleura, liver, spleen, or abdominal wall.

Participants were included only if a macroscopically complete resection was achieved during the surgery. The lymphadenectomy, when performed, was conducted immediately after tumor removal, as a surgical extension.

“All centers had to prove their proficiency in performing a complete lymphadenectomy before being qualified to participate in the trial,” investigators explained. ”

Accordingly, a median of 57 lymph nodes were removed from each patient in the lymphadenectomy group, including 22 paraaortic and 35 pelvic nodes, a number that was “higher than in previous gynecologic oncologic clinical trials analyzing this issue,” they wrote.

Interestingly, while more than half (55%) of patients in the lymphadenectomy group had metastasis in their lymph nodes, the approach did not improve overall survival — the trial’s main goal — or the time patients lived without disease progression.

Indeed, patients whose lymph nodes were removed lived a median of 65.5 months, compared to 69.2 months for the no-lymphadenectomy group. The time to disease progression or death was 25.5 months for both groups.

The addition of open lymphadenectomy to the surgical procedure caused no significant differences on quality of life. However, the approach increased the duration of surgery, amount of blood lost, the percentage of patients requiring a transfusion, and the proportion of patients admitted to an intermediate or intensive care unit.

Patients in the lymphadenectomy group also were more frequently treated for infections and were more likely to require a laparoscopic surgery to resolve complications like bowel leakage or fistulas. The mortality rate 60 days after surgery also was higher in this group — 3.1% vs. 0.9%.

Overall, the findings “indicated that substantial additional morbidity was associated with this procedure,” researchers wrote.

“In this trial, patients with advanced ovarian cancer who underwent macroscopically complete resection did not benefit from systematic lymphadenectomy. In contrast, lymphadenectomy resulted in treatment burden and harm to patients,” they concluded.