MILACC study: could undetected lymph node micrometastases have impacted recurrence rate in the LACC trial?

The etiology of inferior oncologic outcomes associated with minimally invasive surgery for early-stage cervical cancer remains unknown. Manipulation of lymph nodes with previously unrecognized low-volume disease might explain this finding. We re-analyzed lymph nodes by pathologic ultrastaging in node-negative patients who recurred in the LACC (Laparoscopic Approach to Cervical Cancer) trial.

Included patients were drawn from the LACC trial database, had negative lymph nodes on routine pathologic evaluation, and recurred to the abdomen and/or pelvis. Patients without recurrence or without available lymph node tissue were excluded. Paraffin tissue blocks and slides from all lymph nodes removed by lymphadenectomy were re-analyzed per standard ultrastaging protocol aimed at the detection of micrometastases (>0.2 mm and ≤2 mm) and isolated tumor cells (clusters up to 0.2 mm or <200 cells).

The study included 20 patients with median age of 42 (range 30-68) years. Most patients were randomized to minimally invasive surgery (90%), had squamous cell carcinoma (65%), FIGO 2009 stage 1B1 (95%), grade 2 (60%) disease, had no adjuvant treatment (75%), and had a single site of recurrence (55%), most commonly at the vaginal cuff (45%). Only one patient had pelvic sidewall recurrence in the absence of other disease sites. The median number of lymph nodes analyzed per patient was 18.5 (range 4-32) for a total of 412 lymph nodes. A total of 621 series and 1242 slides were reviewed centrally by the ultrastaging protocol. No metastatic disease of any size was found in any lymph node.

There were no lymph node low-volume metastases among patients with initially negative lymph nodes who recurred in the LACC trial. Therefore, it is unlikely that manipulation of lymph nodes containing clinically undetected metastases is the underlying cause of the higher local recurrence risk in the minimally invasive arm of the LACC trial.