Fat-dissociation method speeds up CRC lymph node detection without accuracy trade-off

A new fat-dissociation method (FM) of examining positive lymph nodes (LNs) from surgically removed mesentery reduces the overall time required for detection without sacrificing accuracy, a recent study has found.

The researchers conducted a single-centre, open-label, randomized controlled analysis of 130 colorectal cancer (CRC) patients who underwent primary CRC surgery.

The primary endpoint was the time required for LN identification, while the secondary outcomes were the number of LNs detected and the 5-year cancer-specific survival (CSS). In all criteria, FM was compared against the conventional palpation method (PM).

The study sample was split evenly between the PM and FM arms, and both groups were generally comparable in terms of baseline characteristics.

The median searching time in the PM arm was 45 minutes, while the FM participants underwent a procedure that was only 15 minutes long. The resulting time required for LN identification was significantly shorter in the FM group (p<0.001).

Despite the drop in operating time, the median number of LNs that could be pathologically examined did not differ between the PM and FM groups (16 vs 18; p=0.546). After FM, most fats had successfully been dissociated from the mesentery, clearly exposing vessel structures and LN. This could have facilitated LN identification.

In subsequent subanalyses, the number of LNs detected by FM was significantly greater than PM in right-sided CRCs (p=0.031), but no such difference was reported for left-sided cancers.

In terms of outcome, 5-year CSS did not differ between the PM and FM groups (p=0.344), and neither did 5-year relapse-free survival (p=0.877). The researchers also noted no additional difficulty in diagnosing cancer after applying FM.