Background: The lymph node harvest from colorectal specimens is pivotal for patients with colorectal cancer (CRC), independent of N stage.

Aims: To determine whether the use of GEWF solution (glacial acetic acid, ethanol, distilled water and formaldehyde) could improve the lymph node harvest in CRC specimens.

Methods: Consecutive fresh colonic (n = 60) and rectal (n = 60) specimens from patients with primary CRC resected at Aarhus University Hospital THG between March 2006 and July 2007 were randomised to either conventional preparation or GEWF preparation and examined in a standard manner.

Results: For colonic as well as rectal specimens, the GEWF solution increased the mean lymph node harvest from 9 and 10 to 16 and 17 lymph nodes per specimen compared to conventional prepared specimens (p<0.001). Using the recommended threshold of 12 lymph nodes to ensure adequacy of nodal harvest, the adequacy increased from less than half to almost three quarters independent of tumour origin (p<0.037). The proportion of node-negative specimens was not significantly different between the two preparation groups.

Conclusion: The use of GEWF solution in patients with CRC significantly increases the lymph node harvest of resected specimens.