Research article

Molecular detection (k-ras) of exfoliated tumour cells in the pelvis is a prognostic factor after resection of rectal cancer?

Annette Torgunrud Kristensen^1,2 , Johan N Wiig¹ , Stein G Larsen¹ , Karl-Erik Giercksky^1,2 and Per O Ekstrøm¹

¹Section for Surgical Oncology, Rikshospitalet-Radiumhospitalet Medical Center, Montebello, Oslo, Norway

²The Faculty of Medicine, University of Oslo, Norway

author email corresponding author email

BMC Cancer 2008, 8:213doi:10.1186/1471-2407-8-213

Published:	27 July 2008

Abstract

Background

After total mesorectal excision (TME) for rectal cancer around 10% of patients develops local recurrences within the pelvis. One reason for recurrence might be spillage of cancer cells during surgery. This pilot study was conducted to investigate the incidence of remnant cancer cells in pelvic lavage after resection of rectal cancer. DNA from cells obtained by lavage, were analysed by denaturing capillary electrophoresis with respect to mutations in hotspots of the k-ras gene, which are frequently mutated in colorectal cancer.

Results

Of the 237 rectal cancer patients analyzed, 19 had positive lavage fluid. There was a significant survival difference (p = 0.006) between patients with k-ras positive and negative lavage fluid.

Conclusion

Patients with k-ras mutated cells in the lavage immediately after surgery have a reduced life expectation. Detection of exfoliated cells in the abdominal cavity may be a useful diagnostic tool to improve the staging and eventually characterize patients who may benefit from aggressive multimodal treatment of rectal cancer.