Precise resection in colon cancer may boost survival

Researchers from the Leeds Institute of Molecular Medicine at the University of Leeds assessed the quality of colon cancer surgery and noted that there was marked variability in the plane of surgery achieved in colon cancer.

Improving the plane of dissection might improve survival, particularly in patients with stage III disease, they said.

The group, led by Professor Philip Quirke, performed an observational study of all resections for primary colon adenocarcinoma done at Leeds General Infirmary between 1997 and 2002. The specimens were photographed and graded according to the plane of mesocolic dissection. Tissue morphometry was done on 253 tumors. Univariate and multivariate models were used to ascertain whether there was an association with 5-year survival. The primary outcome measure was overall survival defined as death from any cause.

The study sample ultimately consisted of 399 specimens. They found “marked variation in the proportion of each plane of surgery: muscularis propria in 95 of 399 (24%) specimens, intramesocolic in 177 of 399 (44%) specimens, and mesocolic in 127 of 399 (32%) specimens” (Lancet Oncology online, July 28, 2008).

They also found that the mean cross-sectional tissue area outside the muscularis propria was significantly higher with mesocolic plane surgery, compared with intramesocolic and muscularis propria plane surgery.

Finally, they noted that, independent of all tumor sites, there was also a significant increase in the distance from the muscularis propria to the mesocolic resection margin with mesocolic plane surgery compared with intramesocolic and muscularis propria plane surgery.

“The plane of surgery and amount of mesocolon removed varied between the different sites with better planes in left-sided resections than right-sided ones, which were better than transverse resection,” they commented.

In univariate analysis, they calculated a 15% overall survival advantage at 5 years with mesocolic plane surgery compared with surgery in the muscularis propria plane, especially in patients with stage III cancers, but this association lost significance in the multivariate model.

“We have now shown there is marked variability in the plane of surgery achieved in colon cancer. Improving the plane of dissection might improve survival, especially in patients with stage III disease,” they concluded.

These results may be confirmed by clinical trial data from the National Cancer Research Institute’s Fluoropyrimidine, Oxaliplatin and Targeted Receptor pre-Operative Therapy for colon cancer (FOxTROT) trial.

FOxTROT is a trial of neoadjuvant chemotherapy in advanced resectable colon cancer.