Purpose: Recent reports have suggested that intraabdominal
postoperative infection is associated with higher
rates of overall and local recurrence and cancer-specific mortality.
However, the mechanisms responsible for this association
are unknown. We hypothesized that the greater
inflammatory response in patients with postoperative intraabdominal
infection is associated to an increase in local and
systemic angiogenesis.
Methods: We designed a prospective cohorts study with
matched controls. Patients with postoperative intra-abdominal
infection (abscess and/or anastomotic leakage) (group 1;
n=17) after elective colorectal cancer resection operated on
for cure were compared to patients with an uncomplicated
postoperative course (group 2; n=17). IL-6 and VEGF levels
were determined by ELISA in serum and peritoneal fluid at
baseline, 48 hours and postoperative day 4 or at the time
the peritoneal infection occurred.
Results: No differences were observed in age, gender, preoperative
CEA, tumor stage and location and type of procedure
performed. Although there were no differences in
serum IL-6 levels at 48 hours, this pro-inflammatory
cytokine was higher in group 1 on postoperative day 4
(group 1: 21533 + 27900 vs. group 2: 1130 + 3563 pg/ml; p
< 0.001). Serum VEGF levels were higher in group 1 on
postoperative day 4 (group 1: 1212 + 1025 vs. group 2: 408
+ 407 pg/ml; p < 0.01). Peritoneal fluid VEGF levels were
also higher in group 1 at 48 hours (group 1: 4857 + 4384 vs.
group 2: 630 + 461 pg/ml; p < 0.001) and postoperative day
4 (group 1: 32807 + 98486 vs. group 2: 1002 + 1229 pg/ml;
p < 0.001). A positive correlation between serum IL-6 and
VEGF serum levels was observed on postoperative day 4
(r=0.7; p<0.01).
Conclusions: These results suggest that not only the
inflammatory response but also the angiogenic pathways are
stimulated in patients with intra-abdominal infection after
surgery for colorectal cancer. The implications of this finding
on long-term follow-up need to be evaluated.