Modified selection criteria for complete cytoreductive surgery plus HIPEC based on peritoneal cancer index and small bowel involvement for peritoneal carcinomatosis of colorectal origin.

BACKGROUND

Complete cytoreductive surgery (CCRS) plus hyperthermic intraperitoneal chemotherapy (HIPEC) is on the verge of becoming the gold standard treatment for selected patients presenting peritoneal metastases (PM) of colorectal origin. PM is scored with the peritoneal cancer index (PCI), which is the main prognostic factor. However, small bowel (SB) involvement could exert an independent prognostic impact.

AIM: To define an adequate cut-off for the PCI and to appraise whether SB involvement exerts an impact on this cut-off.

PATIENTS AND

METHODS

Patients (n = 139) treated with CCRS plus HIPEC were prospectively verified and retrospectively analyzed. One hundred presented with SB involvement of different extents and at different locations.

RESULTS

All the patients with a PCI ≥ 15 exhibited SB involvement. Five-year overall survival was 48% when the PCI was <15 vs 12% when it was ≥ 15 (p < 0.0001. The multivariate analysis retained two prognostic factors: PCI ≥ 15 (p = 0.02, HR = 1.8), and the involvement of area 12 (lower ileum) (p = 0.001, HR = 3.1). When area 12 was invaded, it significantly worsened the prognosis: 5-year overall survival of patients with a PCI <15 and area 12 involved was 15%, close to that of patients with a PCI ≥ 15 (12%) and far lower than that of patients with a PCI <15 and no area 12 involvement (70%).

CONCLUSION

A PCI greater than 15 appears to be a relative contraindication for treatment of colorectal PM with CCRS + HIPEC. Involvement of the lower ileum is also a negative prognostic factor to be taken into consideration.