PERFUSION TO COLORECTAL-CANCER LIVER METASTASES IS NOT UNIFORM AND DEPENDS ON TUMOR LOCATION AND FEEDING VESSEL

Future effective therapies for hepatic metastases may depend on a bett er understanding of perfusion to these tumors. The purpose of this pro ject was to define blood flow to colorectal cancer liver metastases us ing quantitative autoradiography (QAR). Liver tumors were established in F-1 hybrids of WF x BN rats by intrasplenic injection of a DMH-indu ced rat colon adenocarcinoma. Rats underwent laparotomy 4-5 weeks late r and [C-14]iodoantipyrine (a radiotracer) was infused via the hepatic artery (HA) or portal vein (PV). Livers were harvested, frozen in liq uid nitrogen, and sectioned at 20 mu m through all tumors. QAR compare d optical density of cross sections of tumors to surrounding normal li ver tissue. Tumor:liver perfusion ratios (T/L PR) and tumor center:tum or periphery perfusion ratios (C/P PR) were calculated. All groups wer e analyzed with regard to tumor location and size. Seventy-seven tumor s in 6 rats in the HA infusion group were analyzed; 74 tumors in 8 rat s in the PV group were analyzed. Statistical analysis was by repeated measures analysis of variance. Mean HA T/L PR = 0.97 +/- 0.13, mean PV T/L PR = 0.25 +/- 0.11. Mean HA T/L PR for deep tumors was 1.38 +/- 0 .17 and for superficial tumors was 0.57 +/- 0.15 (P < 0.01). Mean HA T /L PR for small tumors was 1.09 +/- 0.12 and for large tumors was 0.86 +/- 0.21 (P = 0.27). Mean PV T/L PR for deep tumors was 0.27 +/- 0.14 and for superficial tumors was 0.24 +/- 0.15 (P = 0.71). Mean PV T/L PR for small tumors was 0.31 +/- 0.15 and for large tumors was 0.20 +/ - 0.14 (P = 0.54). Mean HA C/P PR = 1.15 +/- 0.15, mean PV C/P PR = 0. 81 +/- 0.14 (P = 0.06). Mean HA C/P PR for small tumors was 1.37 +/- 0 .16 and for large tumors was 0.92 +/- 0.17 (P = 0.01). Mean PV C/P PR for small tumors was 0.78 +/- 0.18 and for large tumors was 0.72 +/- 0 .13 (P = 0.71). HA perfusion of tumors is significantly higher than PV perfusion compared to surrounding normal liver tissue. HA perfusion v aries significantly depending on tumor location. There was a trend tow ard HA perfusion to the tumor center being slightly greater than to th e periphery whereas the reverse was seen for PV perfusion. Tumor size did not affect overall perfusion but it did affect regional HA tumor p erfusion. (C) 1997 Academic Press.