Randomised phase 2 trial of SIR-Spheres plus fluorouracil/leucovorin chemotherapy versus fluorouracil/leucovorin chemotherapy alone in advanced colorectal cancer. Randomised trial of SIR-Spheres plus chemotherapy vs. chemotherapy alone for treating patients with liver metastases from primary large bowel cancer.
Selective internal radiation therapy (SIRT) with SIR-Spheres(R) is a new technique for selectively targeting high doses of radiation to tumours within the liver. The primary objectives of this randomised trial were to compare the response rate, time to progressive disease (PD), and toxicity of a regimen of systemic fluorouracil/leucovorin chemotherapy versus the same chemotherapy plus a single administration of SIR-Spheres in patients with advanced colorectal liver metastases. The trial was designed to presage a larger trial that would have survival as the primary outcome.
                Twenty-one patients with previously untreated advanced colorectal liver metastases, with or without extrahepatic metastases, were randomised into the study.
                Using RECIST criteria, the response rate for 11 patients receiving the combination treatment was significantly greater than for 10 patients receiving chemotherapy alone (First Integrated Response; 10 PR, 1 SD vs. 0 PR, 6 SD, 4 PD, P < 0.001 and Best Confirmed Response; 8 PR, 3 SD vs. 0 PR, 6 SD, 4 PD P < 0.001). The time to PD was greater for patients receiving the combination treatment (18.6 months vs. 3.6 months, P < 0.0005). Median survival was significantly longer for patients receiving the combination treatment (29.4 months vs. 12.8 months, P = 0.02). One patient in the combination arm died from chemotherapy induced neutropenic sepsis after the fourth chemotherapy cycle. There were more Grade 3 and 4 toxicity events in patients receiving the combination treatment. There was no difference in quality-of-life over a 3 month period between the two treatments when rated by patients (P = 0.96) or physicians (P = 0.98).
                This small phase 2 randomised trial demonstrated that the addition of a single administration of SIR-Spheres to a regimen of systemic fluorouracil/leucovorin chemotherapy significantly increased both treatment related response, time to PD, and survival with acceptable toxicity. The combination of SIR-Spheres plus systemic chemotherapy is now the subject of ongoing trials to further define patient benefit.
                (c) 2004 Wiley-Liss, Inc. SIR-Spheres are radioactive yttrium90 microspheres (SIR-Spheres, Sirtex Medical Limited, Australia) used to selectively target high levels of ionising radiation to tumors within the liver. This trial was designed to measure any increased patient benefit by adding a single administration of SIR-Spheres to a regimen of regional hepatic artery chemotherapy (HAC) administered as a 12 day infusion of floxuridine and repeated at monthly intervals, vs. the same chemotherapy alone.
                A phase III randomised clinical trial entering 74 patients was undertaken on patients with bi-lobar non-resectable liver metastases from primary adenocarcinoma of the large bowel. Patient benefit criteria assessed in the trial were tumor response, time to disease progression in the liver, overall survival, quality of life, and treatment related toxicity. Tumor response was measured by serial changes in both cross-sectional tumor areas and total tumor volumes, provided any response lasted not less than three months as well as changes in serum carcino-embryonic antigen (CEA).
                The partial and complete response rate (PR + CR) was significantly greater for patients receiving SIR-Spheres when measured by tumor areas (44%) vs. 17.6%, P = 0.01) tumor volumes (50% vs. 24%, P = 0.03) and CEA (72% vs. 47%, P = 0.004). The median time to disease progression in the liver was significantly longer for patients receiving SIR-Spheres in comparison to patients receiving HAC alone when measured by either tumor areas (9.7 vs. 15.9 months, P = 0.001), tumor volumes (7.6 vs. 12.0 months, P = 0.04) or CEA (5.7 vs. 6.7 months, P = 0.06). The one, two, three and five-year survival for patients receiving SIR-Spheres was 72%, 39%, 17% and 3.5%, compared to 68%, 29%, 6.5% and 0% for HAC alone. Cox regression analysis suggests an improvement in survival for patients treated with SIR-Spheres who survive more than 15 months (P = 0.06). There was no increase in grade 3-4 treatment related toxicity and no loss of quality of life for patients receiving SIR-Spheres in comparison to patients receiving HAC alone.
                The combination of a single injection of SIR-Spheres plus HAC is substantially more effective in increasing tumor responses and progression free survival than the same regimen of HAC alone.
There is a need for well designed, adequately powered phase III trials assessing the effect of SIRT when used with modern combination chemotherapy regimens. Further studies are also needed for patients with refractory disease with a particular focus on the impact on quality of life.