SIR-Spheres microspheres are well-tolerated and effective internal radiotherapy for unresectable, heavily pre-treated colorectal cancer liver metastases, according to results from a new study of more than 600 patients presented at the 2012 American Society of Clinical Oncology (ASCO) Annual Meeting.
The data were presented by lead investigator Andrew Kennedy, from Cancer Centers of North Carolina and North Carolina State University.1 SIR-Spheres microspheres (Sirtex) are the only fully FDA-approved microsphere radiation therapy for the treatment of colorectal liver metastases.
“This is the largest, most comprehensive study to date evaluating the use of Selective Internal Radiation Therapy (SIRT) in liver metastases from colorectal cancer,” said Kennedy. “The data presented at ASCO confirm the safety and efficacy of this treatment option for patients and provide truly useful, validated information for clinicians. It is our hope that these results will help encourage appropriate patient selection discussion during tumor boards and with individual patients and their families.”
The investigator-initiated retrospective study presented at ASCO analysed the outcomes of using SIR-Spheres microspheres in US patients treated since 2002. The study’s endpoints included safety and tolerability, tumor response and survival.
The study focused on 606 patients (233 women; 373 men) at 10 institutions, who received a total of 966 SIRT treatments. Their mean age was 61.5 years (range, 20.8 to 91.9 years). Active extra-hepatic disease was present prior to the first SIRT procedure in 35.1% of patients. The vast majority (at least 92.6%) of patients had received prior chemotherapy, with over 30% having also received prior liver surgery or ablation.
The median overall survival for these heavily pre-treated patients was 9.6 months (95% CI 9.0–11.1) from their first SIRT treatment, with a median follow-up of 8.6 months (0.1–77.7 months). Reported adverse events were typically transient in duration and mild or moderate in severity. In total, 45% of patients had fatigue, 28% experienced nausea and 1% had liver failure. Only 2.1% of all treatments required an overnight stay following the procedure.
The modern US experience of SIRT using SIR-Spheres microspheres for unresectable, heavily pre-treated colorectal liver metastases confirms recently published data from international studies by Hendlisz, Seidensticker and Bester, who independently reported median overall survivals of 10.0, 8.3 and 11.9 months, respectively, in similar cohorts of patients with chemotherapy refractory disease.2–4
“The results of this study, collected from experienced treatment sites across the US, are further evidence of the safety and efficacy of SIR-Spheres microspheres in heavily pre-treated patients,” said Mike Mangano, president, Sirtex Medical. “This also highlights that SIR-Spheres microspheres provide clear survival benefits with limited toxicity in a patient population with few treatment options.”
SIR-Spheres microspheres are a novel outpatient treatment for colorectal liver metastases, both alone and in combination with chemotherapy. SIR-Spheres microspheres were FDA approved for use in colorectal liver metastases in 2002 and are now available at more than 400 cancer centres worldwide.
SIR-Spheres microspheres are approved for use in Australia, the United States of America (FDA approval), and the European Union (CE mark) and additionally supplied in countries such as Hong Kong, Malaysia, Singapore, Thailand, Taiwan, India, Israel and Turkey.
- Kennedy AS, Ball D, Cohen SJ et al. USA patients receiving resin 90Y microspheres for unresectable colorectal liver metastases: A multi-center study of 506 patients. ASCO Annual Meeting 2012, Journal of Clinical Oncology 2012; 30 (suppl): Abs. 3590. (updated results, as presented)
- Hendlisz A, Van den Eynde M, Peeters M et al. Phase III trial comparing protracted intravenous fluorouracil infusion alone or with yttrium-90 resin microspheres radioembolization for liver-limited metastatic colorectal cancer refractory to standard chemotherapy. Journal of Clinical Oncology 2010; 28: 3687–3694.
- Seidensticker R, Denecke T, Kraus P et al. Matched-pair comparison of radioembolization plus best supportive care versus best supportive care alone for chemotherapy refractory liver-dominant colorectal metastases. Cardiovascular and Interventional Radiology 2011 Jul 29; ePub doi: 10.1007/s00270-011-0234-7.
- Bester L, Meteling B, Pocock N et al. Radioembolization versus standard care of hepatic metastases: Comparative retrospective cohort study of survival outcomes and adverse events in salvage patients. Journal of Vascular and Interventional Radiology 2012; 23: 96–105.