Brian Hoyle

March 29, 2012

March 29, 2012 (Orlando, Florida) — Results of the largest study to date assessing the efficacy of radioembolization with yttrium-90 microspheres in the treatment of unresectable hepatic tumors have indicated the superiority of the approach over conventional therapy.

The latest data were presented in an oral presentation at the 65th Annual Cancer Symposium of the Society of Surgical Oncology (SSO).

"While the study has the limitations of a retrospective uncontrolled analysis and a lack of pathological information in the database, it is the largest comparison so far of radioembolization and conventional treatment. Our data with a range of tumor types demonstrate that radioembolization is a promising treatment in patients with unresectable tumors," said presenter Akshat Saxena, BMedSc, Department of Surgery, St. George Hospital, Kogarah, New South Wales, Australia.

The liver is a common site of primary cancer, which is diagnosed in about 28,000 Americans annually and which kills about 20,000 each year. It is also a source of metastatic disease, particularly colorectal cancer. An estimated 143,000 Americans develop colorectal cancer annually.

Surgery is the only curative option for liver cancer but is unsuitable for some 80% of patients. As an alternative, the use of yttrium-90 radioisotope enclosed in microspheres as a means of specific tumor targeting has shown potential. Yet, little is known about the outcomes of patients compared with those of patients treated conservatively.

In this retrospective study, the investigators analyzed data from 537 patients treated with yttrium-90 radioembolization between February 2006 and February 2011, most frequently for colorectal cancer (n = 287). According to a battery of biochemical, physiologic, and imaging tests, 422 patients were considered suitable for the treatment; the remaining 115 patients were unsuitable.

Median follow-up for all patients after initial evaluation was 11.5 months (range, 2 to 59 months).

Median survival of patients treated with yttrium-90 microspheres was 10.5 months, with 1- and 3-year survival rates of 44% and 20%, respectively. Median survival of conventionally treated patients was 4.0 months, with 1- and 3-year survival rates of 29% and 15%, respectively. The survival difference between the treatment groups was statistically significant (P < .001).

Patients with colorectal cancer collectively displayed a median survival time of 11.2 months. Median survival durations for those treated by radioembolization and those treated conventionally were 11.4 and 6.7 months, respectively (P = .003).

In patients with non–colorectal cancer, the collective median survival was 8.7 months. Median survivals for the radioembolization and conventional treatment groups were 9.1 months and 2.5 months, respectively (P < .001).

Although confounding factors not identified in the retrospective study probably were influential, the data indicate the value of yttrium-90 microsphere radioembolization in patient survival.

"Superior survival was demonstrated compared to best supportive care in patients with colorectal and noncolorectal tumor types," Saxena told Medscape Medical News.

"This is an excellent presentation. I'll be interested in knowing how this approach compares with the conventional in terms of difficulty, cost, survival prolongation, and side effects," session moderator Suzanne Klimberg, MD, University of Arkansas for Medical Sciences, Little Rock, commented after the presentation.

"In the treatment of colorectal cancer it's been difficult among the different treatment disciplines to get a consensus regarding when to introduce a regional radioembolization approach. A patient with a slower progression of disease may be a better candidate than one with faster progression," said attendee Roderich Swartz, MD, PhD, University of Texas Southwestern Medical Center, Dallas.

Dr. Klimberg has a financial relationship with AngioDynamics. Dr. Swartz has a financial relationship with Novartis. Akshat Saxena has disclosed no relevant financial relationships.

Society of Surgical Oncology (SSO) 65th Annual Cancer Symposium: Abstract #7. Presented March 23, 2012.


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