Y-90 microspheres extend survival in 50 percent of metastatic colorectal cancer patients

Salvage patients, those with colorectal metastases to the liver who do not to respond to both first and second lines of treatment, are responding significantly to radioembolization with Y-90 microspheres. The dual-action treatment has been shown to lead to more than 12 months of overall survival, according to a study published Nov. 1 in the Journal of Nuclear Medicine.

As the second most prevalent cancer in women, the second most in men and the third leading cause of cancer death, colorectal malignancy is often aggressive and resistant to therapy in its most advanced stages. In about 50 percent of cases, colorectal cancer metastasizes to the liver. 

A team of researchers including Charlotte E.N.M. Rosenbaum, PhD, from the department of radiology at the University Medical Center Utrecht in Utrecht, The Netherlands, conducted a review of radioembolization using yttrium-90 microspheres, which both provide a killing dose to surrounding tissues and block blood to metastases. The main objective of the review was to evaluate tumor response and to find out whether it improves the dismal survival of salvage patients. Results of the analysis showed that about 50 percent of patients who undergo Y-90 radioembolization achieve at least 12 months survival following therapy.

“Although quite some reviews are printed on the subject of radioembolization, we felt that a structured and comprehensive review on survival and response data for these patients was lacking,” said Rosenbaum in a press release. “… Our paper shows all published data on this subject from the first randomized trial onwards. Furthermore, we have determined 12-month survival proportions for all included articles to provide a better overview and to better allow for comparisons. Finally, this overview of the literature shows which topics have not been the focus of much research and may thus be interesting for further work.”

The systematic review included 13 articles regarding Y-90 radioembolization alone and 13 additional articles as combined with chemotherapy to treat metastatic colorectal cancer. In instances of monotherapy, Y-90 led to disease control rates between 29 and 90 percent in 901 patients. For the 472 patients receiving combined therapy, those rates jumped to 59 to 100 percent.

Current protocol for calls for first-line treatment of colorectal cancer liver metastases is chemotherapy with fluoropyrimidine and secondly with irinotecan. A potential third line is monoclonal antibody therapy such as panitumumab or cetuximab. Typically Y-90 radioembolization is prescribed after these lines have failed. Three actively recruiting randomized controlled trials are set to compare first-line chemotherapy versus solely second-line chemotherapy with radioembolization.

“These results have to be awaited to determine the exact place of Y-90 radioembolization in general clinical practice in comparison with chemotherapy for patients with [colorectal cancer liver metastases],” wrote the authors.