Accelerated progression of metastatic disease shortly after Y90-microsphere treatment: Is there a causative relation?

Objectives There is debate in literature whether immediate local ablation of tumors may cause accelerated progression of metastatic disease. This is observed especially in colorectal cancer patients and the underlying mechanism still remains unclear. This study was done to assess whether intraarterial Y-90 microsphere therapy as being one of the local ablative therapies may cause an accelerated progressive disease in a patient population with miscellaneous diagnoses.

Methods 97 patients underwent intraarterial Y90-microsphere therapy between the years 2009-2011. Among those, 64 patients who underwent early follow-up PET/CT scan at 1-3 months following therapy were included. Follow-up PET/CT results in correlation with CT and/or MRI were evaluated to detect any new extrahepatic or hepatic metastases in untreated region.

Results Out of 64 patients, 12 (19%) developed newly diagnosed either extrahepatic or hepatic metastases in untreated region. Distribution of metastases were extrahepatic as bone, lung and lymph node in 7, untreated hepatic region in 2 and both hepatic and extrahepatic regions in 3 patients. Diagnoses of 12 patients with early metastatic progression after therapy were dominantly colorectal cancer (33%) followed by breast and cholangiocellular cancer (17% each) and others (23%).

Conclusions Our results may support the idea that rapid ablation of tumor tissue by intraarterial microsphere therapy may give rise to accelerated progression of metastatic disease at both untreated hepatic and extrahepatic regions. The reason might be overstimulation of angiogenesis due to rapid disappearance of angiogenesis inhibiting factors following tumor ablation. Depending on this observation, adjunctive use of angiogenesis inhibitors may be considered to be prescibed to patients undergoing radiomicrophere therapy