Monitoring for liver metastasis is key
UM metastases are most likely to strike the liver, and prognoses are especially poor when they do. According to a 2019 analysis of 175 patients with metastatic UM in the Netherlands, “the presence of liver metastases is negatively associated with survival (hazard ratio = 2.09; 95% confidence interval, 1.07-4.08). … In 154 (88%) patients, the liver was affected, and only 3 patients were reported to have brain metastases.”2
As a result, physicians recommend close monitoring in patients with UM. Thomas Jefferson University’s Dr. Orloff uses tumor stages and genetic risk profiles to guide surveillance. “Very large tumors and/or monosomy 3 and 8q amplification or a Class 2 gene signature would suggest a higher-risk tumor,” she said. “For these patients we recommend MRI of the abdomen every 3 months for 2 years, CT of the chest every 6 months for 2 years, labs every 3 months for 2 years, then MRI every 6 months until year 5 with chest imaging yearly, then at 5 years everything yearly. For lower- or intermediate-risk patients we recommend MRI of the abdomen every 6 months for 5 years, chest imaging yearly, labs every 6 months, then at 5 years everything yearly.”
In the United States, patients with metastatic disease are typically sent to referral centers at institutions such as Duke, Yale (New Haven, Conn.), and Thomas Jefferson universities.
Metastasis treatments offer limited relief
There are no FDA-approved treatments for metastatic MU, and the treatments that physicians do use don’t seem to have much of an effect on life span. A 2019 study examined 73 patients with MU metastasis to the liver who were treated from 2004 to 2011 and 2012 to 2016. Among both cohorts, those who had no treatment lived nearly as long (median of 15 months) as those treated with local therapy (median of 18.7 months). Median survival for the entire population was 15 months (95% CI: 11–18 months). There was no statistically significant difference between the periods.3
However, there are signs that a move away from first-line chemotherapy in recent decades has led to longer life spans. Dr. Seedor led a 2018 study4 that compared two cohorts of MU patients with liver metastasis at her university: 98 patients from 1971 to 1993 (81% received systemic chemotherapy as their initial therapy) and 574 from 2000 to 2017 (they received various liver-directed initial treatments such as chemoembolization, drug-eluting beads, immunoembolization, and radioembolization).
The patients in the second group lived longer after treatment of initial UM than the first group (5.1 years vs. 3.3 years, P < .001) and after the development of liver metastasis (16.4 months vs. 4.8 months, P < .001). A 2020 follow-up study reported similar findings and noted that a “combination of liver-directed and newly developed systemic treatments may further improve the survival of these patients.”5
At Thomas Jefferson Medical Center, liver-directed therapy includes radioembolization, chemomobilization, and microwave ablation, Dr. Seedor said. “Which one we choose is based on how big the tumors are.”