A joint research team has confirmed the therapeutic effects and side effects of carotid artery radiation embolization in single-module liver cancer of five centimeters or larger is similar to liver resection surgery.
Liver cancer is the seventh most common cancer in Korea. According to the National Cancer Registry, there were 15,605 new cases of liver cancer in 2019, accounting for 6.1 percent of the total cancer incidence. Cancer shows a poor survival rate as liver cancer patients' five-year relative survival rate is 37.7 percent, only half of the overall cancer survival rate of 70.7 percent.
Notably, liver cancer larger than 5 cm in size has a particularly poor prognosis.
Even after liver resection, the standard treatment, recurrence occurs in about 30 percent of patients within two years. Also, as the size of the liver decreases after surgery, there is a high risk of deterioration of liver function.
Physicians had turned to carotid artery chemoembolization as an alternative treatment for patients who could not undergo liver resection due to underlying diseases. However, the treatment has side effects such as severe fever and abdominal pain in proportion to the size of cancer.
Therefore, radiation embolization, which has fewer side effects and is more effective than carotid artery chemoembolization, is attracting attention as an alternative treatment for liver resection. Radiation embolization is a method of treating cancer by administering microbeads loaded with yttrium-90, a radioactive material, to liver cancer through the hepatic artery to generate radiation from inside the tumor.
To confirm the efficacy of the treatment on large liver cancers with a size of more than 5 cm, the team, led by Professors Lee Jeong-hoon at Seoul National University Hospital and Kim Ji-hye at Seoul National University Bundang Hospital, divided large-sized single-nodule liver cancer patients into a radiation embolization group (57 patients) and liver resection surgery group (500 patients) and followed up on treatment effects and side effects.
The research team statistically corrected factors such as age (old age), comorbidity of systemic disease, tumor size, invasion of both left and right lobes of the liver, and invasion of the portal vein in consideration of the unfavorable situation in the radiation embolization group before treatment.
As a result, the team confirmed no statistical difference between the two groups regarding overall survival and relapse duration.
At 38.4 months after the first treatment, the radiation embolization and liver resection surgery groups' mortality rates were 21.1 and 20.4 percent, respectively.
Also, the cumulative recurrence rates for two years after the first treatment were 50 and 58 percent.
However, there was a difference in the degree of side effects after treatment. The proportion of patients with side effects such as abdominal pain and fever in the radiation embolization group was 43.9 percent compared to 100 percent in the liver resection group.
The length of hospitalization was also three days in the radiation embolization group and 12 days in the liver resection group, showing a significant difference.
"Through this study, it is encouraging to find out that radiation embolization is a sufficiently effective and safe treatment for large liver cancer compared to liver resection, recommended in global medical guidelines," Professor Lee said.
Professor Kim also said, "The curative treatment for large liver cancer is resection, but considering the residual liver function and the possibility of recurrence, surgery is often difficult, and liver transplantation is limited."
Radiation embolization may be hope as an alternative treatment for liver cancer patients who are difficult to operate on, Kim added.
The Journal of Nuclear Medicine published the study in its latest online edition.