ICC Rates on the Rise Among Certain Patient Groups

Nearly 20 years of surveillance data confirm that the incidence of intrahepatic cholangiocarcinoma (ICC) is on the rise, especially among male patients who are White, and that surgical intervention improves survival rates.

The report was published in Annals of Hepatic-Biliary-Pancreatic Surgery and was based on data from the Surveillance Epidemiology and End Results (SEER) database from 2000 to 2017.

The authors said that although ICC is considered a rare cancer, it is the second most common type of primary hepatic malignancy. Yet, while it is generally believed that rates of ICC are increasing, they said there has yet to be a population-level analysis done that incorporates survival data.

The SEER database is believed to include 28% of the US population as of the year 2010. The authors found 13,866 cases of ICC, mostly among patients who are White (10,976 cases), and nearly evenly split between male and female patients. However, male patients had a higher age-adjusted incidence of 1.1 cases per 100,000 persons compared with 0.8 cases per 100,000 persons among female patients.

“Our analysis shows that females carry a reduced risk of ICC compared with males after adjusting for age and race (P < .03), which could be due to a higher incidence of disorders that cause hepatic inflammation like hepatitis C, liver cirrhosis, and primary sclerosing cholangitis in males compared with females,” the authors said.

Blacks had a lower rate ratio of ICC vs Whites (0.83; 95% CI, 0.77-0.88), but people of Asian descent had a higher incidence than White patients (1.4; 95% CI, 1.32-1.47).

In terms of survival outcomes, the 1-, 3-, and 5-year survival rates were 36.3%, 12.8%, and 8.1%, respectively. The authors said the low 5-year survival rate may partially be due to age, as 75% of the people included in the analysis were over the age of 60.

“Younger patients aged less than 60 years had a better median survival time of 9 months than those above 70 years (6 months) in our analysis,” they said.

The data affirmed the benefits of surgery. Those who underwent surgery had a 72.1% lower risk of death than those who had nonsurgical interventions. Those who had surgery alongside chemoradiotherapy, radiotherapy alone, or chemotherapy alone had reduced death risks of 75.3%, 64.2%, and 73.1%, respectively, compared with nonsurgical interventions.

Still, the investigators noted that surgery might not be an option for all patients, such as those with metastatic disease.

They also examined whether lymph node removal during surgery affected outcomes, and they found that it did. Patients who underwent lymph node resection had a 64.1% lower risk of mortality compared with those who did not.

The authors said the study makes clear that ICC rates are a growing concern. Between 2000 and 2006, the age-adjusted incidence was 0.6 cases per 100,000 people. By 2012 to 2017, the rate had increased to 1.1 cases per 100,000 people. The authors said the higher caseload could be secondary to higher rates of hepatic infections related to increases in opioid and heroin use.

“Further, the rising incidence could be attributed to increasing rates of liver cirrhosis, nonalcoholic fatty liver disease, and obesity in the United States, which are established risk factors for ICC,” they said.

They concluded that this study and its breadth should be a useful tool in combating the growing problem.

“New information regarding ICC incidence and survival based on race, sex, and age will have a positive impact on resource planning and management of this disease,” they wrote.

Reference

Ali H, Tedder B, Waqar SH, Mohamed R, Cate EL, Ali E. Changing incidence and survival of intrahepatic cholangiocarcinoma based on Surveillance, Epidemiology, and End Results Database (2000-2017). Ann Hepatobiliary Pancreat Surg. Published online July 11, 2022. doi:10.14701/ahbps.21-173