Incidence of Colorectal Cancer with Synchronous Liver Metastases Changed Little Over Time

The patterns of incidence and outcomes between synchronous and metachronous liver metastases from colorectal cancer showed little change over time in colorectal cancer with synchronous liver metastases compared with a 2-fold decrease in the probability of developing metachronous liver metastases, according to a study published in JAMA Open Network. The investigators noted that although the liver is the main site for distant metastases in patients with colorectal cancer, data about the incidence of synchronous liver metastases are lacking.

“Although liver metastases from colorectal cancer have historically been considered fatal, the existing literature had not adequately described the epidemiological features of liver metastases,” the study authors wrote. “This cohort study had the advantage of providing an unbiased view of temporal patterns in the incidence and outcomes of synchronous and metachronous liver metastases according to tumor site and stage at diagnosis of the primary colorectal cancer.”

The objective of the study was to analyze temporal patterns in the incidence and outcomes of synchronous vs metachronous liver metastases from colorectal cancer. The cohort study used information from a French regional digestive cancer registry accounting for 1,082,000 individuals.

There was a total of 26,813 patients with a diagnosis of incident colorectal adenocarcinoma diagnosed between January 1, 1976, and December 31, 2018. The data were analyzed from February 7 to May 20, 2022.

Out of the 26,813 patients with colorectal cancer, 4546 presented with synchronous liver metastases. The incidence rate of synchronous liver metastases was 6.9 per 100,000 individuals in men and 3.4 per 100,000 individuals in women with no significant variation since 2000.

The 5-year cumulative incidence of metachronous liver metastases dropped from 18.6% during the period of 1976-1980 to 10% during the period of 2006-2011.

“The higher incidence of synchronous and metachronous metastases in men than in women was consistent with findings of previously published studies. This disparity may reflect sex differences in behavioral, biological, hormonal, and immune regulatory factors,” the study authors wrote. “Our study found that standardized incidence had not changed significantly over the last 40 years, with the exception of a slight increase in colon cancer with synchronous liver metastases in men from 1976 to 2000. This lack of any decrease in incidence, despite the implementation of mass screening in 2002 in France, could be due in part to changes in cancer staging related to improved diagnostic procedures.”

The cancer stage at diagnosis was found to be the strongest risk factor for liver metastases. Compared with patients diagnosed with stage 2 cancer, patients with stage 3 cancer were found to have a 2-fold increase in risk for up to 5 years. The net survival at 1 year was 41.8% for synchronous liver metastases and 49.9% for metachronous metastases. Further, net survival at 5 years was 6.2% for synchronous liver metastases and 13.2% for metachronous metastases.

Between the first (1976-1980) and last (2011-2016) periods of evaluation, the adjusted ratio of death after synchronous and metachronous metastases was divided by 2.5 for patients with synchronous status and 3.7 for patients with metachronous status.

The study authors concluded that survival improved substantially for patients with metachronous liver metastases, whereas improvement was more modest for those with synchronous metastases. The investigators suggest future clinical trials to focus on the differences found in the epidemiological features of synchronous and metachronous liver metastases from colorectal cancer.

“The results of our population-based study suggest a gradual improvement in the therapeutic management of colorectal cancer liver metastases,” the study authors concluded. “Patients with synchronous liver metastases from colorectal cancer had worse outcomes than patients with metachronous liver metastases. These results are consistent with those of a recent population-based study, which found that overall survival was still better in patients with late metachronous metastases detected more than 12 months after diagnosis of the primary tumor than in patients with early metastases detected within 12 months of the colorectal cancer diagnosis.”

REFERENCE

Reboux N, Jooste V, Goungounga J, Robaszkiewicz M, Nousbaum J, Bouvier A. Incidence and Survival in Synchronous and Metachronous Liver Metastases From Colorectal Cancer. JAMA Netw Open. 2022;5(10):e2236666. doi:10.1001/jamanetworkopen.2022.36666.