By Will Boggs MD
NEW YORK (Reuters Health) - 27/9/2019
Liver resection is associated with a significant survival benefit in patients with colorectal-cancer liver metastases (CRC-LM), according to an analysis of linked databases.
"It has long been thought that resection of liver metastases from colorectal cancer is beneficial, so much so that a randomized trial has never been performed to prove it," Dr. Yuman Fong of City of Hope National Medical Center, in Duarte, told Reuters Health by email. "Using advanced statistical methods and a very large database, we were able to support this hypothesis that resection of such stage IV disease is beneficial using the highest level of proof short of a randomized trial."
About one in five patients with colorectal cancer have distant disease on diagnosis, with most metastases involving the liver. Even after liver resection, two-thirds of patients develop recurrent liver metastases within five years and a third of these will die of their disease. Liver resection, therefore, is potentially life-prolonging rather than curative for most patients.
Dr. Fong's team used linked data from the California Cancer Registry and the Office of Statewide Health Planning and Development Inpatient Database to estimate the impact of liver resection on overall survival of patients with CRC-LM.
Liver-resection rates varied by neighborhood area (NALR; 50-mile radius of patient's neighborhood) from 8.1% in the lowest quintile to 11.1% in the highest quintile and by Medical Service Study Area (MALR; geographic units defined by the U.S. Census Bureau) from 2.7% in the lowest quintile to 19.2% in the highest quintile.
Regardless of resection rate cutoff levels used in the instrumental analysis, liver resection was associated with significantly longer survival at the one-year mark, the researchers report in the Annals of Surgery, online August 29.
Using median cutoffs for both NALR and MALR rates, liver resection was associated with a 23.6-month longer overall survival.
At these median cutoffs, liver resection was associated with increases in overall survival of 105% at one year, 223% at two years, 375% at three years, 356% at four years, and 370% at five years.
"We are hoping to influence oncologic practice," Dr. Fong said. "Liver surgeons have long been convinced of the benefit of such resections of stage IV liver metastases. Referral for such resections, even in California, is still less than 10% of patients with metastatic liver disease. We estimate that approximately 40% of patients with metastases are candidates for resection. There is a major loss in opportunity to prolong life and possibly provide cure."
"I estimate that in California alone, in the last ten years, if referral for liver resection was more appropriate, we would have had a net gain of 150,000 years of life for California patients," he said. "Furthermore, since chemotherapy is very costly and attaining cure allows patients to come off chemotherapy, we would have saved at least 1 billion dollars."
"As our systemic therapies get better, our outcomes for resection of advanced disease will get even better," Dr. Fong said.
Ann Surg 2019.
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