Researchers have been able to identify similarities in outcomes between colorectal liver metastases that cannot be completely removed by surgery (unresectable) and patients with the KRAS mutation. Surgical resection is considered a standard for liver metastases. However, most patients present with unresectable lesions.
The subject was presented at the 2021 International Conference of the Society of Surgical Oncology on Surgical Cancer Care and reported by Cancer Network.
Hepatic Arterial Infusion Pump Therapy (HAI)
Blood reaches the liver through nutrient-rich blood drained from the portal vein (the portal circulation) and from hepatic arterial circulation.
HAI is a procedure that delivers chemotherapy into the liver. It is primarily used with systemic (whole-body) chemotherapy for patients with colorectal cancer that has metastasized to the liver.
KRAS Mutation vs. Wild Type KRAS
In reviewing the effects of KRAS mutations on tumor response, researchers confirmed that overall outcomes with HAI pump therapy combined with systemic chemotherapy were inferior to those of wild-type KRAS.
The natural gene, or unchanged form, is called Wild-type KRAS.
The changed (mutated) form of KRAS has been discovered in various types of cancer such as lung, colorectal and pancreatic cancers. It is believed that cancer cells may spread through the body as a result of these mutations.
About the Retrospective Study
Dr. Hordur Kolbeinsson of Michigan University’s General Surgery Residency presented the data. The researchers reviewed a study that compared systemic chemotherapy combined with HAI against systemic chemotherapy alone. That study showed improved survival outcomes when patients received HAI and provided the rationale for the new retrospective study.
The new study which took place between August 2017 and September 2020, included thirteen patients with wild-type KRAS. Eleven patients in the study had the KRAS mutation.
All patients in the study had unresectable colorectal liver metastases and were administered HAI. The objective response rate (ORR) served as the primary measurement.
The KRAS mutant group’s ORR was sixty-four percent while the wild-type group registered one hundred percent.
Dr. Kolbeinsson commented that the results of the study were not unexpected and yet an ORR of sixty-four percent for the KRAS group was a positive response.
These data show potential for patient education and clinical prognostics but Dr. Kolbeinsson cautions that it should not be thought of as a guide for the selection of HAI chemotherapy. He added that more studies are needed to determine the best timing relating to unresectable colorectal liver metastases.