(ChemotherapyAdvisor) – Patients with metastatic colorectal cancer (mCRC) involving more than 2 distant organs or with a primary tumor in the rectum or descending colon should be considered for neuroimaging to rule out metastatic tumors in the brain (BM), according to a retrospective cohort study presented at the American College of Gastroenterology’s 77th Annual Scientific Meeting in Las Vegas, NV.
“Patients with stage 4 CRC, who have >2 additional organs involved and those with metastases to lungs, lymph nodes or bones, are more likely to have BM,” reported lead author Darshan Dhingani of the Cleveland Clinic in Cleveland, OH, and coauthors.
Metastases to the liver or primary tumor in the sigmoid colon, however, were associated with a protective effect against brain involvement, they found.
The authors analyzed medical records for 301 patients, 206 (68.4%) of whom were diagnosed with metastatic tumors in >2 organs, most commonly liver (n=226; 76%). Median survival time after initial CRC diagnosis was 17.5 months.
Brain metastasis was significantly more likely to occur among patients with mCRC in >2 other distant organs (OR, 4.32; P<0.001); those with lower blood levels of carcinoembryonic antigen (CEA) at the time of initial diagnosis of CRC (P<0.001); or lung, bone, or lymph involvement (P<0.001), and was less likely to occur in patients with liver involvement (P<0.001), the authors reported.
“Those with a primary tumor location in the rectum and descending colon (P=0.028) were more likely to have BM; those with a primary (tumor) in the sigmoid were less likely to have BM (P=0.024),” they noted.
Patients with brain metastases were significantly more likely than others with mCRC to have undergone all forms of treatment (P<0.001).
“These results can be helpful in identifying CRC patients at higher risk of BM,” the authors wrote.
Brain imaging to identify metastases “may be important” even in the absence of signs or symptoms of brain tumors among patients with CRC metastatic disease confirmed in more than two organs, the authors argued.