Most patients with colorectal liver metastases receive systemic chemotherapy.
Dr Stéphane Benoist and colleagues from France determined the significance of a complete response on imaging of liver metastases after chemotherapy.
The team treated 586 patients for colorectal liver metastases between 1998 and 2004 in one institution.
Of these patients, 38 were included in the study.
The patients had surgery with intraoperative ultrasound within 4 weeks of imaging, no extrahepatic disease, and follow-up at least 1 year after surgery.
The researchers found that 66 liver metastases disappeared after chemotherapy as seen on a computed tomography scan.
Persistent macroscopic disease was observed at surgery at the site of 20 of 66 liver metastases.
|23 of 31 liver metastases considered in complete response had recurred in situ|
|Journal of Clinical Oncology|
The team noted the disease despite computed tomography scan showing a complete response.
The sites of 15 initial liver metastases that were not visible at surgery were resected.
Pathologic examination of these sites of liver metastases, considered in complete response, showed viable cancer cells present in 12 of 15 cases.
The researchers found that the sites of 31 initial liver metastases that were not visible at surgery were left in place during surgery.
After 1 year of follow-up, 23 of 31 liver metastases considered in complete response had recurred in situ.
Overall, persistent macroscopic or microscopic residual disease or early recurrence in situ were observed in 55 of 66 liver metastases.
The team observed that these metastases had a complete response on imaging.
Dr Benoist's team concluded, “In most patients receiving chemotherapy for colorectal liver metastases, a complete response on computed tomography scan does not mean cure.”