Missing Liver Metastases in colorectal cancer as a clinical challenge. Single centre experience

Abstract

Background: Chemotherapy regimens have changed the current scenario of CRC LM, making some difficult to identify through classic radiological techniques. Missing Metastases (MM) arise as a clinical challenge for the surgeon. Methods: The aim of this study was to identify “Missing Metastases”, defined as lesions on baseline imaging that were not identifiable on pre-operative MRI. Retrospective review of hepatic resections for colorectal metastases between 01/2014 and 12/2016 was performed to evaluate the rate of complete radiological and pathologic response. Results: In the 2 year period we performed liver resection (LR) in 172 patients, of which 13 presented MM. The total number of MM identify on baseline imaging for these patients was 51. At surgical pathology 6 of 16 lesions resected demonstrated viable tumor. Twenty two of 35 lesions left in situ presented a sustained clinical response, meanwhile 13 of 35 relapsed in the same location. Conclusion: Despite disappearance on MRI imaging, pathology exam showed viable tumor in 37% of resected LM. On the other hand, in patients with MM left in situ, more than the third part relapse during the first year. New radiological techniques such as Fusion CEUS-CT and Fiducial markers could help the surgeon to identify the original location and perform a complete resection.