Colorectal cancer (CRC) patients suffer from the second highest mortality among all
cancer entities. In half of all CRC patients,
colorectal cancer liver
metastases (CRLM) can be observed. Metastatic
colorectal cancer is associated with poor overall survival and limited treatment options. Even after successful surgical resection of the primary
tumor, metachronous liver
metastases occur in one out of eight cases. The only available curative intended treatment is hepatic resection, but metachronous CRLM frequently recur after approximately 1 year. In this study, we performed a
proteome analysis of three recurrent liver
metastases of a single CRC patient by mass spectrometry. Despite surgical resection of the primary CRC and
adjuvant chemotherapy plus
cetuximab treatment, the patient developed three metachronous CRLM which occurred consecutively after 9, 21 and 31 months. We identified a set of 1132
proteins expressed in the three metachronous CRLM, of which 481 were differentially regulated, including 81
proteins that were associated with the extracellular matrix (ECM). 56 ECM associated
proteins were identified as upregulated in the third
metastasis, 26 (46%) of which were previously described as negative prognostic markers in CRC, including
tenascin C,
nidogen 1,
fibulin 1 and
vitronectin. These data may reflect an ascending trend of
malignancy from the first to the third metachronous
colorectal cancer liver
metastasis. Additionally, the results indicate different ECM phenotypes for recurrent metachronous
metastasis, associated with different grades of
malignancy and highlights the importance of individual analysis of molecular features in different, consecutive metastatic events in a single patient.