Development of hepatic metastases in colorectal cancer – new insights

Introduction: Colorectal cancer (CRC) is the third most common malignancy in world. One third of all treated patients continue to develop hepatic metastases. Understanding the mechanism of spread and the establishment of metastases in the liver is vital in planning potentially curative treatment strategies for these patients.

Methods: A Pubmed and Medline literature search using keywords and their variations of colorectal, rectal, colon, cancer, hepatic metastasis and mechanisms was performed. Since all the retrieved mechanisms could not be included in this review, the search was further refined by using terms in the multistep process of hepatic metastasis of CRC.

Results: The initial search retrieved 2474 articles. Seven mechanisms were identified for the review by performing a highly selective search. They were based on the multistep process of hepatic metastasis, recently discovered pathophysiological and related molecular factors. These were, proteolytic enzymes, venous invasion, circulating tumour cells, evasion of host immune system, adhesion molecules, angiogenesis and tumour hypoxia.

Conclusion: The search identified a wide range of molecular mechanisms contributing to the metastatic process of CRC to the liver. Their inclusion in this review was based on the authors' selection criteria with a high probability of selection bias. Nevertheless, an understanding of the complex molecular mechanisms of developing hepatic metastases would enhance the ability to treat patients in view of prevention of disease progression to liver and improving overall outcome.

DOI: http://dx.doi.org/10.4038/sljs.v30i1.4501

The Sri Lanka Journal of Surgery 2012; 30(1):13-17