The short arm of chromosome 8 is frequently deleted in advanced human colorectal cancers, suggesting the presence of one or more tumor suppressor genes having a major role in tumor progression and metastasis. Comprehensive sequencing of over 18,000 genes in colon and breast cancers identified somatic mutations in CUB and Sushi Multiple Domains 1 Gene (CSMD1)which is located on the p arm of chromosome 8. In this report, we describe a novel, robust, high-throughput gene mutation profiling strategy based on massively parallel picotiter plate pyrosequencing and have used this approach to identify additional somatic mutations to CSMD1 in early and late stage colorectal cancers. Using this strategy, we identified five nonsynonymous somatic mutations in CSMD1 among 26 colorectal cancers. Interestingly, these mutations occurred predominantly in advanced colorectal tumors,suggesting a role for CSMD1 in the development of late-stage metastatic disease.