Chondrosarcoma is the third most common primary
bone cancer, requiring surgical resection. However, differentiation of low-grade
chondrosarcoma (grade 1) from
enchondroma that is benign and only requires regular follow-up is one of the most frequent diagnostic dilemmas facing orthopedic oncologists in clinical management. Although multiple techniques are applied to make the distinction, immunohistochemistry is an important ancillary technique, especially when a histopathological
stain of specimen must be obtained in order to guarantee an accurate confirmation. Currently, no adequate immunohistochemical diagnostic
protein biomarkers are available to distinguish low-grade
chondrosarcoma from
enchondroma. To discover novel
protein biomarker candidates, an LC-MS/MS approach was applied to directly compare
formalin-fixed,
paraffin-embedded low-grade
chondrosarcoma with
enchondroma tissue samples. The proteomics analysis revealed 17
protein biomarker candidates. A principle was developed to prioritize the candidates using category and ranking. An algorithm, prioritization index of
biomarker candidates for immunohistochemistry on tissue specimens, was developed to rank the candidates inside each category. Using the proteomics data and bioinformatics results, the prioritization index of
biomarker candidates for immunohistochemistry on tissue revealed
periostin as a top candidate. Immunohistochemical staining of
periostin in 23 low-grade
chondrosarcoma and 31
enchondroma tissue specimens disclosed 87% specificity and 70% sensitivity.