Osteocalcin is a noncollagenous protein found in bone and dentin. It is secreted by osteoblasts and thought to play a role in mineralization and calcium ion homeostasis. It As osteocalcin is manufactured by osteoblasts, it is often used as a biochemical marker, or biomarker, for the bone formation process. Most of the use has been for monitoring treatment for osteoporosis but some use it for following metastatic bone disease. There are no guideline or consensus recommendations supporting this test for routine use.
Seregni E, Martinetti A, Ferrari L, et al: Clinical utility of biochemical marker of bone remodelling in patients with bone metastases of solid tumors. Q J Nucl Med 2001; 45(1):7-17.
Brown JP, Josse RG, & Scientific Advisory Council of the Osteoporosis Society of Canada: 2002 clinical practice guidelines for the diagnosis and management of osteoporosis in Canada. CMAJ 2002; 167(10 Suppl):S1-S34.
Yoichi Arai et al, Osteocalcin: Is it a useful marker of bone metastasis and response to treatment in advanced prostate cancer? The Prostate Volume 20 Issue 3, Pages 169 – 177
Posted by M L on September 25, 2009 | Permalink|Comments (0)|TrackBack (0)
Traditional methods of examining lymph nodes (LNs) for metastases involve microscopically examining hematoxylin and eosin (H&E) stained 5µm sections of each LN. However, this method has important limitations. Previstage™ GCC Colorectal Cancer Staging Test attempts to overcome problems with sampling errors, marker specificity and persistence of expression in CRC and metastases. Using ultrasensitive quantitative RT-PCR, the assay interrogates the patient’s lymph nodes to identify levels of GCC consistent with that found in LNs with histologically-confirmed, clinically significant metastases from stage III CRC patients.
This is a new and yet unproven method of lymph node sampling It may be superior to traditional methods of sampling but that needs to be proven and clincial benefit confirmed. Currently, I consider it to be investigational.
Alex Mejia and Scott A Waldman Previstage™ GCC test for staging patients with colorectal cancer Expert Review of Molecular Diagnostics September 2008, Vol. 8, No. 5, Pages 571-578