Promising Salivary Protein Biomarkers Identified for Prediction of Oral Squamous Cell Carcinoma
In new research in the journal Clinical Cancer Research,1 scientists from the University of California-Los Angeles discovered a panel of five protein biomarkers that could predict the presence of oral squamous cell carcinoma (OSCC) in whole saliva samples with 93 percent accuracy. The study is the first proteomic analysis of whole saliva samples from patients with OSCC, the most common type of oral cancer, and generated online news coverage from Reuters,2 WebMD,3 and other outlets.
The UCLA scientists collected unstimulated whole saliva samples from 64 healthy subjects and 64 patients who were recently diagnosed with oral squamous cell carcinoma. Pooled saliva samples from the two groups were completely matched with regard to gender and ethnicity. After immunoassay validation and a comparison of salivary protein profiles, the authors found that five candidate protein biomarkers (profilin, catalase, M2BP, MRP14, and CD59) had a high predictive accuracy in screening samples from OSCC patients.
The finding complements previous research from the team of UCLA scientists, including a 2004 study4 that found seven messenger RNA (mRNA) biomarkers with 91 percent predictive accuracy for screening OSCC. The UCLA research team plans to conduct a larger, multi-center validation study to determine if a combined panel of salivary biomarkers, both RNA and protein, can lead to the improved detection of oral squamous cell carcinoma.
With funding support from the National Institute of Dental and Craniofacial Research, the UCLA laboratory is one of several research centers that are pursuing the development of rapid, point-of-care oral fluid screening tests to help identify individuals at increased risk for oral and systemic diseases. While the discovery of candidate protein biomarkers for OSCC screening holds tremendous promise, the authors emphasize that extensive validation of the protein biomarkers is required, including long-term longitudinal studies with large populations of patients with oral cancer and other high-risk populations (e.g., tobacco users).
Based on estimates from the American Cancer Society,5 over 35,000 new cancer cases of the oral cavity and pharynx will be diagnosed in the United States this year. As noted in the UCLA study, oral squamous cell carcinoma is often detected in later stages when it is more advanced and harder to treat. The poor prognosis and five-year survival rates for oral cancer patients underscores the importance of ongoing research to validate candidate biomarkers for oral fluid diagnostic tests to assist with early oral cancer detection.
With expanded research in the field of oral fluid (salivary) diagnostics, there will be significant potential to develop simple, non-invasive screening tests that could help identify individuals at increased risk for oral cancer and other oral and systemic diseases. Early detection is of paramount importance for improving oral cancer survival, as is tobacco-use cessation is for preventing or lowering risks of oral cancer and other primary diseases. To support oral cancer prevention and improved oral health, dentists are encouraged to take an active role in oral cancer screening and in promoting tobacco cessation, moderate consumption of alcohol, frequent visits to the dentist, and appropriate oral hygiene. For additional information, visit the ADA.org Oral Health topic page on oral cancer and the National Cancer Institute’s Web site for patient information on lip and oral cavity cancer treatment.
1. Hu S, Arellano M, Boontheung P, Wang J, Zhou H, Jiang Z, Elashoff D, Wei R, Loo JA, Wong DT. Salivary proteomics for oral cancer biomarker discovery. Clin Cancer Res 2008;14(19):6246-6252. Available at: http://clincancerres.aacrjournals.org/cgi/content/abstract/14/19/6246. Accessed October 8, 2008.
2. Spit proteins could lead to oral cancer test: study. Reuters, October 1, 2008. Available at: http://www.reuters.com/article/idUSTRE49011X20081001. Accessed October 8, 2008.
3. Colihan K. Could saliva one day detect oral cancer? WebMD, October 1, 2008. Available at: http://www.webmd.com/oral-health/news/20080930/could-saliva-one-day-detect-oral-cancer. Accessed October 8, 2008.
4. Li Y, St John MA, Zhou X, Kim Y, Sinha U, Jordan RC, Eisele D, Abemayor E, Elashoff D, Park NH, Wong DT. Salivary transcriptome diagnostics for oral cancer detection. Clin Cancer Res 2004 Dec 15;10(24):8442-50. Abstract available at: http://clincancerres.aacrjournals.org/cgi/content/abstract/10/24/8442.
5. Cancer Facts and Figures, 2008. American Cancer Society, 2008. Available at: http://www.cancer.org/downloads/STT/2008CAFFfinalsecured.pdf. Accessed October 9, 2008.
Document Posted October 2008