Background: Biomarkers in head and neck squamous cell carcinoma (HNSCC) emerge rapidly in recent years, especially for new targeted therapies and immunotherapies.Methods: Recent, relevant peer‐reviewed evidence were critically reviewed and summarized.Results: This review article briefly introduces essential biomarker concepts, including purposes and classifications (predictive, prognostic, and diagnostic markers), and the phases of biomarker development. We summarize current biomarkers in order of clinical utility; p16 and human papillomavirus status remain the most important and validated biomarkers in HNSCC. The rationale for biomarker study design continues to evolve with technological advances, especially whole‐exome or whole‐genomic sequencing. Noninvasive body fluid and liquid biopsy biomarkers appear to hold strong potential for development as tools for early cancer detection, cancer diagnosis, monitoring of disease recurrence, and outcome prediction. In light of discrepancies among different technologies, standardized approaches are needed.Conclusion: Biomarkers from cancer tissue or blood in HNSCC could direct new anticancer therapies.

Circulating tumour cells (CTCs) in a blood circulation system are associated with cancer metastasis. The analysis of the drug-resistance gene expression of cancer patients’ CTCs holds promise for selecting a more effective therapeutic regimen for an individual patient. However, the current CTC isolation schemes might not be able to harvest CTCs with sufficiently high purity for such applications. To address this issue, this study proposed to integrate the techniques of optically induced dielectrophoretic (ODEP) force-based cell manipulation and fluorescent microscopic imaging in a microfluidic system to further purify CTCs after the conventional CTC isolation methods. In this study, the microfluidic system was developed, and its optimal operating conditions and performance for CTC isolation were evaluated. The results revealed that the presented system was able to isolate CTCs with cell purity as high as 100%, beyond what is possible using the previously existing techniques. In the analysis of CTC gene expression, therefore, this method could exclude the interference of leukocytes in a cell sample and accordingly contribute to higher analytical sensitivity, as demonstrated in this study. Overall, this study has presented an ODEP-based microfluidic system capable of simply and effectively isolating a specific cell species from a cell mixture.

Background: The role of circulating tumor cells (CTCs) for predicting the recurrence of cancer in lung cancer patients after surgery remains unclear. Methods: A negatively selected protocol of CTC identification was applied. For all the enrolled patients, CTC testing was performed before and after surgery on the operation day (day 0), postoperative day 1, and day 3. The daily decline and trend of CTCs were analyzed to correlate with cancer relapse. The mixed model repeated measures (MMRM) adjusted by cancer characteristics was applied for statistical significance. Results: Fifty patients with lung mass undergoing surgery were enrolled. Among 41 primary lung cancers, 26 (63.4%) were pathological stage Tis and I. A total of 200 CTC tests were performed. MMRM analysis indicated that surgery could contribute to a CTC decline after surgery in all patients with statistical significance (p = 0.0005). The daily decrease of CTCs was statistically different between patients with and without recurrence (p = 0.0068). An early rebound of CTC counts on postoperative days 1 and 3 was associated with recurrence months later. Conclusion: CTC testing can potentially serve as a tool for minimal residual disease detection in early-staged lung cancer after curative surgery.

Tuberculosis (TB) causes a heavy health burden worldwide, especially in developing countries. The need for the rapid and accurate diagnosis of TB has not been satisfied, especially for extra-pulmonary specimens or specimens with acid fast stain (AFS)-negative condition. Development and validation of a novel, sensitive and specific assay for diagnosing TB is essential. We developed IS4 primer/probe based on insertion sequence 6110 (IS6110). A qPCR assay was designed for detecting a specific region in IS6110 by BLAST. The IS4 primer/probe concentration, qPCR efficiency and various of PCR additives were evaluated and optimized. Thirty-four species of commonly isolated microorganisms were used for evaluating the analytical specificity. Moreover, 130 clinical specimens were collected for evaluating the performance versus Cobas TaqMan MTB (CTM) assay kit and culture. The amplification efficiencies of IS4 were 99.61% and 102.61% without and with internal control DNA (Bacteriophage Lambda), respectively. Dimethyl sulfoxide outperformed glycerol or BSA for eliciting the most effective amplification and the lowest limit of detection. In evaluating the clinical performance, various specimen types were collected. IS4 demonstrated a high degree of agreement (kappa = 0.71) with CTM. The clinical sensitivity and specificity of IS4 and CTM were 92.11% (35/38), 82.61% (76/92), 84.21% (32/38) and 95.65% (88/92), respectively. The clinical sensitivity and specificity of IS4 were similar for both pulmonary [92.00% (23/25) and 76.92% (30/39), respectively] and extrapulmonary [92.31% (12/13) and 86.79% (46/53), respectively] specimens. Among AFS-negative cases, the clinical sensitivity and specificity remained 90.48% (19/21) and 83.91% (73/87), respectively, with culture as the gold standard. We concluded that IS4, a new primer/probe pair for TaqMan based qPCR assay, was developed, optimized, and validated for the sensitive and specific detection of TB among various specimen types. The performance was not compromised under AFS-negative conditions.