Clinical applications of liquid biopsy in HPV‐negative and HPV‐positive head and neck squamous cell carcinoma: advances and challenges

Clinical insights into circulating free-DNA in patients with bone sarcomas and ewing sarcoma

BACKGROUND AND OBJECTIVES

Sarcomas represent a heterogeneous group of malignancies characterized by varying clinical behaviors and treatment responses. Liquid biopsy has emerged as a promising non-invasive method for monitoring tumor dynamics by detecting actionable mutations in cancer patients. The emergence of circulating DNA as a non-invasive biomarker offers promising avenues for improving diagnostic accuracy and treatment monitoring in sarcoma patients.

METHODS

In this study, the authors employed mutation-specific droplet digital PCR (ddPCR) to analyze tumor-derived cell-free DNA, also known as circulating tumor DNA (ctDNA), belonging to plasma samples of sarcoma patients, aiming to characterize mutation profiles in the IDH2 and TP53 genes. Between July 2019 and June 2023, the authors collected and analyzed 38 samples from patients diagnosed with osteosarcoma, chondrosarcoma, or Ewing's sarcoma. Histopathological confirmation of diagnoses was performed, followed by ddPCR analysis on 36 valid plasma samples.

RESULTS

The results showed mutations in three out of thirty-six sarcoma patients. Patient 1 exhibited a 12.6 % mutant IDH2 (R172S) allele fraction, Patient 2 had a 0.27 % mutant TP53 (R175H), and Patient 3 showed a 17 % mutant IDH2 (R172K). Notably, Patients 1 and 2 were diagnosed with chondrosarcoma, while Patient 3 had osteosarcoma.

CONCLUSIONS

The present study provided evidence for the feasibility of ctDNA detection in sarcoma patients, where mutations were found in IDH2 and TP53 genes, including a novel IDH2 mutation in osteosarcoma. The evaluation of ctDNA has the potential to transform clinical strategies in this challenging group of malignancies and this may be further confirmed in larger cohort studies. Continued research efforts are essential to optimize ctDNA detection methods and validate its utility across diverse sarcoma subtypes.

Cervical cancer screening: comparative study of human papillomavirus detection between cervical cytology and urine samples

OBJECTIVE

To evaluate the efficacy of urine-based human papillomavirus detection in detecting high-grade cervical lesions (CIN2+) compared to cervical cytology examination.

METHOD

The data of 458 patients with cytological abnormalities and/or positive human papillomavirus test results were retrospectively selected from December 1, 2017, to March 31, 2022, at the Beijing Obstetrics and Gynecology Hospital affiliated with Capital Medical University. Cervical cytology and urine samples were used to detect human papillomavirus status and analyze the correlation between the results and cervical biopsy results.

RESULTS

Among the selected 458 samples, 386 were positive for human papillomavirus through cervical cytology examination, with a detection rate of 84.3%. Out of 458 urine samples, 362 were positive, with a detection rate of 79.0%. The data shows a high consistency between cervical cytology and urine sample testing, with a kappa value of 0.637 (P < 0.01). The most prevalent subtypes in cervical samples included HPV16, HPV58, and HPV52, while the detection rates of HPV16 and HPV58 subtypes were relatively high in urine samples. The comparison of subtype distribution between cervical and urine samples showed that the positivity rate of HPV44 subtype was consistent, both at 3.9%. Among the five HPV subtypes corresponding to the HPV nine-valent vaccine, the kappa value of HPV16 in cervical and urine samples was 0.791 (P < 0.05), the kappa value of HPV52 was 0.766 (P < 0.05), HPV18 was 0.762 (P < 0.05), HPV33 was 0.539 (P < 0.01), and HPV31 was 0.458 (P < 0.05). Among 458 specimens, the sensitivity of human papillomavirus detection in cervical cytology was 96.7%, with a specificity of 20.2% (P < 0.01). The sensitivity of human papillomavirus detection in urine samples was 85.2%, with a specificity of 23.2% (P < 0.01).

CONCLUSION

Urine human papillomavirus testing, as a non-invasive screening method, has significant application effects. The screening results are highly consistent with cervical cytology screening and may improve the compliance of women who do not want to undergo invasive gynecological examinations. This screening method simplifies the screening process and has great potential in screening cancer lesions and preventing cervical cancer.

A pilot study on salivary HPV DNA detection to monitor active disease from patients with recurrent respiratory papillomatosis

PURPOSE

Recurrent respiratory papillomatosis (RRP) is a human papillomavirus (HPV)-related disease affecting the upper airway and saliva could be an important non-invasive sampling source for viral screening and clinical monitoring. We investigated whether HPV DNA could be detected in saliva (cellular pellets and supernatant) from RRP patients and influence on clinical manifestation of the disease.

MATERIALS AND METHODS

In this pilot study, saliva samples from 14 RRP patients were obtained in preoperative condition (n = 7) and in disease-free interval (DFI; n = 7). Healthy donors (n = 14) were also included. HPV DNA was investigated by polymerase chain reaction (PCR)-based assays.

RESULTS

From cellular pellets, HPV-positive saliva was only detected from preoperative collections (5/7; 71.4 %) and showed a mean cycle threshold (Ct) value of 24.33 (±1.25), whereas all patients in DFI were HPV-negative (Ct ≥ 32.16), revealing significant difference between these two clinical moments (p = 0.021). Patients in DFI and healthy donors showed similar Ct values. From saliva supernatant, detectable HPV cell-free DNA (cfDNA) occurred in 42.9 % (3/7) and 57.1 % (4/7) of preoperative collections using the commercial cfDNA kits from Norgen and Qiagen, respectively. Salivary cfDNA size distribution obtained by TapeStation analysis showed a predominant size range of 150 to 400 bp in both patients and healthy controls, corresponding to mononucleosomal and dinucleosomal fragments.

CONCLUSIONS

In conclusion, HPV DNA screening in saliva (both cellular pellets and cfDNA) may have clinical utility to monitor active disease of RRP patients.