Cancer Immunology and HPV

The effects and safety of PD-1/PD-L1 inhibitors on head and neck cancer: A systematic review and meta-analysis

BACKGROUND

Inhibitors of programmed cell death-1 (PD-1) and its ligand (PD-L1) have been increasingly used in head and neck cancer therapy and reported to improve the outcomes with an acceptable safety profile. This systematic review and meta-analysis was conducted to assess the benefit and risk of PD-1/PD-L1 inhibitors in patients with head and neck cancer.

METHOD

The PubMed, Cochrane Library, EMBASE and Web of Science databases were systematically searched to find potentially eligible studies up to May 30, 2019. Primary outcomes were overall survival (OS), progression-free survival (PFS), objective response rate (ORR), disease control rate (DCR) and adverse events.

RESULTS

Overall, this analysis consisted of nine eligible studies, with two randomized controlled trials and seven single arm trials. In the treatment of recurrent or metastatic head and neck cancer, PD-1 inhibitors showed significantly lower relative risk of death than standard-of-care therapy (odds ratio [OR] = 0.60, 95% confidence interval [CI]: 0.44-0.82, I²  = 0%, P = .001). Programmed cell death-1 inhibitors also decreased the risk of disease progression, however, there was no statistically significant difference of PFS between the treatments (OR = 0.69, 95% CI: 0.48-1.01, I²  = 0%, P = .05). Subgroup analysis showed that human papillomavirus (HPV) positive patients had higher response rates than HPV negative patients in PD-1/PD-L1 inhibitors-treated population (ORR: 18.8% vs 12.2%; DCR: 42.8% vs 34.4%). The most common any-grade and grade ≥3 treatment-related adverse events were fatigue (14.7%, 95% CI: 12.3%-17.1%) and aspartate aminotransferase increased (1.6%, 95% CI: 0.3%-2.9%), respectively.

CONCLUSION

Programmed cell death-1 inhibitors prolonged OS in comparison with standard-of-care therapy in recurrent or metastatic head and neck cancer patients. Human papillomavirus positive patients were superior to HPV negative patients in the treatment of PD-1/PD-L1 inhibitors. More phase III randomized controlled trials are warranted to confirm our findings.

Characteristics and impact of programmed death-ligand 1 expression, CD8+ tumor-infiltrating lymphocytes, and p16 status in head and neck squamous cell carcinoma

BACKGROUND

No predictive biomarker of immune checkpoint inhibitors in head and neck squamous cell carcinoma (HNSCC) has been well established. The impact of programmed death-ligand 1 (PD-L1) expression, CD8+ tumor-infiltrating lymphocytes (TILs), and p16 status in HNSCC is unclear and may vary according to ethnicity.

METHODS

HNSCC patients treated between 2007 and 2013 were reviewed. Archival tissues were retrieved for PD-L1, CD8+ TILs, and p16 analyses. PD-L1 expression was evaluated by using the validated SP142 assay on the VENTANA platform. CD8+ TILs were defined by using semiquantitative scoring.

RESULTS

A total of 203 patients were analyzed. PD-L1 expression was observed in 80% of patients and was significantly associated with older age (P < 0.001). A high CD8+ TIL score (≥ 6) was significantly associated with never-smoking (P = 0.020), oral cavity cancer (P < 0.001), and stage M0 at presentation (P = 0.025). The p16 status was positive in 12% of patients. Patients with a high TIL score had a significantly longer OS (P = 0.032). Patients with PD-L1 expression of 1-49% and ≥ 50% were associated with a significantly shorter OS compared with those with PD-L1 < 1% (P = 0.027 and P = 0.011, respectively). Multivariate analysis showed that PD-L1 ≥ 50% was significantly associated with a poor OS. (HR 2.98 [95% CI 1.2-7.39]; P = 0.019.) CONCLUSIONS: A high prevalence of PD-L1 expression was observed in HNSCC using the validated SP142 assay. PD-L1 expression was associated with older age, while highly PD-L1 expression (≥ 50%) was an independent prognostic factor for poor OS in anti-PD1/PD-L1 untreated HNSCC patients.

The Role of Human Papillomavirus in Oropharyngeal Squamous Cell Carcinoma

Context.—

Human papillomavirus (HPV) is implicated in the development of oropharyngeal squamous cell carcinomas (OPC), particularly those cancers developing in tonsillar tissue.

Objectives.—

To review the prevalence, subtypes, and methods of detecting HPV in OPC and to review the epidemiology, histology, staging, management, and prevention of these cancers.

Data Sources.—

The study comprised a review of the literature.

Conclusions.—

The incidence of HPV-OPC is rising globally and in the United States, but rates of HPV-positivity vary with the anatomic site(s) and the population studied, as well as the method of detecting HPV infection. These tumors are more common in men. In contrast to HPV− OPC, the rates of smoking and alcohol abuse are lower. The HPV 16 subtype is predominant, and immunohistochemistry staining for p16 and in situ hybridization are the most widely used methods clinically to detect transcriptionally active HPV. Moreover, HPV-OPC has a unique tumor phenotype with predominantly nonkeratinizing morphology and a variety of patterns. These cancers often present with cystic lymph node metastases. The prognosis for HPV-OPC is significantly better than HPV− OPC and has led to differences in grading, staging, and management. Although there are similarities to cervical cancer, there are challenges in preventing such cancers.