The American Joint Committee on Cancer staging for metastatic head and neck cutaneous squamous cell carcinoma: A multi-institutional study of within-stage heterogeneity and impact on prognostic performance

Impact of AJCC 8 pT staging in cutaneous head and neck squamous cell carcinoma in a nonselected real-world patient sample

OBJECTIVE

Our aim was to evaluate characteristics associated with worse survival and the effectiveness of AJCC 8 in a real-world cohort of HNCSCC from South Brazil.

METHODS

A 10-year retrospective cohort study (2011-2020) at a tertiary care center comprising 647 HNCSCC excised from 435 patients.

RESULTS

At multivariable analysis, ear/nose/zygomatic or periorbital site, compromised or exiguous margins, and advanced pT stage were independent factors associated to DFS, while age, pN, and loco-regional recurrence were independent factors associated to DSS. Cox-regression multivariable models showed that the pT stage was statistically significant for the DFS, but not DSS. A significant distinction was only observed between T1 and T2.

CONCLUSION

It was only in the lower categories of AJCC 8 (T1 and T2) that we were able to demonstrate the ability to stratify tumors with a significant risk of poor disease-related outcomes.

Evolution of Head and Neck Cutaneous Squamous Cell Carcinoma Nodal Staging—An Australian Perspective

Simple Summary

Australia has the highest incidence of cutaneous squamous cell carcinoma of the head and neck (HNcSCC) in the world. Although the majority of HNcSCCs are cured by simple surgical excision, those that spread to lymph nodes require aggressive and debilitating surgery in conjunction with radiation therapy, with a significant risk of treatment failure and subsequent loss of life. Cancer staging is critical to guide prognosis, treatment (to maximise disease control and minimise morbidity), and for research. Australian institutions have been at the forefront of prognostication for HNcSCC with lymph node spread. Despite this, the search for a well performing staging system is ongoing. This review chronologically explores and summarises the Australian contribution to date and highlights the ongoing challenges.

Abstract

Cutaneous squamous cell carcinoma of the head and neck (HNcSCC) is one of the commonest malignancies. When patients present with regional metastatic disease, treatment escalation results in considerable morbidity and survival is markedly reduced. Owing to the high incidence, Australian institutions have been at the forefront of advocating for reliable, accurate, and clinically useful staging systems that recognise the distinct biological characteristics of HNcSCC. As a result, an extensive body of literature has been produced over the past two decades, which has defined critical prognostic factors, critiqued existing staging systems, and proposed alternative staging models. Notwithstanding, a suitable staging system has proved elusive. The goal of cancer staging is to group patients according to cancer characteristics for which survival differs between groups (distinctiveness), consistently decreases with increasing stage (monotonicity), and is similar within a group (homogeneity). Despite implementing major changes based on published data, the latest edition of the American Joint Committee on Cancer (AJCC) staging manual fails to satisfy these fundamental requirements. This review chronologically explores and summarises the Australian contribution to prognostication and nodal staging of HNcSCC and highlights the ongoing challenges.

Associations of GWAS-Identified Risk Loci with Progression, Efficacy and Toxicity of Radiotherapy of Head and Neck Squamous Cell Carcinoma Treated with Radiotherapy

Background

Head and neck squamous cell carcinoma (HNSCC) ranks the sixth most common cancer worldwide. This study aims to evaluate the associations of GWAS-identified HNSCC risk loci with progression, efficacy and toxicity of radiotherapy of HNSCC treated with radiotherapy.

Methods

Six GWAS-identified risk loci were genotyped and evaluated. Multivariate logistic regression was used to determine the associations of these SNPs with progression, efficacy and toxicity of radiotherapy of HNSCC treated with radiotherapy.

Results

We found that rs259919 was significantly associated with higher TNM stage (allele A vs G: OR=1.49; 95% CI: 1.09–2.03; P=0.012), while rs3135001 was significantly associated with better efficacy of radiotherapy (allele T vs C: OR=1.80, 95% CIs=1.19–2.73, P=0.005). Both SNP rs1265081 (allele A vs C: OR=1.41, 95% CIs=1.08–1.86, P=0.012) and rs3135001 (allele T vs allele C: OR=0.53, 95% CIs=0.35–0.79, P=0.002) were significantly associated with the occurrence of grade 3–4 oral mucositis.

Conclusion

We identified that three GWAS-identified HNSCC risk loci were significantly associated with progression, efficacy and toxicity of radiotherapy of HNSCC. Our findings strengthen the understanding of the essential role of genetic background in the progression and therapeutic effects of HNSCC.