Validation of the 8th edition UICC/AJCC TNM staging system for HPV associated oropharyngeal cancer patients managed with contemporary chemo-radiotherapy

Abstract

Background To compare outcomes of high-risk human papilloma virus-related oropharyngeal squamous cell carcinoma (HPV OPSCC) treated with modern radiation treatment (RT) and daily image-guidance, staged with the 7 th versus the 8 th Edition (Ed) Union for International Cancer Control (UICC)/American Joint Committee on Cancer (AJCC) TNM staging systems. Methods All eligible patients with HPV OPSCC treated definitively over a 10-year period (2007–2016) at a single institution were included. Protocols consisting of either RT or chemo-radiation (CRT) (weekly cisplatin or cetuximab) +/− neoadjuvant chemotherapy for those with bulky disease were used. All patients were Fluorine-18-deoxyglucose positron emission tomography (FDG-PET) staged at baseline and at intervals for up to 2 years post-treatment. Patients received parotid-sparing intensity modulated or volumetric modulated arc therapy with simultaneous integrated boost to either 70Gy in 35 fractions or 66Gy in 30 fractions. The overall survival (OS) was determined for each stage using the 7 th Ed and subsequently with the updated 8 th Ed staging system. Results One hundred fifty-three patients were analysed. Patient stage groupings varied between the 7 th and 8 th Eds respectively; Stage I (0.7% vs 64.7%), Stage II (8.5% vs 22.2%), stage III (21.6% vs 12.4%) and stage IV (69.3% vs 0.7%). In the 7 th Ed, the 5 year probability of OS for stages I to III was 90%, versus stage IV 85.5%. There was no statistically significant difference between the staging groups ( p = 0.85). In the 8 th Ed there was a statistically significant difference in 5 year OS for stage I and stage II disease (96.9% vs 77.1% respectively; p < 0.0001), but not between stage II and III disease ( p = 0.98). Conclusions The new 8 th Ed UICC/AJCC TNM staging system better discriminates between stage I and Stage II HPV OPSCC with respect to OS compared with the 7 th Ed staging system. Further investigation is required for stage III or IV patients.

Molecular mechanisms underlying increased radiosensitivity in human papillomavirus-associated oropharyngeal squamous cell carcinoma

“…Currently, according to the 8th edition of the American Joint Committee on Cancer (AJCC) Cancer Staging Manual, OPSCC is classified into two different phenotypes, according to the expression of p16 [34]. HPV-related OPSCC patients are considered to be a unique group.…”

CTEN Induces Tumour Cell Invasion and Survival and Is Prognostic in Radiotherapy-Treated Head and Neck Cancer

“…Human papillomavirus (HPV) status is the only molecular stratifier used routinely in current clinical practice [ 5 ] (mostly identified by using p16 expression as a surrogate marker) and is the single most significant non-anatomical prognostic marker [ 6 ]. Despite a higher incidence of positive lymph node involvement at presentation, which tended to skew staging information in the American Joint Committee on Cancer (AJCC) 7th Edition Manual towards advanced disease [ 7 ], patients with HPV +ve tumours have repeatedly been shown to have improved disease-free and overall survival compared to those with HPV −ve disease [ 8 , 9 , 10 ], although notably, a significant subset have more aggressive disease with poor clinical outcome [ 11 ].…”

Primary vs nodal site PET/CT response as a prognostic marker in oropharyngeal squamous cell carcinoma treated with intensity‐modulated radiation therapy

“…Patients who were AJCC 7 stage III became AJCC 8 stage I 73% of the time, stage II 24% of the time, and III 3% of the time. 23 Mizumachi et al did the same with a cohort of 111 patients and found that patients who were AJCC 7 stage IV became AJCC 8 stage I 56% of the time, stage II 20% of the time, and stage III 24% of the time. Patients who were AJCC 7 stage III became AJCC 8 stage I 47% of the time, and stage II 53% of the time.…”