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Selected Publication:
Strasser, A.
Is the 8th version of tumor classification for p16-positive and p16-negative oropharyngeal cancers of adequate quality
Humanmedizin; [ Diplomarbeit ] Medizinische Universität Graz; 2021. pp. 102
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- Authors Med Uni Graz:
- Advisor:
- Pondorfer-Schäfer Prisca
- Thurnher Dietmar
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- Abstract:
- Background: Evaluation of the quality and the predictive value of the 8th UICC TNM compared to the 7th UICC TNM staging manual regarding oropharyngeal squamous cell carcinoma associated with human papillomavirus (HPV) are currently active fields in research. Methods: Medical records of patients of a tertiary care center in Styria were retrospectively analyzed, included all eligible patients initially diagnosed with OPSCC from 2015 through 2018. These patients were primarily treated either surgically or with (chemo)radiotherapy or both at a single comprehensive cancer center. HPV status was determined by p16 testing. All patients were retrospectively staged according to both the 7th Edition (TNM7) and 8th Edition (TNM8) of UICC TNM classification for comparison. Overall survival (OS) and disease-free survival (DFS) were calculated using the Kaplan-Meier method. Results: A total of 178 patients were included; 49,4% of tumors were p16-positive, 44,4% were p16-negative, and in 6,2% the p16-status could not be determined in the medical records. Therefore, for analyses based upon the p16-status, that 6,2% of undefined patients were not considered. A notable shift in the TNM stage was observed for patients with p16-positive OPSCC, comparing 7th Edition vs. 8th Edition of UICC TNM classification: N=4 (TNM7) vs. n=39 (TNM8) patients were staged as stage I, n=7 (TNM7) vs. n=19 (TNM8) as stage II, n=8 (TNM7) vs. n=27 (TNM8) as stage III. According to TNM7, n=59 patients have been classified as stage IVA, n=7 as stage IVB, and n=3 as stage IVC, whereas only n=3 patients were left to be classified as stage IV with TNM8. When applying TNM7, the OS functions showed that patients with p16-positive OPSCC with stage III and IVA had a better OS than those with stage I and II. This misrepresentation changed when TNM8 was applied. The 3-year OS-rate for stage I tumors was 94%, for stage II 85% and for stage III 81%. When comparing overall stages, TNM8 showed a significant difference (p<0,001). This changed when adjacent stages were compared pairwise, only stage III and IV differed significantly (p<0,001). The analysis of DFS of patients with p16-positive OPSCC led to similar results. The DFS of stage III was superior to the one of stage I in TNM7. When applying TNM8 the 3-year DFS-rate for patients with stage I carcinoma was 80%, for stage II tumors 59% and for stage III tumors 63%. Again, the only statistically significant difference within this study cohort could be found between stage III and IV (p<0,001). Conclusion: The 8th Edition of UICC TNM classification has improved compared to its predecessor regarding the predictive value for p16-positive OPSCC. Further adaption may help to improve the classification and prognosis even more, particularly for stage II and III.