ESTRO 2024 - Abstract Book

S1374

Clinical - Head & neck

ESTRO 2024

The median age of this cohort was 65 years (range: 27-83) with most pts having involved nodes at initial diagnosis (92%). In contrast to similar studies, a relatively high proportion of pts in this cohort were female (21%). Pts were treated with either standard chemoradiation or surgical resection followed by adjuvant radiation+/- chemotherapy, with six pts (5%) receiving extreme de-escalated dose with the DART regimen. Median follow-up was 14.8 months. The majority of pts had pretreatment testing (87%) as a baseline to determine TTMV score, which was compared to the change after treatment to evaluate complete resolution or persistence and then correlated with clinical and diagnostic exams to determine PPV. Pretreatment test scores had a median TTMV of 757 (range: 7 - 407,471). The scores of males and females were not statistically significantly different (t-test of log10-transformed scores, p=0.9). The pretreatment sensitivity of the p16-positive cohort was 88.2% (95% CI: 80.9 - 95.4%). These results correlate well with the combined data of seven other studies published by large academic centers, which showed a sensitivity of 90.4% (95% CI: 87.4 - 93.4%). In pts with a positive pretreatment test, 93% had their score resolve to zero within 3 months after initial treatment and none exhibited clinical evidence of residual disease on clinical exam or PET-CT imaging. Pts with high nodal burden (N2-N3 disease) were less likely to achieve test resolution than Pts with N0-N1 disease (Fisher's exact test, p = 0.0294). In surveillance, 78% of patients received one or more tests (range: 1-11 tests). . Currently, two pts whose TTMV nadired to zero tested TTMV-HPV DNA positive without clinical detection of recurrence (at how many months out?) who were treated with the DART adjuvant regimen. Both patients are without radiographic recurrence and remain under active surveillance.

Conclusion:

As one of the earliest community-based HN-MDC programs to adopt both Pre- and Post treatment TTMV-HPV DNA testing for HPV-OPSCC, our findings are in line with larger academic centers and support the clinical utility of TTMV HPV DNA testing in the setting of a community-based practice. The higher percentage of women in our cohort is unusual. Furthermore, although there was no statistical significance comparing pre-treatment test sensitivity in female and male subgroups, there was a trend toward lower sensitivity in females which warrants further investigation in a larger cohort.

Keywords: TTMV, HPV, ctDNA

2065

Digital Poster

HPV status, cancer stem cell expression and hypoxia are prognosticators in intermediate risk HNSCC

Annett Linge 1,2,3 , Hannah Hiepe 1,2 , Steffen Appold 1,2 , Dominik Haim 4 , Max Kemper 5 , Korinna Jöhrens 6 , Michael Baumann 7 , Steffen Löck 1,2,3 , Mechthild Krause 1,2,3 1 OncoRay – National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden - Rossendorf, Dresden, Germany. 2 Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany. 3 German Cancer Research Center (DKFZ), Heidelberg,