ESTRO 2024 - Abstract Book

S5327

Radiobiology - Tumour biology

ESTRO 2024

Data revealed an increase in NRF2 expression and total antioxidant capacity in several HNSCC cell lines in vitro over the course of five daily fractions of 2 Gy (figure 1).

Figure 1 Antioxidant capacity of Fadu, UM-SCC6, UT-SCC24A cells. Data are represented as mean + SD. Statistical significance was determined by one-way Anova with multiple comparisons, comparing each condition to unirradiated. *, p < 0.05; **, p < 0.01; ***, p < 0.001; ****, p < 0.0001 In accordance, also in patients’ HNSCC tumors NRF2 expression increased, which was associated with increased serum total antioxidant capacity during RT. Increasing serum total antioxidant capacity during RT was related to impaired local tumor control (figure 2).

Figure 2 Local disease control in patients with increased total antioxidant capacity (TAC) at T2 and patients with steady TAC. Data are represented as mean ± SD. Statistical significance was determined by Mantel-Cox survival analysis.

Conclusion: