ESTRO 2024 - Abstract Book

S1545

Clinical - Lower GI

ESTRO 2024

characteristics

Number of patients

25

Gender: -

15 10

Female

- Male

Age

61 (36-82)

Median radiation dose (range)

56 ( 46-56) Gy

Stage: Early

10 15

Stage

(T1/2

and

N0)

Advanced stage (T3/4 and or N1)

The cutoff point for HIF-1α expression was determined at 50% in comparison to the positive control, classifying patients into two groups: "high HIF1-α" (> 50%) and "low HIF-1α" (≤ 50%). Notably, There was no significant difference between the two groups regarding tumor stages as indicated by the Chi-square test (p-value 0.87). Regarding patient outcomes, the median overall survival (mOS) for the "high HIF-1α" group was 34.6 months, while for the "low HIF-1α" group, mOS had not been reached at the time of this analysis (P value: 0.044). Similarly, the median Disease-free survival (mDFS) for the "high HIF-1α" group was 33.8 months, and mDFS for the "low HIF-1α" group had not been reached at the time of this analysis (p-value: 0.028) (figure 1)

Finally. The median loco-regional control (LRC) for the “high HIF-1 α” group was 30.3 months, whereas for the “low HIF-1 α” group, mLRC had not been reached at the time of the analysis (p-value 0.019) (figure 1)

Figure 1 a) Kaplan Meier curves for OS, DFS, and LRC. b) example from a patient's specimen with low HIF-1 α expression < 1% and c) example from a patient's specimen with high HIF-1 α expression >90%

Conclusion: