ESTRO 2024 - Abstract Book

S2424

Clinical - Urology

ESTRO 2024

sites (1 vs >1) (HR 6.5, 95% CI 2.4-17.2, p-value<0.001) emerged as predictors of DPFS. At bivariate analysis the number of metastatic lesion was strongly associated with DPFS (HR 5.7, 95% CI 2.2-15.3, p-value<0.001), while T0 CTC did not reach significance, but the range showed a trend toward an increased HR (HR 2.2, 95% CI 0.87-5.6, p value=0.1). To further test the potential independence of T0-CTC as prognostic biomarker, we stratified patients into three groups according to their combined values of the number of metastatic lesions (1 vs >1) and CTC level (low vs high): “Low risk”, including patients with CTC - low and 1 lesion; “Intermediate risk” for patients with CTC -low and >1 lesion or CTC- High and 1 lesion; “High risk” for patients with CTC -High and >1 lesion. Kaplan-Meier analysis discerned a class of patients with excellent prognosis (those having 1 metastatic lesion and CTC<5 at T0), compared with all other patients (p=0.022; Fig. 2)

Table 1 Clinical characteristics of population

N (%)

Number of patients

34 (100)

Age at enrolment, median (IQR), y

73 (70-75)

T stage T2a

2 (5.9)

T2b T2c T3a T3b

4 (11.8) 13 (38.2) 8 (23.5) 7 (20.6)

ISUP grade group ISUP 1

3 (8.8)

ISUP 2 ISUP 3 ISUP 4 ISUP 5

5 (14.7) 13 (38.2) 8 (23.5) 5 (14.7)

iPSA (ng/ml), median (IQR) Primary treatment Radical Prostatectomy

8.8 (5.0-15.9)

2 (5.9)

Radiation Therapy

6 (17.6) 5 (14.7) 21 (61.8)

Radical Prostatectomy + adjuvant Radiation Therapy Radical Prostatectomy + salvage Radiation Therapy

ADT at primary treatment No

17 (50.0) 17 (50.0)

Yes

Biochemical control duration, median (IQR), m

26.0 (14.0-44.5)

ADT for biochemical relapse No

26 (76.5) 8 (23.5)

Yes

Time to Oligorecurrent disease, median (IQR), m

41.0 (20.5-51.0)

Number of previous SBRT treatment for Oligorecurrent disease 0

26 (76.5) 7 (20.6)

1 2

1 (2.9)

PSA at enrollment (ng/mL), median (IQR)

1.2 (0.6-2.5) 4.8 (3.6-8.8)

PSA-DT, median (IQR), m

Oligorecurrence site Lymph node only

25 (73.5) 4 (11.8) 5 (14.7)

Bone only

Both