ESTRO 2024 - Abstract Book

S1862

Clinical - Mixed sites, palliation

ESTRO 2024

2010 to January 2023 for studies of adult patients with oligoprogressive disease treated with SABR to all oligoprogressive lesions. Oligoprogression was defined by the ESTRO-EORTC consensus guidelines and the number of OP lesions was defined 5 or fewer [9]. We included prospective or retrospective studies. If studies combined patients with oligometastatic, oligoprogressive, and oligorecurrent disease and outcomes could not be stratified, studies were excluded. Studies must have reported progression-free survival (PFS), overall survival (OS) or time to change to next-line of systemic therapy (CST). We extracted data on study design, study duration, sample size, primary cancer, follow-up, and clinical outcomes (OS, PFS, CST). Descriptive statistics were used to summarize the data collected including counts and percentages for categorical variables. Pooled analyses of proportions were conducted for prostate, kidney and other primary sub-groups using the binary random effects model for PFS1 (1 year progression free survival) and OS1 (1-year overall survival). Risk of bias among included studies was assessed using Newcastle-Ottawa Scale. Between studies heterogeneity was quantified using I2 values. Of the 21,274 results, 8908 duplicates were removed. 12,366 titles/abstracts screened, of which 24 met eligibility criteria and were included the review. All studies were published after 2017 with approximately 80% of the publications in 2021 and 2022 (Figure 1). Twenty-one studies (88%) were retrospective design and three (12%) were prospective. 23 (96%) studies had moderate risk of bias and one study (4%) had low risk of bias. Seventeen studies (71%) used a threshold of 5 or fewer progressing lesions to define oligoprogression, while 5 studies (21%) used 3 or fewer lesions. The tumour primary was prostate (n=8, 33%), kidney (n=6, 25%), colorectal (n=4, 17%) followed by breast (n=2, 8%) and other (n=4, 17%). PFS, OS and CST were reported in 21 (88%), 22 (92%) and 19 (79%) studies. At 1 year, the pooled progression free survival (PFS1) was 53% in prostate cancer patients (95% confidence interval [CI]: 45-60%, I2=46%), 49% (95% CI: 33-65%, I2=88%) in kidney cancer patients and 38% (95% CI: 17-59%, I2=93%) in other cancers (Figure 2). Reported median PFS was 8.9 to 16.6 months for prostate and 9.2 to 12.1 months for kidney cancer. The pooled OS at 1 year was 95% (95% CI: 92-97% I2=1%) for prostate, 89% (95% CI: 86-93% I2=0%) for kidney and 80% (95% CI: 70-91% I2=83%) for other cancers. The median OS ranged from 38.3 to 50.6 months in prostate (n=2) and 36.3 to 60.8 months in kidney (n=3). A median CST of 15.2 to 22.0 months was reported in 6 studies for OP prostate cancer, 12.6 to 18.2 months for kidney cancer (n=3), 4.9 to 5.2 months for colorectal (n=2) and 8.0 months for breast cancer (n=1). Results: