Local Therapy for Oligoprogressive Disease: A Systematic Review of Prospective Trials

Purpose: The successes of local therapy for oligometastatic cancers cannot be extrapolated to oligoprogressive disease (OPD) because they are distinct clinical entities. Given the limited prospective data on OPD to date, summative analyses are urgently needed. Methods and Materials: Inclusion criteria for this Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)-guided systematic review were as follows. First, only prospective data were included. Second, progression had to have occurred on active/ongoing systemic therapy. Third, the number of progressing areas of disease had to be explicitly listed and ≤5 in number. Fourth, all progressing sites had to undergo local therapy (radiation therapy [RT] /surgery/nonradiation ablative procedures). Results: Eight trials met criteria (summing 290 patients), the vast majority of which used stereotactic RT as the local modality (most commonly, 19-20 Gy in 1 fraction, 27-33 Gy in 3 fractions, or 35-50 Gy in 5 fractions). A study on non-small cell lung cancer (NSCLC) demonstrated that stereotactic RT improved progression-free survival (PFS) and overall survival compared with historical values with systemic therapy alone. Two additional studies on epidermal growth factor receptor mutated (EGFRm) NSCLC also showed acceptable PFS with local therapy, particularly in patients who oligoprogressed on osimertinib. The only randomized trial analyzed herein showed that local therapy improved PFS for NSCLC but not breast cancer. Two trials in castration-resistant prostate cancer illustrated that a substantial proportion of patients did not require any changes in hormonal therapy or delayed the need to change systemic therapies. Lastly, 2 trials of renal cell carcinoma showed high (90%-100%) local control and median PFS of 9 months, and potentially a prolonged time to change systemic therapy. Lastly, from all patients in all trials, local therapy was tolerated well, with only 7 instances of grade 3+ toxicities. Conclusions: Based on the limited data, local therapy for oligoprogression is safe and yields encouraging short-term preliminary outcomes, but trials with larger sample sizes and longer follow-up are required for more robust conclusions.