Benefits of local consolidative treatment in oligometastases of solid cancers: a stepwise-hierarchical pooled analysis and systematic review

Abstract

Purpose: Any available evidence regarding the application of local consolidative therapy (LCT) for oligometastases is from phase 2 and observational studies. This study aimed to evaluate the oncologic benefits of LCT in oligometastatic setting. Methods: The MEDLINE, EMBASE, and Cochrane library were searched. We applied stepwise analyses that enabled the evaluation of data from randomized controlled trials (RCTs), balanced studies (e.g. without significant differences regarding major prognosticators between arms), and all studies separately and in a hierarchical manner Results: Thirty one studies including seven randomized trials were reviewed. Pooled analyses of the effect of LCT on overall survival (OS) revealed odds ratios (ORs) of 3.04 (95% confidence interval [CI]: 2.28~4.06, p<0.001), 2.56 (95% CI: 1.79~3.66, p<0.001), and 1.41 (95% CI: 1.02~1.95, p=0.041) for all studies, balanced studies, and RCTs, respectively. The corresponding ORs for progression free survival were 2.82 (95% CI: 1.96~4.06, p<0.001), 2.32 (95% CI: 1.60~3.38, p<0.001), and 1.39 (95% CI: 1.09~1.80, p=0.009), respectively. The benefit of LCT was higher in non small cell lung cancer (OR: 3.14, p<0.001; pooled 2 year OS: 65.2% vs. 37.0%) and colorectal cancer (OR: 4.11, p=0.066; pooled two year OS: 66.2% vs. 33.2%) than in prostate (OR: 1.87, p=0.006; pooled three year OS: 95.6% vs. 92.6%) and small cell lung cancer (OR: 1.04, p=0.942; pooled one year OS: 60.7% vs. 42.8%). Complications were generally mild. Conclusion: LCT provides oncologic benefits in the oligometastatic setting, although such benefits were less evident in RCTs than in data from observational studies. The appropriate LCTs should be carefully selected, considering their feasibility and disease types.

Benefits of local consolidative treatment in oligometastases of solid cancers: a stepwise-hierarchical pooled analysis and systematic review

“…This is a meta-analysis article that has used data retrieved directly from the text, figures, tables, and supplementary files of published articles. A list of all 31 articles used during this meta-analysis can be found in the following metadata record: https://doi.org/10.6084/m9.figshare.13292213 54 .…”

International consensus on radiotherapy in metastatic non-small cell lung cancer

“…Similarly, in patients with three or fewer metastases, consolidative radiotherapy or surgery extended the median PFS from 4.4 to 14.2 months and median overall survival (OS) from 17.0 to 41.2 months (12). Although these results are appealing, the role of radiotherapy in oligo-metastatic NSCLC warrants validation in prospective clinical trials (13).…”

“…The treatment paradigm for metastatic NSCLC has been rapidly transformed by the advent of ICI's, which have become a new standard of care in first-line settings (21)(22)(23). The synergistic anti-tumor effect of radiation and immunotherapy has formed the basis of several prospective trials evaluating the safety and efficacy of this combination therapeutic strategy (13,(24)(25)(26)(27)(28). As different dose-fractionation regimens have been found to result in heterogeneous immunologic effects, it is of clinical importance to explore the optimal regimen to maximize the efficacy of combined radiotherapy and ICI therapy.…”