Luca Nicosia1, Francesco Cuccia2, Rosario Mazzola2, Francesco Ricchetti2, Vanessa Figlia2, Niccolò Giaj-Levra2, Michele Rigo2, Davide Tomasini3, Nadia Pasinetti4, Stefanie Corradini5, Ruggero Ruggieri2, Filippo Alongi2,6. 1. Advanced Radiation Oncology Department, IRCCS Sacro Cuore Don Calabria Hospital, Cancer Care Center, via Don Sempreboni 5, 37034, Verona, Negrar, Italy. lucanicosia.rg@gmail.com. 2. Advanced Radiation Oncology Department, IRCCS Sacro Cuore Don Calabria Hospital, Cancer Care Center, via Don Sempreboni 5, 37034, Verona, Negrar, Italy. 3. Radiation Oncology Department, ASST Spedali Civili di Brescia, Brescia University, Brescia, Italy. 4. Department of Radiation Oncology, Ospedale di Esine, ASL Valle Camonica-Sebino Esine, Esine, Italy. 5. Radiation Oncology Department, University Hospital, LMU Munich, Munich, Germany. 6. University of Brescia, Brescia, Italy.
Abstract
PURPOSE: Stereotactic body radiotherapy (SBRT) or stereotactic ablative radiotherapy (SABR) has been shown to increase survival rates in oligometastatic disease (OMD), but local control of colorectal metastases remains poor. We aimed to explore the natural course of oligometastatic colorectal cancer and to investigate how SBRT of lung metastases can delay the progression to polymetastatic disease (PMD). METHODS: 107 lung oligometastases in 38 patients were treated with SBRT at a single institution. The median number of treated lesions was 2 (range 1-5). Time to PMD (ttPMD) was defined as the time from SBRT to the occurrence of >5 new metastases. Genetic biomarkers such as EGFR, KRAS, NRAS, BRAF, and microsatellite instability were investigated as predictive factors for response rates. RESULTS: Median follow-up was 28 months. At median follow-up, 7 patients were free from disease and 31 had progression: 18 patients had sequential oligometastatic disease (SOMD) and 13 polymetastatic progression. All SOMD cases received a second SBRT course. Median progression-free survival (PFS) was 7 months (range 4-9 months); median ttPMD was 25.8 months (range 12-39 months) with 1‑ and 2‑year PFS rates of 62.5% and 53.4%, respectively. 1‑ and 2‑year local PFS (LPFS) rates were 91.5% and 80%, respectively. At univariate analysis, BRAF wildtype correlated with better LPFS (p = 0.003), SOMD after primary SBRT was associated with longer cancer-specific survival (p = 0.031). Median overall survival (OS) was 39.5 months (range 26-64 months) and 2‑year OS was 71.1%. CONCLUSION: The present results support local ablative treatment of lung metastases using SBRT in oligometastatic colorectal cancer patients, as it can delay the transition to PMD. Patients who progressed as SOMD maintained a survival advantage compared to those who developed PMD.
PURPOSE: Stereotactic body radiotherapy (SBRT) or stereotactic ablative radiotherapy (SABR) has been shown to increase survival rates in oligometastatic disease (OMD), but local control of colorectal metastases remains poor. We aimed to explore the natural course of oligometastatic colorectal cancer and to investigate how SBRT of lung metastases can delay the progression to polymetastatic disease (PMD). METHODS: 107 lung oligometastases in 38 patients were treated with SBRT at a single institution. The median number of treated lesions was 2 (range 1-5). Time to PMD (ttPMD) was defined as the time from SBRT to the occurrence of >5 new metastases. Genetic biomarkers such as EGFR, KRAS, NRAS, BRAF, and microsatellite instability were investigated as predictive factors for response rates. RESULTS: Median follow-up was 28 months. At median follow-up, 7 patients were free from disease and 31 had progression: 18 patients had sequential oligometastatic disease (SOMD) and 13 polymetastatic progression. All SOMD cases received a second SBRT course. Median progression-free survival (PFS) was 7 months (range 4-9 months); median ttPMD was 25.8 months (range 12-39 months) with 1‑ and 2‑year PFS rates of 62.5% and 53.4%, respectively. 1‑ and 2‑year local PFS (LPFS) rates were 91.5% and 80%, respectively. At univariate analysis, BRAF wildtype correlated with better LPFS (p = 0.003), SOMD after primary SBRT was associated with longer cancer-specific survival (p = 0.031). Median overall survival (OS) was 39.5 months (range 26-64 months) and 2‑year OS was 71.1%. CONCLUSION: The present results support local ablative treatment of lung metastases using SBRT in oligometastatic colorectal cancerpatients, as it can delay the transition to PMD. Patients who progressed as SOMD maintained a survival advantage compared to those who developed PMD.