Stereotactic body radiotherapy prolongs the progression-free survival and delays the change of systemic therapy regimen in patients with lung oligoprogressive metastatic colorectal cancer.

PURPOSE

To analyze the effect of stereotactic body radiotherapy (SBRT) on colorectal cancer (CRC) patients with lung oligoprogression (OP).

METHOD

Patients with lung OP from CRC treated by SBRT at our center were included in this retrospective analysis. The progression-free survival (PFS), change of systemic therapy (CST), local control (LC), and overall survival (OS) were analyzed. Cumulative incidence was used to report CST, and the Kaplan-Meier method was used to evaluate PFS and LC.

RESULTS

A total of 17 patients with 38 lung OP lesions treated by SBRT from October 2012 to December 2018 were involved. All patients had undergone radical resection for primary CRC and administered with standard systemic therapy regimens (seven for the first line and 10 for the second line). Among them, nine (52.9%) had received targeted therapy before SBRT, 14 (82.4%) patients underwent chemotherapy, and 12 received targeted therapy after SBRT. Six patients (35.3%) underwent CST after a median time of 5.2 months (range: 1.7-27.5 months). The median follow-up was 9.9 months, and the 1-year OS rate for all patients was 73.5%. Progression was observed in of 14 of 17 patients (82.4%), and the 6-month PFS for all patients was 25.9%. Univariate analysis indicated that only targeted therapy before SBRT was a beneficial prognostic indicator for 6-month PFS (P = .026) and N-PFS (P = .013). The 1-year LC for all 38 lesions was 77.8%, and during and after SBRT, no grade 3 or higher toxicities were observed.

CONCLUSION

SBRT combined with systemic therapy made partial CRC patients with lung OP avoid the progress within 6 months and delayed the need for CST to 5.2 months, and targeted therapy before SBRT was a positive indicator of PFS.