The role of stereotactic body radiation therapy in oligometastatic colorectal cancer: Clinical case report of a long-responder patient treated with regorafenib beyond progression.

RATIONALE: Regorafenib is the new standard third-line therapy in metastatic colorectal cancer (mCRC). However, the reported 1-year overall survival rate does not exceed 25%.

PATIENT CONCERNS: A 55-year-old man affected by mCRC, treated with regorafenib combined with stereotactic body radiotherapy (SBRT), showing a durable response.

INTERVENTIONS: After 6 months of regorafenib, a PET/CT scan revealed a focal uptake in a solid lung nodule which was treated with SBRT, whereas continuing regorafenib administration. Fourteen months later, the patient had further progression in a parasternal lymph node, but treatment with regorafenib was continued. The regorafenib-associated side effects, such us the hand-foot syndrome, were favorable managed by reducing the dose from 160 to 120 mg/day.

OUTCOMES: Patient-reported outcome was characterized by a progression-free survival of approximately 3 years.

LESSONS: in presence of oligometastatic progression, a local SBRT while retaining the same systemic therapy may be a better multidisciplinary approach. Moreover, disease progression is no longer an absolute contraindication for continuing the regorafenib treatment.