Real-world treatment patterns and outcomes in refractory metastatic colorectal cancer

Abstract

Aim: To investigate treatment patterns and outcomes of metastatic colorectal cancer (mCRC) patients beyond second progression (PD2) since regorafenib and TAS-102 became available in Hong Kong. Methods: The clinical records of consecutive mCRC patients who were treated beyond PD2 at Department of Clinical Oncology, Queen Mary Hospital between June 2013 and February 2018, were retrospectively reviewed. Results: Of 176 PD2 patients (76.7% Eastern Cooperative Oncology Group performance status 0/1 and a median follow-up time of 6.6 [range, 0.4–37.2] months), 104 (59%) underwent palliative care only and 72 (41%) received active third-line (3L) treatment: regorafenib (n = 22), TAS-102 (n = 6), chemotherapy + antiepidermal growth factor receptor (n = 12), chemotherapy + antivascular endothelial growth factor (n = 28) or clinical trials (n = 4). Patients on active 3L treatment had significantly longer OS than those on palliative care only: 11.7 versus 5.5 months (adjusted hazard ratio = 0.41, 95% confidence interval: 0.28–0.61, P < 0.001). For those on active treatment, OS was significantly associated with the time from diagnosis of metastasis to PD2 (P < 0.001) and post-3L treatments (P = 0.009). When analyzing treatment eligibility according to trial criteria, half of the eligible patients (54/109) did not receive active treatment, but both eligible and ineligible patients achieved better OS when receiving active 3L treatment versus palliative care only (P < 0.001 and P = 0.002). No unexpected toxicity was reported. Conclusion: Active 3L and beyond treatment significantly prolonged OS versus palliative care, even in selected “trial ineligible” patients. Given a high rate of palliation only care in eligible patients, improved patient access to medicine and counseling may be needed to maximize outcomes.