Real-world Treatment Patterns and Outcomes in Refractory Metastatic Colorectal Cancer

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 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.