Treatment Patterns Of Metastatic Colorectal Cancer (Mcrc) In Commercially-Insured Populations In Washington State.

e15011 Background: Few studies have examined patterns of care relating to guideline-recommended therapies for metastatic colorectal cancer (mCRC) in real-world settings. The goal of this study was to investigate treatment patterns for initial and subsequent therapies for mCRC patients in two large commercial plans in Washington State, USA. Methods: We utilized the Hutchinson Institute for Cancer Outcomes Research linkage of Western Washington Cancer Surveillance System (CSS) SEER data with claims from Regence BlueShield and Premera BlueCross (representing 20% of the WA insured population) for patients diagnosed with mCRC between 2012 and 2016. We identified all patients with Stage IV CRC at diagnosis or stage I-III CRC with subsequent claims suggesting metastatic recurrence. We conducted descriptive analysis and multivariate modeling to evaluate the association between age, race, gender, and rurality with receipt of systemic therapy. We examined 1L (first line) regimens received in the first 15 days of treatment, and classified them as adherent or not to NCCN guidelines. In light of recent FDA approval for regorafenib (9/2012) and TAS-102 (9/2015), we examined use of these therapies for refractory mCRC. Results: Among 4,536 CRC cases identified in the database, 426 patients had evidence of metastatic disease and met all inclusion criteria. 87 (20.4%) received no systemic therapy. Of the 339 (79.5%) who received systemic therapy, FOLFOX was the most common 1L regimen (29.5%), followed by FOLFOX+bevacizumab (12.3%). There was evidence of 1L treatment outside of NCCN guidelines – 8.5% of patients received single-agent bevacizumab, and 8.0% received single-agent oxaliplatin. Patients who did not receive systemic therapy were more likely to be older and live in a large metropolitan area. For subsequent therapies, 24 (7.1%) patients received regorafenib, and 5 (1.5%) received TAS-102. Conclusions: In a commercially-insured mCRC cohort, a majority received 1L guideline-based therapy. Many patients did not receive systemic therapy despite current recommendations - further evaluation of factors contributing to these decisions are warranted. Use of regorafenib and TAS-102 was uncommon.