Metastatic colorectal cancer (mCRC) patterns of care: Implications for clinical trial design

Abstract

4079 Background: New approaches have expanded options for patients (pts) with mCRC. To characterize current practice paradigms that might bear on clinical trial design, we analyzed decision-making and treatment patterns in pts treated at a Comprehensive Cancer Center since the introduction of cetuximab (CET), and bevacizumab (BV). Methods: A retrospective review of all pts diagnosed with mCRC between 3/1/04 and 8/28/06 treated at Fox Chase Cancer Center. Results: 160 pts were treated, with 157 pts receiving at least one therapy regimen by 10 attending oncologists. There were 350 changes in therapy with 246 (70%) including continuation of at least one prior drug (92 BV, 111 fluoropyrimidines, 43 other). The most common reasons for treatment change were toxicity (33%), progressive disease (PD) (29%), treatment breaks (15%), and metastasectomy (11%) ( Table ). PD was a more common cause for treatment discontinuation in later phases of treatment (18% initial regimen vs. 36% subsequent regimens, p=0.0002). 24% of pts treated with oxaliplatin (OX) discontinued due to neuropathy. Hypersensitivity caused discontinuation in 5% of pts with OX and 7% of pts with CET. Resection of metastases was undertaken in 38% of pts. 43% of these pts received neoadjuvant therapy, and 56% received adjuvant therapy. 30% of pts have died, 29% remain on active treatment, 28% are on a treatment break, 3% are on hospice, and 11% are lost to follow-up. Conclusions: PD is no longer the primary reason for change of therapy in pts with mCRC. Metastasectomy is common and OX neuropathy is often treatment-limiting. These findings have important implications for endpoint selection and design of clinical trials in mCRC. Future clinical trials in mCRC must recognize treatment complexities and capture key components of decision-making that may result in prolonged survival. Furthermore, treatment breaks represent a potential window for the evaluation of new drugs. [Table: see text] No significant financial relationships to disclose.