Effect of Reasons for Screen Failure on Subsequent Treatment Outcomes in Cancer Patients Assessed for Clinical Trials.

Abstract

The cancer research community increasingly question the rigidity of eligibility criteria in clinical trials. Common reasons for "screen failure" (RFSF) are well documented; however, their effect on subsequent standard therapy (SST) and outcomes is unclear. This retrospective study evaluated patients aged ≥18 years with solid malignancy who were listed as ineligible on a screening log between February 2011 and March 2018. Patients screen-failed for biomarker results or incorrect cancer stage/prior treatment profile were excluded. Data were collected from electronic hospital records, including demographics, cancer history, RFSF, subsequent therapy, and outcomes. Overall, 217 patients were eligible. The most common histologies were lung (28%), melanoma, colon, and pancreatic (all 11%); 90% were metastatic. The most common RFSF were rapid disease progression (PD; 16%), performance status (PS) ≥2 (12%), and abnormal liver function tests (aLFT; 12%). After screen failure, 129/217 (59%) had SST; 9 were dose-reduced. Treatment-naïve or phase III trial-ineligible patients were more likely to receive SST than those pre-treated or phase I trial-ineligible (72/104 vs. 52/113, p = 0.0006; 71/109 vs. 15/42, p = 0.00013), respectively. RFSF stabilised/improved in 104/217 (48%); the main RFSF was co-morbidity (19/104). The most common RFSF to deteriorate were rapid PD (27/72), PS ≥2 (20/72), and aLFT with liver metastases (LM; 13/72). RFSF related to organ function rarely deteriorate unless directly involved with underlying malignancy. Most RFSF do not prevent patients from having SST, nor increase dose reductions, especially in treatment-naïve/phase III trial-ineligible patients. Those with RFSF of poor PS, rapid PD, and aLFT from LM are less suitable for SST. Careful broadening of trial eligibility is warranted.