Comparison of clinical outcomes among cancer patients treated in and out of clinical trials

Abstract

Abstract Background. It is unknown if participation in a cancer clinical trial confers clinical benefits to patients. There is not enough scientific evidence in this regard and the available publications are scarce and provide ambiguous and limited information. Objective. Compare overall and progression-free survival and response to treatment among those who met the eligibility criteria and accepted to participate and those who refused to participate in cancer clinical trials. Methods. An observational cross-sectional study with an analytical component was carried out, which included patients diagnosed with cancer who participated in phase III clinical trials and patients who, being eligible, refused to participate. The patients were cared for at the National Institute of Cancerology in Colombia between 2019 and 2022. Analysis of differences in proportions and means of sociodemographic and clinical variables was included; overall survival and progression-free survival time were described and the survival curves between groups were compared. Variables related to survival were determined using a Cox regression model and Hazard Ratios were calculated. Results. 112 patients were included (51 participants and 61 refusers). Median progression-free survival for participants was 18.1 months (95%CI 14.0-22.2) vs 24.0 months (95%CI 16.4-31.5) in refusers p=0.23 and median overall survival for participants was 21.9 months (95CI % 17.6-26.1) vs refusers 33.2 months (CI95% 24.0-42.3), for the participating women it was 21.6 months (14.7-28.5 IC95%) vs refusers 22.7 months (9.3-36.0 IC95%) and for the group of participating men was 16.7 months (14.3-19.1 IC95%) and for refusers 32.4 months (25.5-39.3 IC95%). In the Cox proportional hazards model, only ECOG 1 was a better predictor of survival HR 0.48 (95%CI 0.23-0.97) p=0.042. Conclusion. This investigation found that participation in a clinical trial regarding rejection was associated with improved response rates, with no significant difference in overall or progression-free survival outcomes.