ABSTRACT
BACKGROUND: Survival-based surrogate endpoints such as progression-free survival (PFS) are commonly used in oncology clinical trials. The evaluation-time bias in the assessment of median disease progression in randomized trials has been suggested by several simulation studies, but never demonstrated in the clinic. We aimed to demonstrate the existence of potential evaluation-time bias by assessing the impact of the timing of tumor assessments on median PFS from control arms without any active treatment of randomized controlled trials involving advanced cancer patients. MATERIALS AND METHODS: A systematic literature search of English language publications from 1 January 2000 to 7 January 2021 was performed using MEDLINE (PubMed). Eligible trials for our meta-analysis included all randomized clinical trials evaluating anticancer drugs in adult patients with advanced cancers with a control arm without any anticancer drug consisting of best supportive care with or without a placebo. We performed a meta-regression analysis to analyze the correlation between the timing of the first tumor assessment and median PFS in patients randomized in the control arms without any active treatment. RESULTS: Of 3551 studies screened, 97 eligible trials were retrieved involving 36 747 patients, including 14 229 patients randomized into the control arms. A later first tumor assessment correlated with a prolonged median PFS (R2 = 0.44, P < 10-5). CONCLUSIONS: Our results confirm the existence of potential evaluation-time bias in clinical research that had been suggested by simulation studies. The timing of tumor assessments should be kept the same in precision medicine trials using the PFS ratio as an efficacy endpoint.
Subject(s)
Antineoplastic Agents , Neoplasms , Adult , Antineoplastic Agents/therapeutic use , Humans , Neoplasms/drug therapy , Progression-Free Survival , Randomized Controlled Trials as TopicABSTRACT
AIMS: The EXTREME regimen is the standard for recurrent and/or metastatic head and neck squamous cell carcinoma (HNSCC). However, many patients have a poor performance status and/or comorbidities, making them unfit for this regimen. We have treated them with carboplatin and cetuximab (simplified EXTREME regimen) since 2007. Our aim was to assess the efficacy and tolerance of this regimen in this frail population. MATERIALS AND METHODS: A retrospective chart review of all patients treated with the simplified EXTREME regimen for recurrent and/or metastatic HNSCC in three academic hospitals between 2007 and 2017 was carried out. The primary end point was overall survival. Secondary end points were progression-free survival (PFS), overall response rate (ORR) and toxicity. RESULTS: One hundred and three patients were included. The median age was 63 years, 40% had performance status 2-3. The median follow-up was 30.2 months. The median overall survival and PFS were 7.2 and 3.7 months, respectively. The median overall survival was 10.1 months in patients with performance status 0-1 versus 4.6 months in patients with performance status 2-3 (P = 0.01). ORR was 39%. Acute grade 3-4 haematological and non-haematological toxicity rates were 25.2% and 27.2%, respectively. Patients with grade 1 or more skin toxicity had a higher ORR (hazard ratio = 3.44; P = 0.03), a prolonged overall survival (hazard ratio = 0.37; P < 0.0001) and PFS (hazard ratio = 0.29; P < 0.0001). During treatment, 29% of patients had pain reduction, 13.5% had weight gain and 17.2% had an improvement in performance status. CONCLUSIONS: This is the largest cohort of patients treated with simplified EXTREME for HNSCC. It was well tolerated, with a high ORR. Interestingly, skin toxicity correlated with treatment efficacy.