Regarding simple pre-post assessments of QoL in single-arm studies, it is probably unnecessary to state that
they are generally not appropriate for judging influences on QoL, since it is affected by many factors. Concerning survival (Table 3), some of the RCTs show a statistically significant benefit while others find more show a statistical trend or no difference. Most of the non-RCTs (which included larger patient numbers) show a major impact. The validity of the studies is limited because of their small sample size (median only 52 participants per RCT), and because 8 of the 9 RCTs were imbedded in the same (large) epidemiological cohort study. This study was started in the 1970s, before modern standards of data quality control (ICH-GCP, GEP) were established, and it therefore does not fulfil modern standards in this respect. The 9th RCT had enrolled more patients but was conducted even earlier, and suffers from a major attrition rate due to protocol violation ; the subsequent analysis followed the “”as treated”" instead of the “”intention-to-treat”" principle . Hence https://www.selleckchem.com/products/lee011.html bias cannot be excluded. None of the survival studies was blinded, but survival is generally not easily affected by observer bias or suggestive effects [138–140]. Seen altogether, although results were consistent, questions regarding survival
remain and validity of evidence is moderate at best. An independent, GCP-conform trial with sufficient power would be desirable to further evaluate potential survival benefit. Regarding tumour behaviour, evidence from RCTs is Niraparib in vivo scanty; most benefits were shown in non-randomized studies. In single-arm studies of patients with no concomitant conventional cancer treatment, high-dose or local application of whole VAE led to substantial remission of tumour or malignant effusion. This was also observed in animal studies: local application resulted in tumour-growth inhibition and increased survival. However, this application and dosage is not standard and cannot be recommended widely
due to potential risks of high dose or local application. With ordinary Ribonucleotide reductase VAE application, schedule and dosage, spectacular tumour remissions tend to be the exception [20, 36]. No tumour remission was observed after application of rMLs. Remission in CIN cannot be distinguished from spontaneous remission rates, which are frequent in this indication. Apart from the discussed issues, the following validity aspects have to be considered: An attrition rate above 10% was present in 10 RCTs. In 5 of these RCTs [49–51, 53], patients were excluded before baseline assessment. Here the patients were provisionally enrolled into the matching and pairwise randomization procedure; subsequently they were asked for informed consent, and were excluded from the study if they declined, together with their matched twin.