Development-free survival (PFS) is a surrogate endpoint is outlined as follows (by ChatGPT):
In essence, PFS refers back to the size of time throughout a medical research or remedy routine the place a affected person’s illness doesn’t worsen or progress. As an illustration, in most cancers analysis, it measures the time from the beginning of remedy till the most cancers reveals indicators of progress, unfold, or relapse.
Understanding PFS is significant as a result of it helps clinicians and researchers assess the effectiveness of a remedy in controlling the illness. An extended PFS means that the remedy is efficiently slowing down the development of the sickness. This metric is especially necessary in medical trials when evaluating completely different remedy approaches or medicine.
A key query is, do sufferers care about PFS? The reply could also be sure, as a result of higher PFS is most frequently (however not all the time) correlated with longer survival. Nevertheless, do sufferers worth PFS impartial of OS? Maybe so if their high quality of life is healthier (i.e., they’ve fewer signs) in the course of the pre-progression section. Or, maybe they’ve decrease nervousness in the event that they know their most cancers has not progressed.
What does the literature say?
A paper by Raphael et al. (2019) performed a scientific literature evaluation of research that consider whether or not sufferers with superior most cancers perceive and worth PFS. General, 17 research met their inclusion standards. Of those:
Ten research particularly introduced sufferers with the time period progression-free survival as an attribute selection. Within the phrases used to outline the attribute of PFS, 6 research used the time period survival. 5 research clarified that PFS could not translate into higher total survival, and 5 research defined that enhancements in PFS could not mirror how properly the affected person could really feel. No research clarified {that a} PFS occasion might symbolize both development or demise, and no research outlined for the affected person what constituted development. The research assessed herein underrepresented ethnic and racial minorities (imply share of white sufferers, 88%; vary, 77%-96%). Values and preferences could differ throughout cultural backgrounds on condition that completely different relative preferences have been assigned to value and efficacy outcomes in North American vs Asian research, though just a few research have been evaluated.
As you’ll be able to see from the desk under, there may be vital heterogeneity by way of how PFS was introduced to the most cancers affected person respondents.
In a few of the research, PFS was crucial attribute. In others, high quality of life components have been extra necessary. General, nonetheless, it’s clear that extra analysis is required to totally perceive how sufferers understand the worth of PFS.