For every therapy, there will be several patients who respond to it ("responders") and other patients who do not ("non-responders"). Unfortunately, the physician cannot recognize before the onset of the therapy whether the patient will be a responder or a non-responder. This fact has devastating consequences for the care of cancer patients:
- A worrying percentage of the cancer patients treated with drugs are non-responders1. For every one of them the therapy had no chance of success from the outset.
- After months of treatment of a non-responder, the cancer will have progressed, and precious time will have been lost for other treatments that would have worked in earlier stages.
- The adverse reactions that many non-responders suffer from will lead to unnecessary impairment in the patients' quality of life.
- The enormous costs of the therapy for the numerous non-responders is a meaningless burden on both the health care system and the co-insured patients.
From these facts, it is evident that there is an urgent need for drugs with higher specificity for cancer cells (targeted therapies), as well as a need for biomarkers able to anticipate therapy response (predictive biomarkers). This need will increase in the future as the continual growth of the world population2 will lead to a steady increase in cancer incidence and demand for cancer therapies.
- The response rate among the various targeted therapies varies between 22% and 80% (Gyawali B et al., 2020, J Natl Compr Canc Netw. 18:36-43) and among the various treatments of the chemotherapy between 20% and 60% (Epperla N & Weissman DE, 2015, Fast Fact and Concept #99, 3rd edition, Edited by Marks S and Rosielle D). In the particular case of the advanced and metastatic cancer, the average response rate for targeted therapies is 4.9% (Marquart J et al., 2018, JAMA Oncol 4:1093-1098) and for chemotherapy 48% (Maldonado EB et al., 2020, Future Sci OA 6(8):FSO600. doi: 10.2144/fsoa-2020-0024).
- Worldwide, the number of elderly people (65 years or older) will rise from 728 million in 2020 to 1,549 million in 2050. In the more developed regions (Europe, Northern America, Australia, New Zealand and Japan) 19% of the population is already 65 years or older. That proportion is expected to reach 27% in 2050 (United Nations, Department of Economic and Social Affairs (2019) World Population Prospects 2019, Volume II: Demographic Profiles).