What constitutes an “unmet medical need” in oncology? An empirical evaluation of author usage in the biomedical literature

The phrase "unmet medical need" has important regulatory implications, but there is no empirical analysis of its real world usage. We sought to determine the annual US incidence, 5-year survival, and number of National Comprehensive Cancer Network (NCCN)-recommended regimens for indications described in the literature as an "unmet medical need." We queried Google Scholar to identify publications where authors used the phrase "unmet medical need" to refer to a specific cancer indication. For each indication, we investigated the annual US incidence, 5-year survival, and number of NCCN recommended regimens. We identified 237 cancer indications considered by authors an "unmet medical need." The term was found most frequently appended to breast cancer indications comprising 30 of the 237 citations (12.7%). This was followed by lung 24/237 (10.1%), hepatocellular 18/237 (7.6%), and prostate cancer 13/237 (5.4%). In 55 of 237 (23.2%) instances where an indication was described by the authors as an unmet medical need, the incidence was 1,000 cases per year, there were five regimens recommended by NCCN, and there was a 50% or greater 5-year survival. Forty-three of 237 (18.1%) indications had at least an incidence of 10,000 cases a year, 10 recommended regimens, and a 50% 5-year survival. In conclusion, "unmet medical need" has been used to describe cancer indications that are rare, and have few options and poor survival outcomes. However, the term has also been used to describe indications that occur commonly, have many treatment alternatives, and are clinically indolent with more encouraging expectations for survival. Some standardization is needed.