2.2. Search Strategy

In order to ensure a comprehensive search of the literature, the electronic search was conducted in the PubMed and Scopus databases according to the study aim by combining a wide series of potentially relevant terms using Boolean operators. Keywords focused on muscle strength, cancer, and different types of nutrition treatment based on protein and amino acids; search terms regarding the types of studies or outcomes were not included to avoid restricting the search. As the aim of this review was focused on the available most recent evidence, the search was restricted to primary research articles published in the last 10 years (i.e., from 2010 to 2020), also excluding papers not published in English. Table 1 shows the final search strings run in the selected databases. The latest search was performed on 31 March 2020.

Final strings used for searches run in the PubMed and Scopus databases.

*: truncation symbol (“wildcard”) used to search all terms having a same root.