Background and importance Immune checkpoint inhibitors (ICI) have shown significant clinical benefit for patients diagnosed with varied types of cancer. With an increasing use of these therapies, it is of urgent interest to achieve a comprehensive understanding of the overall patient experience and to confirm if the results of patient reported outcome (PROs) in clinical ICI trials are reflected in clinical practice.

Aim and objectives We conducted a systematic review of the published literature to identify and categorise PRO instruments and examine related utility and measurement issues in studies reporting on ICI.

Material and methods Literature was searched using PubMed and Embase (October 2021). Search terms included controlled vocabulary and specific keywords related to: (1) ICI, (2) PRO and (3) Oncology. Two reviewers independently screened titles/abstracts followed by a full-text selection based on predefined criteria. We included qualitative and quantitative studies in clinical practice.

Results We screened 235 references and included 14 publications in our analysis: 6 reported PRO data from cross-sectional survey, 4 were prospective observational studies, 2 were case-control studies, 1 was a randomised controlled pilot trial and 1 as a qualitative study. 10 were single-centre and 4 were multicentre studies. The median number of patients included was 67 (range 6–412), 7 focused on melanoma patients, 2 on lung cancer, 1 on genitourinary cancer and 4 included various diagnostics. Regarding treatment, 7 studies were carried out in patients undergoing treatment and 7 in long-term survivors. The most frequent questionnaires used were cancer-specific (6 EORTC-QLQ-C30, 2 FACT-G), although the variability between the studies was very important, with 16 different scales identified, of which 9 were evaluated in a single study.

Conclusion and relevance Cancer-specific or generic quality-of-life (QoL) questionnaires are the most widely used PRO measures in clinical practice ICI studies. As ICI therapies exhibit unique characteristics different from conventional cancer therapies, such broad instruments may not capture the specific ICI-related symptoms, toxicities, and impact on the patient’s QoL. Hence, the adaptation or development of ICI-specific PRO tools should be further investigated.

Conflict of interest No conflict of interest