OBJECTIVES: Patient-Reported Outcomes (PRO) are increasingly utilized in clinical research. These methods quantify medical needs from a patient perspective. However, adoption of PRO studies are still limited. This systematic literature review sought to compare the number of published PRO studies in oncology between Japan and the United States.

METHODS: The PubMed database was searched for published articles using a combination of search terms between January 1st, 2013 and December 31st, 2017. The search yielded hits for 19 types of cancer - lung, cervical, stomach, breast, pancreatic, liver, prostate, kidney, colorectal, bladder, esophagus, blood, thyroid, brain, ovary, skin, gallbladder, larynx, and testis. The top 6 published cancers in Japan were further screened for sample size, study type, and the type of PRO.

RESULTS: Our search strategy returned a total of 1038 hits for Japan and 3074 for United States. The cancer types with the greatest number of hits in Japan and United States were stomach and breast, respectively. The top 6 cancer types were further screened returning 180 and 26 hits for stomach, 171 and 1099 for breast, 154 and 346 for lung, 111 and 531 for prostate, 91 and 250 for colorectal, 59 and 98 for liver in Japan and the United States, respectively.

CONCLUSIONS: Individual search hits for Japan was consistently lower than US except for stomach cancer. In particular, the greatest difference between US and Japan was breast cancer (~6 fold) followed by prostate cancer (~4 fold). These indicate a need for PRO studies in oncology within Japan to measure patient satisfaction.