Introduction Breast cancer is the leading cancer type among women in Japan, with more than 10,000 women of reproductive age developing the disease annually. Therefore, this study aims to develop a decision aid (DA), handbook and algorithms to support decision-making for cancer patients regarding fertility preservation.

Methods DAs and brochures that address these aims were collected from preceding studies on fertility preservation decision-making in breast cancer patients, the Ottawa Hospital Research Institute A to Z Inventory, patient booklets, and medical institutions websites. The researchers of this study attended an educational program for developing decision aids and created a DA draft based on the International Patient Decision Aid Standards instrument (IPDASi), decision support algorithms, and a DA handbook. A series of tests were administered to both three breast cancer patients, seven physicians, and two nurses.

Results The results demonstrated that the following points should be considered in the proposed DA structure: first, the impact of breast cancer treatment on fertility and fertility preservation therapy should be explained, followed by questions about what decisions must be made by what stage in the treatment process; information applicable to many medical institutions should be provided in terms of when fertility preservation therapy and subsidies are available; the text should avoid Illustrations reminiscent of children; and patients should be able to organize their thoughts as they fill out the DA.

Discussion The original draft DA, algorithms, and handbook were revised based on the study results to develop the final version.

Conclusion It is anticipated that the DA, algorithms, and the handbook, modified in accordance with the study results, will be commonly understood by both health care providers and patients. Future research will now concentrate on evaluating the feasibility of the proposed solution.