Willingness to contribute monetarily for hereditary breast cancer risk testing and the influencing factors: The first Indonesian exploration in the province with the highest prevalence.

Breast cancer (BC) is the leading cancer among women worldwide until 2050. Indonesia has developed a 10-year national cancer plan to increase screening uptake. Having a BRCA1/2 gene mutation, the most common cause of hereditary BC, was found to increase uptake. Unfortunately, an expensive, non-government-funded test is necessary to check mutation status. Therefore, this study is the first in Indonesia to explore willingness to pay (WTP) for the test, along with knowledge, perceptions, acceptance, and the significance of having a mutation on intention to screen. An exploratory, cross-sectional, online, 7-section survey using non-probability sampling in October-November 2025 among females aged ≥25 residing in Daerah Istimewa Yogyakarta. Unadjusted Spearman's rank, unadjusted Kruskal-Wallis, Cochran's Q, and McNemar's tests were used to determine relationships. Of 400 females, most had low knowledge levels, perceived high benefits and moderate barriers, and were willing to undergo testing and pay for it. However, the average maximum WTP from 282 who provided an amount was Rp1,345,638 (US$81.17) ± Rp1,766,723 (US$106.57), with a co-payment rate of 0.24. Income, education, knowledge, age, number of households, number of biological daughters, sons, and children, marital status, residence, occupation, and insurance were associated with maximum WTP (p ≤ 0.05). In hypothetical scenarios, a positive BRCA1/2 mutation result was associated with greater BC screening intention (p < 0.001). The combination of a low co-payment rate, income having the strongest association with maximum WTP, and most participants demanding full government coverage made it clear that the next step should be a country-based cost-effectiveness study.