JMIR Publications

ABSTRACT

Background:

Despite clinical advances, breast cancer screening adherence remains stagnant in Japan (<50%) compared with the US (>70%). Understanding distinct cross-cultural barriers is essential; however, traditional methodologies often fail to capture visceral, real-world individual experiences and hidden deterrents to screening.

Objective:

To characterize and compare cross-cultural informatics profiles of barriers to breast cancer screening in Japan and the US using large-scale social media discourse.

Methods:

We developed an automated natural language processing (NLP) pipeline on a cloud-based informatics platform to analyze 35,488 Japanese and 38,956 English posts from X (formerly Twitter) collected in 2025. The methodology integrated lexicon-based sentiment polarity scoring with strict negation-handling, co-occurrence network topology analysis, and advanced distributional visualizations, including raincloud and ridgeline plots. Subgroup comparisons (pre- vs post-screening, and ultrasound with vs without mammography) were evaluated.

Results:

Among the 74,444 screening-related posts, distributional analyses revealed a profound cross-cultural divergence in sentiment (P < .001). Within the US cohort, discourse exhibited a concentrated, moderate negative sentiment regarding systemic barriers, featuring "Cost" as the primary barrier (6.7%, n=2,594), while "Pain" ranked considerably lower (2.4%, n=927). In contrast, the Japanese cohort demonstrated a highly bimodal sentiment distribution, anchored by a "Pain-Fear" cycle. Logistical access barriers provoked extreme negative sentiments in Japan, where "Pain" emerged as the overwhelmingly dominant barrier (23.4%, n=8,291). In the US, "dense" breasts (3.8%, n=1,461) explicitly manifested as a specific clinical and financial barrier. The Japanese subgroup analyses identified a temporal transition from anticipatory psychological anxiety (64.5%, n=873) before screening to acute physical trauma (56.4%, n=2,898) post-screening. Furthermore, sentiment scores for mammography were significantly more negative than those for ultrasound (P < .001), and pain-related descriptors for ultrasound spiked from 9.4% (n=204, ultrasound-only) to 26.7% (n=1,220) when performed concurrently with mammography.

Conclusions:

Simple mean comparisons obscure true patient experiences. A fundamental dichotomy has emerged: while the US discourse explicitly centers on systemic financial burden, the Japanese narrative is structurally governed by a synergistic burden of physical pain and severe logistical access barriers, producing a highly bimodal emotional response. Mammographic trauma degrades the efficacy of concurrent painless modalities. Improving screening adherence in Japan requires the implementation of individualized pain-mitigating compression protocols, optimization of clinical workflows, and addressing occupational disparities to improve equitable access.