Social Media Discourse on Breast Cancer Screening Barriers in Japanese and English: Cross-Sectional Infodemiology Study.

BACKGROUND

Despite clinical advances, breast cancer screening adherence remains stagnant in Japan (<50%) compared with the United States (>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

This study aims to characterize and compare cross-cultural informatics profiles of barriers to breast cancer screening across Japanese-language and English-language social media discourse.

METHODS

We developed an automated natural language processing pipeline on a cloud-based informatics platform to analyze 46,823 screening-related posts (30,027 in Japanese and 16,796 in English) from X (formerly Twitter) collected in 2025, derived from an initial 76,955 posts after noise exclusion. The methodology integrated large language model-assisted sentiment polarity scoring with strict negation-handling, co-occurrence network topology analysis, and advanced distributional visualizations, including raincloud and ridgeline plots. Subgroup comparisons (prescreening vs postscreening and ultrasound with vs without mammography) were evaluated.

RESULTS

Among the 46,823 screening-related posts, overall sentiment distributions showed no practically meaningful cross-cultural divergence (Cohen d=0.049); however, domain-specific analyses revealed sharp disparities in barrier prevalence. Within the English-language cohort containing 16,796 posts, discourse exhibited a concentrated, moderate negative sentiment regarding systemic barriers, featuring "Cost" as the primary barrier (n=1239, 7.4%), while "Pain" ranked considerably lower (n=842, 5.0%). In contrast, the Japanese-language cohort containing 30,027 posts was heavily bottlenecked by psychosomatic barriers, governed by a tightly interconnected network of "Pain," "Fear," and "Appointment." "Pain" emerged as the overwhelmingly dominant barrier (n=5788, 19.3%). In the English-language cohort, "Dense" breasts emerged as a prominent clinical topic due to elevated public awareness, distinct from the financial narrative. The Japanese subgroup analyses identified a temporal transition from anticipatory psychological anxiety ("Fear," 739/3805, 19.4%) and logistical concerns ("Appointment," 1556/3805, 40.9%) before screening to a strong persistence of the discomfort memory of "Pain" (1160/7419, 15.6%). Furthermore, sentiment scores for mammography were significantly more negative than those for ultrasound alone (P<.001, Cohen d=0.264), and pain-related descriptors for ultrasound spiked from 5.0% (106/2110, ultrasound alone) to 18.2% (733/4017) when performed concurrently with mammography.

CONCLUSIONS

Despite comparable overall emotional equilibrium, a fundamental dichotomy emerged. The English-language discourse predominantly reflects US-specific systemic financial burdens, whereas the Japanese experience is characterized by emotional volatility transitioning from anticipatory anxiety to a tightly interconnected "Pain-Fear-Appointment" network. Physical discomfort of mammography dominates the screening narrative, overshadowing concurrent painless modalities like ultrasound. Improving adherence in Japan requires individualized pain-mitigating compression protocols and optimized clinical workflows to decouple mammographic discomfort from supplemental screening, thereby preventing pain-associated defensive avoidance and reducing logistical hurdles to improve equitable access.