Globally, women are most likely to develop breast cancer, representing more than one in ten new cancer diagnoses each year, and breast cancer is the second most common cause of cancer-related death for women.1 Symptoms of breast cancer are sometimes discovered after the tumor has developed. However, many women with this disease will not display symptoms. Therefore, routine breast cancer screening is vital.2 Breast cancer is likely to be successfully treated if detected and treated early; nevertheless, many societal, financial, environmental, and other barriers may limit access to affordable, timely, and effective breast healthcare services.3

Fundamentally, there has been an increasing incidence of breast cancer with advancing age, and the median age of a woman with a breast cancer diagnosis is 61 years old.1 Based on regional differences in breast cancer incidence, it is evident that although the incidence of breast cancer in Asia remains lower than that in North America, Western Europe, and Oceania, rates have risen rapidly in recent decades.4 Asian countries now account for 40 percent of all breast cancer cases worldwide. Besides, Asian women have also seen an increase in breast cancer mortality compared to women in North America, Western Europe, and Oceania.5 Concerning the lack of population-based screening programs for breast cancer in some Asian countries, most patients present with advanced disease, and patients in Asia are more likely to be hormone receptor-negative, and the cancers may be more severe.6

In Taiwan, the nationwide breast cancer screening program has been established by the government since 2004 to allow women aged 50−69 to receive free breast cancer screenings from the Health Promotion Administration every two years7; however, mammography is performed on approximately twenty-two percent of Taiwan's women aged 50−69,8 and the adherence rate to screening in this age group is staggeringly low compared to Western countries.8 Screening for breast cancer with mammography is necessary to diagnose and treat breast cancer in its early stages. Despite this, disabled people are likely to receive unsatisfactory health care due to their inability to access healthcare services.9 There were several barriers to accessing health care utilization in a group of women with disabilities, which can lead to health inequality among them; especially, they encountered societal and cultural biases (misconceptions, unfavorable attitudes, dismissal, violence, verbal abuse, and limited understanding of health), financial constraints (poverty, joblessness, exorbitant transportation expenses), and systemic barriers (inadequate knowledge, scarcity of information, absence of openness, and communication difficulties).10 In accordance with the findings from the previous study on community-based approaches among women with disabilities, the obstacles that hindered their abilities to reach breast cancer screening services encompassed insufficient knowledge and regard from healthcare providers towards individuals with disabilities, limited accessibility, the enduring stigma, and exhaustion stemming from receiving treatment.11 Regarding the above-mentioned previous studies, Taiwanese women with disabilities could face challenges when undergoing breast cancer screening or general health examinations. As a consequence, if women with disabilities are not diagnosed with cancer early, they will have a low survival rate.12 According to the results of a previous study on breast cancer screening, women with disabilities were less likely to undergo breast cancer screening compared to those without disabilities.13 Remarkably, there were some studies regarding breast cancer among the general population in Taiwan.14,15; nonetheless, little is known about breast cancer among women with disabilities.

Consequently, this study aimed to explore the distribution of breast cancer stages at diagnosis, the risk of suffering from an advanced breast cancer stage, and the mortality risk of suffering from breast cancer among women with and without disabilities.