Effectiveness of Mobile Messenger-initiated Reminder on Biannual Mammography Adherence in Breast Cancer Screening

Female breast cancer is the most common cancer and fifth leading cause of cancer death worldwide. In the past decade, breast cancer consistently to be the most common cancer for women in Hong Kong, so much that it accounts for 27% of all female cancers, with 4,600 new cases of breast cancer registration every year and the lifetime breast cancer risk for females is 1 in every 14. At the same time, breast cancer ranks the third in cancer death in Hong Kong, with a five-year relative survival rate of 84%. Regular mammography screening has been shown to reduce the mortality of breast cancer. International guidelines recommend annual or biannual mammography screening for women aged 50 or above.

The adherence to regular mammography screening remains a challenge. Studies had shown that the adherence decreased over time. Mailed and telephone reminder were being proven to be effective tools to increase the adherence to regular breast screening using mammography. However, both mailing and telephone strategies are associated with labor intensity and high cost.

Over the past two decades, the advent of internet and smartphone provided a fertile platform for the development of mobile-health technologies. WhatsApp Messenger is one of the most frequently used free-of-charge mobile messenger that permits users to send secure messages across different device platforms. A recent randomized controlled trial from our team has suggested its clinical utility in improving adherence to regular colorectal cancer screening using fecal immunochemical test. This encouraging data prompted us to investigate the potential role of WhatsApp Messenger in breast cancer screening. We hypothesized that text reminder sent via WhatsApp Messenger improves the longitudinal adherence to biannual mammography in a community-based, opportunistic breast screening program.