In a recent study published in JAMA, researchers delved into the trajectory of breast cancer mortality rates in the United States from 1975 to 2019. Their findings shed light on the remarkable decline in mortality rates and the pivotal role played by advancements in breast cancer treatment.
Deep diving into forty years of clinical trials
Over the course of four decades, breast cancer mortality rates witnessed a significant drop, plummeting from 48 deaths per 100,000 women in 1975 to 27 deaths per 100,000 women in 2019. This downward trend, according to the study, can be largely attributed to the remarkable progress made in breast cancer treatment modalities. The researchers examined data from over 2,000 phase 3 clinical trials registered in ClinicalTrials.gov, identifying 30 drugs that gained approval from the US Food and Drug Administration between 2010 and 2020 specifically for breast cancer treatment. Notably, the majority of these drugs—26 in total—were designed to target metastatic cancer, underscoring the growing focus on combating advanced stages of breast cancer.
Three main contributors were identified
Employing simulation models developed within CISNET, the study sought to quantify the impact of various interventions on breast cancer mortality rates. These interventions encompassed screening mammography, therapy for stage I to III breast cancer, and treatment for metastatic breast cancer. The results of the analysis revealed a remarkable reduction in breast cancer mortality rates attributable to these interventions. Specifically, stage I to III treatment emerged as the most significant contributor, accounting for 47% of the reduction, followed closely by metastatic treatment at 29%, and screening at 25%.
Increased efficacy of evolving treatments for various subtypes of breast cancer
Moreover, the study uncovered promising improvements in survival rates following metastatic recurrence, particularly evident from 2000 to 2019. Notable enhancements in median breast cancer-specific survival after metastatic recurrence were observed across various subtypes of breast cancer, underscoring the efficacy of evolving treatment approaches. The study underscores the profound impact of advancements in breast cancer treatment on reducing mortality rates in the United States. According to 4 simulation models, breast cancer screening and treatment in 2019 were associated with a 58% reduction in US breast cancer mortality compared with interventions in 1975. While screening remains a critical component of early detection, ongoing improvements in therapy, particularly for metastatic disease, are paramount in furthering the progress achieved in combating breast cancer mortality.
Past successes compels continued research and innovation
Despite the strides made in understanding and managing breast cancer, the study acknowledges certain limitations. The accuracy of the models hinges on assumptions due to limited data availability, and the potential disparities in screening dissemination and treatment efficacy among different demographic groups were not comprehensively addressed. This comprehensive analysis not only offers valuable insights into past successes but also underscores the imperative of continued research and innovation to enhance outcomes for individuals affected by breast cancer.
Source & Image Credit: JAMA