Abstract 321P
Background
Breast cancer mortality has been decreasing over the past decades mainly due to earlier diagnosis and better treatment strategies. Nevertheless, a recent Brazilian populational database analysis showed a concerning increase in breast cancer mortality rates among patients under 40 years old. Considering this, we aimed to evaluate the trends in the proportion of new breast cancer cases and deaths occurring in patients younger than 40 years over the last decade in a large tertiary cancer center.
Methods
We evaluated all the cohort of consecutive breast cancer patients treated from 2009 to 2020 in a public Brazilian cancer center. Patients were classified according to age at breast cancer diagnosis in two groups, younger than 40 years or 40 years or more. The proportions of new cases and deaths occurring in patients younger than 40 years was compared between two time periods (2015-2020 versus 2009-2014) using Chi-Square test. Linear regression was used to evaluate the trends in the proportion of new cases and deaths in patients younger than 40 years over the years.
Results
From 2009 to 2020, a total of 12.569 breast cancer patients started treatment at our institution; 1.441 were younger than 40 years. From 2009-2014, 9.9% were patients younger than 40 years compared to 12.9% from 2015-2020 (P < 0.001). Similarly, an increase in the proportion of deaths among breast cancer patients younger than 40 years occurred during the period (2009-2014: 9.6%; 2015-2020: 12.4%; P = 0.026). The linear regression model confirmed the trend for an increasing proportion of new breast cancer cases occurring in patients younger than 40 years (F(1, 10) = 12.83, P = 0.005). The proportion raised from 7.9% in 2009 to an alarming proportion of 21.8% in 2020. The trend for the increase in the proportion of deaths in this young population was also confirmed (F(1, 10) = 9.93, P = 0.01), with a proportion of 5.5% in 2009 versus 14.5% in 2020.
Conclusions
The proportion of new breast cancer cases and deaths among patients younger than 40 years has increased in a public Brazilian cancer center over the past decade. These results raise the concern for the need to reconsider primary and secondary prevention strategies for young women.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
R.R.D.C.C. Bonadio: Financial Interests, Personal, Expert Testimony: Aché; Financial Interests, Personal, Invited Speaker, financial support for attending symposia: Roche; Financial Interests, Personal, Invited Speaker, financial support for educational program: AstraZeneca. All other authors have declared no conflicts of interest.