A recent Brazilian populational database analysis showed a concerning increase in breast cancer mortality rates among patients under 40 years. 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 Brazil.
We evaluated all consecutive breast cancer patients treated from 2009 to 2020 in a Brazilian tertiary cancer center. The proportions of new cases and deaths in patients younger than 40 years was compared between two time periods (2015–2020 versus 2009–2014) using Chi-squared test. Linear regression was used to evaluate the trends in the proportion of new cases and deaths in young patients over the years.
From 2009 to 2020, a total of 12,569 breast cancer patients started treatment at our institution; 1441 were younger than 40 years. From 2009 to 2014, 9.9% (95% CI 9.2–10.7%) were patients younger than 40 years compared to 12.9% (95% CI 12.1–13.8%) from 2015 to 2020. Similarly, the proportion of deaths among breast cancer patients younger than 40 years increased during the period (2009–2014: 9.6%, 95% CI 7.8–11.6%; 2015–2020: 12.4%, 95% CI 10.9–14%). The linear regression model showed a trend for an increasing proportion of new breast cancer cases occurring in patients under 40 years (P = 0.005). Proportion increased from 7.9% (95% CI 6.2–9.8%) in 2009 to 21.8% (95% CI 19.1–24.8%) in 2020. The trend for the increase in the proportion of deaths in this young population was also observed in the linear regression model (P = 0.01).
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.
- • Breast cancer cases and deaths among women under 40 years is increasing in Brazil.
- • In 2021, 21.8% of breast cancer cases in a tertiary cancer center were in young ages.
- • Health policies are required to improve prevention strategies for this young group.
Breast cancer is the most common type of cancer among women worldwide . In young women (20–39 years), breast cancer is also the most prevalent neoplasm, as well as the leading cause of cancer mortality in most countries . Brazilian and United Kingdom data highlights an unfavorable disease behavior in this age group . In the United States (US), 3% of all breast cancer deaths occur in women younger than 40 years .
In Brazil, 66,280 new breast cancer cases were estimated in the female population in 2021, representing 29.7% of all neoplasms (Brasil, Ministério da Saude) . National screening guidelines from the public health system recommend biannual mammogram starting at age 50 . The national guidelines do not provide recommendations for high-risk patients. For this group, management is usually done according to availability by hereditary cancer specialists following international guidelines. Another limitation is that germline testing for high-risk patients is not available in the public health system that attends more than 70% of the Brazilian population. Considering this, assistance for young women with high breast cancer risk still needs to be improved in the country.
Recent Brazilian data are worrying and point to a possible increase in breast cancer incidence and mortality at young ages. Santos et al. evaluated the incidence rates of breast cancer among young women from 1988 to 2008 in Brazilian state capitals, showing an overall increase in the incidence, with the highest increase in the cities of Porto Alegre and Goiânia .
A study carried out in São Paulo state suggested a trend of increased mortality for this population . From 2004 to 2017, an annual percentage increase of 2.4% was observed for patients under 40 years old (P < 0.001) . In a Brazilian time-series analysis from 1996 to 2017, 19,105 young women deaths due to breast cancer were observed . The young women mortality rate augmented in all Brazilian regions during the period, with a national annual increase of 2.2% for women from 20 to 29 years and 4.6% for those from 30 to 39 years .
In this study, we aimed to evaluate the trends in the proportion of new breast cancer cases and deaths occurring in women younger than 40 years over the last decade, in a large tertiary cancer center.