Rates of metastatic breast cancer in U.S. women skyrocket, revealing disparities and impact of pandemic

New research shows that metastatic breast cancer We examine rates and reveal how age, race, and pandemic disruptions impact diagnosis and survival outcomes.

study: Surveillance, epidemiology, and end results data show increasing incidence of distant-stage breast cancer at presentation among U.S. women. Image credit: Chinnapong / Shutterstock

Recent research published in journals Radiology Researchers used Surveillance, Epidemiology, and End Results (SEER) data from 2004 to 2021 to examine trends in distant or metastatic breast cancer at initial diagnosis among women in the United States (US). did. The researchers looked at variations based on age. We specifically focus on trends during the coronavirus disease 2019 (COVID-19) pandemic.

background

Breast cancer is the leading cause of cancer-related death in women, and survival rates are closely related to stage at diagnosis. Early detection through mammography is known to significantly improve survival rates. However, many women do not have regular check-ups.

The characteristics of distant stage breast cancer are as follows. metastasis The prognosis at diagnosis is particularly poor, with survival rates far below those for localized cancer. Additionally, trends in metastatic breast cancer vary by age and race, with younger women and racial minorities often having worse outcomes. Social and medical disparities also contribute to delays in diagnosis and treatment.

Furthermore, the COVID-19 pandemic has further disrupted breast cancer care, leading to lower screening rates and delays in diagnosis. Despite the challenges posed by these disruptions, the pandemic has highlighted persistent inequalities between demographic groups in access to timely and effective breast cancer treatment. There is limited data on how these factors influence trends in metastatic cancer across different demographics.

About research

In this study, researchers conducted a retrospective analysis of breast cancer incidence by stage using the SEER 22 database, which covered data from 2004 to 2021. The SEER database represents approximately 48% of the U.S. population and includes a wide variety of races and ethnicities. group. This analysis focused on distant-stage breast cancer, defined as metastatic disease at diagnosis.

Age-adjusted and delay-adjusted incidence rates were calculated for three age groups: 20–39 years, 40–74 years, and 75 years and older. Additionally, trends in metastatic breast cancer diagnoses were examined across racial and ethnic groups, including Asian, white, black, American Indian, and Hispanic women. The researchers also used a variety of statistical analyzes to identify changes in trends over time, calculate annual percentage change (APC), and determine the significance of observed patterns.

This study accounted for potential reporting delays by adjusting for recent incidence rates. The SEER dataset extracted race and ethnicity data from medical records and identified Hispanic ethnicity through the North American Central Cancer Registry Association algorithm. In addition, incidence rates were standardized to the age distribution of the US population in 2000.

The researchers also conducted subgroup analyzes to examine trends in the incidence of metastatic breast cancer by combining age, race, and ethnicity. Of note, Native American women had an upward trend in the incidence of metastatic breast cancer prior to the COVID-19 pandemic, but data limitations prevented this trend in the years following the pandemic. Detailed group analysis was not possible. The analysis also addressed the potential impact of the COVID-19 pandemic on infectious disease trends, particularly in 2020-2021. Breast cancer screening and diagnostic services were significantly disrupted.

The researchers noted that data on Native American women and other small populations are limited, so caution should be used when interpreting the results. This comprehensive analysis aims to provide a detailed overview of trends in metastatic breast cancer and its changes across demographic groups.

result

The findings showed that from 2004 to 2021, the incidence of distant or metastatic breast cancer at diagnosis increased significantly in most demographic groups in the United States. The fastest increase in the rate of being diagnosed with metastatic breast cancer was among women ages 20 to 39. The annual rate of change is 2.91%.

The proportion of women aged 40 to 74 years increased from 2004 to 2010 and again from 2018 to 2021, and for women aged 75 years and older, a consistent increase was observed throughout the study period.

Racial and ethnic disparities were also significant. The incidence of distant breast cancer was 55% higher in black women than in white women, which also contributed to higher mortality rates in this group. Although all racial and ethnic minority groups showed increasing trends, the increases were particularly pronounced among Asian and Hispanic women. For Native American women, there was an upward trend prior to 2020, but disruptions during the pandemic may have led to underreporting for this group.

The study found that the COVID-19 pandemic caused a temporary decrease in reported morbidity, most likely due to disruptions in health care access and delays in diagnosis. This effect was most pronounced among older women and racial and ethnic minority women. Despite this hiatus, the upward trend resumed in 2021, further highlighting the continuing challenges in breast cancer treatment.

conclusion

Overall, the results demonstrate that rates of metastatic breast cancer are increasing among women in the United States, that there are significant demographic disparities, and that the impact of the COVID-19 pandemic on diagnosis and survival rates is increasing. Showed. Young women and racial minorities were found to be particularly affected, highlighting the need for stronger screening and health care equity. The researchers emphasized that systemic barriers to early detection, such as socioeconomic disparities and inconsistent screening guidelines, need to be addressed to reduce the incidence of advanced-stage disease.