The influence of age on an individual's likelihood of developing breast cancer.
In the United States, breast cancer is the most common type of cancer in females, other than non-melanoma skin cancer. The average age of breast cancer diagnosis is around 62 years old, with about half of U.S. women diagnosed with breast cancer being 62 or younger[1].
The age-specific incidence rates, based on data from 2.3 million women diagnosed between 2001 and 2019, show that women aged 65 to 74 years have the highest age-adjusted incidence rate at about 530.4 cases per 100,000 persons. Women aged 75 to 84 years have a slightly lower incidence at 515.3 per 100,000, while women aged 85 years and older have an incidence of about 376.8 per 100,000[1].
Younger women, especially those under 45 years old, represent about 9% of new breast cancer cases in the U.S., but those diagnosed under age 35 face a higher risk of recurrence[1].
Several factors contribute to the risk of developing breast cancer. Breasts that contain more connective than fatty tissues are more likely to develop breast cancer. Being female is a significant risk factor, as females are 100 times more likely to develop breast cancer than males[2].
Other risk factors include being overweight after menopause, having a personal history of certain noncancerous breast conditions, such as atypical hyperplasia, lobular carcinoma in situ, and ductal carcinoma in situ, being inactive, having a family history of breast cancer, and having radiation therapy to the chest or breasts before the age of 40 years[2].
Changes to the BRCA1 and BRCA2 genes can significantly increase the risk of breast cancer. Females who inherit the BRCA1 or BRCA2 gene mutation have a roughly 70% chance of developing breast cancer by the age of 80 years[2]. Current guidelines suggest that females undergo genetic testing if their ancestry is one in which breast cancer is commonly linked to BRCA1 or BRCA2 gene mutations, for example, Ashkenazi Jewish ancestry[2].
Regarding screening, the U.S. Preventive Services Task Force recommends that females aged 50-74 years at average risk of developing breast cancer should go for screening every 2 years[3]. However, recent studies suggest adjusting screening start ages based on genetic risk (polygenic risk scores), which can identify some women who reach average risk levels earlier than age 50, potentially in their 30s or early 40s[3].
Those aged 40-49 years, particularly those with a higher risk of breast cancer, should discuss the risks and benefits of undergoing regular screening with their doctor[2]. The main benefit of undergoing regular screening is that it increases the chance of detecting breast cancer in its early stages, which can improve treatment outcomes. However, there are potential risks associated with screening, such as false positives, overtreatment, and false negatives[2].
In conclusion, understanding the age-specific incidence rates and risk factors associated with breast cancer can help individuals make informed decisions about screening and prevention strategies. It is essential to discuss these matters with a healthcare provider to determine the best course of action.
References: [1] American Cancer Society. (2021). Breast Cancer Facts & Figures. Retrieved from https://www.cancer.org/content/dam/cancer-org/research/cancer-facts-and-statistics/breast-cancer-facts-and-figures/breast-cancer-facts-and-figures-2021-2022.pdf [2] American Cancer Society. (2021). Breast Cancer Risk Factors. Retrieved from https://www.cancer.org/cancer/breast-cancer/causes-risks-prevention/risk-factors.html [3] U.S. Preventive Services Task Force. (2019). Breast Cancer: Screening. Retrieved from https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/screening-for-breast-cancer-in-women-without-symptoms-and-at-average-risk-of-developing-breast-cancer/final-recommendation-statement
- Younger women, particularly those under 45 years old, diagnosed with breast cancer face a higher risk of recurrence, indicating the importance of early detection and treatment.
- The age-adjusted incidence rate for breast cancer shows that women aged 65 to 74 years have the highest rate, yet those under 45 years old represent about 9% of new cases in the U.S.
- Understanding science and medical-conditions related to breast cancer, such as risk factors, recurrence, and screening guidelines, can help individuals make informed decisions about health-and-wellness and women's health.
- Changes to the BRCA1 and BRCA2 genes can significantly increase the risk of breast cancer, and females who inherit these gene mutations have a roughly 70% chance of developing breast cancer by age 80.
- Current guidelines suggest that females at average risk of developing breast cancer should undergo genetic testing if they have ancestry linked to BRCA1 or BRCA2 gene mutations, such as Ashkenazi Jewish ancestry.
- Regarding screening, discussions with a doctor are essential for those aged 40-49 years, especially those with a higher risk of breast cancer, to determine the benefits and risks associated with undergoing regular screenings for early detection.
