How Breast Cancer Varies by Age: A Comparison of 20s, 30s, and 40s

Breast cancer is a disease that can affect anyone, regardless of age, gender, or ethnicity. However, the risk, causes, symptoms, and outcomes of breast cancer may differ depending on the age of the person. In this article, we will compare and contrast how breast cancer affects people in their 20s, 30s, and 40s.

Breast Cancer Risk by Age

The risk of developing breast cancer increases with age. According to the American Cancer Society, the average risk of a woman developing breast cancer in her lifetime is about 13%, but this varies by age group. For example, the risk of developing breast cancer by age 30 is 0.44%, by age 40 is 1.47%, and by age 50 is 2.38%. This means that one in 227 women will develop breast cancer by age 30, one in 68 women by age 40, and one in 42 women by age 50.

However, age is not the only factor that affects breast cancer risk. There are also genetic, hormonal, environmental, and lifestyle factors that can influence the likelihood of developing the disease. Some of these factors are more common or more relevant in younger women than older women. For example:

Genetic mutations: Some inherited mutations in genes such as BRCA1 and BRCA2 can significantly increase the risk of breast cancer, especially at a younger age. Women who have these mutations have a 72% chance of developing breast cancer by age 80, compared to 12% for women without these mutations¹. About 5% to 10% of all breast cancers are linked to these mutations².
Family history: Having a close relative (such as a mother, sister, or daughter) who had breast cancer before age 50 can double or triple the risk of developing breast cancer². About 15% to 20% of all breast cancers occur in women who have a family history of the disease².
Reproductive history: Having an early onset of menstruation (before age 12) or a late onset of menopause (after age 55) can increase the exposure to estrogen and progesterone, which are hormones that can stimulate breast cell growth and increase the risk of breast cancer². Having no children or having the first child after age 30 can also increase the risk².
Pregnancy-associated breast cancer (PABC): This is a rare type of breast cancer that occurs during pregnancy or within a year after giving birth or breastfeeding³. The incidence of PABC ranges from 17.5 to 39.9 per 100,000 births¹. PABC tends to be more aggressive and less responsive to treatment than other types of breast cancer³.

Breast Cancer Causes by Age

The exact causes of breast cancer are not fully understood, but it is believed that a combination of genetic and environmental factors can trigger abnormal changes in the DNA of breast cells, leading to uncontrolled growth and invasion of surrounding tissues². Some of these factors may vary by age group. For example:

Hormonal factors: Hormones such as estrogen and progesterone play a key role in regulating the development and function of the breast tissue. However, they can also stimulate the growth of some types of breast cancer cells that have receptors for these hormones on their surface². Hormonal factors that can affect breast cancer risk include natural fluctuations during the menstrual cycle and pregnancy, as well as external sources such as oral contraceptives and hormone replacement therapy (HRT)². Younger women are more likely to be exposed to hormonal factors due to their reproductive activity and use of hormonal contraceptives.
Environmental factors: Exposure to certain substances or radiation in the environment can damage the DNA of breast cells and increase the risk of breast cancer. Some examples of environmental factors include tobacco smoke, alcohol consumption, obesity, physical inactivity, dietary factors, air pollution, pesticides, and ionizing radiation². Environmental factors may have different effects depending on the age and developmental stage of the breast tissue. For instance, exposure to ionizing radiation during childhood or adolescence can increase the risk of breast cancer later in life more than exposure during adulthood².
Genetic factors: As mentioned earlier, some inherited mutations in genes such as BRCA1 and BRCA2 can increase the risk of breast cancer significantly. These mutations can impair the ability of the cells to repair DNA damage and prevent tumor formation². Genetic factors are more likely to be involved in younger women with breast cancer than older women. About 25% to 40% of women under age 35 with breast cancer have a genetic mutation, compared to 5% to 10% of women over age 50.

Breast Cancer Symptoms by Age

The most common symptom of breast cancer is a lump or mass in the breast. However, not all lumps are cancerous, and not all breast cancers cause lumps. Other possible symptoms of breast cancer include:

Changes in the size, shape, or appearance of the breast
Changes in the skin of the breast, such as dimpling, puckering, redness, scaling, or thickening
Changes in the nipple, such as inversion, retraction, discharge, or soreness
Swelling or pain in the breast or underarm area
A rash or ulcer on the breast or nipple

The symptoms of breast cancer may vary depending on the age of the person and the type and stage of the cancer. Some factors that can affect the symptoms of breast cancer by age are:

Breast density: Younger women tend to have denser breast tissue than older women. This means that they have more glandular and fibrous tissue and less fatty tissue in their breasts². Dense breast tissue can make it harder to detect lumps or other changes in the breast by touch or by mammography². Dense breast tissue can also increase the risk of developing breast cancer².
Breast cancer type: There are different types of breast cancer that can have different characteristics and behaviors. Some types of breast cancer are more common or more aggressive in younger women than older women. For example, younger women are more likely to develop triple-negative breast cancer (TNBC), which is a type of breast cancer that does not have receptors for estrogen, progesterone, or HER2¹. TNBC tends to grow faster and spread more easily than other types of breast cancer¹. TNBC can also cause different symptoms than hormone receptor-positive or HER2-positive breast cancers, such as larger tumors, skin changes, and inflammatory signs¹.
Breast cancer stage: The stage of breast cancer refers to how much the cancer has grown and spread within the breast or to other parts of the body. The stage of breast cancer can affect the symptoms and prognosis of the disease. Younger women are more likely to be diagnosed with later stages of breast cancer than older women. This is because they may not have regular screening mammograms, they may ignore or dismiss their symptoms, or they may face delays in diagnosis or treatment due to lack of awareness or access to care¹. Later stages of breast cancer can cause more severe symptoms such as pain, swelling, ulceration, weight loss, fatigue, and bone fractures².
Conclusion

Breast cancer is a complex and heterogeneous disease that can affect people of any age. However, there are some differences in how breast cancer affects people in their 20s, 30s, and 40s. These differences include:

The risk of developing breast cancer increases with age, but there are also other factors that can influence the risk, such as genetic mutations, family history, reproductive history, and pregnancy-associated breast cancer.
The causes of breast cancer are not fully understood, but they may involve a combination of genetic and environmental factors that can damage the DNA of breast cells. Some of these factors may vary by age group, such as hormonal factors, environmental factors, and genetic factors.
The symptoms of breast cancer may vary depending on the age of the person and the type and stage of the cancer. Some factors that can affect the symptoms of breast cancer by age are breast density, breast cancer type, and breast cancer stage.

Breast cancer is a serious disease that requires early detection and treatment. Therefore, it is important for people of all ages to be aware of their personal risk factors for breast cancer, to perform regular self-exams and clinical exams of their breasts, and to follow the screening guidelines recommended by their healthcare providers.

Bibliography

[1] Breast Cancer Age: In Your 20s, 30s, Statistics, and More - Healthline(https://www.healthline.com/health/breast-cancer/breast-cancer-20s-30s)

[2] Breast Cancer in Young Women (Under 40) - Cleveland Clinic(https://my.clevelandclinic.org/health/articles/16805-breast-cancer-in-young-women)

[3] How does age affect a person’s risk of breast cancer? - Medical News Today(https://www.medicalnewstoday.com/articles/325654)

[4] Breast Cancer Risk Factors: Age | Susan G. Komen®