The risk of breast cancer increases with age. Only 7% of cases are diagnosed in women under 40. However, younger women are more likely to face poorer outcomes than those diagnosed later in life including increased rate of metastasis and mortality. This could be because cancer cells replicate quicker in young women.
A study published in Cancer aimed to determine whether regular screening is beneficial for women younger than 50 years old and to understand the growth rate of breast cancer in different age groups.They found that for women aged 50-70, the median doubling time of the tumor was 157 days. In women under 50, it was only 80 days.
Generally, fast-growing tumors tend to be more aggressive which contributes to the poorer outcomes seen in young women.
Aggressiveness in cancer refers to how quickly the cancer spreads, how likely it is to metastasize to distant organs, and how likely it is to resist treatment. Fast-growing tumors often indicate a higher rate of cell division and mutation, which can lead to more rapid progression of the disease.
So why does breast cancer grow faster in young women?
1. Higher levels of estrogen:
Younger women generally have higher levels of estrogen than older women. The hormone supports a healthy menstrual cycle and fertility, but can also promote the growth of certain types of breast cancers when chronically elevated. This is because estrogen stimulates a stress response and cell proliferation in the body. In an environment already conducive to cancer, estrogen may promote rapid cell division to support advanced tumor growth.
2. Higher DNA replication rate in young women
Younger individuals typically have cells that divide more rapidly as part of normal growth and development. This heightened cellular activity can inadvertently promote the rapid division of cancer cells, leading to faster tumor growth. Additionally, high rates of cell division increase the likelihood of mutations occurring during DNA replication. These mutations can drive cancer growth and contribute to the aggressiveness of the tumor
3. Increased immune activity in young women
An animal study reported in Clinical Cancer Research found that a younger immune system supports breast cancer growth and metastasis to the brain, whereas an older immune system makes the brain less hospitable to migrating cancer cells.
Researchers demonstrated that young animals have more immune cells called macrophages and microglia. These cells can protect tumors, depending on the situation. The study found that these immune cells help metastatic cancer cells survive in the brain.
It’s important to point out that the risk of getting breast cancer is higher when a woman is older. This may be because of low progesterone levels, among many other factors).These factors contribute to the poorer prognosis and higher recurrence rates observed in younger breast cancer patients.
Conventional cancer screenings are not recommended under the age of 40. Early screening in younger women may expose them to radiation unnecessarily. Mammography, the primary method for breast cancer, may not be as effective in younger women due to dense breast tissue, which can make tumors harder to detect. As a result, many cases are caught in the later, more aggressive stages.
While breast cancer is less common in younger women, it presents more significant challenges. This is why prevention is key. There are several steps we can take in order to decrease our risk including balancing estrogen and progesterone levels, ensuring adequate vitamin D status, and prioritizing a healthy diet, to name a few.