Breast cancer survivors were less likely to get Alzheimer’s if they underwent this treatment: study

A breast cancer battle might come with an unexpected silver lining.

New research suggests survivors may have a lower risk of developing Alzheimer’s dementia (AD) compared to women without a history of the disease.

One treatment, in particular, appears to offer the most protection — but there’s a major catch.

For the study, Korean scientists analyzed health records of over 70,000 women treated for breast cancer between 2010 and 2016, comparing them with a control group of about 180,000 healthy participants.

Over an average follow-up of 7.3 years, 1,229 breast cancer survivors were diagnosed with Alzheimer’s. Compared to the control group, these survivors had an 8% lower risk of developing the disease.

The reduced risk was strongest among women aged 65 and older who received their breast cancer diagnosis later in life.

Radiation therapy, the most common treatment among these patients, uses high-energy rays to kill cancer cells and shrink tumors. It is often administered after surgery to eliminate any remaining cancer cells and reduce the risk of recurrence.

The study found that the treatment also offered the greatest protective effect against Alzheimer’s, reducing the risk by 23%.

The finding surprised researchers, given widespread fears about cognitive decline in breast cancer patients after treatment, often referred to as “chemo brain.”

“Concerns about chemo brain and the long-term adverse effects of breast cancer treatment on cognition are common, but our findings suggest this treatment does not directly lead to [Alzheimer’s disease],” the study authors wrote.

They highlighted earlier studies suggesting that certain breast cancer therapies may help reduce the buildup of amyloid-beta and tau proteins — key markers of Alzheimer’s disease.

The team also found no significant link between other breast cancer treatments, such as chemotherapy or hormone therapy, and Alzheimer’s risk.

However, these findings contradict other studies that have reported a possible increased risk of Alzheimer’s among some cancer survivors, especially older women.

Notably, the researchers found that the protective benefit of breast cancer treatment didn’t extend beyond five years.

“Based on these findings, we hypothesize that the risk of AD could be lowered shortly after cancer treatment but may equalize as the survival period increases,” the study authors wrote.

They also acknowledged several limitations. Data on patients’ breast cancer stage and radiation doses were unavailable, and some Alzheimer’s diagnoses may have been missed.

Since the study focused on patients with “operable” breast cancer, its findings may not apply to elderly patients, those with serious comorbidities or people with advanced-stage disease.

And with a maximum follow-up period of 11 years, the scientists were unable to assess the long-term risk of Alzheimer’s in breast cancer survivors.

“Additional studies with longer observation periods are needed to better understand the relationship between [Alzheimer’s] risk and breast cancer survival duration,” the authors recommended.

Breast cancer is one of the most common cancers among US women, with one in eight expected to develop the disease in their lifetime, according to the American Cancer Society.

Alzheimer’s also poses a growing public health challenge that disproportionately affects women, who account for nearly two-thirds of cases, per the Alzheimer’s Association.

The number of Americans diagnosed every year is projected to double by 2060, impacting 14 million adults.

While there is currently no cure for Alzheimer’s, medications and therapies are available that can help manage symptoms and may slow the progression of the memory-robbing disease — especially when it’s detected early.

“Understanding the potential protective association of breast cancer on AD can enhance surveillance strategies for AD among these survivors,” the researchers wrote.