Breast Cancer Survivors Have Higher Risk of Other Cancers
People with a history of breast cancer are at higher risk of being diagnosed with a second type of cancer, according to a U.K. study published in the journal The Lancet Regional Health Europe.
Key takeaways
Women who had been diagnosed with breast cancer were twice as likely to develop cancer in the opposite breast than women in the general population.
Women with a history of breast cancer also had a much higher risk of developing endometrial cancer, myeloid leukemia, and ovarian cancer.
Men with a history of breast cancer were 55 times more likely to develop cancer in the opposite breast than men in the general population, though this risk was still low.
Out of every 100 men diagnosed with breast cancer at age 50 or older, about three developed cancer in the other breast during a 25-year period.
Men who had been diagnosed with breast cancer were 58% more likely than the average man to develop prostate cancer.
Age at diagnosis was important for women. Women who were first diagnosed with breast cancer when they were younger than 50 were 86% more likely to develop a second cancer than the average woman. Women who were older than 50 when first diagnosed had a 17% higher risk.
What the results mean for you
These results add more evidence to what other studies have shown: People with a history of breast cancer have a much higher-than-average risk of developing other cancers later in life, such as ovarian and endometrial cancer in women and prostate cancer in men.
This is why it’s so important to get follow-up care that’s tailored to your unique situation after active breast cancer treatment ends. Follow-up care includes making a survivorship care plan that details the treatments you’ve had, has information on late or long-term side effects, and includes personalized recommendations for tests and appointments.
If you’re having trouble getting survivorship care or are confused about what the next steps are, you can get free help from CancerCare. The non-profit organization has professional navigators and oncology social workers who can help you find cancer survivorship care and resources in your community.
About the study
The researchers looked at the health records of 581,403 women and 3,562 men who lived in England and were first diagnosed with early-stage breast cancer between January 1995 and December 2019. People with either DCIS or metastatic breast cancer as their first diagnosis were excluded from the study.
Among the people in the study:
78% of the women and 92% of the men were age 50 or older when first diagnosed with breast cancer
the average age at first breast cancer diagnosis was 61 for women and 67 for men
86% of the women and 84% of the men were white
The researchers looked to see how many of the people were later diagnosed with another cancer that wasn’t a recurrence of the first breast cancer.
Half the women were followed for less than 5.5 years, and the other half were followed for longer.
Half the men were followed for less than 4.4 years, and the other half were followed for longer.
Detailed results
During follow-up:
52,620 second cancers were diagnosed in the women
504 second cancers were diagnosed in the men
Women with a history of breast cancer had a 25% higher-than-average risk of developing a second cancer anywhere in the body.
Compared to average risk, women who had been treated for breast cancer had:
double the risk of developing a new cancer in the opposite breast
an 87% higher risk of endometrial cancer
a 58% higher risk of myeloid leukemia
a 25% higher risk of ovarian cancer
Women who were younger than 50 when first diagnosed with breast cancer had:
triple the risk of developing a new cancer in the opposite breast
a 52% higher risk of lung cancer
a 65% higher risk of pancreatic cancer
a 73% higher risk of ovarian cancer
twice the risk of myeloid leukemia
One explanation for these higher risks is that younger women diagnosed with breast cancer may be more likely to have a genetic mutation linked to breast cancer, such as a BRCA1 or BRCA2 mutation, which increases the risk of several other cancers in addition to breast cancer.
Compared to women who lived in the most economically advantaged areas, women in the most disadvantaged areas had:
an 86% higher risk of lung cancer
a 37% higher risk of kidney cancer
a 38% higher risk of head and neck cancer
a 30% higher risk of bladder cancer
a 44% higher risk of esophageal cancer
a 69% higher risk of stomach cancer
The researchers noted that the risks of these cancers might be higher because smoking, obesity, and drinking alcohol, which are associated with a higher risk of getting many cancers, are more common among people who live in the most disadvantaged areas.
Women who received chemotherapy had nearly three times the risk of myeloid leukemia than women who didn’t receive chemotherapy.
Men with a history of breast cancer had a 15% higher-than-average risk of developing a second cancer anywhere in the body.
Compared to the average man, men who had been treated for breast cancer had:
55 times the risk of cancer in the opposite breast
a 58% higher risk of prostate cancer
nearly four times the risk of thyroid cancer
As with younger women, a genetic mutation linked to breast cancer may be the reason that men with a history of breast cancer had a higher risk of second cancers. But age at first breast cancer diagnosis and the economic status of the area the men lived in didn’t affect the risk of a second cancer.
“It’s important for us to understand to what extent having one type of cancer puts you at risk of a second cancer at a different site,” the study’s first author, Isaac Allen, said in a statement. Allen is a doctoral student in cancer epidemiology at the University of Cambridge. “The female and male breast cancer survivors whose data we studied were at increased risk of a number of second cancers,” he added. “Knowing this can help inform conversations with their care teams to look out for signs of potential new cancers.”
Allen, I. et al. Risks of second primary cancers among 584,965 female and male breast cancer survivors in England: a 25-year retrospective cohort study. The Lancet Regional Health Europe. April 24, 2024.
— Last updated on August 31, 2024 at 1:35 PM