Researchers from the University of Cambridge have revealed that survivors of breast cancer are at a significantly higher risk of developing second cancers, such as endometrial and ovarian cancer for women and prostate cancer for men.
The study published in the Lancet Regional Health – Europe was funded by Cancer Research UK (CRUK).
Breast cancer is currently the most commonly diagnosed cancer in the UK, affecting around 56,000 people every year.
Current estimates show that women and men who survive breast cancer are at 24% and 27% greater risk of a non-breast second primary cancer, respectively; however, the exact risk has been unclear.
After analysing data from over 580,000 female and over 3,500 male breast cancer survivors diagnosed between 1995 and 2019 from the National Cancer Registration Dataset, researchers found significantly increased risks of cancer in the unaffected breast and for endometrium in females and prostate cancer males, respectively.
In total, female survivors were at double the risk of developing contralateral breast cancer in comparison to the general population and at a greater risk of developing endometrial cancer (87%), myeloid leukaemia (58%) and ovarian cancer (25%), while male breast cancer survivors were 55 times more likely to develop contralateral cancer and 58% more likely to develop prostate cancer compared to the general male population.
In addition, females diagnosed with breast cancer under the age of 50 were 86% more likely to develop a second primary cancer compared to the general population of the same age, while women diagnosed after age 50 were at a 17% increased risk.
For every 100 men diagnosed with breast cancer at age 50 or over, only three develop contralateral breast cancer during a 25-year period.
Other factors that increased the risk of developing secondary cancers included females from socioeconomically deprived backgrounds.
Katrina Brown, senior cancer intelligence manager, CRUK, commented: “This study shows us that the risk of second primary cancers is higher in people who have had breast cancer and… can differ depending on someone’s socioeconomic background.
“More research is needed to understand what is driving this difference and how to tackle these health inequalities.”