Breast cancer survivors have a higher risk of developing a second cancer

Breast cancer survivors have a higher risk of developing a second cancer

Breast cancer survivors have a significantly higher risk of developing second cancers, including endometrial and ovarian cancer in women and prostate cancer in men, according to a new study examining data from almost 600,000 patients in England.

The research has shown for the first time that this risk is higher in people living in areas of greater socio-economic deprivation.

Breast cancer is the most commonly diagnosed cancer in the UK. Around 56,000 people in the UK develop the disease every year, the vast majority (over 99%) of whom are women. Improvements in early detection and treatment have meant that the five-year survival rate has increased over time, reaching 87% in England in 2017.

People who survive breast cancer are at risk of a second primary cancer, but the exact risk has been unclear. Previously published research suggests that women and men who survive breast cancer have a 24% and 27% higher risk, respectively, of developing a second primary cancer that is not breast cancer than the general population. There is also evidence that the risk of a second primary cancer varies depending on the age at breast cancer diagnosis.

To provide more accurate estimates, a team led by researchers at the University of Cambridge used the National Cancer Registration Dataset to analyze data from over 580,000 female and over 3,500 male breast cancer survivors diagnosed between 1995 and 2019. The results of their analysis are published today inLancet Regional Health – Europe.

It is important for us to understand to what extent having one type of cancer brings with it the risk of a second cancer in another location. The female and male breast cancer survivors whose data we examined had an increased risk of a number of second cancers. Knowing this can help guide conversations with care teams to look for signs of possible new cancers.”

Isaac Allen, lead author, Department of Public Health and Primary Care, University of Cambridge

The researchers found a significantly increased risk of cancer in the contralateral (i.e. unaffected) breast as well as endometrial and prostate cancer in women and men, respectively. Women who survived breast cancer had twice the risk of contralateral breast cancer and an 87% higher risk of uterine cancer, a 58% higher risk of myeloid leukemia, and a 25% higher risk of ovarian cancer compared to the general population.

Age at diagnosis also played a role: women diagnosed with breast cancer under the age of 50 were 86% more likely to develop a second primary cancer than the general population of the same age, while women diagnosed with breast cancer after age 50 were 17% more likely to develop a second primary cancer than the general population of the same age. increased risk. One possible explanation is that a larger number of younger breast cancer survivors may have inherited genetic changes that increase the risk of several types of cancer. For example, women with hereditary changesBRCA1AndBRCA2Genes have an increased risk of contralateral breast cancer, ovarian and pancreatic cancer.

Women from the most socioeconomically disadvantaged backgrounds had a 35% higher risk of a second primary cancer compared to women from the least disadvantaged backgrounds. These differences were primarily due to risks not related to breast cancer, particularly lung, kidney, head and neck cancer, bladder cancer, esophageal cancer, and stomach cancer. This may be because smoking, obesity and alcohol consumption - established risk factors for these cancers - are more common in more disadvantaged groups.

Allen, a PhD student at Clare Hall, added: "This is further evidence of the health inequalities experienced by people from disadvantaged backgrounds. We need to fully understand why they are at higher risk of second cancers so we can intervene and reduce this." Risk."

Male breast cancer survivors were 55 times more likely to develop contralateral breast cancer than the general male population - although the researchers emphasize that the individual risk was still very low. For example, about three in 100 men diagnosed with breast cancer at age 50 or older developed contralateral breast cancer within 25 years. Male breast cancer survivors were 58% more likely to develop prostate cancer than the general male population.

Professor Antonis Antoniou, from the University of Cambridge's Department of Public Health and Primary Care, the study's senior author, said: "This is the largest study to date looking at breast cancer survivors' risk of developing a second cancer. We were." Because of the outstanding data sets available to researchers across the NHS, we are able to carry this out and calculate more accurate estimates.”

The research was funded by Cancer Research UK with support from the National Institute for Health and Care Research Cambridge Biomedical Research Centre.

Katrina Brown, senior cancer intelligence manager at Cancer Research UK, said: "This study shows us that the risk of second primary cancers is higher in people with breast cancer, and this may vary depending on a person's socio-economic background. However, further research is needed." to understand what drives this disparity and how to address these health disparities.”

People who are concerned about their risk of cancer should ask their GP for advice. If you or a loved one have cancer and have any questions, you can call Cancer Research UK nurses on the freephone number 0808 800 4040, Monday to Friday.

Sources: