Breast cancer is being diagnosed more and more often in women under the age of 50, according to American research. The increase is mainly caused by an increase in the number of tumors that are sensitive to estrogen.
According to the WHO, breast cancer is one of the most common forms of cancer. Each year, approximately 2.3 million people worldwide develop this debilitating disease. In the Netherlands, all women aged 50 to 75 receive an invitation every two to three years for population screening to detect breast cancer early. Although the research focuses on women over fifty, more and more women under fifty have been diagnosed with breast cancer in recent decades. This is what researchers conclude Washington University School of Medicine after a large-scale data study.
For the study, researchers analyzed data from more than 217,000 American women who were diagnosed with breast cancer between 2000 and 2019. They looked at the age, population group, tumor type, tumor stage and other characteristics of the patients. It showed that the number of breast cancer cases in women aged 20 to 49 has increased significantly over time. Around the turn of the century, approximately 64 in 100,000 people were diagnosed. In the following years, that number increased slightly, but after 2016 the trend line took a sharp turn upwards, to 74 cases per 100,000 in 2019.
In addition, the researchers saw that there were differences in the incidence of breast cancer between different ethnicities. Women of color in this age group were half as likely to develop breast cancer as white women of the same age group. Asian women, on the other hand, were a quarter less likely to develop breast cancer than white women. The researchers do not know what causes these differences and the increase in the total number.
Most strikingly, the increase in the number of breast cancer cases is entirely due to tumors that are sensitive to estrogen, the researchers say. The so-called ‘estrogen receptor-positive tumors’. These tumors have proteins on their surfaces that bind to estrogen, which stimulates tumor growth. If you do not include this type of tumors, the number of breast cancer cases has actually decreased in the past twenty years. The researchers therefore wonder whether the increase may be related to changes in lifestyle, diet, contraception or other factors.
“To do something about this, we need to understand what causes the specific increase in estrogen receptor-positive tumors,” says researcher Adetunji Toriola. “We also hope to learn from the decline in estrogen receptor-negative tumors. If we can understand what drives that rate down, we may be able to apply this to efforts to reduce or prevent other types of breast tumors.”
Stages 1 and 4
The research shows that the recognition of breast cancer is already going well to some extent. The number of diagnoses in stages 2 and 3 has decreased in recent years. But on the other hand, there is an increase in the number of diagnoses of stage 1 and stage 4 tumors. Toriola says this suggests that screenings have been helpful in recent years, and that there may also be greater awareness when it comes to family history and genetic risk factors for breast cancer. This ensures that many tumors are discovered earlier. But it also indicates that when stage 1 tumors are missed in younger women, the tumors usually aren’t found until they reach stage 4.
Prevention and treatment
The researchers hope that their research will lead to more targeted preventive screening in the future. “For most women, regular breast cancer screening only starts at age 40, so younger women with breast cancer often have tumors at a later stage, when the disease is more advanced and therefore more difficult to treat,” Toriola explains. “We hope that by taking into account the differences in tumor characteristics, stage and ethnicity that we have demonstrated, we can improve diagnosis and treatment in young women with breast cancer.”
The researchers also want to find out which factors are exactly responsible for this increase in this specific form of breast cancer. They also want to investigate whether they can discover which women are at high risk of developing breast cancer at a young age. So that they can keep a better eye on this group and thus reduce the risk.
Cancer at a young age
Other forms of cancer have also become more common in recent years at younger ages. Researchers at Brigham and Women’s Hospital previously found that risk factors for cancer include alcohol consumption, sleep deprivation, smoking, obesity and eating processed foods. And precisely these culprits have increased significantly since the 1950s. Nowadays we eat a lot more processed foods, we drink a lot of sugary drinks and alcohol and many people suffer from obesity and type 2 diabetes. Therefore, the team hypothesizes that factors such as the Western diet and lifestyle are probably a major contributor to the current ‘cancer epidemic’. to deliver. “The younger the generation, the greater the risk of cancer at every stage of life,” researcher Tomotaka Ugai previously explained in conversation with Scientias.nl. “This is probably due to food, environment and lifestyle.” And so he advocates change. “We really need to be aware of the increased risk of cancer and therefore take measures earlier,” Ugai underlines. “For example, we must ensure better and healthier conditions for young children. Not only will this prevent cancer, but it will also have many additional health benefits.”