Cancer Trends Toward Younger People
Summary
- The American Cancer Society’s annual report conveyed a deep drop in cancer deaths.
- Within the data, there are reasons for concern, including cancer diagnoses for women rising significantly in relation to diagnoses for men.
- Sylvester Comprehensive Cancer Center researchers are delving into the biological, environmental and behavioral factors involved in cancer.
The annual cancer trends report released by the American Cancer Society earlier this year revealed strikingly divergent paths, exposing cancer’s new reality.
On the positive side, overall death rates from the disease plunged 34% between 1991 and 2022. That’s nearly 4.5 million fewer deaths. The steep drop is linked to declines in the four most common cancers: lung, colorectal, breast and prostate. It can be attributed to earlier diagnoses, dramatically less tobacco use and major advances in cancer treatment, such as precision medicine. While there were spikes in colorectal and testicular cancers among younger men, these were balanced out by drops in other cancers, including prostate cancer.
Overall, the numbers sew optimism. But a closer look reveals a more complex picture. In 1992, there were 1.6 cancer diagnoses among men for each woman, but in 2021, the ratio dropped to 1.1 diagnoses for men for each case among women.
Researchers at Sylvester Comprehensive Cancer Center, part of the University of Miami Miller School of Medicine, are delving into the biological, environmental and behavioral factors involved in cancer. They’re aiming to develop solutions.
Lung Cancer
Lung cancer remains the leading cause of cancer-related deaths in the U.S., responsible for roughly one in five cancer mortalities. Historically, lung cancer rates were significantly higher in men than in women, mainly because of differences in smoking habits. But smoking rates among men peaked earlier in the 20th century, while women began smoking in large numbers later. As a result, lung cancer diagnoses among women have risen 84% over the past 42 years, while decreasing 36% among men during the same period. This year, the American Cancer Society projects that more women than men will be diagnosed with the disease.
“The American Cancer Society’s report matches what I’m seeing in my practice,” said Estelamari Rodriguez, M.D., M.P.H., clinical research lead of the Thoracic Site Disease Group and associate director of outreach at Sylvester. “At our lung cancer clinic, we’re seeing more and more women. And their average age used to be 68, but now that is going down. We have women as young as 34.”
Increased rates of smoking, coupled with genetic predispositions, hormonal influences, environmental exposures such as air pollution and filtered cigarettes that allow smokers to inhale more deeply are possible factors contributing to the rise in lung cancer among women.
“While we carry out more research on these other possible effects, one surefire way to slow down new cases is to screen patients better,” Dr. Rodriguez said. “We know that lung cancer screening can detect cancer at its most curable stage. National screening guidelines for lung cancer are biased toward older populations, 50 to 80, with a high risk of smoking. Our younger patients don’t meet the age criteria, and many don’t have a smoking history, so they will basically never be offered a test. That has to change.”
Brain Cancer
Defne Bayik, Ph.D., assistant professor of molecular and cellular pharmacology at the Miller School, is a cancer immunologist focused on uncovering host regulatory pathways as targets for brain tumor immunotherapy. In a recent study, she and her colleagues investigated the basis of sex differences in glioblastoma, a highly aggressive brain cancer. Approximately 60% of cases of glioblastoma occur in men, and 40% occur in women, with men having worse outcomes compared to women.
Possible reasons for these differences between men and women are under investigation. For example, estrogen and progesterone, the primary female sex hormones, may have protective effects against the disease. And women typically have stronger immune responses than men, which may help them better control tumor growth.
Understanding the unique biology of tumors in men versus women can help researchers develop more effective treatments. For example, Dr. Bayik’s team found that gamma-aminobutyric acid (GABA), a common chemical messenger used for neuronal communication, could be a factor impacting glioblastoma in women but not men.
Additionally, the researchers discovered that blocking GABA’s effects might help extend life for women with glioblastoma, suggesting a new line of study for this aggressive cancer. The study also found that certain medications, such as pregabalin (often used for pain and seizures), may speed up tumor growth and shorten survival in women.
“Overall, our study highlights how differential responses of men and women to glioblastoma might inform treatments,” said Dr. Bayik, who continues to investigate factors that might affect glioblastoma. “It raises concerns about common drugs such as pregabalin potentially making things worse for women with glioblastoma, but not for men. This is an early observation that we need to study in more detail. Moving forward, we hope to develop better, more personalized treatments by studying how GABA and similar factors influence cancer growth differently in males and females.”
Breast Cancer
Breast cancer remains one of the most pressing health crises in the Caribbean, where mortality rates outpace those in high-income countries. Since 20% of Miami-Dade County’s population is of Caribbean descent, health findings have potentially significant effects in Miami, as well as on those who continue to live in the Caribbean.
Two studies led by Sophia George, Ph.D., associate professor in the Miller School’s Department of Obstetrics, Gynecology and Reproductive Sciences, shed light on factors contributing to the alarming trend of higher breast cancer death rates in the Caribbean.
Her first study paints a troubling picture. In addition to higher death rates from the disease, women in the Caribbean are being diagnosed with breast cancer at significantly younger ages than their counterparts in the U.S. The findings, which span seven Caribbean nations, suggest that these trends may be linked to women having had fewer babies at earlier ages than those in previous generations and experiencing their first periods at an earlier age.
Dr. George’s second study found that hereditary cancer is disproportionately high in women from the area. In the Bahamas, 28% of breast cancer patients carried BRCA1 or BRCA2 mutations, which greatly increase cancer risk. That rate is among the highest in the world. Dr. George also discovered a wide range of genetic changes linked to breast and ovarian cancer, and that the PALB2 gene played a big role in breast cancer, especially in women from Jamaica and Barbados.
A lack of access to screenings may lead to later cancer diagnoses that are more difficult to treat. Dr. George advocates for more advanced genetic testing.
“Our research suggests that, instead of only testing for BRCA1 and BRCA2, doctors should use more advanced genetic testing to identify those at risk earlier,” she said.
Lifestyle Effects on Cancer
Studies show that lifestyle choices play a significant role in cancer risk and outcomes.
“The evidence is clear. Limiting alcohol, maintaining a healthy weight, eating a healthy diet and engaging in regular physical activity can reduce cancer risk and improve outcomes for those diagnosed with the disease,” said Tracy Crane, Ph.D., RDN, director of lifestyle medicine, prevention and digital health, and co-lead of Sylvester’s Cancer Control Program. “This scientific foundation underscores the importance of using evidence-based guidelines, as they are based on rigorous research and proven to be most effective.”
The differences in cancer rates between men and women and the rise in younger people being diagnosed with the disease reflect a complex interplay of genetic and lifestyle factors. Understanding the reasons for these trends is crucial for developing targeted prevention and treatment strategies. The many types of research taking place at Sylvester in this area provide deeper insights into why these differences exist and how best to address them.
Tags: breast cancer, cancer research, Dr. Defne Bayik, Dr. Estelamari Rodriguez, Dr. Sophia George, Dr. Tracy Crane, glioblastomas, lifestyle medicine, lung cancer, nutrition, Sophia George, Sylvester Comprehensive Cancer Center, women's health