Unlike previous generations, millennials are experiencing an increase in cancers, such as colorectal, pancreatic, and certain breast cancers, indicating that multifactorial reasons are influencing this trend. The rising cancer rates are a significant concern, with research suggesting that environmental and epigenetic factors are major contributors.
Impact of early-life exposures: In recent decades, Millennials are the first generation to grow up amidst significant technological advancements like industrialization with chemical carcinogens, pesticides, pollutants in the air, water, and food and endocrine-disrupting substances in everyday products have been associated with various types of cancer. These toxins can directly damage DNA, causing mutations that may lead to cancerous cells. Moreover, lifestyle changes, such as higher consumption of processed foods, increased sugar intake, and more red and processed meats, have contributed to the obesity epidemic, which is a known risk factor for cancers like colorectal and pancreatic cancer. The increase in sedentary activities, due to screen time and desk jobs, further aggravates this risk.
Exposure to harmful substances during early life can also cause lasting epigenetic changes, increasing cancer risk later in life. For example, prenatal and childhood exposure to endocrine disruptors and other chemicals can lead to persistent epigenetic alterations that heighten cancer risk into adulthood. Epigenetic modifications, which alter gene activity without changing the DNA sequence itself, are increasingly recognized as significant factors in cancer development. These changes can be influenced by environmental factors, lifestyle choices, and diet, making millennials particularly susceptible. For instance, exposure to toxins, poor nutrition, and chronic stress can trigger the activation or repression of certain genes, including those involved in tumor suppression. Such epigenetic alterations can elevate the risk of cancer even in the absence of inherited genetic mutations.
One example of an epigenetic mechanism is DNA methylation, where methyl groups attach to the DNA molecule, potentially changing gene expression. Abnormal patterns of DNA methylation are associated with various cancers and are often driven by environmental factors. Another epigenetic process, histone modification, can also influence gene expression and contribute to cancer when disrupted by external influences.
Review on article : A recent study, "Differences in Cancer Rates Among Adults Born Between 1920 and 1990 in the USA: An Analysis of Population-Based Cancer Registry Data," provides a detailed examination of how cancer rates have varied among different birth cohorts in the United States. It reveals significant disparities in cancer rates among people born in different periods.
A key finding is the variation in cancer patterns across birth cohorts. Individuals born around 1920 showed higher rates of cancers such as lung cancer, which were strongly associated with smoking—a prevalent behavior in that era, particularly during the mid-20th century. This high incidence of lung cancer reflects the long-term effects of smoking, even though smoking rates and related cancers have decreased in more recent generations due to public health efforts and greater awareness of smoking risks.
On the other hand, individuals born closer to 1990 have exhibited higher rates of cancers linked to modern lifestyle factors, such as colorectal, pancreatic, and certain breast cancers. The increase in obesity, dietary changes, reduced physical activity, and more sedentary behaviors are major contributors to the growing incidence of these cancers among younger people. This trend illustrates the evolving nature of public health issues, as these contemporary risk factors could have long-term health implications for future generations.
The study also examines how advancements in medical technology and healthcare access have affected cancer rates. Improvements in early detection, screening, and treatment have had a significant impact on cancer incidence and survival rates. For instance, the widespread adoption of mammography and colonoscopy has enabled earlier detection of breast and colorectal cancers, leading to higher survival rates and potentially a rise in reported incidence. This part of the study emphasizes the importance of distinguishing between genuine increases in cancer rates and those attributable to improved detection techniques.
Additionally, the study explores how environmental factors affect cancer trends across various age groups. For instance, reductions in exposure to carcinogens due to stricter regulations and improved workplace safety have led to decreases in certain types of cancer. Changes in reproductive patterns, such as having fewer children and delaying childbirth, have also impacted the incidence of hormonally related cancers like breast and ovarian cancer.
The research emphasizes the intricate nature of cancer epidemiology, illustrating that cancer rates are shaped by numerous elements, including lifestyle choices, environmental factors, medical advancements, and public health initiatives. The results underscore the importance of tailoring cancer prevention and control strategies to specific cohorts, recognizing that the risk factors and health behaviors of one generation may differ greatly from those of another. Developing targeted approaches that address the unique risk factors of each generation is essential for effective cancer prevention and management in the future.
The increase in cancer rates among millennials is driven by a combination of environmental and epigenetic factors. As this generation continues to age, the full impact of these influences may become more evident, highlighting the need for targeted prevention strategies. Reducing environmental exposures, promoting healthier lifestyles, and understanding the epigenetic mechanisms involved are crucial in addressing this cancer surge. Public health initiatives aimed at minimizing exposure to carcinogens, encouraging physical activity, and improving diet quality are essential for reducing cancer rates in this vulnerable population.
(Author: Dr. Amrit Kaur Kaler, Consultant, Molecular Pathology, Kokilaben Dhirubhai Ambani Hospital Mumbai)
