Impact of early-life exposure: In recent decades, Millennials are the first generation to have grown up amid significant technological advances such as industrialization, which has seen chemical carcinogens, pesticides, pollutants in air, water, and food, and endocrine-disrupting substances in everyday products linked to a variety of cancers. These toxins can directly damage DNA, causing mutations that can lead to cancer cells. In addition, lifestyle changes, such as higher intake of processed foods, higher sugar intake, and more red and processed meat, have contributed to the obesity epidemic, a known risk factor for cancers such as colorectal and pancreatic cancer. Increased sedentary activities, due to screen time and desk jobs, further increase this risk.
Exposure to harmful substances during early life can also cause permanent epigenetic changes, increasing cancer risk later in life. For example, exposure to endocrine disruptors and other chemicals before birth and in childhood can cause persistent epigenetic changes that increase cancer risk in adulthood. Epigenetic modifications, which alter gene activity without changing the DNA sequence, are increasingly recognized as important factors in cancer development. These changes can be influenced by the following: environmental factors, lifestyle choicesand diet, to which millennials are particularly susceptible. For example, exposure to toxins, poor nutrition, and chronic stress can trigger the activation or repression of certain genes, including genes involved in tumor suppression. Such epigenetic changes can increase cancer risk even in the absence of an inherited genetic mutation.
An example of an epigenetic mechanism is DNA methylation, where methyl groups attach to the DNA molecule, potentially altering gene expression. DNA Methylation are associated with various cancers and are often induced by environmental factors. Another epigenetic process, Histone modificationsDisruption by outside influences can also affect gene expression and contribute to cancer.
Review Article: A recent study, “Differences in Cancer Rates Among Adults Born Between 1920 and 1990 in the United States: An Analysis of Population-Based Cancer Registry Data,” examines in detail 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.
An important finding is the variation in cancer patterns across birth cohorts. Individuals born around 1920 had higher rates of cancers such as lung cancer, strongly associated with smoking – a prevalent behavior in that era, particularly in the mid-20th century. This higher incidence of lung cancer reflects the long-term effects of smoking, even though smoking rates and related cancers have decreased in recent generations due to public health efforts and greater awareness of the risks of smoking.
On the other hand, individuals born closer to 1990 have higher rates of cancers associated with modern lifestyle factors, such as colorectal, pancreatic and some breast cancers. Increases in obesity, dietary changes, less physical activity and more sedentary behavior are major contributors to the rising incidence of these cancers in young people. This trend reflects the evolving nature of public health issues, as these contemporary risk factors may have long-term health implications for future generations.
The study also examines how advances in medical technology and access to healthcare have affected cancer rates. Improvements in early detection, screening, and treatment have had a significant impact on cancer incidence and survival rates. For example, the widespread use of mammography and colonoscopy has made it possible to detect breast and colorectal cancers earlier, thereby increasing survival rates and potentially increasing reported incidence. This part of the study emphasizes the importance of distinguishing between true increases in cancer rates and increases that are caused by better detection techniques.
Additionally, the study also explores how environmental factors affect cancer trends in different age groups. For example, reduced exposure to carcinogens due to stricter regulations and improved workplace safety has led to a decrease in some types of cancer. Changes in reproductive patterns, such as having fewer children and delaying childbearing, have also affected the incidence of hormone-related cancers, such as breast and ovarian cancer.
Sitting for too long increases the risk of heart disease and cancer
The research emphasizes the complex nature of cancer epidemiology, showing that cancer rates are shaped by many elements, including lifestyle choices, environmental factors, medical advances, and public health initiatives. The results underscore the importance of tailoring cancer prevention and control strategies to specific groups, recognizing that the risk factors and health behaviors of one generation may differ greatly from those of another. Developing targeted approaches that address each generation’s unique risk factors is essential for effective cancer prevention and management in the future.
The increase in cancer rates in 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 pronounced, highlighting the need for targeted prevention strategies. Reducing environmental exposures, promoting healthy lifestyles, and understanding the epigenetic mechanisms involved are key to tackling this problem. Cancer surgePublic health initiatives aimed at reducing exposure to carcinogens, encouraging physical activity, and improving diet quality are essential to reduce cancer rates in this vulnerable population.
(Author: Dr. Amrit Kaur Kaler, Consultant, Molecular Pathology, Kokilaben Dhirubhai Ambani Hospital Mumbai)
