Cancer is one of the most dreaded diseases of our time. Cancer refers to any malignant growth or tumor that can occur in any organ or tissue in the body, caused by abnormal and uncontrolled cell growth.
Cancer is caused by changes to the DNA in cells. Genetic changes that result in cancer can be inherited, or result from certain environmental exposures, or from errors that occur when cells divide. During the last decade there has been a shift in thinking, from viewing cancer as a genetic disease to viewing cancer as a mitochondrial metabolic disorder, with more of the latest research supporting this thinking. Research has shown that the energy metabolism of tumour cells varies greatly from normal cells. Metabolism refers to the way cells use carbohydrates, fats, and proteins from food to produce the energy that cells need to grow, reproduce via cell division, and stay healthy.
Emerging evidence from research is consistent with the notion that impaired mitochondrial function seems to be at the root of the development of cancerous cells, as mitochondrial dysfunction has been observed in a wide spectrum of human cancers. Cancer is deemed to originate from damage to the mitochondria.
Normal cells obey the instructions contained in the DNA, but cancer cells are rebels, refusing to obey these instructions by continuing to grow and divide uncontrollably, and avoiding programmed cell death by not dying off when they should. This out-of-control growth result in the cancerous cells piling up and forming tumors, which can spread into surrounding tissue, or break away to travel to other areas in the body.
While cancer typically affects people in the age group 50 years and older, recent studies have indicated a dramatic increase in the incidence of cancer in people between the ages of 20 and 50 in many parts of the world since the 1990s. Cancer in this age group is referred to as early-onset cancer and pose a higher risk of long-term health problems, including infertility, cardiovascular conditions, and secondary cancers. Side-effects from cancer treatment add to these health problems.
Studies into the rise of cancer in young people:
To understand why more people in the 20-50 age group are being diagnosed with cancer, scientists conducted extensive analysis of cancer registry records from 44 countries, mostly middle- and high-income nations, and found a rise in the early-onset incidence of 14 types of cancers. (The available data from low-income countries are currently limited.)
While the upswing can partly be ascribed to more sensitive testing for certain cancer types, testing does not completely account tor this trend. The researchers then looked for studies that examined trends of possible risk factors, followed by a review of the literature that describes clinical and biological tumor characteristics of early onset cancer, compared to cancers after age 50 (late-onset cancer).
The findings:
Since the 1990s the incidences of cancer in adults younger that 50 years of age have been rising in many parts of the world. The researchers found that this risk is increasing with each generation.
Over the past decades the early life “exposome” has changed substantially, with changes to the individual’s diet, lifestyle, weight (obesity on the rise), environmental exposures, and the microbiome (with eight of the 14 cancers related to the digestive system).
(“Exposome” refers to the measure of all the exposures of an individual in a lifetime and how those exposures relate to health. It starts before birth and include exposure from environmental and occupational sources. Substantial multigenerational changes have occurred in the exposome since the mid-20th century.)
Incidences of early-onset cancers were found in the following cancer types: colorectum, breast, endometrium (lining of the womb), esophagus, gallbladder, extrahepatic bile duct, head and neck, kidney, liver, pancreas, prostate, stomach, bone marrow, and thyroid.
According to the researchers, the study showed the impact that diet, exercise, and environment might play in the development of early-onset cancer.
Risk factors for early-onset cancers:
The rise in these cancer incidences is suggested to be due to several risk factors, some of which are known, while others need to be investigated. These risk factors are probably working together to affect the incidences of cancer.
Many of the known risk factors have been linked to cancer, such as obesity, increased rates of Type 2 diabetes, smoking habits, physical inactivity and a sedentary lifestyle, lower breastfeeding rates and increased consumption of formula milk, increased alcohol consumption, environmental pollution, lack of proper sleep (a tendency also seen in children due to bright lights during the night), and Western diets (high in red meat, high in saturated fats, low in fruits and vegetables, added sugars in food and beverages, and highly processed foods), and night shift work – which increases the incidence of risk factors such as obesity and diabetes.
There are many unknown risk factors as well, which have not been linked to cancer yet through studies, with food additives and pollutants coming to mind.
As eight of the 14 types of cancers are related to the digestive system, diet and nutrition play a major role, along with changes to the microbiome – the microorganisms and their genetic material living in the gut. The food we eat affects the composition of these microorganisms and changes can affect disease risk and outcomes. The higher use of antibiotics also affects the microbiome, as it kills good bacteria along with the bad ones.
Obesity in particular carries a high risk, as people are becoming obese earlier in life, which means cancer risks are building decades earlier than for previous generations. Obesity has been linked to various cancers, including breast, colorectal, and uterine cancer.
The risk of multiple cancers is associated with lifestyle factors (obesity, physical inactivity, poor diet) which can increase the risks directly, by increased inflammation, insulin resistance, and disrupting cellular regulatory processes, and indirectly by causing other chronic diseases which may increase cancer risk.
Lifestyle factors linked to early-onset cancer may also affect cancer risk later in life.
Reducing the risk of early-onset cancer:
Although incidences of early-onset cancer are still rising, researchers are of the opinion that some of these cancers can be prevented by adopting healthy lifestyles, such as:
- Avoiding sugar.
- Regular exercise.
- Avoid typical western-style diets, which are rich in animal fat, red meat, and highly processed foods. Rather consume well-balanced nutritious foods and drinks.
- Avoid smoking.
- Avoid alcohol.
- Avoid bright light at night and get into a regular pattern of good sleep.
Cancer risk can be reduced by raising awareness of the ever-rising incidences of early onset cancer among health-care professionals and the public, coupled with improved health literacy and health interventions to promote a healthy lifestyle.
Conclusion:
The researchers concluded it is likely that environmental exposures in early life and young adulthood from the mid-20th century onwards are linked to early-onset cancer risk factors. Longitudinal studies are however needed to confirm their results.
Understanding these risk factors for early-onset cancer could assist with the prevention, early detection, and treatment of early-onset cancer.
References:
A global epidemic of cancer among people younger than 50 could be emerging. Published 17 October 2022. CNN Health. (www.edition.cnn.com)
Is early-onset cancer an emerging global epidemic? Current evidence and future implications. Published online 6 September 2022, and in Nature Reviews, Clinical Oncology, 19, 656-673 (2022). (www.nature.com)
Why more people under age 40 are being diagnosed with cancer. Published 23 May 2022. Healthline. (www.healthline.com)
Dramatic rise in cancer in people under 50. Published 8 September 2022. Harvard Medical School. (www.news.harvard.edu)
Why are so many people under 50 getting cancer? Published 13 September 2022. Medical News Today. (www.medicalnewstoday.com)
HEALTH INSIGHT
