The Reality of "Age" as a Major Factor Influencing Cancer Risk, Beyond Alcohol and Tobacco

When asked about the "causes of cancer," what do most people think of first?

Smoking, alcohol consumption, ultraviolet rays, obesity, diet, lack of exercise. Some might also think of genetics.

Of course, many of these are indeed related to cancer risk. Smoking, in particular, has a clear connection with multiple types of cancer, and alcohol consumption is known to be associated with cancers of the mouth, throat, esophagus, liver, colon, and breast, among others.

However, when looking at cancer as a whole, there is another factor that has an extremely significant impact.

That factor is "age."

In an explanation introduced by the British newspaper The Independent, "aging" is highlighted as the risk factor most strongly associated with cancer.

At first glance, this might sound surprising.

Health information often focuses on factors that can be changed through behavior, such as "eating certain foods can cause cancer" or "avoiding certain things can reduce risk."

However, age is something that no one can avoid.

And as our society continues to live longer, the importance of this "unavoidable risk" will only increase.

Why does cancer increase with age?

In the human body, a vast number of cells divide every day.

Each time cells divide, DNA is replicated, but this mechanism is not perfect. While many abnormalities are repaired or abnormal cells are eliminated, genetic changes gradually accumulate over the years.

Cancer does not necessarily occur suddenly from a single genetic abnormality.

It often arises when multiple changes accumulate in mechanisms that promote cell growth, stop growth, repair DNA, and eliminate abnormal cells, ultimately leading to uncontrolled cell proliferation.

In other words, living longer means that cells are exposed to various influences for a longer period.

Furthermore, with aging, DNA repair capabilities, immune functions, inflammatory responses, and the environment surrounding tissues also change.

Abnormal cells that would have been eliminated in youth may survive more easily, or changes accumulated over many years may exceed a certain threshold.

The U.S. National Cancer Institute also explains that increasing age is one of the most important risk factors for cancer overall.

Cancer is a disease deeply tied to the passage of time, rather than a disease that suddenly appears.

If "age is the greatest," does that mean quitting smoking or reducing alcohol is meaningless?

It is important to note here that

"If aging is the greatest risk, isn't living a healthy lifestyle meaningless?"

is a misconception.

In conclusion, that is not the case.

The discussion that "age is a very significant risk factor" does not contradict the importance of reducing risks such as smoking and drinking.

Age is an unchangeable risk factor.

In contrast, smoking, drinking, obesity, lack of exercise, and excessive exposure to ultraviolet rays can be changed to some extent.

For example, you cannot turn back the age of 70 to 60.

However, a 70-year-old who continues to smoke can quit smoking.

What is important is,

"Can all risks be reduced to zero?"

but rather,

"Can we reduce the risks that can be changed as much as possible?"

This is the perspective to consider.

In fact, research analyzing global cancer mortality shows that modifiable factors such as smoking, drinking, and high BMI still contribute significantly to the cancer burden.

Therefore, one should not jump to the conclusion that "lifestyle habits don't matter because aging is the greatest factor."

Rather, it is closer to reality to think that multiple factors such as smoking, drinking, genetics, infections, obesity, and ultraviolet rays overlap on the large foundation of age.

In a society where people live longer, cancer patients are more likely to increase

The background to why this issue is becoming important is global aging.

In the past, many people died at relatively young ages due to infectious diseases or cardiovascular diseases.

As medical care and public health advance and life expectancy increases, more people live to ages that were previously unattainable.

This is a great success for society.

On the other hand, more people experience diseases that increase with age.

Cancer is one of the representative examples.

The feeling that "cancer has increased compared to the past" is not only due to changes in the environment or lifestyle but also due to demographic changes where more people live to ages where cancer is more likely to occur.

In Canada, which was cited as an example in the original article, the elderly population is expected to increase further.

And as the elderly population increases, naturally, the number of elderly cancer patients will also increase.

The issue is not just that "the number of cancer patients is increasing."

It is also necessary to transform the existing cancer medical system to suit an aging society.

Should a 75-year-old patient be judged solely by the number "75"?

There are challenging issues in cancer treatment for the elderly.

Even at the same age of 75, physical conditions can vary greatly among individuals.

Some 75-year-olds walk several kilometers daily, continue working or doing housework, and have few chronic illnesses.

On the other hand, some 75-year-olds have multiple chronic diseases, take many medications, have a high risk of falling, and require assistance in daily life.

In terms of age alone, they are the same.

However, the likelihood of withstanding chemotherapy or surgery differs significantly.

This is where "Geriatric Assessment" comes into focus.

This is not simply about confirming age.

It comprehensively assesses physical function, walking and fall risk, cognitive function, nutritional status, mental state such as depression, chronic illnesses, medication status, and social support.

The American Society of Clinical Oncology (ASCO) also recommends using such assessments to identify vulnerabilities that cannot be captured by standard cancer care for elderly cancer patients.

What is important is not the idea of "weakening treatment because of old age."

On the contrary,

"Not giving up effective treatment solely due to age if the elderly patient is healthy"

is also important.

Adjusting treatment according to the physical condition of each patient is the fundamental concept of geriatric oncology.

Strong treatment is not the only "good treatment"

In cancer treatment, reducing tumor size and extending survival time are important goals.

However, for elderly patients, other values may hold greater significance.

For example,

"I want to live independently at home, even if it means a slightly shorter lifespan."

"I want to avoid treatments that could significantly impair cognitive function."

"I want to keep hospital stays as short as possible."

"I want to stay healthy until my grandchild's wedding."

These are the kinds of wishes.

The most medically powerful treatment and the best treatment for the patient do not always align.

This is why the original article emphasizes the importance of confirming "what is most important to the patient" by specialists in elderly care.

It's not just about whether treatment is possible,

but also about "how that treatment will change the person's life."

This consideration is necessary.

This approach is likely to apply not only to the elderly but also to future cancer care as a whole.

Why specialized cancer care for the elderly is not widespread

If this approach is effective, why isn't it implemented in all hospitals?

One of the biggest issues is human resources.

There are limited physicians who specialize in elderly care.

Additionally, collaboration among oncologists, geriatric specialists, nurses, pharmacists, nutritionists, physical therapists, and social workers requires both time and personnel.

Traditional cancer care has developed as a specialist-centered system focused on the cancer itself.

While treatment technologies such as surgery, radiation, chemotherapy, targeted therapy, and immunotherapy have rapidly advanced, changing the system of care to evaluate the whole patient and decide on treatment takes time.

The original article points out that this "inertia" in the medical system is also a barrier.

Another aspect that cannot be overlooked is age-related stereotypes.

"Because they are 80, aggressive treatment is unnecessary."

Or conversely,

"Because it is standard treatment, the same treatment should be given even at 80."

Both judgments can be dangerous.

What is needed is not a uniform line based on age but a judgment based on the individual's health status and values.

Geriatric assessments may also reduce healthcare costs

Interestingly, assessing elderly patients in detail does not necessarily "only increase healthcare costs."

A study examining a geriatric oncology clinic in Canada reported that conducting a geriatric assessment before treatment led to a reduction of about 7,400 Canadian dollars in healthcare costs per patient.

This was due to the reassessment of excessive treatments that did not match the patient's condition.

However, it cannot be concluded that "introducing geriatric assessments will always reduce healthcare costs."

Another clinical trial showed that the cost-effectiveness was not clear when looking at the entire patient population, and results vary depending on the healthcare system, patient demographics, and treatment goals.

Nonetheless, it is important to note that the simple equation of "detailed assessment increases healthcare costs" is not accurate.

Avoiding treatments that do not fit the patient and reducing hospitalizations and functional decline due to side effects could potentially reduce the burden on both the patient and the healthcare system.

On social media, reactions like "Is it ultimately about age?"

The theme "age is the greatest risk factor" is frequently debated on social media.

 

On Reddit, in response to a post discussing the increasing number of cancer patients,

comments include "We need to consider the aging population,"

"In countries with longer life expectancies, more people live to ages where cancer is more likely,"

and "Advancements in testing technology have made it easier to detect cancer than before."

Some users even shared personal experiences, such as being diagnosed with prostate cancer at 70, pointing out the impact of the increasing elderly population.

In another discussion,

comments focused on aging and cellular changes, such as "Ultimately, it's because DNA replication errors accumulate over the years"

and "The immune system changes with age."

These reactions indicate that many people feel uneasy with the image of "cancer as a result of lifestyle."

Especially when someone who led a healthy lifestyle gets cancer, those around them might start searching for a cause.

"What did they eat?"

"Did they drink alcohol?"

"Is it because they didn't have children?"

This reflects a tendency to attribute the cause to the patient's actions.

In August 2026, a Reddit user who developed breast cancer in their 30s shared their discomfort with being linked to their lifestyle choices by those around them, garnering many reactions.

Cancer involves a complex interplay of many factors, and in many cases, it is impossible to pinpoint a single cause for an individual patient.

Knowing risk factors and blaming patients are entirely separate matters.

On the other hand, there are voices saying "Don't underestimate lifestyle habits"

There is also a counter-discussion on social media.

When studies related to smoking and drinking are posted,

comments such as "You shouldn't explain it away with age alone,"

"Many cancers are preventable,"

and "The cancer risk of alcohol should be more widely known" are frequently seen.

This reaction is also important.

The headline "Age is the greatest risk" alone could lead to fatalism, as in "Then it doesn't matter what we do."

But in reality, that's not the case.

Even if you can't change your age, there are