A
research team led by Dr. Yu who is the associate professor of Epidemiology at
the University School of Medicine, New York analyzed the relationship between
cancers and type 2 diabetes in patients spread across the 7 Asian countries.
‘Routine cancer screening should be made mandatory for Asians who suffer from diabetes’
Previous
studies have shown a relationship between type 2 diabetes and the risk of
developing cancer. Such studies have been restricted mostly in Western populations;
however, with the increase in incidence in diabetes in Asian countries, there
is a need to understand the risk for cancer in these populations. Asians have
always shown a greater predisposition towards developing cancer, with an
increased susceptibility to insulin resistance, when compared to Europeans.
While there have been previous studies conducted on Asians, they suffer from
the following roadblock
- Only one or a few
types of cancers were included
- Only a small
sample of patients with diabetes were included
- Other important
risk factors like obesity were not controlled for
The
current study, led by Dr. Yu used data from the
Asia Cohort Consortium (ACC), which combines 29 cohorts to
understand the influence of the environment, genes and disease in a population
of people more than 1 million. Out of these cohorts, only 19 were chosen, which
resulted in
- 658,611 East
Asians
- 112,686 South
Asians from Singapore, Taiwan, South Korea, India, Japan, Bangladesh and
China
The
average age of the participants were around 54 years, with 37,343 cancer deaths
identified during a period of follow-up
which lasted 12.7 years. The study involved a large sample size therefore it
captured the diversity of the Asian populations, while there was stratification
that was possible based on age, smoking status, sex as well as alcohol
consumption. This was a landmark study as it was the first study to analyze the
influence of type 2 diabetes on cancer risk among South Asians.
The
study findings showed that
- There was a 26% increase in the risk of death
due to any cancer among people with diabetes, including factors like
alcohol consumption, body mass index (BMI) and smoking
- There was
statistical association between type 2 diabetes and death due to specific cancers
- There was an
increased risk of death due to cancers of the breast, bile duct, liver, pancreas
and the colorectum, when associated with diabetes
- The risk of death
was doubled in cancers of the thyroid, kidney and the liver, when
associated with diabetes
- There was 2.7 times increased risk of death
due to endometrial cancer when
associated with diabetes
- There was 1.7 times increased risk of death
due to breast cancer when
associated with diabetes
This
increase in death risk is compared with the risk associated with an individual
who does not have diabetes.
Increased Risk of
Death Among Asians
The
risk of death due to site-specific cancers like
thyroid, kidney and prostate cancer was higher among Asians than among people
of European origin. Moreover, the risk of death due to cancer was found to be
greater among participants who were less than 60 years of age.
The
scientists involved in the study stated that
- The effect of type
2 diabetes on the risk of death due to overall cancer, breast cancer and
digestive cancer was similar to the risk associated with the
Western population.
- The enormity of the
data analyzed showed that type 2 diabetes should be considered as a
serious risk factor for cancer, especially liver cancer which had a high
incidence in Asians.
There
should be a mandatory cancer screening for people who have been diagnosed with
type 2 diabetes, which would aid in early identification of the disease and a
reduction in the risk of death.
Increase in Body Fat
The
American Institute of Cancer Research
found that hyperinsulinemia, cancer and type 2 diabetes all shared a common
high-risk factor- high body fat.
A high body fat resulted in hormonal changes
which led to an increase in the risk for cancer and for type 2 diabetes. There
are many tumors that have insulin receptors and many studies have shown that
insulin is important in the development of cancer. However, there is no direct
link associated with insulin and cancer. The scientists believe that there
could be other pathways that are triggered by insulin in the growth and
proliferation of cancer.
Earlier
studies show that maintaining an optimum body weight and body fat are essential
to lowering risk of diabetes as well as cancer. Since there is a common pathway
that triggers diabetes and cancer, lowering the risk factors will lower the
risk for both the conditions.
References :- Yu Chen et al. Association
between type 2 diabetes and risk of cancer mortality: a pooled analysis of over
771,000 individuals in the Asia Cohort Consortium, Diabetologia (2017).
DOI: 10.1007/s00125-017-4229-z
- The Diabetes-Cancer Connection - (http://preventcancer.aicr.org/site/News2?page=NewsArticle&id=13631&news_iv_ctrl=0&abbr=res_)
Source: Medindia