Introduction
Diabetes is one of the most common lifestyle diseases of the modern era. Research shows a slowly emerging link between diabetes and many types of cancer. About seventy-five years ago, the link between the two was first pondered. The challenges faced by diabetic cancer patients are unique. The novel advancements in cancer therapy, or the adjuvant use of steroids, can help prevent the aggravation of an already existing condition and prevent further complications. This article deals with the link between the two conditions, cancer and diabetes, their risks, and their management.
What Is Diabetes?
A condition where there are high levels of glucose in the blood is termed diabetes. The body's glucose is regulated by a hormone called insulin. There are two types of diabetes. In type 1, the pancreas does not secrete insulin, so blood glucose levels are elevated. In type 2, the pancreas cannot secrete sufficient amounts of insulin or does not function properly to regulate blood glucose. This is also called insulin resistance. This is more commonly seen in people, while type 1 is found only in about five to ten percent of people. While both types are multifactorial and have hereditary and environmental factors contributing to them, obesity and lifestyle factors predominantly play an essential role in type 2 diabetes. The symptoms of diabetes include increased thirst, excessive urination,
What Is Cancer?
Cancer is a condition where an abnormal type of cell grows and multiplies uncontrolled. It can start anywhere in the body and multiply. In later stages, it can spread to some body parts other than where it began. This is called metastasis. The cancerous cells can either spread into the nearby normal cells and invade them or spread into different body parts. They stay hidden from the immune system, which otherwise usually eliminates anything found abnormal or harmful in the body.
How Is Cancer and Diabetes Linked?
Both conditions have had a global increase in prevalence recently. In the olden days, the prevalence of cancer was difficult to trace, as it was considered rare. However, in 2008, there were 12.4 million new cancer cases registered worldwide. The most common types of cancers include lung or bronchus, breast, and colorectal cancers. The most common ones that had high mortality rates include lung, stomach, and liver cancer. Studies show that 6.6 percent of the world population between twenty and seventy-nine years old was diagnosed with diabetes. This increased to 10.7 percent in 2007, with approximately 1.6 million new cases yearly.
For more than fifty years, research has been ongoing to understand the link between the two conditions. The studies in the 1960s have helped to conclude how the two were related. More recent studies show that people with diabetes have a higher risk of developing some kinds of cancer. The risk of cancers of the liver, pancreas, and endometrium was doubled in people with diabetes. On the other hand, studies also show that the risk of prostate cancer is lesser in men with diabetes. Different types of cancer that have a lesser risk in diabetic patients include colon and rectum, breast, and bladder cancers. However, in cancers like kidney cancer and non-Hodgkin lymphoma, the link has been inconclusive.
Since the pancreas and liver play important roles in the secretion and transport of insulin, cancers in these organs are more susceptible in diabetic patients. Factors that are related to diabetes, like steatosis (build-up of fat in the liver), nonalcoholic fatty liver disease, and cirrhosis (the scarring of the liver cells), also fan the flame. Studies also show that an abnormal glucose metabolism can also be related to pancreatic cancer. Some recent studies also revealed an increase in mortality rates in patients with diabetes and cancer. Elevated levels of C-peptide are an indirect biomarker of insulin resistance. Studies show that this can indicate a poor prognosis in some types of cancers.
Does Diabetic Pharmacotherapy Increase the Risk of Cancer?
The primary treatment for type 2 diabetes is insulin, while type 2 requires insulin along with hypoglycemic drugs. Some cancer research has raised concerns about exogenous insulin (synthetic insulin), especially insulin glargine, which can increase the risk of cancer. There is no conclusive evidence on whether diabetic pharmacotherapy increases the risk of cancer in a diabetic patient, if it worsens the prognosis, or if it increases the mortality rate in a cancer patient. However, pre-clinical studies have shown a non-neoplastic activity of Metformin (a medication used to treat diabetes), and are supported by many epidemiological studies. Nevertheless, no clinical trials to date have been able to stabilize this fact.
How Do Blood Sugar Levels Affect Chemotherapy?
One of the most common treatments for cancer is chemotherapy. Chemotherapy uses some drugs to kill the abnormal cells. However, it can be challenging to keep the blood sugar levels under control while under chemotherapy. Steroids are usually given as an adjuvant to reduce nausea. Steroids, on the other hand, can spike blood sugar levels remarkably. Hence, diabetic medications might need to be revised during chemotherapy, mainly if steroids are used.
Another challenge is injectable insulin, which is usually taken before a meal. The negative impact of chemotherapy can include less appetite, nausea, and vomiting, or diarrhea in some cancer patients. However, these can cause a drop in sugar levels due to insulin injections already taken. Uncontrolled blood sugar and vomiting after chemotherapy can make the patient dehydrated.
All these concerns have to be considered while treating a patient with diabetes or cancer. The primary focus should be the treatment of cancer, while managing diabetes should be followed secondarily. At the same time, precautions should be taken to avoid high blood sugar levels.
Conclusion
Diabetes might increase the risk of some types of cancers. It can also be a cause of higher mortality and recurrence rates. This can also be influenced by other comorbidities that the patient might already have. Healthcare experts might consider all these factors while tailoring appropriate treatment strategies for diabetic patients with cancer. A patient-centered approach by a multidisciplinary team can help to achieve this goal. The primary aim of treatment should be the elimination of cancer from the patient’s body while considering the prevention of blood sugar spikes.
