The Connection between Sugar and Lung Cancer
Biomarker testing and targeted therapies are changing the landscape of cancer treatment. Medical research is also providing more details on cancer development and how lifestyle can affect disease progression. Experts do agree that lifestyle, specifically sugar consumption, may encourage tumor growth.
Two predominant subtypes of non-small cell lung cancer (NSCLC), adenocarcinoma(ADC) and squamous cell carcinoma(SqCC), have distinct clinical presentations, yet, their metabolic signature remains unclear. NSCLC makes up as much as 85 percent of human lung cancers.
In 2019, an estimated 228,150 people in this country received an NSCLC diagnosis, about 50/50 between men and women. The 5-year survival rate for all lung cancer is 19 percent. The 5-year survival rate of metastasized NSCLC is 23 percent and 60 percent for local NSCLC.
One specific type of NSCLS, squamous cell carcinoma, does not respond well to many current interventions. New research, though, may indicate that controlling sugar intake or metabolism may offer hope.
Sugar and Cancer
The idea that sugar may play a role in cancer cell growth is not new. All cells require glucose for energy. They primarily pull that glucose from the blood sugar that comes from food. The glucose gives cancer cells the fuel they need to reproduce. Sugars’ relationship to the treatment of some lung cancers, though, is new information.
A 2017 study published in Nature Communications looks specifically at the metabolic phenotype of these forms of lung cancer to define their vulnerabilities when it comes to sugar.
The Use of Glyclytic Inhibition
Glycolytic inhibition refers to preventing or slowing the breakdown of simple sugars. Breaking down these sugars allows cells, including cancer cells, to utilize them for energy. According to one of the study authors, Jung-Whan Kim, Ph.D. of the University of Texas at Dallas, treatment targeted therapies are increasing survival rates for lung cancer patients. However, there are still a few good options in the treatment of SqCC, which account for up to 25 percent of all lung cancers.
Squamous cells line the airways in the lungs. Cancer in these cells typically grows in the central part of the lung or in one of the primary airways like the bronchus. Ninety-one percent of SqCC is linked to smoking. Respiratory pollutants, such as asbestos or radon, are risk factors, as well.
SqCC can metastasize to:
- Lymph nodes
- Adrenal glands
Through their study, researchers can state that squamous cell carcinoma is heavily reliant on sugar for tumor growth and cell survival. That reliance could make it vulnerable to glycolytic inhibition
The Study Details
The research team analyzed the differential gene expression in tumors taken from patients diagnosed with either SqCC or ADC. Samples came from The Cancer Genome Atlas (TCGA) database and included:
- 501 SqCC samples
- 517 ADC samples
An analysis of the mRNA-sequencing gene expression profiles allowed scientists to identify differentially expressed genes, DEGS, between the two cancer types. Further investigation found that the glucose transporter GLUT1(SLC2A1) was more significant in the DEG elevated in the SqCC samples.
The research suggests that squamous cell carcinoma may be vulnerable to either the inhibition of sugar metabolism or the dietary restriction of sugar. Put simply, high levels of blood sugar may encourage tumor growth and negatively influence a person’s chance of survival from squamous cell carcinoma in the lungs. Conversely, controlling sugar may inhibit tumor growth. Both traditional chemotherapies and targeted treatments have not proven that effective in this form of cancer, so this is a potentially significant discovery.