“The key finding of our new study in mice is that a ketogenic diet alone does have some tumour-growth inhibitory effect in squamous cell cancer,” said the University of Texas researchers.
When the diet was combined with chemotherapy and SGLT2 inhibitor treatment – a drug class that prevents glucose in the blood from being reabsorbed by the kidneys – it was even more effective.
Dr Jung-Whan Kim, corresponding author of the multinational study, said: “Both the ketogenic diet and the pharmacological restriction of blood glucose by themselves inhibited the further growth of squamous cell carcinoma tumours in mice with lung cancer.
“While these interventions did not shrink the tumours, they did keep them from progressing, which suggests this type of cancer might be vulnerable to glucose restriction.”
The researchers also examined glucose levels in blood samples from 192 patients with either lung or esophageal squamous cell cancer, as well as 120 patients with lung adenocarcinoma. None of the patients had been diagnosed with diabetes.
Dr Kim said: “Surprisingly, we found a robust correlation between higher blood-glucose concentration and worse survival among patients with squamous cell carcinoma. We found no such correlation among the lung adenocarcinoma patients.
“Manipulating host glucose levels would be a new strategy that is different from just trying to kill cancer cells directly. I believe this is part of a paradigm shift from targeting cancer cells themselves. Immunotherapy is a good example of this, where the human immune system is activated to go after cancer cells.”
Dr Kim stressed that glucose restriction did not have any effect on non-squamous-cell cancer types and the results could not be generalised to all forms of cancer.
The study was published in the journal Cell Reports.