The ASCO paper did not mention sugar, but as Clare McKindley, a clinical dietitian, explained, “too much daily sugar can cause weight gain. And, unhealthy weight gain and a lack of exercise can increase your cancer risks.”6
In fact, a study recently published in The Lancet Diabetes & Endocrinology determined that diabetes and obesity were the cause of nearly 6% of all cancers in 2012, accounting for some 792,600 cases around the world. And, the authors estimated, at current rates of increase in the prevalence of diabetes and obesity, “a substantially larger share of cancers would be attributable to these risk factors.”7
Still, a direct connection between sugar and tumor growth remains elusive. Dr Thevelein noted, however, that there is a clear correlation between diabetes and cancer, which may be a result of higher sugar levels in their blood. And, he continued, some recent clinical trials indicate that “sugar-poor diets are beneficial for recovery of patients with cancer. For instance, patients who undergo chemotherapy recover better with a sugar-poor diet.”
An immediate takeaway of his study’s findings, he added, is that hospitals should revisit the practice of giving patients glucose infusions to help strengthen them for continued chemotherapy.
“The message now is that strengthening of the normal cells with high sugar may actually lead to activation of the cancer,” he said.
The challenge, Dr Thevelein said, is that all cells need sugar, so eliminating sugar intake completely would not only kill cancer cells, but normal cells as well. If, however, oncologists can block the hyperactivity of the sugar to lactic acid conversion pathway only, normal cells might be spared.
The study’s results might therefore still offer a new target for cancer treatment.
“I think that we have a lead to find the primary cause of the high influx of sugar into the cancer cells,” Dr Thevelein said. “This hyper-rapid influx of sugar into the cancer cells is not present in regular mammalian cells.
“We can go for drugs that inhibit this hyper-rapid sugar influx and these drugs should then make life for the cancer cells very difficult because the cancer cells need this rapid influx for survival. This is what we are following up now.”
- Peeters K, Van Leemputte F, Fischer B, et al. Fructose-1,6-bisphosphate couples glycolytic flux to activation of Ras. Nat Commun. 2017;8(1):922. doi: 10.1038/s41467-017-01019-z
- Shulman RG, Rothman DL. The glycogen shunt maintains glycolytic homeostasis and the Warburg effect in cancer. Trends Cancer. 2017;3(11):761-7. doi: 10.1016/j.trecan.2017.09.007
- Liberti MV, Locasale JW. The Warburg effect: how does it benefit cancer cells? Trends Biochem Sci. 2016;41(3):211-8. doi: 10.1016/j.tibs.2015.12.001
- Fernández-Medarde A, Santos E. Ras in cancer and developmental diseases. Genes Cancer. 2011 Mar;2(3):344-58. doi: 10.1177/1947601911411084
- Ligibel JA, Alfano CM, Courneya KS, et al. American Society of Clinical Oncology position statement on obesity and cancer. J Clin Oncol. 2014;32(31):3568-74. doi: 10.1200/JCO.2014.58.4680
- Espat A. Does sugar cause cancer? The University of Texas MD Anderson Cancer Center website. https://www.mdanderson.org/publications/focused-on-health/may-2015/FOH-cancer-love-sugar.html. Published May 2015. Accessed November 2017.
- Pearson-Stuttard J, Zhou B, Kontis V, Bentham J, Gunter MJ, Ezzati M. Worldwide burden of cancer attributable to diabetes and high body-mass index: a comparative risk assessment. Lancet Diabetes Endocrinol. 2017 Nov 28. doi: 10.1016/ S2213-8587(17)30366-2 [Epub ahead of print]