In the literature, there are references to childhood obesity as the apparent cause of various malignancies including those of the endometrium, uterus, prostate, gall bladder, breast, colon, esophagus, pancreas, kidney, and even lung. People became accustomed to the idea that tumors lurk in the distance, waiting to strike some day, like maybe in middle age.
Bad things might happen later in life, but the consequences, it seemed, would be postponed and, from the youthful point of view, “some day” means never. However, it becomes increasingly clear that obese young people can get cancer before they are old enough to legally drink, vote, or marry.
In children, both kidney and thyroid cancer are rare — though not as rare as they used to be, and they seem to have increased in tandem with childhood obesity. The tipoff came from researchers who noticed that these same cancers have become more common in adults since the obesity epidemic took hold.
Using a kind of working-backwards reasoning, they looked at what has been happening with children, and found cause for alarm. These numbers may not sound like much of a clue, but when the lives of children are at stake, every fraction of a percentage point counts:
For thyroid cancer, the diagnosis total was almost 5,000 cases, and the rate climbed from nearly six cases per million children to eight per million children in 2009.
For kidney cancer, the total was 426 and the rate climbed from 0.5 cases per million to 0.7 cases per million.
Research into esophageal cancer found that overweight kids are more prone to develop it than normal-weight kids.
Pediatric endocrinologist Steven Mittelman has spent many years investigating the link between childhood obesity and leukemia, and asking why obesity increases cancer risk and makes the disease harder to cure. For instance, kids who were obese at the time of their diagnosis, and who were treated with the standard protocols, were discovered to have about a 50% higher chance of relapse than their normal-weight peers. In other words, obesity both increases the chance that a child may contract leukemia, and decreases the chance of surviving it.
Dr. Mittelman learned that fat cells protect leukemia cells from chemotherapy, and that fat has other ways of accelerating the progression of leukemia, which is the most common type of cancer in children. Among other things, fat tissue…
Attracts leukemia cells to migrate closer to fat cells.
Absorbs and metabolizes some chemotherapy drugs, making them unable to reach the leukemia cells.
Releases fuels such as amino acids and fatty acids that help leukemia cells survive.
Secretes substances that signal the leukemia cells, making them more able to resist chemotherapy.
Just to make these propositions absolutely clear, we will also quote the description of his research (in collaboration with Drs. Nora Heisterkamp and Anna Butturini) as it appears in his professional biography:
His laboratory is currently investigating how obesity and cancer interact, using both mouse models and tissue cultures. He has found evidence that fat tissue may absorb some chemotherapies, so that these drugs are not available to kill the cancer cells. He also found that fat cells play an active role in the cancer microenvironment, participating in a two-way communication with cancer cells, and producing metabolic fuels and survival factors which protect cancer cells from chemotherapies.
Dr. Mittelman serves as director of the Diabetes & Obesity Program at Children’s Hospital Los Angeles and as director of the Keck/Caltech Combined MD/PhD Program. He is already familiar to readers of Childhood Obesity News, because he is principal investigator in the current study of Dr. Pretlow’s W8Loss2Go smartphone application.
Your responses and feedback are welcome!
Source: “Study suggests cancer-obesity link in children,” ProvidenceJournal.com, 09/15/14
Source: “Overweight children may be at higher risk of oesophageal cancer,” SpireHealthcare.com, 02/09/15
Source: “Steven D Mittelman,” USC.edu, undated
Source: “Steven Mittelman, MD, PhD,” CHLA.org, undated
Photo credit: frankie.baldo via Visual Hunt/CC BY-SA