Do Overweight People Live Longer than Others with This Type of Cancer?

Most sentences do not start this way: “Obese people may survive longer than…” However, a new study suggests that people who have kidney cancer who are obese or overweight may survive longer than slimmer people. [1]

The World Health Organization (WHO) says that obesity triggers 500,000 cancer cases every year. So far, the WHO’s International Agency for Research on Cancer (IARC) has linked excess body weight to 13 types of cancer, including kidney cancer.

But according to senior and corresponding author Dr. Toni K. Choueiri, director of the Lank Center for Genitourinary Oncology at the Dana-Farber Cancer Institute in Boston, in the case of metastatic renal cell carcinoma, the extra padding may prolong a patient’s life.

For the study, researchers looked at 4 databases containing the records of my more than 7,000 patients. In one database of nearly 2,000 people with this type of kidney cancer, those who were obese or overweight survived 25.6 months, compared to 17.1 months for patients of normal weight. Overweight patients were found to be 16% less likely to die during the study period. Similar findings came from the other 3 databases. [2]

Choueiri said:

“Paradoxically, when overweight individuals developed kidney cancer, especially in its advanced, metastatic form, their disease progressed more slowly and they lived longer than their normal-weight counterparts.”

Choueiri and his colleagues couldn’t find any differences in the tumors’ DNA, such as gene mutations, that might explained why heavier patients fared better than thinner ones.

The one difference the researchers did find was that the rate at which the cells used genetic information to create proteins in a gene – called fatty acid synthase (FASN) – was decreased in obese and overweight patients, compared with normal-weight ones. [3]

FASN is vital for making fatty acids. High levels of the protein have been found in many types of cancer, and usually indicate a patient is more likely to have a poor outcome.

Choueiri said the decreased amount of FASN in obese and overweight patients may help explain why these individuals have a better prognosis than normal-weight patients. [2]

Dr. Joseph Vassalotti, chief medical officer at the National Kidney Foundation, said:

“This study might lead to other investigations that could yield new therapies for kidney cancer that target fatty acid metabolism.”

But that doesn’t mean people should dismiss maintaining a healthy weight, since obesity is known to cause the very same disease.

Said Vassalotti:

“That would definitely be the one thing we would not want to recommend.”

Sources:

[1] Medical News Today

[2] Everyday Health

[3] HealthDay News