The Unexpected Benefit Of Bariatric Surgery: Lowering Risk Of Cancer


Bariatric surgery resolves severe obesity and health issues that emerge from severe obesity. The list of comorbidities that can be improved, or even cured, with the help of bariatric surgery is long:

  • Sleep apnea
  • Asthma and other obesity-related breathing disorders*
  • High blood pressure
  • Heart failure
  • Cholesterol abnormalities
  • Arthritis
  • Steatosis (fatty liver )
  • Urinary stress incontinence
  • Gastroesophageal reflux disease
  • Venous stasis
  • Cellulitis
  • Glucose metabolism abnormalities

* Obesity Hypoventilation Syndrome, Exertional dyspnea, Snoring, etc.

Not to mention the social stigma associated with obesity and impairment in relationships and sex life, obesity is also related to 13 types of cancers such as brain cancer, multiple myeloma, cancer of the esophagus, postmenopausal breast cancer, cancers of the thyroid, gallbladder, stomach, liver, pancreas, kidney, ovaries, uterus, and colon. In the past few decades, the connection between these co-morbidities and weight loss has been thoroughly researched.

Bariatric surgery lowers the risk of cancer. Several studies published in 2017 confirmed that severely obese patients won’t just lose weight after bariatric surgery, but the risk of different types of cancers in those patients will cut by up to 33 %. While the exact mechanism of risk reduction remains to be unknown, studies brought a clear message to the scientific community. Bariatric surgery significantly lowers the risk for cancer development, particularly obesity-related types of cancer.

Here is a short review of the most important studies published in 2017 about the correlation between bariatric surgery and cancer risk reduction:

Endometrial cancer risk decrease [1]
Obesity is strongly linked to the increase of a risk for endometrial cancer. In 2017, the team of medical experts led by Dr. Linkov from the University of Pittsburgh demonstrated that after bariatric surgery, levels of endometrial cancer risk biomarkers dropped back to normal. Blood samples were collected from 107 female patients preoperatively and 6 months after the surgery. The results were quite interesting – the cancer risk biomarkers dropped to the levels of the age-matched non-obese women.

Colorectal Cancer Risk decrease [2]
The link between obesity-related colorectal cancer has not been well defined so far. It seems that one specific technique (Roux-en-Y Gastric Bypass, also known as RYGB) decreases the markers of colorectal cancer risk over time ( the study published in 2017). Samples of rectal mucosa ( biopsy) and blood were collected from 20 non-obese control participants and 22 obese patients before and 6.5 months after the surgery. The results in the group of obese patients were the surprising-significant reduction of tumorigenic potential markers ( pro-inflammatory genes and proto-oncogenes expression, systemic inflammation and glucose homeostasis) was observed which suggests that bariatric surgery may lower the risk of colorectal cancer.

Bariatric Surgery and the Risk of Cancer in a Large Multisite Cohort [3]
One of the biggest studies ever, about the risk of cancer and bariatric surgery correlation, was published in October 2017. The study included more than 22,000 patients who had bariatric surgery and more than 66,000 nonsurgical patients matched on age, body mass index, sex and comorbidity index. The complex statistical models were used to examine the incidence of cancer up to 10 years after the surgery.

The cancer risk reduction in the group of patients who had bariatric surgery was 33% in total. The numbers were even stronger when the risk assessment was restricted only to obesity-associated cancers (postmenopausal breast cancer, colon cancer, endometrial cancer, and pancreatic cancer).

Cancer risk reduction according to study findings:

– The risk of postmenopausal breast cancer dropped by 42 percent
– The risk of endometrial cancer dropped by 50 percent
– The risk of colon cancer dropped 41 percent
– The risk of pancreatic cancer was lowered by 54 percent.

The exact mechanism how bariatric surgery lowers the risk of cancer remains to be unknown.

Reader Take Away:

Being obese is not just the condition of having an excessive amount of fat in the body. Obesity triggers a number of hormonal, biochemical, and anatomical problems that over time evolve into the serious health issues which shorten the life expectancy of obese patients.

It seems that bariatric surgery (not weight loss alone) provides a surprising benefit – it lowers the risk for cancer development ( not only obesity-related cancers). The studies published in 2017 offered some interesting numbers – 33 % overall risk reduction and up to 54 % risk reduction in case of obesity-related cancers. The exact mechanism remains to be unknown, but in the coming years, it seems that we will witness some interesting breakthroughs in this field of medicine.

References:
[1] https://www.ncbi.nlm.nih.gov/pubmed/28797697
[2] https://www.ncbi.nlm.nih.gov/pubmed/28990150
[3] https://www.ncbi.nlm.nih.gov/pubmed/28938270