Obesity is a growing health concern worldwide, and it has been linked to a range of serious conditions, including heart disease, diabetes, and certain types of cancer. One area of particular concern is its connection to gastroesophageal cancer, which includes cancers of the esophagus and the stomach. These cancers can be aggressive and difficult to treat, but understanding the link between obesity and gastroesophageal cancer is key to reducing risk.
The connection between obesity and gastroesophageal cancer is most notably seen with esophageal adenocarcinoma, a type of cancer that begins in the lower part of the esophagus. Studies show that people who are overweight or obese are significantly more likely to develop this form of cancer. But why is this the case?
Obesity increases the risk of gastroesophageal reflux disease (GERD), a condition where stomach acid regularly flows back into the esophagus, causing heartburn and discomfort. Over time, this acid reflux can damage the esophageal lining and lead to a condition called Barrett’s esophagus, which can increase the likelihood of developing cancer. The excess weight from obesity can put additional pressure on the abdomen, making acid reflux more likely to occur.
In addition to GERD, obesity is associated with inflammation. This is due to fat tissue creating a pro-inflammatory environment, which can contribute to the development of cancer over time.
It’s important to recognise that while obesity significantly increases the risk of gastroesophageal cancer, losing weight can potentially help reduce that risk. This can be done with four important interventions.
- Lifestyle interventions:
- Diet: A balanced, reduced-calorie diet tailored to individual needs can promote weight loss. Diets such as the Mediterranean diet or low-carbohydrate diets have shown effectiveness.
- Exercise: Regular physical activity, including aerobic and resistance training, not only aids in weight loss but also improves overall health and well-being.
- Behavioral Therapy: Counseling and behavioral modification techniques help address emotional eating, stress management, and lifestyle changes crucial for long-term weight management.
- Medications:
Medications (pharmacotherapy) is a good adjunct for weight loss. It can be combined with diet and exercise, or with endoscopic or surgical interventions, to maximise weight loss and co-morbidity improvement. However, medications come with side effects and often have to be taken long term, with a real risk of weight regain/rebound upon stopping medications.
Some medications that may be used for weight loss are:
- Orlistat: Reduces fat absorption in the intestine, leading to weight loss. Side effects may include gastrointestinal discomfort.
- Phentermine: Suppresses appetite and increases feelings of fullness. Side effects may include increased heart rate, insomnia, and cognitive difficulties.
- SGLT-2 Inhibitors (E.g., Canagliflozin): Diabetes medications that can lead to modest weight loss through increased urinary glucose excretion. Side effects may include increased risk of urinary tract infections and diabetic ketoacidosis.
- Liraglutide, Semaglutide, Tirzepatide and other GLP1-Receptor Agonists: Used for patients with diabetes and/or obesity, these drugs help with weight loss by slowing digestion and reducing appetite. Side effects may include nausea, vomiting, and pancreatitis. Dosing may be via a simple injection (once daily or weekly) or in tablet form.
- Endoscopic Procedures:
- Intra-Gastric Balloons: Inflatable devices placed in the stomach to induce a feeling of fullness. Placement may be done with endoscopic guidance or by simply swallowing a balloon pill (inflating it under X-ray guidance once it enters the stomach)! Balloons are a non-surgical and reversible, but may cause discomfort and require removal after several months.
- Endoscopic Sleeve Gastroplasty (ESG): Suturing the stomach from the inside to reduce its capacity. Less invasive than traditional surgery with shorter recovery time but may have lower weight loss outcomes.
- Surgery:
Individuals with a BMI greater than 32.5 kg/m2 are advised to consider surgery for obesity (also referred as “Bariatric Surgery”) when all other treatment options have been unsuccessful. In some patients with poorly controlled obesity related conditions (like Diabetes Mellitus), surgery can be considered for BMI greater than 27.5 kg/m2. Surgery enables you to successfully lose weight and treat obesity-related diseases. It also helps to sustain your weight loss for years, thus improving overall quality of life.
Surgery has proven to be an effective treatment for patients who are morbidly or severely obese for the last 4 decades. It is in fact backed up by a recent study of more than 22,000 patients that patients could expect to lose more than 60% of their excess weight after bariatric surgery. Another study showed that following surgery, up to 80% of patients experienced complete resolution or improvement of their co-morbid conditions, such as diabetes, hypertension and sleep apnoea. A study from Singapore in 2021 showed that obese patients with diabetes who underwent bariatric surgery lived 9.3 years longer than patients who were managed without surgery. For obese patients without diabetes, those that underwent bariatric surgery lived 5.1 years longer.
In the last decade, with “keyhole” or minimally invasive surgery, bariatric surgery has become much less invasive than the conventional surgery. Bariatric Surgery usually involves a modification of the digestive tract with the aim of reducing the size of gastric reservoir with or without reducing the ability of the gut to absorb food. Further advances in medical technology have also added the option of robotic surgery, to perform more precise and delicate surgery for patients.
Prior to surgery, each patient should be assessed by a multidisciplinary team. It is also emphasised that lifestyle changes such as healthy eating and regular exercise are essential to sustain weight loss after surgery.
Some commonly performed surgeries are:
- Sleeve Gastrectomy: Removal of a large portion of the stomach to create a smaller, sleeve-shaped stomach. Offers significant weight loss and improvement in co-morbidities.
- Roux-en-Y Gastric Bypass (RYGB): Creation of a small stomach pouch and rerouting of the digestive tract. Rapid weight loss and effective resolution of co-morbidities. Ideal for patients with gastrointestinal reflux disease and obesity.
- One Anastomosis Gastric Bypass (OAGB): Similar to RYGB but with a single connection (anastomosis) to the small intestine. Effective weight loss and technically simpler than RYGB.
If you are overweight or obese, talk to your doctor about steps you can take to improve your general health and also potentially reduce your risk of cancer. Regular screenings for GERD and other digestive issues (with endoscopy) may also be recommended, especially if you have symptoms like persistent heartburn or difficulty swallowing. Remember, early detection of cancer or pre-cancerous conditions is key, but cancer prevention is even better!
By understanding the link between obesity and gastroesophageal cancer, we can take proactive steps toward better health and cancer prevention.
About Our Cancer Stories
Our Cancer Stories is a research project funded by National University of Singapore (NUS) Initiative to Improve Health in Asia (NIHA) under the management of the Global Asia Institute (GAI).
