Gastric cancer is a leading cause of cancer and cancer related deaths worldwide. While accounting for only 1.5% of cancers in the United States, gastric cancer has one of the highest incidences of disease-associated malnutrition. Understanding the nutrition challenges from tumor related symptoms, side effects of treatments, and post gastrectomy syndrome allows for effective patient care. More studies are needed to understand how to best manage the unique nutritional needs of this patient population as it is well established that better nutrition contributes to improved quality of life and greater overall survival for patients with gastric cancer. The goal of this review is to outline gastric cancer-associated malnutrition, treatment related gastrointestinal symptoms, considerations for perioperative and postoperative nutrition for patients undergoing surgery for gastric cancer, and to provide recommendations aimed at optimizing nutrition care for this at-risk patient population.
INTRODUCTION
Gastric cancer is the fifth most common malignancy and fourth leading cause of cancer death worldwide.1-2 Although gastric cancer rates have declined in the United States over the past decade, prevalence rates are rising in other parts of the world, especially East Asia. It is estimated that 26,380 Americans were diagnosed and 11,090 died from the disease in 2022.3 Early diagnosis results in a 5-year relative survival rate of 72%, unfortunately only 28% of gastric cancers in the U.S. are localized at diagnosis dropping the overall survival rate to 35%.2,3 Malnutrition and nutrient deficiencies often develop throughout the disease course. Studies show that nutrition monitoring and timely interventions lead to improved quality of life (QoL) and better survival for patients with gastric cancer.4 This review will discuss nutrition care for gastric cancer-associated malnutrition, treatment related gastrointestinal symptoms, and for perioperative and postoperative nutrition for patients undergoing surgery for gastric cancer.
Diagnosis and Treatment
Risk factors for gastric cancer are listed in Table 1 and include hereditary diffuse gastric cancers, Helicobacter pylori infection, diets high in salt-preserved foods, heavy alcohol intake, and low intake of fruits and vegetables. Data analysis from 25 studies in the Stomach cancer Pooling Project (StoP) observed a 39% lower risk of gastric cancer associated with the highest versus lowest intake of fruits and vegetables.1-3,5 Over the past 20 years the most common location of gastric cancers has shifted from the body and antrum of the stomach to the proximal stomach and esophagogastric junction. The cause for this change is unclear, however it correlates with the rise in obesity.3 Of note, proximal stomach tumors are considered to be more aggressive with worse prognosis than distal gastric cancers.
In the early stages of gastric cancer symptoms may be vague and include indigestion, early satiety, postprandial bloating, and nausea. As the disease progresses symptoms can include weight loss, dysphagia, vomiting, anemia, ascites, and jaundice.6,7 See Table 2.
When gastric cancer is suspected, an upper endoscopy with biopsy is performed. If detected, further testing may check for HER2 genes and H. pylori infection. After diagnosis, staging studies may include endoscopic ultrasound, computed tomography scan (CT scan) of chest, abdomen, and pelvis (if not previously performed), positron emission tomography scan (PET scan), magnetic resonance imaging (MRI), and laparoscopy.7,8 Staging follows the American Joint Committee on Cancer (AJCC) Tumor, Lymph node, Metastasis (TNM) classification system.7
Treatments for gastric cancer depend on the location and disease stage as well as an individual’s overall health and goals of care. For early-stage, surgery with regional lymphadenectomy is standard therapy. For locoregional disease, multimodal treatment regimens are typically used and may include surgery, chemotherapy, radiation, targeted drug therapy, and immunotherapy.7,8 Endoscopic mucosal resection can be used for very early-stage gastric cancers; however, partial, and total gastrectomy are the primary surgeries for gastric cancers. Types of surgical reconstruction include Billroth I, Billroth II, and Roux-en-Y.7,8 Non-surgical candidates and patients with widely metastatic disease may be treated with multimodal therapy or best supportive care.
| Nutrition and Lifestyle | Other |
|---|---|
Cigarette smoking Diets high in salted, smoked, or preserved foods Diets low in fruits and vegetables Alcohol (3 or more drinks per day) Obesity (cardia region) | Advanced age Male sex H. pylori gastric infection Epstein-Barr virus infection Chronic atrophic gastritis Intestinal metaplasia Pernicious anemia Gastric adenomatous polyps Family history of gastric cancer Ménétrier’s disease Familial syndromes |
The primary goals for medical nutrition therapy for patients undergoing cancer treatment are to prevent or resolve nutrient deficiencies, achieve, or maintain a healthy weight, preserve lean body mass and function, minimize nutrition-related side effects, and maximize QoL.9
Malnutrition in Gastric Cancer
It is estimated that 60-80% of gastric cancer patients experience malnutrition at some point in their cancer journey.4 The side effects from treatment make it difficult for patients to eat and drink to maintain their nutritional status. Treatment side effects include decreased appetite, nausea, vomiting, diarrhea, and altered taste. Gastric cancer surgery is associated with a 10-30% weight loss, most of which occurs in the first 6 months after surgery; greater weight loss and sarcopenia are significantly associated with postoperative complications and shorter survival.10-13 Nutrition counseling has been found to be an effective intervention to improve nutritional status and QoL post-gastrectomy. Compared to patients that did not receive nutrition counseling, patients that received individualized dietary counseling post-gastrectomy met their calorie and protein goals at a higher rate, had less weight loss, and had significantly lower levels of fatigue.14 See Table 3.
Perioperative Nutrition for Gastric Cancer Surgery
Perioperative nutrition recommendations for gastrectomy are addressed by the Enhanced Recovery After Surgery (ERAS®) Society’s 2014 consensus guidelines.15 ERAS is a single program that incorporates a multimodal perioperative care pathway designed to achieve early recovery for patients undergoing major surgery. The nutrition guidelines focus on preoperative nutrition, early advancement of postoperative diet, and indications for enteral and parenteral nutrition. Preoperative enteral nutrition (EN) in malnourished patients was associated with improved 3-year overall survival when compared to patients with inadequate dietary intake before surgery.15 Routine use of EN is discouraged, however, failure to meet 60% of nutrient requirements after one week warrants evaluation for EN support. Parenteral nutrition (PN) should be reserved for those with a non-functional or inaccessible gut.15
The use of Enhanced Recovery Protocols (ERPs) in Asian patients with gastric cancer has demonstrated improved outcomes.16 Recent studies comparing gastric cancer surgery outcomes before and after implementation of ERPs in two U.S. hospitals found ERPs were safe, feasible, and potentially decrease postoperative length of stay without increasing complications.15-17
Postoperative Nutrition After Gastric Cancer Surgery
Normally, the stomach sends hunger signals to the brain, accommodates a large quantity of food, mechanically grinds food for absorption, and controls the rate of chyme emptying into the small intestine. The extent of diet modifications needed after gastric cancer surgery will depend on the volume of remnant stomach and the type of reconstruction.4, 18,19 The ERAS 2014 consensus guidelines provide recommendations for early initiation and patient-directed intake of food and drink with cautious increase according to tolerance (Table 4); allowing food from post op day 1 is supported and has not been associated
with any adverse events in trials with patient status post total gastrectomy. The traditional post-operative clear liquid diet that includes high sugar, hyperosmolar fluids such as juice, soda, Jell-OTM, and popsicles may not be well tolerated following gastrectomy and should be avoided.
| Early Onset Symptoms | Late Onset Symptoms |
|---|---|
Decreased appetite • Early satiety • Abdominal pain or vague abdominal discomfort • Heartburn and indigestion • Nausea • Fatigue | Unintentional weight loss Dysphagia Vomiting Heme-positive stools Anemia Ascites Jaundice |
Post Gastrectomy Syndrome
Post gastrectomy syndrome refers to complications that may occur with a partial or total gastrectomy and it includes dumping syndrome, maldigestion and malabsorption, delayed gastric emptying, bile acid reflux, and micronutrient deficiencies.18,19
Dumping syndrome (DS) results from partial or total loss of the stomach reservoir capacity and rapid gastric emptying of hyperosmolar contents into the proximal small intestine. Incidence of DS ranges from 20-50% depending on the type of reconstruction.20 There are two types of DS, early and late, that are classified by the timing of onset and constellation of symptoms. Early DS occurs within 10-30 minutes after eating and is characterized by abdominal cramping, bloating, nausea, diarrhea, and vasomotor symptoms of postprandial weakness, flushing, dizziness, and sweating. Late DS occurs 1-3 hours after eating and is characterized by weakness, sweating, nausea, hunger, and tremors.
| Side Effect | Strategies |
|---|---|
| Decreased Appetite | Schedule small, frequent meals. Increase intake when appetite is at its best. Eat nutritious, high calorie, high protein foods and fluids. Examples: nuts/nut butters, avocado, yogurt, tofu, eggs, smoothies Consume most liquids between meals to prevent dumping and exceeding the gastric remnant’s volume capacity. Engage in light physical activity such as walking to help stimulate the appetite. |
| Nausea/Vomiting | Eat small meals every few hours. Include well tolerated foods such as oatmeal, rice, boiled potatoes, toast, skinless poultry, yogurt, soft, mild fruits, and vegetables – melons, bananas, grapes, cucumber, cooked carrots, zucchini, and winter squash. Sip on clear liquids – diluted juice, broth, ginger, and peppermint tea. Avoid strong odors (allow fresh air inside to clear odors). Relax and stay upright after meals. Limit fried, greasy, and rich foods. |
| Diarrhea | Drink plenty of fluids throughout the day – well tolerated fluids include water, diluted juice, broth, chamomile tea, and oral rehydration solutions. Eat small meals every few hours. Add a food rich in soluble fiber at each meal – oatmeal, barley, bananas, applesauce, peeled fruits, peeled, and cooked vegetables such as carrots, zucchini, and sweet potatoes. |
| Altered Taste | Practice good oral hygiene. Rinse mouth with a baking soda, salt, and water rinse before eating. Add strong flavors to foods with the addition of spices, herbs, marinades, lemon juice, and sauces. Use plastic utensils, cups, and plates in place of metal if with a metallic taste. |
| Diet Guidelines for Post Gastrectomy |
|---|
Eat on a schedule with 6 – 8 small meals a day. ■ Immediately after surgery, start with 2-4 oz of food per meal ■ Slowly increase portion sizes over time as tolerated Eat slowly and chew food thoroughly. Sit upright during meals and for an hour after meals. Eat the last meal of the day 2 hours before bedtime. Separate fluids from solids by 30-60 minutes. Include protein with each meal (e.g., eggs, skinless poultry, fish, legumes, lean meats, dairy products, high protein drinks or protein powder with less added sugars (<5 grams of added sugar per serving)). Include calorie dense foods such as avocado, smooth nut butter, or a sprinkle of cheese. Limit foods and drinks with added sugars to small amounts (e.g., sodas, desserts, candy). For the first 6 weeks after surgery limit fibrous meats and foods high in insoluble fiber in whole form. Raw fruits and vegetables with thick skins Nuts, seeds, and legumes After six weeks can gradually add fibrous foods into the diet as tolerated Include foods with fiber in small particle size as tolerated (e.g., blended vegetable soups, fruit and vegetable smoothies, canned fruits, creamy nut butters, instant oatmeal, tofu, and hummus). If there is gastrointestinal discomfort after eating, keep a short-term food diary to identify problematic foods and eating patterns. |
While the exact mechanism is unknown, late DS is attributed to reactive hypoglycemia. It is thought that the rapid absorption of carbohydrates exaggerates the glucose-mediated insulin response. Dietary modification is recommended as the initial treatment for DS. Patients are advised to:4, 18-20
- Reduce meal size
- Eat slowly
- Chew well
- Wait at least 30 minutes after eating to drink fluids
- Increasing fiber and protein rich foods
- Limit rapidly absorbed carbohydrates present in sweets, sugar sweetened beverages, and fruit juices
Maldigestion along with malabsorption may occur after a partial or total gastrectomy. Contributing factors include a decrease in hormonal stimulation of pancreatic secretion, rapid transit time, poor mixing of chyme and bilio-pancreatic secretions, and small intestine bacterial overgrowth (SIBO). Clinical signs of fat malabsorption are steatorrhea and weight loss with symptoms such as bloating, foul-smelling gas, and diarrhea or large floating stool. In addition to poor mixing of chyme with bile and pancreatic enzymes, pancreatic exocrine insufficiency (PEI) is thought to impact digestion in a total gastrectomy with an estimated incidence of 47- 100%; the greatest prevalence is in patients with Roux-en-Y reconstruction.21 Common diagnostic tests for PEI include quantitative or qualitative fecal fat and fecal elastase 1 (FE-1). In some clinical practices, pancreatic enzyme replacement therapy (PERT) is empirically commenced when symptoms of fat malabsorption are present. Two randomized controlled trials evaluating the effectiveness of PERT use after gastric cancer surgery have been conducted.22,23 After starting PERT patients reported feeling better overall and improved stool consistency was seen in cases of severe steatorrhea. Despite these positive findings, the studies concluded the effect of PERT on post gastrectomy malabsorptive symptoms was marginal. In cases of partial gastrectomy when there is potential for gastric acid to inactivate lipase, concomitant use of an acid suppressing agent or buffered enzyme product may improve PERT efficacy.21, 24 See Table 5.
Gastric stasis may occur with a partial gastrectomy from damage to the vagus nerve during surgery. Symptoms may include postprandial bloating and fullness that can last for many hours after meals. Delayed gastric emptying increases risk for SIBO, bezoar formation, nausea, vomiting, weight loss, and ultimately malnutrition. In addition to following general post-gastrectomy diet recommendations, patients with delayed gastric emptying can be counseled to select calorie and protein containing liquids and foods in small particle size for improved tolerance. While more research is needed, a small particle size diet has been shown to reduce upper gastrointestinal symptoms in patients with gastroparesis via increasing the rate of gastric emptying. Foods in small particle size are easily mashed into small pieces such as pureed fruits and vegetables, hummus, blended soups, smoothies, mashed avocado, mashed boiled eggs, and soft tofu.4,18,19,25
Bile acid reflux occurs when bile flows back into the esophagus or the gastric remnant. It is caused by loss of the pylorus and is most frequently found after Billroth II reconstruction. This complication may not occur until 1-3 years after gastrectomy and is often triggered by physical positioning. Symptoms include burning epigastric pain, nausea, and bilious vomiting. In addition to following the post-gastrectomy diet, sleeping with the head of the bed elevated at least 30°, bending at the knees rather than leaning forward, and avoiding constipation may improve bile reflux symptoms. Acid suppressing medications are ineffective for bile reflux in patients with achlorhydria after total gastrectomy. Mucosal protectants and bile acid sequestrants may be helpful to protect the mucosal lining and reduce the caustic effects of the bile acids, but these must be balanced to prevent worsening fat malabsorption.4, 18,19
| Initial Dose | 500-2,500 lipase units/kg/meal 250-1,250 lipase units/kg/snack |
| Timing of Dose | Take with meals and snacks. If taking several capsules, take ½ the dose with the first bite and the other ½ during or at the end of the meal. |
| Follow Up | Monitor response to treatment. If symptoms of malabsorption persist, use strategies for optimization of PERT (below). |
| Step Wise Optimization of PERT | Assess compliance of dosing with all meals and snacks. Double PERT dose. Not to exceed 10,000 units of lipase/kg per day. Trial a different PERT product. For partial gastrectomy, concomitant acid suppressing agent or buffered enzyme product may improve efficacy. |
PERT: pancreatic enzyme replacement therapy
| Vitamin B12 Malabsorption due to lack of gastric acid and intrinsic factor Occurs within 1 year for total gastrectomy Deficiency can cause irreversible neurological symptoms | Maintenance 1000 mcg of vitamin B12 subcutaneous once monthly or 1,000 mcg orally daily Sublingual preparation preferred in patients with diarrhea, vomiting, or difficulty taking oral medications |
| Folate Secondary to malabsorption | Maintenance 400-800 mcg of folate daily Repletion 5 mg of folate daily for 3-4 months |
| Iron Malabsorption due to lack of gastric acid and bypass of the absorption sites in the duodenum and proximal jejunum Occurs in 50% of patients More common after total gastrectomy and Roux-en-Y reconstruction | Maintenance Total gastrectomy – 45-60 mg of elemental iron daily* with 500 mg vitamin C to improve absorption Repletion 200 mg elemental iron* daily for 3-4 months Take at least 2 hours apart from calcium |
| Calcium Malabsorption due to lack of gastric acid and bypass of the duodenum and proximal jejunum Possible postoperative lactose intolerance Metabolic bone disease may occur in up to 69% of gastrectomy patients 3-5 years after surgery | Maintenance 400-500 mg, three times daily (total 1200-1500 mg daily) Take at least 2 hours apart from iron supplements Note: Calcium citrate is less dependent on gastric acid for absorption and therefore the preferred form, take with or without food.* |
| Vitamin D Decreased absorption with maldigestion and malabsorption | Maintenance Recommended dose is based on serum levels Repletion 3000 – 4000 IU D3 daily until levels are greater than sufficient (30 ng/mL) Note: Vitamin D3 is the preferred form. |
*Needs to be crushed or chewed for the first 3 months
Micronutrient deficiencies are expected after gastrectomy; however, the degree of deficit depends on the extent of resection. Total gastrectomy poses the greatest risk for deficiencies. Established guidelines for nutrient monitoring and supplementation after gastric cancer surgery are lacking.18,19 However, given the extensive body of literature available for micronutrient deficiencies and repletion therapies after bariatric surgery, it is recommended to reference the American Society of Metabolic and Bariatric Surgery (ASMBS) guidelines when treating patients with gastric cancer. Ongoing monitoring of nutritional status at 1,3,6, and 12 months after surgery, then annually and monitoring bone mineral density via dual-energy X-ray absorptiometry (DEXA) scan within two years after surgery is advised. Recommended blood tests include vitamin B12, methylmalonic acid, red blood cell folate, iron panel with ferritin, and 25-hydroxy-vitamin D.18,19, 33 See Table 6.
CONCLUSION
Gastric cancer, and the available treatments, put patients at a high risk of developing malnutrition and micronutrient deficiencies. Patients that undergo gastric cancer surgery may face additional nutritional challenges resulting from post gastrectomy syndrome and weight loss. However, evidence shows that nutrition therapy interventions can improve patient outcomes, function, and QoL. Nutrition counseling, close monitoring, treatment of gastrointestinal symptoms, and identifying and supplementing nutrient deficiencies are key elements of optimizing care for patients with gastric cancer.
References
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