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Introduction

 Before telling you about gastric cancer, for better understanding, let me brief you the anatomy and function of stomach. Stomach is a J shaped part of upper part of gastrointestinal system. Its size differs from person to person and in between meals as it is easily extensible (figure 1).

Stomach has the following five parts (Figure 2): 

1. Cardia – is the first part that prevents gastric contents from returning to the esophagus.
2. Fundus– a round part that is found on the left and below the diaphragm
3. Body – this biggest part of the stomach where food is digestion
4. Antrum – contains the digested food until it is ready to enter to small intestine
5. Pylorus – this part serve as a pipeline where the digested food enters the first part of small intestine (duodenum).

The stomach wall has four layers (see figure 3)

1. Mucosa – is the inner layer
2. Submucosa – is the second layer and contains extensive blood vessels, lymphatics and nerves.
3. Muscularis propria – is the muscular layer of the stomach and itself is made up of three layers
4. Serosal layer – is the outer cover of the stomach

The stomach has the following three major functions:

1. Storage of the food that come from esophagus for two hours or more
2. Food Digestion
3. The inner layer secretes hydrochloric acid and other enzymes which are useful for digestion

Gastric cancer is an ancient disease described as early as 3000 BC in hieroglyphic inscriptions and papyri manuscripts from Egypt. According to the latest report from GLOBOCAN, in 2018 alone, there were 1,033,701 incident cases and 782,685 deaths globally, of gastric cancer making it the fifth and third cause of morbidity (5.7%) and mortality (8.2%) respectively. Gastric cancer shows significant geographical, ethnic and socioeconomic differences in distribution. Around 70% of the cases occur in low income countries.  A gradual decline in the incidence of gastric cancer has been observed in Western Europe and North America over the past 60 years in both sexes in (2). However, there has been a steady and dramatic increase in the incidence of proximal cancers (lesser curvature, cardia, Gastroesophageal Junction) over the past 20 years, especially in western hemisphere and parts of Europe (3). In contrast, distal tumors continue to constitute the predominant gastric cancers in the Far East and other parts of the world. Risk factors of gastric cancer are shown in table 1 below.

According to GLOBOCAN 2018, in Ethiopia, gastric cancer is the 13th common and the 10th cause of death (1). Similarly, an estimates of Cancer incidence in Ethiopia in 2015 from 8,539 patients from Addis Ababa population-based cancer registry (AACR) and supplemented data on 1,648 cancer cases collected from six Ethiopian regions showed that gastric cancer is the 10th most common type of cancer (5).

Symptoms of Gastric cancer

Most patients have incurable disease at the time of presentation even in developed countries. Nonspecific symptoms predominate.

• Abdominal discomfort, swelling
• Dysphagia (difficulty swallowing)
• Early satiety, anorexia – diffusely infiltrative tumor
• Persistent Vomiting
• Wt loss
• Symptoms of bowel obstruction
• Hematemesis (blood stools)
• Anemia-related weakness

How is the Diagnosis of gastric cancer made?

Diagnosis of gastric cancer involves proper history taking about the symptoms and doing proper physical examination. Moreover, laboratory tests and imaging studies including CT scan need to be done. However, histologic confirmation of from endoscopic biopsy of the stomach is a must.

Treatment of Gastric cancer

Similar to other cancers, the treatment of gastric cancer considers the following points

• The stage of the disease
• The patients general condition
• Comorbidities
• Availability of professionals and treatment facility
• Patient need

The options of treatment include the following and can be used alone or in combination in different sequences.

• Surgery
• Chemotherapy
• Radiotherapy
• Palliative Care

Is Gastric Cancer preventable?

To some extent we can prevent gastric cancer by doing the practices:

• Avoiding or modifying the modifiable risk factors
• Eating vegetables and fruits daily
• Decreasing salty foods and avoiding salt a preservative
• Checking the presence of H.pylori infection and getting eradication treatment if present
• Consult your physician if you have any of the above mentioned symptoms
• Avoid cigarette smoking

Is there a screening for Gastric cancer?

Except in countries like Japan, screening for gastric cancer is not practiced. This is due to the large number of patients found in Japan and also they have the capability to screen and treat.
Dr. Abdu Adem 
Assistant Professor of oncology

Referrences

1. https://gco.iarc.fr/today/data/factsheets/cancers/7-Stomach-fact-sheet.pdf accessed on 21/1/2020
2. Smyth EC, Verheij M, Allum W, Cunningham D, Cervantes A, Arnold D. Gastric cancer: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up. Annals of oncology. 2016 Sep 1;27(suppl_5):v38-49.
3. Ajani JA, Barthel JS, Bekaii-Saab T, Bentrem DJ, D’Amico TA, Das P, Denlinger C, Fuchs CS, Gerdes H, Hayman JA, Hazard L. NCCN gastric cancer panel. Gastric cancer. J Natl Compr Canc Netw. 2010 Apr;8(4):378-409.
4. Brady LW, Perez CA, Wazer DE. Perez & Brady’s principles and practice of radiation oncology. Lippincott Williams & Wilkins; 2018.
5. Memirie ST, Habtemariam MK, Asefa M, Deressa BT, Abayneh G, Tsegaye B, Abraha MW, Ababi G, Jemal A, Rebbeck TR, Verguet S. Estimates of cancer incidence in Ethiopia in 2015 using population-based registry data. Journal of global oncology. 2018 Mar;4:1-1.