Stomach Cancer : Cases very high in NE Region, particularly in Mizoram, ArP

Dr Thaodem Tomcha Singh *

Stomach is a "J" shaped tubular structure in the upper abdomen. It is a part of the digestive system that connects oesophagus above and duodenum below. It stores, helps in digestion, assimilation and elimination of waste products. The stomach wall has got 5 layers. Most of stomach cancers arise from the innermost layer (Mucosa), while only few from the stroma (Connective tissue).

Incidence

Gastric cancer remains one of the most common and deadly cancers worldwide, especially among older males. Based on GLOBOCAN 2018 data, stomach cancer is the 5th most common neoplasm constituting 5.7% of all new cancer cases and the 3rd most deadly cancer, with an estimated 783,000 deaths in 2018.

Gastric cancer incidence and mortality are highly variable by region and highly dependent on diet and Helicobacter pylori infection. Incidence rates are highest in Eastern and Central Asia and Latin America. The incidence of stomach cancer is also very high in NE Region particularly in Mizoram, Kamrup District of Assam and Arunachal Pradesh mainly due to habit of tobacco use, smoked food and alcohol.

Risk Factors

Following are some of the risk factors for stomach cancer:

Diet

Salt/Salt rich food: Regular consumption of excess salt may increase risk of stomach cancer. Salt is present in most of readymade foods that we eat on daily basis like bread, pickle, cake, biscuit, cereal, preserved meat, ready meals etc.

*Lack of fruits & vegetables : Less consumption of fruits and vegetables increase risk of developing stomach cancer. The United States Food and Agricultural Organization recommends at least 400 gm of fruits and vegetables per person per day spread out 5 servings a day (80 gm each).

* Smoked food: Any food which is smoked not only reduces food value but also increases risk of developing gastro-intestinal cancers due to development of carcinogens like heterocyclic amines, polycyclic aromatase hydrocarbons etc.

* Red meat and processed meat : Diet rich in red meat/ processed meat such as ham, bacon, sausages and salami is linked with stomach cancer. Government of India recommends a limit of 90 gm of these items a day and advises to reduce it to 70 gm or even less.

* Improperly preserved food : Improperly preserved food may invite microbial infestations, some of which especially fungi and algae can cause stomach cancer.

* Tobacco consumption : Smokers have about 1.5-2.5 times increased risk of stomach cancer than non-smokers. Smokeless form of tobacco use also has the same harmful effect.

* Alcohol : Heavy drinking increases the risk of stomach cancer.

Helicobactor pylori

It is a bacteria commonly found inside the lining of the stomach and duodenum. It has been established as root cause of most of stomach ulcers and gastritis. If neglected these ulcers and gastritis can lead to stomach cancer. Presence of H. pylori has a 2 fold increase risk for stomach cancer.

Other medical conditions : Long term inflammation of the stomach, anaemia due to Vit 12 deficiency, stomach polyp, obesity etc may increase risk of stomach cancer. Risk factors that are not modifiable

Age : More common in older people especially above 70 years but now-a-days, younger people are also affected.

Sex : Males are twice as likely to develop stomach cancer

Blood Group A: More common

Genetic: Those whose mother/father/brother/sister have history of stomach cancer have higher risk.

Warning signals of stomach cancer:
o Difficulty in swallowing
o Feeling bloated / full after eating small amounts of food
o Indigestion, anorexia
o Discomfort in upper abdomen
o Severe, persistent heartburn or indigestion
o Unexplained persistent nausea
o Stomach ache
o Persistent vomiting with or without blood
o Weight loss
o Constipation
o Dark stool
o Fullness of abdomen
o Breathlessness

How to diagnose:

Upper GI Endoscopy : This is done by passing a thin, flexible & lighted tube containing a micro-camera at the tip. This lets the doctor visualize the inner lining of stomach. If a suspicious growth is detected, a small piece of tissue is taken for biopsy which can confirm diagnosis.

Endoscopic Ultrasound (EUS) : A small transducer is placed on the tip of an endoscope and passed down the throat till it reaches stomach. The different layers of the stomach wall are examined. If cancer is suspected, the regional lymph nodes and adjoining areas are also inspected for involvement. If needed, EUS can also be used to help in guiding a needle into the suspected area to get a tissue sample.

Imaging : Different imaging techniques like Barium swallow, Ultrasound, CT scan, MRI and even PET scans can be used for proper staging, diagnosis, and prognosis. These images can also serve as a base-line investigation to be compared with images taken intra treatment, post treatment and during follow-up to draw opinion about cure, or presence of residual or recurrent disease status.

Biopsy : A small tissue piece is taken from suspicious looking area found during endoscopy. Biopsy may also be taken from nearby lymph nodes or other suspicious appearing areas to confirm the diagnosis.

Treatment

There are 7 types of standard treatment for stomach cancer
* Endoscopic mucosal resection
* Surgery (Partial or complete Gastrectomy)
* Radiation therapy
* Chemotherapy
* Chemoradiation
* Targeted therapy
* Immunotherapy

Endoscopic mucosal resection : This procedure uses an endoscope to remove early stage cancer and pre-cancerous growths from the lining of stomach without surgery. This treatment is possible only in the very early stages.

Surgery : Surgery is the most practiced treatment of all stages of gastric cancer. It can be used as a curative treatment in early stages or as a palliative (To relieve symptoms) in advanced stages.

The following types of surgery can be used
* Sub-total gastrectomy: To remove part of stomach containing the cancer, nearby lymph nodes and part of other tissues/organs near the tumour

* Total gastrectomy: Removal of entire stomach, nearby lymph nodes and other tissues near the tumour. When the tumour cannot be removed in entirety as happens in late stages, the following palliative procedures can be adopted:

* Endoluminal stent placement: When there is obstruction of gastric lumen by the tumour, a stent can be put under endoscopic vision to open up the closure to let food pass through the stomach.

* Endoluminal laser therapy: A laser (Intense beam of light) can be attached to an endoscope and used to burn/cut off the tumour.

Radiation Therapy

* Radiation therapy is a cancer treatment that uses high energy X-rays or other types of radiation to kill cancer cells or keep them from growing. The principle of its action is owing to its capability to cause ionization in the cancer cells. Often it is used as an adjunct to surgery and sometimes as a stand-alone treatment when patient is contraindicated for surgery.

Chemotherapy: Chemotherapy is a type of cancer treatment that uses cytotoxic drugs to stop the growth of cancer cells either by killing the cells or stopping them from dividing. When chemo is given by mouth or injected into a vein or muscle, the drug enters the bloodstream and can reach cancer cells throughout the body (Systemic effect).

Chemoradiation : When a small dose of chemotherapy is used concomitantly with radiation therapy, the beneficial effect (Cancer control) of radiation is enhanced. It is already a standard practice in many disease sites and can be used as an alternative to surgical treatment especially when the latter is not suitable.

Targeted Therapy : It is a type of treatment that uses drugs or other substances to identify and attack specific cancer cells. Targeted therapies cause less side effects compared to chemotherapy as it mostly concentrates in the cancer cells with minimal spread to normal tissues.

Immunotherapy : Immunotherapy is a type of cancer treatment that stimulates patient's immune system and allow it fight with cancer disease. It uses substances / chemicals made by the body or made in a laboratory to boost, direct or restore the body's natural defenses against cancer. This type of treatment is also known as biotherapy or biologic therapy.

Summary : Stomach cancer is very common in North-East India. It is also quite a fatal disease. Luckily majority of the disease can be prevented by changing our life style and avoiding risk factors already highlighted. A number of treatment options are available now-a-days.

A single treatment may be sufficient in early stages but a combination of different treatments is usually the norm for late stages. The earlier the treatment, the better is the cure. All the treatment options including experts are available in Manipur.

(Nov is National Stomach Cancer Awareness Month)