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Stomach Cancer


OVERVIEW OF Stomach Cancer :

When cells multiplies out of control in the gastric region(stomach) it might leads to the Stomach cancer.


STRUCTURE of Stomach Cancer :

The stomach is an organ which aids in the digestive mechanism. It consists of fundus, body and pyloric region. Cardia is the first part and it is closest to the esophagus. Fundus is the uppermost part of the stomach. Body is the main part of the stomach. And the pyloric region is the last part od the stomach and it contains the valve which mediates the passage of food into the small intestine. Antrum is the lower portion of the stomach where the gastric fluids( acid) mixes with the food.


EPIDEMIOLOGY :

It is more commom among men when compared to women.


CAUSES :

  • Gastroesophageal reflux disease
  • Obesity
  • A diet high in salty and smoked foods
  • A diet low in fruits and vegetables
  • Family history of stomach cancer
  • Infection with Helicobacter pylori
  • Long-term stomach inflammation (gastritis)
  • Smoking
  • Stomach polyps


PATHOPHYSIOLOGY :

Types of Stomach Cancer:

Adenocarcinomas:

Adenocarcinomas develops from the gland cells in the innermost lining of the stomach.

There are two types of stomach adenocarcinomas:

Intestinal: These tends to have better prognosis.

Diffuse: This type tends to grow and spread more quickly. It is less common and it tends to be harder than to treat.

Gastrointestinal stromal tumours(GIST):

They are started in the wall of the stomach called interstitial cells of Cajal. They commonly occurs in the stomach.

Neuroendocrine Tumours (Including Carcinoids):

Neuroendocrine tumors (NETs) start in cells in the stomach (or other parts of the digestive tract) that act like nerve cells in some ways and like hormone-making (endocrine) cells in others. Most NETs tend to grow slowly and do not spread to other organs, but some can grow and spread quickly.

Lymphomas:

They gets started in the immune system called lymphocytes. Lymphocytes usually can start in other parts of the body but it can also start in the wall of the stomach.


COMMON CLINICAL SIGNS AND SYMPTOMS :

  • Difficulty swallowing
  • Feeling bloated after eating
  • Feeling full after eating small amounts of food
  • Heartburn
  • Indigestion
  • Nausea
  • Stomach pain
  • Unintentional weight loss
  • Vomiting
  • Changes in the bowel habits.

 


DIAGNOSTIC :

Biopsy:

It is the removal of a small amount of tissue for examination under the microscope. A biopsy is the confirmatory test for stomach cancer.

Fine needle aspiration:

In this type of biopsy the physician moves the fine needle  through the abdomen and take the tissue needed for the diagnosis.

Endoscopic biopsy:

In this type of biopsy, the physician uses an endoscope an hollow tube . light emitting structure to down the stomach and tissues are obtained.

Molecular diagnosis of the tumour:

Specific genes, proteins and other unique genes can be identifies in this test.

PD-L1 and high microsatellite instability which is called as mismatch repair defect.

Human epidermal growth factor is secreated in larger amount in this disease. And these things should be  noted carefully.

Blood test:

Patient with the stomach cancer  tends to show low levels of platelets, white blood cells, red blood cells.  This results in the aneamia in patients. Complete blood count might reveal whether the bleeding is occurring or not.

Computed tomography:

A CT scan takes three dimensional pictures of the abnormal tissues from different angles.

Magnetic Resonance Imaging:

A MRI scan uses the combination of the magnetic and radiowave frequency to view the abnormal tissues.

An dye is injected in the vein or the patient is asked to swallow the dye and the results are observed.

Ultrasound:

A sound waves to create the picture of the internal organs to find out if the cancer is spread or not.

Abdominal ultrasound:  with the patient symptoms it can be used to view the pancreas. But it cannot reveal the spread of pancreas.

Endoscopic ultrasound: in this method the doctor uses an ultrasound probe, and with the guidance of endoscope it is passed in to the small intestine and then into the pancreas to view the structures.

Barium Swallow:

The patient is asked to swallow the liquid Barium. Barium gets deposited in the lining of the stomach ,

esophagus and small intestine.

If X rays are taken at this time it might show some blockages in the stomach and other areas clearly.

Positron emission tomography (PET) or PET-CT scan:

A PET scan is a way to create pictures of organs and tissues inside the body. A small amount of a radioactive sugar substance is injected into the patient’s body. This sugar substance is taken up by cells that use the most energy. Because cancer tends to use energy actively, it absorbs more of the radioactive substance. However, the amount of radiation in the substance is too low to be harmful. A scanner then detects this substance to produce images of the inside of the body. With the help of the PET scan one can be able to find out the stage of cancer.

Liver function test:

              The bilirubin levels and the level of other digestive enzymes and liver enzymes such as Alanine transaminase, Aspartate transaminase and Alkaline phosphatase should be checked.

Liver function test is useful when Liver acts as a secondary site.

Tumour marker:

  • CA 19-9
  • Carcinoembryonic antigen (CEA)
  • Stage 0:
  • The cancer is not spread but has potential development of the cancer in the future which is termed as carcinoma insitu.
  • Stage 1:
  • The cancer cells are consider to the localized area. This is also called the early stage cancer
  • Stage 2 and Stage 3:
  • It indicates that the cancer cell has spread to the nearby lymphnodes or tissues.
  • Stage 4:
  • It indicates that the cancer has spread to distant organs.


TREATMENT AND PROGNOSIS :

Surgery:

The removal of an organ and the surrounding healthy tissue is done during the operation. But the surgery involvement depends upon the stage of cancer.

Stage 1 cancer can be removed by Endoscopic mucosal resection. That is the tumour is removed with the help of endoscopic guidance.

If the cancer has spread to the outer surface wall , surgery with or without chemotherapy orelse radiotherapy is indicated.

Gastrectomy is the removal of whole stomach and it might result in dumping syndrome which might include cramps, dizziness, nausea, vomiting even after taking small amount of food.

If the stage has crossed 4 and has spread to other organs surgical removal of the organ is not indicated and other following measures can be taken to relieve from symptoms.

Chemotherapy:

 chemotherapy is after the sugery or before the surgery to shrink the cancer cells. A chemotherapy is nothing but the delivery of drug intravenously

Radiation therapy:

It uses powerful x rays or emission of protons to destroy the cells. The radiation therapy also aids  in shrinkage of the cells and also relief the symptoms caused by the cancer. Radiation therapy results in the shrinkage of the tumour or it might be given after the surgery.

Immunotherapy

It is a drug treatment that uses your immune system to fight cancer. Your body's disease-fighting immune system may not attack your cancer because the cancer cells produce proteins that blind the immune system cells from recognizing the cancer cells. This immunotherapy boos those cells and helps the body to fight against it.

Targeted therapy

This treatment uses drugs that are focused on a specific features of pancreatic causing cancer cells such as the specific genes, proteins and tissue environment which favours the cancer growth. Targeted therapies work by blocking the ability of pancreatic cancer cells to multiply and divide, cutting off the blood supply needed for the cells to live, or killing the cells directly. Targeted therapy is less likely to harm normal cells.

Drugs: Olaparib, Erlotinib

Palliative therapy:

 During this therapy the patient is given the moral support and mainly this therapy encourages to deteriorate the symptoms in the patients.


PROGNOSIS :

The five year survival rate of the cancer which is diagnosed earlier and does not spread to the distant organ is 70%

The fiver year survival rate of the cancer with distant spread is 30%.

 


PREVENTION :

Avoid alcohol consumption

Check the blood sugar regularly

Follow the healthy diet

Be physicaly active

Don’t neglect the initial symptoms and have the proper treatment.

Avoid spicy foods.


Medicines used in the Treatment :

  • Cisplatin
  • Paclitaxel
  • Capecitabine
  • Fluorouracil (5-FU)
  • Irinotecan
  • Leucovorin
  • Nab-paclitaxel
  • Nanoliposomal irinotecan
  • Oxaliplatin
  • Gemcitabin


REFERENCE :

https://www.cancer.net/cancer-types/stomach-cancer/types-treatment

https://www.mayoclinic.org/diseases-conditions/stomach-cancer/symptoms-causes/syc-20352438

https://www.cancer.org/cancer/stomach-cancer/about/what-is-stomach-cancer.html

https://www.nhs.uk/conditions/stomach-cancer/

https://www.cancer.net/cancer-types/stomach-cancer/statistics#:~:text=If%20the%20cancer%20is%20diagnosed,year%20survival%20rate%20is%2032%25.