G I TRACK: CANCER

Sumit Mohite 11

Vishal Mangukiya 12

Jitendra Mourya 13

Prasad Bhandlikar 14

Sanjeev Kumar 15

Cancer: General Etiology and Pathogenesis

What is cancer?

Abnormal cell growth (neoplasia)Malignant as opposed to benign

Benign: slow growth, non-invasive, no metastasisMalignant: rapid growth, invasive, potential for

metastasis

What causes the mutations that lead to cancer?

Viruses: HPV --> cervical cancerBacteria: H. pylori --> gastric cancerChemicals --> B[a]P --> lung cancerUV and ionizing radiation --> skin cancer

What do these agents have in common?

Mutagens

Viruses: insertional mutagenesis

Chemicals: DNA adducts

UV and ionizing radiation: single and double strand DNA breaks

What types of genes get mutated in cancer?

Oncogenes are activatedNormal function: cell growth, gene transcription

Tumor suppressor genes are inactivatedNormal function: DNA repair, cell cycle control, cell

death

Phenotype of a cancer cell

The Six Hallmarks of CancerSelf-sufficient growth signals

Constitutively activated growth factor signalling

Resistance to anti-growth signalsInactivated cell cycle checkpoint

ImmortalityInactivated cell death pathway

Phenotype of a cancer cell (cont'd)

The Six Hallmarks of CancerResistance to cell death

Activated anti- cell death signalling

Sustained angiogenesisActivated VEGF signalling

Invasion and metastasisLoss of cell-to-cell interactions, etc.

p53—a classic tumor suppressor

“The guardian of the genome”Senses genomic damageHalts the cell cycle and initiates DNA repairIf the DNA is irreparable, p53 will initiate the

cell death process

Esophageal cancer :-Esophageal cancer usually develops in the inner layer cells and grows outward.

Treatment :-Endoscopic treatments such

as photodynamic therapyRadiofrequency ablation

Sign & Symptoms :-chronic irritation and inflammation resulting from a backwash of acidic stomach.Painful or difficult swallowing.Weight loss.Pain behind the breastbone.Hoarseness and cough.Indigestion and heartburn.

Stomach Cancer

 What is Stomach Cancer? Stomach Cancer (Gastric cancer)-malignant tumor arising

from the lining of the stomach. Stomach cancers are classified according to the type of tissue

where they originate. Most common type of stomach cancer-

Adenocarcinoma(Starts  in the glandular tissue of the stomach)

 Accounts-90% to 95% of all stomach cancers. Other forms of stomach cancer-lymphomas, which involve

the lymphatic system, and sarcomas, which involve the connective tissue (such as muscle, fat, or blood vessels). 

Who Does it Effect? Males over the age of 55. A diet low in fruits and vegetables. A diet high in salted, smoked, or preserved foods. Chronic gastritis. Pernicious anemia. Family history of gastric cancer.  Smokers People who use tobacco or drink alcoholic beverages

regularly. Workers in certain industries-the coal mining, nickel

refining, and rubber and timber processing industries.

Causes Gender - men have more than double the risk of getting stomach

cancer than women. Genetics - genetic abnormalities and some inherited cancer syndromes

may increase your risk. Advanced age -stomach cancer occurs more often around ages 70 and

74 in men and women, respectively. Family history of gastric cancer can double or triple the risk of

stomach cancer. Lifestyle factors such as smoking, drinking alcohol, and eating a diet

low in fruits and vegetables or high in salted, smoked, or nitrate-preserved foods may increase your risk

Helicobacter pylori (H. pylori) infection of the stomach. H. pylori is a bacterium that infects the lining of the stomach and causes chronic inflammation and ulcers.

Signs and Symptoms  In the early stages of stomach cancer,Indigestion and stomach discomfort

A bloated feeling after eating

Mild nausea

Loss of appetite

Heartburn

Cont… In more advanced cancer,Discomfort in the upper or middle part of the abdomen.

Blood in the stool (which appears as black, tarry stools).

Vomiting or vomiting blood.

Weight loss.

Pain or bloating in the stomach after eating.

Weakness or fatigue associated with mild anemia (a deficiency in red blood cells). 

Stomach Cancer Diagnosis

By  physical examination-enlarged lymph nodes, an enlarged liver, increased fluid in the abdomen (ascites), or abdominal lumps felt during a rectal exam.

Test such as Upper GI series

Gastroscopy and biopsy

 CT scans, PET scans, bone scans, laparoscopy and endoscopic ultrasound.( to check if cancer is spread)

How Is Stomach Cancer Treated?

Stomach cancer may be treated with the following, in combination, or alone:

Surgery, called gastrectomy, to remove all or part of the stomach, as well as some of the tissue surrounding the stomach.

Chemotherapy.

Radiation therapy.

 Prognosis/ Survival Rate Prognosis depends on the stage of the disease. Stomach cancer metastasizes in as many as 80% of

cases, resulting in a very poor prognosis. In Japan, where stomach cancer often is diagnosed

early, the 5-year survival rate is about 50%. In the United States and most of the Western world,

the 5-year survival rate ranges from 5–15%. 

 ManagementFollow-up care is necessary for stomach cancer

patients. Regular physical examination and tests (e.g., CT scan,

MRI scan) are used to detect recurrent or advanced disease.

In addition, patient’s dietary intake must be monitored regularly to promote health. 

Liver cancer :-•Starts somewhere else and spreads to the liver.•Reason viral hepatitis4 main types :-1) Angiosarcoma, A rare type of cancer that starts in the blood vessels of the liver.2) Hepatoblastoma, Another rare type of liver cancer occurring chiefly in young children.3) Cholangiocarcinoma, Which starts in the bile ducts4) Hepatocellular carcinoma, Also known as Hepatoma. The most common liver cancer is hepatocellular carcinoma which accounts for approximately 84% of liver cancers. As is the case with stomach cancer, liver cancer is hard to diagnose.

Treatment :-•Chemotherapy •Radiofrequency Ablation•Gene Therapy •Magnetic-Chemotherapy

Colorectal cancers :-• Colorectal cancers are common, and occur more frequently in people over the age of 50. • Colorectal cancers are highly treatable when detected early, but the symptoms are often not obvious in early stages.

Sign & Symptoms :-

•Blood (either bright red or very dark) in the stool.

•Diarrhea & constipation.

•Stools that are narrower than usual.

•Frequent gas pains, bloating, fullness, or cramps.

•Weight loss for no known reason.

•Feeling very tired.

•Vomiting.

Treatment :-

•Surgery (most often a colectomy) to remove cancer cells

•Chemotherapy to kill cancer cells Chemotherapy drugs are :-capecitabine, fluorouracil, irinotecan, leucovorin, oxaliplatin

•Radiation therapy to destroy cancerous tissue

Management of CancerKeep to a normal weightAvoid alcoholTake regular exerciseAvoid smokingAdd Garlic to everything you EatEat plenty of Fruits and VegetablesLimit Fats and oily foodAvoid unnecessary Scans