Gastric Cancer

Dr. Amina Abdul RahmanJunior ResidentDept. of Radiotherapy

Epidemiology Anatomy Classification Pathology Clinical Features Staging Prognosis

Gastric Cancer

Epidemiology

Fourth most common cancer in the world Second most common cause of cancer

related death Marked geographic variation High risk areas : Japan, Korea, Latin

America, USSR Low risk areas: USA, Israel, Kuwait, Canada

Epidemiology

Geographic Variations in Incidence

Over all Global decline in Gastric Ca

But the incidence of proximal gastric cancers is increasing in the west…

Sub site specific incidence in the UK

The Trend in our Hospital

Most common site was Antrum 48% 40% was found to be in the body 10% was found to be in the proximal

stomach

Cardia Vs Non Cardia Cancers

GEJ TumorsCardia

Tumors

Risk factors for Gastric Cancer

Acquired High salt consumptionHigh nitrate consumptionPoor food preparation (smoked, salt cured)Lack of refrigerationDiet low in Vit A and CSmoking, heavy alcohol consumption

Helicobacter pylori 3 to 6 times increase in risk of gastric

cancer intestinal type of cancer in the distal

stomach Decreases acid production causing chronic

atrophic gastritis

Risk factors for Gastric Cancer

Radiation exposure

Prior Gastric surgery for benign ulcer disease

Risk factors for Gastric Cancer

Genetic FactorsType A blood groupPernicious anemiaFamily historyHNPCCLi-Fraumeni syndromePeutz Jegher SyndromeBRCA2 mutation

Risk factors for Gastric Cancer

Fresh fruits and vegetables

NSAIDs

Protective Factors

CDH1mutation

Codes for E-Cadherin

Prophylactic gastrectomy

Hereditary Diffuse Gastric Cancer

Proximal Gastric Cancer Distal Gastric Cancers

Includes GEJ, Tumors of the Cardia Includes Body and Antrum

Rapidly increasing incidence in the west

World wide incidence is declining steadily

Mainly diffuse type Mainly intestinal type

M:F = 1:1 M>F

Younger age Older age

More aggressive Less aggressive

More in the developed countries More in developing countries

Not associated with H. pylori Associated with H. pylori

Associated with GERD Associated with atrophic gastritis

Proximal Vs Distal cancers

ANATOMY

ANATOMY

The Stomach

Relations of the Stomach

Arterial supply of the Stomach

Venous drainage of the Stomach

Lymphatic Drainage

Lymphatic Drainage of the Stomach

Lymph Node Station 1 to 6

Lymph node stations 7 to 11

12 – Hepatoduodenal ligament13 – On the posterior surface of the head of pancreas14 – Root of mesentery15 – Para aortic16 - Paracolic

Lymph node stations 12 to 16

Stomach layers

Histology of Stomach layers

Classification of Gastric Tumors

Siewert’s Classification of GEJType I : Adeno Ca Distal Esophagus, infilt GEJ from above

Type II : Adeno Ca of the real cardia, true GEJ

Type III : Subcardial Gastric Adenoca, infilt GEJ from above

Early Gastric Cancer• T1a and T1b, any N

Advanced Gastric Cancer• T2 and above

Japanese classification of EGC

Borrmann classification

PATHOLOGY

WHO Classification• On histologic appearance alone

Lauren’s Classification• Histology and morphology

PATHOLOGY

Epithelial tumorsAdenocarcinomaSmall cell carcinomaCarcinoid tumor

Malignant LymphomaMaltomaMantle cell lymphomaDLBCL

WHO Classification

Non epithelial tumorsLeiomyomaSchwannomaGranular cell tumorLeiomyosarcomaGISTKaposi Sarcoma

WHO Classification

ADENOCARCINOMA Tubular Papillary Mucinous Signet ring cell carcinoma Undifferentiated

Pathology

Intestinal type• 54%

Diffuse type• 32%

Lauren’s classification

Form exophytic or ulcerated growth More in the distal stomach Due to H. pylori This type is declining worldwide Older patients with a male preponderance M:F = 2:1 Better prognosis Form glandular elements in histology

Intestinal type

Intestinal type

Chronic atrophic gastritis

Intestinal metaplasia

Dysplasia

Carcinoma in situ

Intestinal type

Mainly affects cardia Form infiltrative lesions No precancerous lesions Loss of CDH1 gene Discohesive cells that do not form glands Signet ring cells Younger age, M = F Worse prognosis

Diffuse Type

Diffuse type

Her2-neu amplification in 12 to 27% More in intestinal type than diffuse type Prognostic significance has not been

identified 4 tier scoring Trastuzumab in Her2-neu 3+ or FISH

positive locally advanced or metastatic stomach cancer

Immunohistochemistry

CLINICAL FEATURES

Lesions of proximal stomach – Dysphagia Diffuse infiltrative lesions produce early

satiety Gastric outlet obstruction Trousseau sign Blumer’s Shelf Virchow’s node (Troisier’s sign) Irish node Sister Mary Joseph Nodule

CLINICAL FEATURES

Adjacent organ invasion

Hematogenous spread

Peritoneal Seeding: Krukenberg tumor Blumer Shelf Lymphatic spread: Virchow’s node (Troisier’s sign) Irish node

ROUTES OF SPREAD

TNM Staging

T Staging

N0 : No regional lymph node metastases N1 : 1to 6 regional lymph node metastases N2 : 7 to 15 regional lymph node metastases N3 : More than 15 regional lymph node

metastases

N Staging

Involving Lymph node stations 12 onwards Omental deposits Positive peritoneal cytology

M Staging

Prognostic Factors

Age Sex Primary tumor Site Lauren Classification Number of Positive and Negative lymph

nodes Depth of invasion

Prognostic Nomogram

Disease specific survival

To Be Continued….