1. Gastric Cancer Pathology

2. Malignant Neoplasms of the Stomach Primary Adenocarcinoma (94%) Lymphoma (4%) Malignant GIST (1%) Haematogenous spread Breast Melanoma Direct invasion Pancreas; Liver; colon; ovary

3. Gastric Cancer Histology –Lauren Classification Intestinal Diffuse Mixed type

4. Intestinal gastric cancer Tumor resembles a carcinoma elsewhere in the tubular GIT Forms polypoid tumors or ulcers Arises in areas of intestinal metaplasia

5. Diffuse gastric cancer Infiltrates deeply into the stomach without forming obvious mass lesions Spreads widely in the gastric wall Worse prognosis

6. Gastric cancer classification cont’d Early gastric cancer Advanced gastric cancer

7. Early gastric cancer Cancer limited to mucosa and submucosa ± LN involvement (T1, any N) This can be protruding, superficial or excavated ( Japanese classification) Curable 5yr survival rate > 90%

8. Japanese classification

9. Advanced gastric cancer Involves the mascularis Macroscopic appearance – Bormann classification Poor prognosis

10. Bormann classification type I – polypoid type II – fungating type III – ulcerated type IV – infiltrated type V – unclassifiable

11. Gastric Cancer TNM staging TxPrimary tumor can not be assessed T0No evidence of primary tumor TisIntraepithelial tumour (carcinoma in situ) T1Tumour invades LP or submucosa T2Tumour invades muscularis propria T3Tumor penetrates subserosal connective tissue without invasion of visceral peritoneum or adjacent structures. T4aTumor invades serosa (visceral peritoneum). T4bTumor invades adjacent structures

12. Gastric Cancer TNM staging N0No regional lymph node metastases N1Metastasis in 1 to 6 regional lymph nodes N2Metastasis in 7 to 15 regional lymph nodes N3Metastasis in more than 15 regional lymph nodes

13. Gastric Cancer TNM staging M0No distant metastasis M1Distant metastasis

14. Anatomic Stage/Prognostic Groups stageTNM 0TisNoMo IAT1NoMo IBT2NoMo T1N1M0 IIAT3NoMo T2N1Mo T1N2Mo IIBT4aN0Mo T3N1Mo T2N2Mo T1N3Mo

15. Anatomic Stage/Prognostic Groups stageTNM IIIAT4aN1Mo T3N2M0 T2N3Mo IIIBT4bN0Mo T4bN1Mo T4aN2Mo T3N3Mo IIICT4bN2Mo T4bN3Mo T4aN3Mo IVAny TAny NM1