Decreasing incidence in US in past 50 yr, increasing incidence in Japan. Higher incidence in patients with blood type A (pernicious anemia predisposition in the same group).

Correlates w severe H. pylorigastritis (Nejm 2001;345:784) and gastric ulcers but not duodenal disease. Polyps do not predispose, but probably diet constituents of unknown type do (maybe nitrosamines from cured/fermented foods)

Sx:Pain (51%), cachexia and weight loss (62%), hematemesis or melena (20%), dysphagia (26%)

Si:

Acanthosis nigricans; when present in patient over age 40 yr, patient has a high chance of having a gi adenocarcinoma; r/o lymphoma, hereditary ataxia telangiectasia, obese patients, children, or diabetics, esp insulin-resistant diabetics (Nejm 1978;298:1164)

Guaiac-positive stools

Rapidly downhill even with surgery; overall 5-yr survival: 10-15%; with surgery and negative nodes may be as high as 45%; better in Japan

Bleeding. Metastases to lung, esp via lymphatics and may appear as a diffuse pulmonary process; to ovaries, esp if signet ring cell type (Krukenberg's ovarian tumor); to bone, esp vertebrae

r/o gastric lymphoma (MALT: mucosa-associated lymphoid tissue), low-grade B-cell lymphoma associated w H. pyloriinfection and 50% cure rate w antibiotic rx of H. pylori(Ann IM 1999;131:88)

Lab:Endo:Gastroscopy with 6+ biopsies and brushings (Ann IM 1984;101:550); also typical staging studies

Rx:

Prevention in future perhaps byH. pylori screening and rx (Jama 2004;291:187, 244; Nejm 2001;345:829)

Surgical, perhaps preceded by chemoRx (Nejm 2006;355:11, 75), or followed by local irradiation and chemoRx (Nejm 2001;345:725)

Chemotherapy, palliative only, but multiple drug, eg: 5-FU, Adriamycin, mitomycin C