Upper GI Surgery JC058: Weight Loss And Vomiting: Gastric Cancer, Abdominal Imaging Flashcards
***Mechanical GI obstruction
記: 4 Cardinal presentations Intestinal obstruction:
1. **Abdominal distension
2. **Abdominal pain
3. **Vomiting
4. **Constipation
High obstruction:
- **Frequent vomiting
- **No distension
- Intermittent pain but not classic crescendo type
Middle obstruction:
- Moderate vomiting
- Moderate distension
- Intermittent pain (crescendo, colicky) with free intervals
Low obstruction:
- **Late vomiting (Faeculent)
- **Marked distension
- Variable pain (may not be classic crescendo type)
Esophagus:
- Dysphagia
- Regurgitation (Not vomiting ∵ not much muscular action + contain little amount of content)
Stomach:
- Vomiting (∵ capable muscular action to produce sudden force to release content + can contain large amount of content)
Upper GI obstruction
- Nature of vomitus (differentiate Proximal vs Distal to D2)
- ***Bile stained —> distal to D2
- NOT Bile stained —> proximal to D2 - Bulge (distension) in epigastrium
- Succussion splash
- ***gastric outlet obstruction
Vomiting, Weight loss, Gradual onset, Elderly:
- consider ***Gastric cancer with outlet obstruction
Epidemiology of Gastric adenocarcinoma
- ↓ Incidence
- 3rd leading cause of cancer deaths worldwide (6th in HK)
- Incidence varies globally (High incidence in Asia)
- Still very common (∵ aging population)
- Disease of elderly
Risk factors of Gastric adenocarcinoma
- Diet
Harmful dietary factors
- **N-nitroso compounds (e.g. nitrates) (make meat pink)
- **Preserved, smoked, salted food
Protective dietary factors
- Trace elements
- Vit C
- ***Fresh fruits and vegetables
- ***Smoking
- ***Atrophic gastritis
- ***Pernicious anaemia
- Adenomatous polyps
- Menetrier’s disease
- ***Previous partial gastrectomy (>20 years)
- ***EBV (apart from NPC, Burkitt lymphoma)
- Industrial (dusty, high temperature, rubber, coal mining, metal processing, chromium production)
- Common variable immunodeficiency (CVID)
- Hereditary (E-cadherin mutation)
- ***H. pylori (WHO group 1 carcinogen) (2-3% chance)
Linitis plastica
A type of Gastric cancer:
- “Leather bottle” stomach
- Cancer invade + spread via **Submucosal layer —> Mucosa can appear “normal” on endoscopy —> easily missed
- **Thickened gastric wall (>5mm)
- Rigid, cannot be distended with air
Features:
- **Smaller stomach
- **Cannot distend lumen with air insufflation
Solution:
- Take deeper bite on biopsy on suspicion
Mode of spread of Gastric adenocarcinoma
- Direct invasion
- anterior: Liver
- lateral: Spleen
- inferior: Colon
- posterior: Pancreas - Lymphatic
- richly supplied by lymphatic network -
**Transcoelomic / **Transperitoneal
- seedlings of peritoneum (small, easily missed by CT)
- associated **Ascites
- **Krukenberg tumour: Ovarian metastasis - Haematogenous
- Liver, Lung
***Clinical presentation of Gastric adenocarcinoma
Notoriously difficult to make an early diagnosis
1. Asymptomatic
2. Distending discomfort, **Vomiting (Splash) (if Obstruction)
3. **Anaemia, Pallor, Melena, Haematemesis (if Bleeding)
4. Perforation with acute peritonitis (Rare)
5. **Epigastric pain
6. Anorexia, Weight loss (late presentation), Malaise, Weakness
7. Dysphagia (if Cardia involved)
8. **Abdominal mass (Primary, Omental, Krukenberg)
9. **Acanthosis nigricans (Dark discolouration of body folds, also present in DM)
10. Paraneoplastic syndrome (e.g. Nephrotic syndrome)
11. **Metastatic disease
- **Ascites
- **Jaundice (biliary obstruction by LN metastasis, liver metastasis)
- **Left supraclavicular LN (Virchow’s node, Troisier’s sign), Left axillary node (Irish’s)
- **Dyspnea (pleural effusion, lymphangitis carcinomatosis: diffuse lung metastasis through LN in lung parenchyma)
- **Hepatomegaly
- **Sister Mary Joseph node (indicate peritoneal spread, also present in intraabdominal malignancy with peritoneal spread)
- Acute renal failure / hydronephrosis (obstruction of ureter)
- Rectal (Blumer’s) shelf (rectum feel like hard tube)
Investigations
- CBP, LRFT
- ***Upper endoscopy + Biopsy (diagnostic)
- CXR
- **CEA, **CA19.9 (for monitoring after treatment, follow up)
2 main questions after diagnosis
- Stage of disease
- TNM
—> AJCC
—> UICC
—> JGCA
- T: Depth of invasion
- N: No. of LN with metastasis
- M: Presence / Absence of systemic metastasis - Whether patient is fit for surgery / treatment?
Clinical staging
- History, P/E
- LFT
- CXR
- USG / CAT scan (i.e. CT abdomen)
- ***PET / CT
- ***Endoscopic USG
- for regional local staging (gastric wall / LN involvement) - ***Laparoscopy
- for peritoneal spread
- done immediately before surgery
Treatment of Gastric adenocarcinoma
- Depends on fitness + clinical stage
- Resection: only hope for cure for resectable disease
- In HK, 70% present with diseases ***>= Stage 3
Early cancer (T1, mucosal)
- rare in HK
- Japan: Screening endoscopy
- **EMR (Endoscopic Mucosal Resection): not useful for larger lesions
- **ESD (Endoscopic Submucosal Dissection) (片皮鴨)
- ***Laparoscopic gastrectomy
—> Laparoscopic assisted vs Total Laparoscopic
—> Hand sewn vs Stapled
—> Billroth 1 vs 2
Resectable gastric cancer
- Gastric resection with ***D2 LN dissection
- ***Distal resection (for distal lesion)
- ***Proximal resection (for GEJ lesion)
-
**Total gastrectomy (for proximal / body lesion)
- **Roux-en-Y reconstruction —> prevent bile reflux
- ***Esophagojejunostomy - Adjuvant chemotherapy (for ***advanced cancer: Stage 2/3)
- Neoadjuvant chemotherapy (for selected patients: ***Downstaging first)
Others:
7. Targeted therapy (e.g. gastric cancer with **HER2 mutation —> **Trastuzumab)
8. Immunotherapy
Unresectable disease
- Supportive care, Pain control
- ***Palliative resection for bleeding
-
Palliative bypass (Gastrojejunostomy) for outlet obstruction
- higher morbidity
- provide better QOL - ***Systemic chemotherapy (for younger patients)
- ***Endoscopic stenting
- less morbidity
- limited diameter
Chemotherapy
- Primary
- Adjuvant
- Neoadjuvant
Value of diagnostic imaging
- Staging
- CXR
- CT
- PET - Diagnosis
- **Intestinal obstruction
- **Malignant biliary obstruction
- ***Malignant ureteric obstruction - Monitoring response to treatment