Stomach: Gastric cancer Flashcards
(121 cards)
1
Q
What is the definition of gastric cancer?
A
Malignant neoplasm of gastric mucosa with glandular differentiation
This definition highlights the nature of the cancer affecting the stomach lining.
2
Q
What is the global incidence ranking of gastric cancer?
A
4th most common cancer in the world
This ranking indicates its prevalence compared to other cancer types.
3
Q
In which regions is the incidence of gastric cancer highest?
A
Asia, South America, and Caribbean
4
Q
Where is the incidence of gastric cancer lowest?
A
Africa and North America
This indicates a geographic disparity in cancer occurrence.
5
Q
What is the gastric cancer rate in New Zealand?
A
7/100000
6
Q
Which demographics have a higher rate of gastric cancer in New Zealand?
A
Maori and Pacific Islanders > European
This highlights disparities in cancer rates among different ethnic groups.
7
Q
What is the male to female ratio for gastric cancer incidence?
A
M>F 2:1
This ratio indicates a higher prevalence in males.
8
Q
What type of gastric cancers are traditionally more common?
A
Distal cancers
However, there is an increasing rate of cardia and gastroesophageal junction cancers.
9
Q
At what age is gastric cancer uncommon?
A
Before age 50
The peak incidence occurs in the 70s.
10
Q
What role does H. pylori play in gastric cancer?
A
Central role in the development of gastric cancer
It is associated with a long latent period from infection to cancer formation.
11
Q
What is the duration of the latency period for H. pylori infection to cancer development?
A
40-50 years
This extended timeline indicates the complexity of cancer development.
12
Q
What is the precancerous cascade?
A
A series of steps from chronic active inflammation to malignancy
It includes loss of gastric glands and intestinal metaplasia.
13
Q
What characterizes nonatrophic gastritis?
A
Focal acute inflammation on a background of chronic inflammation
Commonly seen in H. pylori gastritis.
14
Q
Does nonatrophic gastritis inherently increase the risk of cancer?
A
No
Only a small number of patients with H. pylori progress down the cascade.
15
Q
What is atrophic gastritis?
A
Leads to loss of gland and increase in gastric pH
Associated with bacterial overgrowth and progressive inflammation.
16
Q
What is intestinal metaplasia?
A
Maladaptation where gastric mucosa is replaced with intestinal type mucosa
This can occur in the context of atrophic gastritis.
17
Q
What are the types of intestinal metaplasia?
A
Complete and incomplete
Complete expresses only intestinal mucin; incomplete expresses a mixture of gastric and intestinal mucin.
18
Q
What is the risk of progression to cancer for low-grade dysplasia?
A
Approx 23% develop into cancer
This indicates a significant risk factor.
19
Q
What is the risk of progression to cancer for high-grade dysplasia?
A
60-80% progress to cancer
This shows an even greater risk compared to low-grade dysplasia.
20
Q
What are the five steps of the precancerous cascade?
A
- Non atrophic gastritis
- Atrophic gastritis
- Intestinal metaplasia
- Dysplasia (aka intraepithelial neoplasms)
- Carcinoma
21
Q
What is non atrophic gastritis.
What infection is non atrophic gastritis associated with?
Where in the stomach is non atrophic gastritis most prominent?
Does it increase the risk of cancer?
A
Focal acute inflammation on backgroud of chronic inflammation
Commonly seen in H.pylori gastritis
Most prominate in antrum
No inherient increase risk of cancer.
Only a small number of pt with H.pylori progress down cascade
22
Q
What is is lost in atrophic gastritis?
What does this result in?
A
Leads to loss of gland
Increase in Gastric pH
Overgrowth bacteria and nitrate reduction
Progessive inflammation
23
Q
What is intestinal metaplasia (in the context of the precancerous cascade -> gastric cancer)
What are the 3 subtypes subtypes of intestinal metaplasia, and what characterises these?
A
Maladaptation where gastric mucosa replaced with intestinal type muscosa
Type 1: Complete - expresses only intestinal mucin
Type 2 & type 3: Incomplete - express mixture of gastric and intestinal Mucin
24
Q
What is dysplasia, in the context of the precancerous cascade -> gastric cancer
A
Direct precursor of gastric cancer
Grade
Low grade - approx 23% develop into Ca (HUGE)
High grade dysplasia - 60-80% progress to Ca (HUGER!)
Classification
Via …….
Some would consider this insitu cancer
25
What are the precursor lesions and associated conditions for gastric cancer?
Atrophic gastritis, pernicious anaemia, previous gastric surgery, neoplasmic changes, gastric polyps, gastric intestinal metaplasia and dysplasia, Menetrier’s disease
## Footnote
Menetrier’s disease is associated with excessive gastric folds, excess mucous, and low acid, and may be linked to H. pylori infection.
26
What is the risk of malignant transformation in gastric polyps larger than 2 cm?
5-10%
## Footnote
This risk underscores the importance of monitoring gastric polyps.
27
What are the risk factors for the intestinal type of gastric cancer?
Atrophic gastritis, pernicious anaemia, previous gastric surgery, gastric polyps, gastric intestinal metaplasia and dysplasia, Menetrier’s disease
## Footnote
Menetrier’s disease is characterized by excessive gastric folds.
28
What are the genetic risk factors for diffuse gastric cancer?
Hereditary diffuse gastric cancer syndrome, CDH1 gene mutation, Lynch syndrome, Li-Fraumeni syndrome, FAP, juvenile polyposis syndrome, Peutz-Jeghers syndrome, family history, blood group A
## Footnote
The CDH1 gene encodes E-cadherin, which is crucial in cell adhesion.
29
What are the environmental risk factors associated with gastric cancer?
H. pylori infection, smoking, obesity, socioeconomic factors, coalmining, pottery, dietary factors (high salt, smoked/burnt food, bacon, red meat), vitamin A, C, E deficiency
## Footnote
H. pylori infection is considered a very important risk factor.
30
What is the Lauren classification of gastric cancer?
Diffuse, intestinal, mixed
## Footnote
This classification was established in 1965.
31
Which population is primarily affected by diffuse gastric cancer?
Younger population, M=F
## Footnote
Diffuse gastric cancer is characterized by submucosal infiltrative growth resulting in linitis plastica.
32
What characterizes intestinal gastric cancer?
Affects older patients, high risk countries, more antrum, metastasis to liver
## Footnote
Intestinal type is more prevalent in older demographics.
33
What are the types of adenocarcinoma classified by the WHO?
Tubular, papillary, mucinous, poorly cohesive (including signet cell), mixed
## Footnote
These classifications do not necessarily aid in management or prognosis.
34
What is the macroscopic classification of gastric cancer?
Bormann Classification
## Footnote
This classification is used to describe the macroscopic appearance of gastric tumors.
35
True or False: There are no formal precancerous lesions associated with diffuse gastric cancer.
True
36
What is the Bormann classification?
Macroscopic classification of gastric cancer
1. Polypoid tumours
2. Fungating carcinomas
3. Ulcerated carcinomas
4. Infiltrating carcinomas
37
What percentage of gastric cancer cases in the USA present at T3/T4 stage?
65%
## Footnote
This indicates a late-stage presentation of most tumours.
38
What percentage of gastric cancer cases are accompanied by lymph node metastases?
85%
## Footnote
Lymph node metastases are common in gastric cancer.
39
What proportion of gastric cancer cases are irresectable at presentation?
>50%
## Footnote
This highlights the advanced stage at which many patients present.
40
How does early gastric cancer typically present?
Usually asymptomatic
## Footnote
Early gastric cancer is often detected through screening programs.
41
In which regions is early gastric cancer more commonly detected due to screening?
High risk regions such as Japan
## Footnote
Western societies currently do not indicate screening due to low risk.
42
What are common symptoms of advanced gastric cancer?
* Dyspepsia
* Weight loss
* Early satiety
* Vomiting
* Dysphagia
* Anorexia
* Bleeding
* Pain or abdominal mass
## Footnote
These symptoms often lead to diagnosis of advanced stages.
43
How does chronic bleeding often present in advanced gastric cancer?
Iron deficiency anaemia
44
What physical exam findings may indicate locally advanced gastric cancer?
* Abdominal mass
* Obstruction - gastric outlet
* Cachexia
45
What are potential signs of metastasis in advanced gastric cancer?
* Peritoneal metastasis
* Ascites/oedema
* Hepatomegaly
* Lymph node metastases (e.g., Virchow’s node)
## Footnote
Metastasis indicates a more advanced disease state.
46
True or False: Acute bleeding is a common symptom in advanced gastric cancer.
False
## Footnote
Acute bleeding (e.g., melena) occurs in only 20% of cases.
47
What is the prevalence of anaemia at presentation in gastric cancer patients?
40%
## Footnote
Anaemia is a common finding in patients presenting with gastric cancer.
48
Which tumour markers are elevated in gastric cancer?
CEA, CA 125, CA 19-9, CA 72-4
## Footnote
These markers have low sensitivity and specificity, limiting their routine use.
49
What is the most important modality for investigating gastric cancer?
Endoscopy
## Footnote
Endoscopy allows direct visualization and assessment, as well as biopsy of lesions.
50
What should be done with ulcers found in the stomach during endoscopy?
Biopsy
## Footnote
Approximately 5% of malignant ulcers may appear benign.
51
What challenge does diffuse gastric cancer present during endoscopy?
Difficult to discern mucosal abnormality
## Footnote
This is due to submucosal infiltration.
52
What is the accuracy of CT scans for assessing lymph node status in gastric cancer?
63-80%
## Footnote
CT is useful for detecting distant metastases and T3/T4 disease.
53
What does EUS assess in gastric cancer investigations?
Tumour depth, size, lymph node status
## Footnote
EUS is particularly good for distinguishing T1/T2 from T3/T4 tumours.
54
Is EUS routinely used as part of the pre-operative workup for gastric cancer?
No
## Footnote
EUS may be used to assess for possible lymph node involvement if needed.
55
What is the main indication for PET-CT in gastric cancer?
More sensitive than CT in detecting distant metastases
## Footnote
Investigation - workup
Routine investigations
Laboratory
Bloods – Hb 40% anaemia at presentation.
Tumour markers CEA, CA 125, CA 19-9 and CA 72-4 have all been shown to elevate in gastric cancer, however low rates of sensitivity and specificity preclude their routine use
Endoscopy
most important modality. Allows direct visualisation, assessment of location and biopsies
NB should biopsy any ulcers in stomach (approx 5% of malignant ulcers appear benign)
Maybe difficult to discern any mucosal abnormality, if cancer is diffuse with submucosal infiltration
CT – chest/abdo/pelvis
most useful for detection of distant metastases. Can identify T3/T4 disease, accuracy of 63-80% for lymph node status, can identify peritoneal nodules >5mm.
Selective investigations
EUS
Can assess tumour depth, size, and some assessment of lymph
56
What is the significance of a negative PET scan in gastric cancer?
Not necessarily helpful
## Footnote
Role not well established
57
What is the purpose of staging laparoscopy in gastric cancer?
Assess for invasion, ascites, small volume metastatic disease
## Footnote
It is performed in patients with invasive disease undergoing curative resection.
58
What percentage of patients have their treatment decision changed after staging laparoscopy?
20%
## Footnote
Of those found resectable, 8% may be irresectable at laparotomy.
59
What unexpected finding can occur in patients with T1 stage disease based on EUS results?
Peritoneal metastases despite negative CT scan
## Footnote
20-30% of such patients may have peritoneal metastases.
60
What does Tis represent in tumor staging?
Tis indicates very early tumors that are insitu, epithelial disease.
61
What does T1 indicate in tumor staging?
Mucosa & submucosa
## Footnote
T1 tumors are characterized by invasion into the mucosa and submucosa layers.
62
What does T2 signify in tumor staging?
Advancement into muscularis propria
## Footnote
T2 tumors have progressed beyond the submucosa into the muscular layer.
63
What does M1 include in metastatic disease?
Peritoneal cytology
## Footnote
M1 indicates metastasis, including peritoneal cytology, even without macroscopic evidence.
64
What is the overall prognosis for all patients with advanced disease?
19% 5 year survival
## Footnote
This reflects a high proportion of patients presenting with advanced disease.
65
What is the 5-year survival rate for patients undergoing surgery with curative intent?
40%
## Footnote
This survival rate applies to patients who have surgery aimed at cure.
66
What is the standard of care for management?
Multimodality approach
## Footnote
A combination of different treatment modalities is standard.
67
What are the treatment options available?
Endoscopic resection; surgery with neoadjuvant therapy
## Footnote
Treatment options vary based on tumor stage.
68
What layers does a T1a gastric cancer invade?
Lamina propria, muscularis mucosae
## Footnote
T1a indicates that the cancer is confined to the innermost layers of the stomach.
69
What criteria make patients suitable for endoscopic management of early gastric cancer?
Disease limited to mucosa or submucosa (T1a) and no nodal or distant metastases
70
List the additional criteria for endoscopic resection in early gastric cancer.
* Confined to mucosa (only T1a)
* Well differentiated
* <2cm in size
* Non-ulcerated
## Footnote
These criteria help determine the appropriateness of endoscopic resection.
71
What is the most common approach for endoscopic resection in Western countries?
Endoscopic mucosal resection (EMR)
## Footnote
EMR is frequently used due to its relative simplicity compared to other methods.
72
What is a significant limitation of EMR regarding specimen evaluation?
Specimen often comes out piecemeal, making completeness of excision impossible to determine
## Footnote
This limitation necessitates separate biopsies of the resection edge.
73
What is the en bloc excision rate for endoscopic submucosal dissection (ESD) compared to EMR?
94.9% for ESD vs 42% for EMR
## Footnote
En bloc excision is advantageous as it allows for better assessment of the cancer margins.
74
What is the risk of recurrence for ESD compared to EMR?
1.1% for ESD vs 2-35% for EMR
## Footnote
Lower recurrence rates make ESD a preferable option when feasible.
75
What are the perforation and bleeding rates for ESD compared to EMR?
* Perforation rate: 2-20% for ESD vs 1% for EMR
* Bleeding rate: 22% for ESD vs 10% for EMR
## Footnote
ESD carries higher risks of complications compared to EMR.
76
How is early gastric cancer described in the Paris classification?
Grades gastric cancer from polypoid to non-polypoid
## Footnote
This classification helps in categorizing the appearance and type of gastric lesions.
77
What does Grade 0-Ip indicate in the Paris classification?
Protruded, pedunculated polyp
## Footnote
This grade describes a specific morphology of the gastric lesion.
78
What does Grade 0-Is indicate in the Paris classification?
Protruded, sessile polyp
## Footnote
This grade refers to lesions that are elevated but not on a stalk.
79
What is described by Grade 0-IIa in the Paris classification?
Slightly elevated polyp
## Footnote
This grade indicates a subtle elevation of the gastric mucosa.
80
What does Grade 0-IIb indicate in the Paris classification?
Flat lesion
## Footnote
This indicates lesions that do not have significant elevation or depression.
81
What does Grade 0-IIc indicate in the Paris classification?
Slightly depressed lesion
## Footnote
This grade describes lesions that are slightly sunken compared to the surrounding mucosa.
82
What does Grade 0-III indicate in the Paris classification?
Excavated (ulcer)
## Footnote
This grade represents lesions that are ulcerated and have a deeper involvement.
83
What makes a tumor unresectable?
Level 3 LN involved or invading major vessel or organ
## Footnote
Level 3 lymph nodes indicate advanced disease.
84
What are the recommended proximal margins for gastric cancer surgery?
5cm proximal margins (up to 8cm for diffuse)
## Footnote
In practice, 3cm may suffice for tumors with distinct borders.
85
Is a 5cm margin required for tumors invading the esophagus?
Not required, but frozen section recommended
## Footnote
Frozen section can help assess tumor margins during surgery.
86
What are the types of resection for gastric tumors?
Total or subtotal gastrectomies
## Footnote
Avoid using 'distal' as it refers to benign disease.
87
Does routine total gastrectomy provide a survival benefit for distal tumors?
No survival benefit
## Footnote
Total gastrectomy has higher morbidity and mortality.
88
What additional structures are excised with the stomach during surgery?
Greater and lesser omentum
## Footnote
Accessory left hepatic artery should be preserved if large.
89
What is bursectomy?
Removal of lesser sac (omental bursa)
## Footnote
Traditionally for T4a tumors, but not recommended due to lack of survival benefit.
90
What is the purpose of splenectomy in gastric cancer surgery?
Theoretically useful for proximal tumors
## Footnote
Significantly increases morbidity and mortality without survival benefit.
91
What is the D1 lymphadenectomy?
Includes stations 1-6 (perigastric)
## Footnote
It is a standard lymph node dissection in gastric cancer surgery.
92
What does a D1+ lymphadenectomy include?
D1 plus nodes along the root of the left gastric
## Footnote
Most surgeons perform D1+ dissection.
93
What does a D2 lymphadenectomy encompass?
Includes stations 1-14 N3 nodes, periaortic nodes
94
How are the lesser and greater curvature stations numbered?
Lesser curvature as odd numbered stations, greater curvature as even numbered stations
95
What are the less invasive approaches for early gastric cancer investigated in Eastern countries?
Proximal gastrectomy or pylorus preserving gastrectomy with D1 lymphadenectomy
## Footnote
These approaches have shown comparable 5-year survival but conflicting long-term results.
96
What is the risk associated with total gastrectomy?
Higher operative morbidity and mortality and increased risk of long-term nutritional issues
## Footnote
Total gastrectomy should be approached with caution.
97
When should en bloc resections be considered?
Consider en bloc with other organs if clear resection margins are achievable
## Footnote
En bloc resection can be beneficial in specific cases.
98
What are the two common reconstructions employed for distal gastrectomy?
Roux-en-Y and Billroth II
99
What is a benefit of Roux-en-Y reconstruction?
No bile reflux, low leak rate, low risk of obstruction with gastric bed recurrence
100
What is a downside of Roux-en-Y reconstruction?
Loss of easy endoscopic access to duodenal papilla, potential for internal hernia
101
What is the standard reconstruction for total gastrectomy?
Roux-en-Y
102
What are early complications of gastrectomy?
* Anastomotic leak
* Duodenal stump leak
* Pancreatic fistula
* Haemorrhage
* Post splenectomy infection
103
What is a major issue with early anastomotic leaks?
Most patients require re-operation
104
What study should be performed in all patients with suspected anastomotic leak?
Gastrograffin study
105
What is the management for duodenal stump leaks?
* Controlled fistula with foley catheter
* Decompress with a tube fed into duodenum via jejunum
* Feeding jejeunostomy useful for nutrition
106
What is a common fluid finding in pancreatic fistula?
High amylase
107
What is the focus of management for pancreatic fistula?
Prevention of infection and abscess control
108
What is the treatment for early haemorrhage?
Re-operation
109
What is a life-threatening cause of secondary haemorrhage?
Leak or pancreatic fistula
110
What should be done pre-operatively if splenectomy is planned?
Vaccination
111
What is a late complication of gastrectomy related to eating habits?
Post prandial satiety
112
What is early dumping syndrome?
Occurs within 30 min of meal, rapid filling of proximal small intestine with hypertonic food
113
What symptoms are associated with early dumping syndrome?
* Palpitation
* Bloating
* Cramping
* Diarrhoea
* Nausea
114
What is late dumping syndrome characterized by?
Faintness, severe hunger, dizziness, cold sweating
115
What causes hypoglycaemia in late dumping syndrome?
Rapid inflow of carbohydrate to jejunum causes hyperinsulinaemia
116
What nutritional deficiency occurs due to total gastrectomy?
Patients require regular IM injections of B12
117
What is the effect of total gastrectomy on vitamin D absorption?
Reduced absorption of fat-soluble vitamins can lead to metabolic bone disorders
118
Why is iron absorption reduced after gastrectomy?
Reduced gastric acid and rapid transit
119
What type of treatment is indicated for patients with pyloric obstruction and poor prognosis?
Stent placement
120
What type of chemotherapy is associated with improved survival?
Numerous regimens but no clear winner; ECF and FLOT increasingly used
121
What is the role of monoclonal antibodies in treatment?
Confer benefit, e.g., Herceptin for HER2 positive tumours is funded in NZ
