Gastrointestinal Cancers Flashcards
1
Q
Define cancer
A
A disease caused by an uncontrolled division of abnormal cells in a part of the body
2
Q
Define primary cancer
A
Cancer arising directly from the cells in an organ
3
Q
Define secondary cancer/metastasis
A
Cancer spread to another organ, directly or by other means (blood or lymph)
4
Q
List the 3 main types of cells/tissues highly susceptible to cancer in the GI tract
A
Epithelial cells (e.g. squamous and glandular epithelial cells)
Neuroendocrine cells (e.g. enteroendocrine cells + Interstitial cells of Cajal)
Connective tissue (e.g. adipose tissue + smooth muscle)
5
Q
List 4 cells of the GI tract susceptible to becoming cancerous
A
Squamous cells
Glandular epithelial cells
Enteroendocrine cells
Interstitial cells of Cajal
Smooth muscle
Adipose tissue
6
Q
Which cancer of the GI tract is derived from squamous epithelial cells?
A
Squamous cell carcinoma (SCC)
7
Q
Which cancer of the GI tract is derived from glandular epithelium?
A
Adenocarcinomas
8
Q
Which cancer of the GI tract is derived from enteroendocrine cells?
A
Neuroendocrine tumors (NETs)
9
Q
Which cancer of the GI tract is derived from interstitial cells of Cajal?
A
Gastrointestinal stromal tumors (GISTs)
10
Q
Which cancer of the GI tract is derived from smooth muscle?
A
Leiomyoma/Leiomyosarcoma
11
Q
Which cancer of the GI tract is derived from adipsoe tissue?
A
Liposarcoma
12
Q
Where are GI neuroendocrine tumors located?
A
Can be located anywhere along the GI tract from the oesophagus to the rectum
13
Q
Squamous cell carcinomas tend to develop in which portion of the oesophagus? Explain why
A
Upper 2/3rds of the oesophagus
The type of epithelium lining the oesophagus above the Z-line is stratified squamous epithelium
14
Q
What is a common cause of squamous cell carcinoma oesophageal cancers?
A
Acetaldehyde pathway
[ACETALDEHYDE PATHWAY -EtOH – alcohol dehydrogenase (ADH) – oxidized acetaldehyde – aldehyde dehydrogenase (ALDH) – oxidized - acetate]
15
Q
Squamous cell carcinoma is a more common oesophageal cancer in which type of countries?
A
Countries in the less developed world
16
Q
Adenomacarcinomas are derived from which type of cells?
A
From metaplastic columnar epithelium
17
Q
Adenocarcinoma oesophageal cancers occur mainly in which part of the oesophagus and why?
A
Occur in distal third of the oesophagus
Below the Z-line, the epithelium is simple columnar and these cells can develop into adenocarcinomas
18
Q
Oesophageal adenocarcinomas are related to which condition?
A
Related to acid reflux
19
Q
Oesophageal adenocarcinomas is more common than squamous cell carcinomas in which types of countries?
A
Countries of the more developed world
20
Q
Briefly describe the transition of reflux into oesophageal cancer
A
Reflux leads to oesophagitis due to inflammation
Chronic inflammation can lead to metaplasia, resulting in presence of Barret’s Oesophagus
There is a chance overtime that metastatic epithelial cells present in Barret’s oesophagus patients can display neoplastic changes, resulting in formation of adenocarcinoma
N.B. Inflammation —> Metaplasia —> Neoplasia
21
Q
What percentage of the UK population experiencing oesophagitis is caused due to GORD?
A
30% of UK population experiencing oesophagitis
22
Q
What percentage of GORD population will end up developing Barret’s Oesophagus?
A
5% of GORD population
23
Q
What is the likelihood of someone with Barret’s oesophagus developing adenocarcinoma?
A
Barrett’s lifetime risk of cancer - 0.5-1%/ year.
24
Q
In comparison to the general population what is the fold risk of developing cancer in patient’s with Barret’s oesophagus?
A
30-100 fold risk of cancer
25
State the Barret's Surveillance Guidelines
BSGs refers to occasional endoscopic surveillance in barret's oesophagus patients frequency changes depending on histological findings
No dysplasia: Every 2-3 years
Low grade dysplasia: Every 6 months
High grade dysplasia: Intervention required
26
For both squamous cell carcinoma and adenocarcinomas, which age group is most likely to be affected?
Affects mainly the elderly
27
How does squamous cell carcinoma rates differ between males and females?
Effects males more than females 10:1
28
How common is squamous cell carcinomas in comparison to other cancers?
9th most common cancer
29
What are two common late presentations of oesophageal cancers?
Dysphagia
Weight loss
30
What percentage of patients diagnosed with oesophageal cancers end up being placed in palliative care?
65%
31
What is the general morbidity and prognosis of oesophageal cancers?
Poor progonosis
Poor 5 year survival \<20% (regardless of age its bad)
High morbidity and complex surgery
Providing adequate palliative care is difficult
32
How are oesophageal cancers diagnosed?
Diagnosed by biopsy taken from endoscopy
33
List 4 examples of imaging techniques used in the staging of oesophageal cancers
CT scan
Laproscopy (Keyhole surgery)
Endoscopic ultrasound (?)
PET scan (?)
34
Depending on the prognosis of osophageal cancer, what are the two types of treatment plan options?
Curative
Palliative
35
What is the curative treatment plan for oesophageal cancer?
Neo adjuvant chemotherapy followed by radical surgery
36
What is the palliative treatment plan for oesophageal cancers?
Chemotherapy
Radiotherapy
Stent to keep oesophagus patent
37
Briefly describe the Ivor Lewis approach to oesophagectomy.
Involves removal of tumar through abdominal incision and thoracotomy in which the upper portion of the stomach is removed and region of the oesophagus in which the tumor is located.
38
What is the most common GI tract cancer in western societies?
Colorectal cancer
39
Colorectal cancer is reponsible for how many portions of cancer deaths?
3rd most common cause of cancer deaths
40
Colorectal cancer is more common in which gender and age groups?
Common in men (1 in 10 vs 1 in 14)
Common above age of 50 (pver 90% of cases)
41
What are the 3 main forms of colorectal cancer?
Sporadic
Familial
Hereditary syndrome
42
State the histopathology of colorectal cancers
Adenocarcinoma
43
What are the 3 main signs that a colorectal cancer formed sporadically?
No family history
Developed at older age (\>50)
A single lesion
44
What are the 3 main signs that a colorectal cancer is in familial form?
Family history of colorectal cancer
Cancer occured in a close relative (1st degree relative)
Cancer developed at younger ages (\<50)
45
What are the 3 main signs that a colorectal cancer formed due to a hereditary syndrome?
Family history of cancer
Cancer developed at a young age
Evidence of specific gene defects
46
Give 2 examples of hereditary syndromes which can result in the development of colorectal cancer.
.Familial adenomatous polyposis (FAP)
Hereditary nonpolyposis colorectal cancer (HNPCC or Lynch syndrome)
47
Hereditary nonpolypososis colorectal cancer (HNPCC) is alternatively known as?
Lynch syndrome
48
Describe the formation of a colon carcinoma
Begins due to APC mutation of normal epithelium which results in hyperproliferation.
Hyperproliferation leads to overexpression of COX2 leading to small adenoma formation
K-ras mutation in the small adenoma results in a large adenoma formation
p53 mutation followed by loss of 18q results in a colon carcinoma
49
Name 5 medications/substances that can have protective effects against devolpment of colorectal carcinoma
Aspirin
NSAIDs
Folate
Calcium
Estorgen (perhaps why males more likely)
50
What 4 past medical history risk factors should be checked for when taking a history of a patient suspected of having colorectal cancer?
Hx of colorectal cancer
Hx of any adenocarcinomas
Hx of Ulcerative colitis
Hx of radiotherapy
51
What 2 family history risk factors should be checked for when taking a history of a patient suspected of having colorectal cancer?
1st degree relative (under 55) with history of colorectal cancer
Any identified hereditary syndromes such as FAP, HNPCC, Peutz-Jegher's syndrome)
52
What 4 dietary/lifestyle risk factors should be checked for when taking a history of a patient suspected of having colorectal cancer?
Carcinogenic foods
Smoking
Obesity
Socioeconomic status
53
The clinical presentation of colon cancer depends on the location. 2/3rds of colon cancers are lcoated in which location?
Descending colon to the rectum
54
The clinical presentation of colon cancer depends on the location. 1/2th of colon cancers are located in which location?
Sigmoid colon and rectum
55
1/2th of colon cancers are located in the sigmoid colon and rectum, what is the significance of this in terms of being diagnosed?
Majority can be identified on a flexible sigmoidoscopy
56
For more uncommon ceaceal and right-sided colon cancers, list 4 clinical presentations.
Iron-deficiency anaemia (most common)
Change in bowel habits (e.g. diarrhoea)
Distal ileum obstruction (late presentation)
Palpable mass (late presentation)
57
What is the most common sign of right-sided/caecal colon cancer?
Iron-deficiency anaemia
58
Give 2 examples of late presenting signs/symptoms of right-sided colon cancer.
Palpable mass
Distal ileum obstruction
59
Give 2 examples of signs/symptoms of left-sided/sigmoid colon cancers.
Thin stool (late presentation)
Rectal bleed with mucus
60
Give 2 examples of signs/symptoms of rectal colon cancers.
PR bleeding and mucus
Tenesmus
Anal, sacral, perineal pain (late presentation)
61
What is a common late presentation of all colon cancers?
Bowel obstruction
62
Give 2 examples of late presenting symptoms of colon cancer related to local invasion
Bladder symptoms
Femal genital tract symptoms
63
List 4 examples of common areas of metasteses of colon cancer and resulting clinical presentations.
Liver (Hepatic pain and jaundice)
Lungs (Cough)
Regional lymph nodes
Peritoneum (Sister Mary Joesph Nodule)
64
Metatstaic umbilical nodules indicative of abdominopelvic malignancies is known as?
Sister Mary Joesph Nodule
65
List 4 common signs of primary colorectal cancer
Abdominal mass
Feeling of mass in digital rectal examination (DRE)
Rigid sigmoidoscopy
Abdominal tenderness and distention (indicative of large bowel obstruction)
66
List 3 common signs of metastatic colorectal cancer
Hepatomegaly
Monphonic wheeze
Bone pain
67
List 6 examples of investigations that can be performed if a patient is under suspicion of having colon cancer
Faecal occult blood test (FOB)
Blood tests
Colonoscopy
CT colonscopy/colonography
CT chest/abdomen/pelvis
MRI pelvis
68
Give two examples of faecal occult blood test and explain what they detect.
Which one is more commonly used?
Guaiac test (aka Haemoccult test): looks at pseudoperoxidase activity of haematin
Feacal immunochemical test (FIT): Detects minute amounts of blood in the faeces
FIT more commonly used nowadays
69
Give two examples of disadvantages of guaiac test (Hemoccult).
Has high specificity but is not very sensitive (40-80%)
Requires dietary restriction (e.g. red meat, melons, horse-radish, vitamin C) and certain medication such as NSAIDs
70
Give two examples of useful blood tests which could be indicative of colon cancer but should **not** be used as a diagnostic tool
FBC: Can detect anemia, and low ferritin
Tumor marker tests such as detection of carcinoembryonic antigen test (CEA)
71
What is a common use of a CAE blood test.
Can be used to monitor the spread of bowel cancers and can indicate whether chemotehrapy is effective
72
Name the antigen most commonly associated with colon cancers
Carcinoembryonic antigen (CAE)
73
Give 2 reasons why colonoscopy is an effective type of investigation into colon cancers.
Can identify lesions \<5mm in size
Can involve identification and removal of small polyps which can reduce incidence of cancer
74
Does colonoscopy require sedation?
Often requires sedation
75
Compare CT colonoscopy to colonoscopy (2)
Can only identify lesions larger than 5mm whereas colonoscopy can identify smaller lesions
Is less invasive versus colonscopy and does not involve sedation
76
If a lesion is idenitfied in a CT colonoscopy, what must be performed after?
Colonoscopy for diagnosis (need a biopsy)
77
What would be the purpose/benefit of ordering an pelvis MRI for a patient diagnosed with rectal cancer?
Can help to identify depth of invasion and if there is mesorectal lymph node involvement
Can aid in decision to strat pre-operative chemotherapy or straight to surgery
78
What is the purpose of pre-operative chemotehrapy?
Can help to reduce the margins if there is uncertainty, making it easier to completely remove the cancer in surgery with clearer margins
79
What is the purpose of a CT chest/abdo/plevis in management of colorectal cancer?
Determines the staging of the cancer before treatment
80
What is the primary management of colon cancer?
Surgery
81
Besides surgery, what are 3 alternative management plans for patients with colorectal cancer?
Chemotehrapy
Radiotherapy
Stent
82
What type of surgery is required for a obstructing colon carcinoma located in the right-sided or transverse section of the colon?
Resection and primary anastamosis (rejoining the proximal instestine with distal after portion is removed)
83
What 3 types of surgery may be required for a obstructing colon carcinoma located in the left-sided section of the colon?
Hartmann's procedure (Proximal end colostomy)
Primary anastamosis
Palliative stent
84
What is Hartmann's procedure
Is the procedure reversible or irreversible?
Type of surgical procedure characterised by resection with a proximal-endcolostomy
The procedure can be reversible after -/+ 6 months
85
What is involved in primary anastamosis of the left-sided bowel?
What is the disadvantage of this procedure vs hartmanns?
Intraoperative bowel lavage with primary anastomosis with defunctioning ileostomy (would be on right side versus left liek hartmanns)
There is a 10% risk of leak so hartmanns is a bit safer
86
Memorise the main blood supply of the colon
87
The type of colon resection is dependant mainly on?
The blood supply of the colon
88
Removal of the caecum and ascending colon is known as?
A right hemicolectomy
89
In a right hemicolectomy, what type of anastamosis is performed?
Ileocolic anastamosis
90
When would an **extended** right hemicolectomy be performed and what does it involve and why?
Would be needed if the tumor is located within most ascending portion fo the right colon/transvere portion.
Procedure involves removal of caecum, right colon and a portion of the transverse colon
Removing any less would disrupt the blood supply
91
What does a left hemicolectomy involved?
Removal of the descending colon with anastomosis with the sigmoid colon
92
What is the most common form of pancreatic cancer?
Pancreatic ductal adenocarcinoma
93
What is the overall prognosis of rectal cancer?
What percentage of patietns would present late and what is the median survival rate of these patients?
Very poor
80-85% present late
Median survival rate \<6 months and 5 year survival 0.4-5%
94
15-20% of pancreatic cancer patients have resectable disease, what is the survival rate in comparison to late presenting
Median survival 11-20 months
5-year survival 20–25%
Virtually all pts dead within 7 years of surgery
95
Pancreatic cancer is most common in which regions of the world, between which of the genders and of what age ranges?
Most common in western world
Affects men more than woman
Affetcts mainly 60-80 year olds (under 45 is rare)
96
Pancreatic cancer is the _ most common cause of cancer deaths?
Pancreatic cancer is the _ most common cause of cancer deaths **in the US**?
4th most common
2nd most common
97
How does the incidence and mortality rate compare in pancreatic cancer patients?
Incidence and mortality very similar e.g.
- 9,921 new cases of PDA
- 9263 deaths from PDA
98
List 9 risk factors associated with pancreatic cancer
Chronic pancreatitis
Type II diabetes (1.8 fold risk)
Smoking
Family history
Diet (weak evidence)
Occupation
Cholelithiasis, previous gastric surgery & pernicious anaemia (weak evidence)
99
What 4 risk factors have the biggest risk of developing pancreatic cancer?
Chronic pancreatitis (18 fold increase)
Smoking (cause of 25-30%) of cases of pancreatic ductal adenocarcinomas
Family history: 2, 6 & 30-fold with: 1, 2 & 3 affected first degree relatives respectively
T2D (1.8 fold risk)
100
What percentage of PDA patients have a family history of the condition?
7-10%
101
List 5 hereditary conditions which can cause pancreatic ductal adenocarcinoma alongside their lifetime risk
Hereditary pancreatitis (40%)
Familial atypical multiple mole melanoma (10-17%)
Familial breast- ovarian cancer syndrome (5-3.6%)
Peutz-Jeghers syndrome (11-36%)
HNPCC (Lynch syndrome) 3.7%
FAP 4.5%
102
Describe the pathogenesis of pancreatic ductal adenocarcinomas
Most common pathological pathway involves Pancreatic Intraepithelial Neoplasias (PanIN)
PDAs evolve through non-invasive neoplastic precursor lesions
PanINs are microscopic (\<5 mm diameter) & not visible by pancreatic imaging (hence difficult to diagnose early)
Acquire clonally selected genetic & epigenetic alterations along the way
103
At least 2/3rds of PDA arise in which region of the body?
The head
104
List 6 symptoms of PDA and explain why they present
Jaundice (with palpable gallbladder) [due to invasion or compression of common bile duct)
Weight loss (due to anorexia, malabsorption secondary to exocrine insufficiency and development of diabetes)
Pain in epigastrum which can radiate to the back (back pain indicative of posterior capsule invasion)
Atypical atatck of acute pancreatitis
Gastrointestinal bleeding (duodenal invasion or varices secondary to portal or splenic vein occlusion)
Persistent vomitting (if there is severe duodenal obstruction)
105
Describe the typical presentation of PDA pain
Pain is located in epogastrum region and in 25% of cases this pain radiates to the back
This is a very common presentation at diagnosis
106
How does cancer affecting the body and tail of the pancreas compare to that affecting the head in terms of symptoms and presentation?
Develop insidiously and are asymptomatic in early stages
There is marked weight loss with back pain in 60% of patients.
Jaundice is uncommon
Vomiting sometimes occurs at a late stage from invasion of the DJ flexure
Most unresectable at the time of diagnosis
107
What symptoms of PDA suggests that the cancer is mainly in the head versus the body/tail?
Jaundice due to common bile duct obstruction (in \>90% of cases)
108
What is the tumor marker for pancreatic cancer and why should this not be used in diagnosis?
What ranges would increase the likelihood of it being a result of pancratic cancer?
CA19-9
Can be falsely elavated in pancreatits, hepatic dysfunction and obstructive jaundice
Concentrations \> 200 U/ml confer 90% sensitivity
Concentrations in the thousands associated with high specificity
109
List 3 useful investigations in the diagnosis of pancreatic cancer
Tumor marker CA19-9
Ultrasonography
Dual-phase CT
110
Give 3 reasons why ultrasonography is useful in diagnosis of pancreatic cancer
Can identify:
Pancreatic tumours
Dilated bile duct
Liver metastases
111
Explain why dual-phase CT in pancreatic cancer patients is useful
Accurately predicts resectability in 80–90% of cases by looking for:
Contiguous organ invasion
Vascular invasion (coeliac axis & SMA)
Distant metastases
112
Why is a CT scan prefered over MRI when investigating for pancreatic cancer?
•MRI imaging detects and predicts resectability with accuracies similar to CT (MRI are expensive, noisy, take a while ect so may as well use CT of both have simialr accuracy)
113
