🍔Gastro🍔 - Gastrointestinal Cancers Flashcards
What is cancer?
A disease caused by an uncontrolled division of abnormal cells in a part of the body
What is primary (in the context of cancer)?
Arising directly from the cells in an organ
What is secondary (in the context of cancer)?
Spread from another organ, directly or by other means (blood or lymph)
Metastasis
What are the types of cancers that arise from epithelial cells?
Squamous cells - squamous cell carcinoma (SCC)
Glandular epithelium - adenocarcinoma
What are the types of cancers that arise from neuroendocrine cells?
Enteroendocrine cells - neuroendocrine tumours (NETs)
Interstitial cells of Cajal - Gastrointestinal Stromal tumours (GISTs)
What are the types of cancers that arise from connective tissue?
Smooth muscle - leiomyoma/leiomyosarcoma
Adipose tissue - liposarcoma
Where can GI NETs arise in the GI tract?
Anywhere along the tract
What is the most common GI cancer (at least in the West)?
Colorectal cancer
Outline the risks and epidemiology of colorectal cancer
Third most common cancer death in men and women
Lifetime risk: 1 in 10 men, 1 in 14 women
Generally affect patients > 50 years
What are the 3 forms of colorectal cancer?
Sporadic - absence of Fmx, older, isolate lesion
Familial
Hereditary syndrome - Fmx, younger, Lynch syndrome etc…
What is the histopathology of colorectal cancer?
Adenocarcinoma
What is the pathogenesis of colorectal cancer?
What are the risk factors for colorectal cancer?
Pmx - colorectal cancer (remission), adenoma, UC, radiotherapy
Fmx - 1st degree relative < 55 yrs
Relatives with identified genetic predisposition
Diet/Environmental:
?carcinogenic foods - debated
Smoking
Obesity
Socioeconomic status
Where are CRCs usually located?
⅔ in descending colon and rectum
½ in sigmoid colon and rectum (i.e. within reach of flexible sigmoidoscopy)
What are the presentations of caecal and right sided CRCs?
Iron deficiency anaemia (most common)
Change of bowel habit (diarrhoea)
Distal ileum obstruction (late)
Palpable mass (late)
What are the presentations for Left sided & sigmoid carcinoma?
PR bleeding, mucus
Thin stool (late)
What are the presentations for rectal carcinoma?
PR bleeding, mucus
Tenesmus
Anal, perineal, sacral pain (late)
What is a common symptom for CRC among all locations?
Bowel obstruction
Late stage disease
What symptoms of local invasion can you get with CRCs, indicative of late stage disease?
Bladder symptoms
Female genital tract symptoms
What are the possible symptoms of metastasis can you get with CRC?
Liver (hepatic pain, jaundice)
Lung (cough)
Regional lymph nodes
Peritoneum - Sister Marie Joseph nodule
What are the signs of primary CRC?
Abdominal mass
DRE: most <12cm dentate and reached by examining finger
Rigid sigmoidoscopy
Abdominal tenderness and distension – large bowel obstruction
What are the classic signs of metastasis and complications for CRC?
Hepatomegaly (mets)
Monophonic wheeze
Bone pain
What are the investigations that can be done in a case of suspected CRC?
Faecal occult blood - FIT (Faecal Immunochemical Test) - detects minute amounts of blood in faeces
Blood tests - FBC: anaemia, haematinics - low ferritin
Tumour markers - CEA useful for monitoring, but not a diagnostic tool
What is the first line invasive investigation for CRC?
Colonoscopy
Can visualize lesions < 5mm
Small polyps can be removed - reduced cancer incidence
Usually performed under sedation
What imaging technique can be used as an investigation for CRC?
CT colonoscopy/colonography
Can visualize lesions > 5mm
No need for sedation
Less invasive, better tolerated
If lesions identified patient needs colonoscopy for diagnosis
What other imaging tests can be performed in a case of CRC (particularly late presenting)?
MRI pelvis – Rectal Cancer
Depth of invasion, mesorectal lymph node involvement
Help choose between preoperative chemoradiotherapy or straight to surgery
CT Chest/Abdo/Pelvis (CT CAP)
Staging prior to treatment
How is colon cancer primarily managed?
Surgery
Some cases can use a stent, radiotherapy or chemotherapy
What is the surgical treatment for an obstructing colon carcinoma of the right and transverse colon?
Resection and primary anastomosis
What is the surgical treatment for obstructing colon carcinoma of the left sided colon?
Hartmann’s procedure
Proximal end colostomy (LIF)
+/- Reversal in 6 months
Primary anastomosis
Palliative stent
What is primary anastomosis?
Surgical procedure that joins together body channels, such as the bowel or blood vessels
Outline a right hemicolectomy
Outline an extended right hemicolectomy
Outline the resection in a left sided cancer?
Outline the resection in rectal cancer?
What are the most significant types of liver cancer?
Hepatocellular carcinoma (HCC)
CRC - secondary to CRC, a metastasis
Gallbladder cancer
Cholangiocarcinoma (ChCA)
Outline HCC
70-90% have underlying cirrhosis
Aflatoxin
Poor prognosis - Median survival without Rx 4-6m, 5yr survival <5%
What is the treatment for HCC?
Systemic chemotherapy ineffective
Optimal Rx surgical excision with curative intent - 5yr survival >30%
5-15% suitable for surgery
Outline gallbladder cancer
Aetiology unknown
Median survival without Rx 5-8m
5yr survival <5%
What is the treatment for gallbladder cancer?
Optimal Rx surgical excision with curative intent - 5yr survival: stage II 64%; stage III 44%; stage IV 8%
<15% suitable for surgery
Outline cholangiocarcinoma
Aetiology - PSC (chronic inflammation of bile ducts) & UC, liver fluke (clonorchis sinesis), choledochal cyst
Median survival (depends on site) without Rx <6 m
5yr survival <5%
Systemic chemotherapy ineffective
GEMCIS - median overall survival 11.7 months*
What is the treatment for cholangiocarcinoma?
Optimal Rx surgical excision with curative intent - 5yr survival 20-40%
20-30% suitable for surgery
Outline Secondary liver metastases (CRC)
15-20% synchronous, 25% metachronous
median survival without Rx <1yr
5yr survival 0%
Systemic chemotherapy improving
What is the treatment for secondary liver metastases from CRC?
Optimal Rx surgical excision with curative intent - 5yr survival rates of 25-50%
25% suitable for surgery
Outline pancreatic cancer
Relatively common & highly lethal
Commonest form of panc CA is pancreatic ductal adenocarcinoma (PDA)
80-85% have late presentation (median survival <6 months)
15-20% have resectable disease
(Median survival 11-20 months
5-year survival 20–25%
Virtually all pts dead within 7 years of surgery)
Incidence & mortality roughly equivalent
What are the risk factors for pancreatic cancer?
Chronic pancreatitis → 18-fold ↑er risk
Type II diabetes mellitus → 1.8x
Occupation (insecticides, aluminium, nickel & acrylamide)
Cigarette smoking → causes 25-30% PDAs
7-10% have a family history (1st degree relatives)
How doe pancreatic cancers arise?
Pancreatic Intraepithelial Neoplasias (PanIN)
PDAs evolve through non-invasive neoplastic precursor lesions
What is the clinical presentation of carcinoma of the head of the pancreas?
Jaundice >90% due to either invasion or compression of CBD - often painless
Weight loss
Pain 70% at the time of diagnosis - radiates to back in 25%, indicating posterior capsule invasion and irresectability
5% atypical attack of acute pancreatitis
GI bleeding
At least two-thirds of PDAs arise in the head
What is the clinical presentation of carcinoma of the body and tail of the pancreas?
Develop insidiously and are asymptomatic in early stages
Often more advanced at diagnosis
Marked weight loss with back pain in 60% of patients
Jaundice uncommon
Most unresectable at time of diagnosis
What are the investigations for pancreatic cancer?
Tumour marker CA19-9
Ultrasonography
Dual-phase CT - accurately predicts resectability in 80–90% of cases
MRI
MRCP
ERCP
Outline tumour marker CA19-9 as a marker for pancreatic cancer
Falsely elevated in pancreatitis, hepatic dysfunction & obstructive jaundice
Concentrations > 200 U/ml confer 90% sensitivity
Concentrations in the thousands associated with high specificity
What investigations can be used to detect occult metastases of pancreatic cancer?
Laparoscopy & laparoscopic ultrasound- detect radiologically occult metastatic lesions of liver & peritoneal cavity
PET mainly used for demonstrating occult metastases
What are NETs?
Neuroendocrine tumours
Arise from the gastroenteropancreatic (GEP) tract
Sporadic tumours in 75%
Associated with a genetic syndrome in 25 such as MEN1
What is MEN1?
Multiple Endocrine NeoplasiaType 1
Parathyroidtumours
Pancreatic tumours
Pituitarytumours
NETs
How do NETs present?
Most NETs are asymptomatic & incidental findings
Secretion of hormones & their metabolites in 40%
Can result in a variety of debilitating effects:
Carcinoid syndrome: vasodilation, bronchoconstriction, increased intestinal motility, endocardial fibrosis
Outline the pancreatic NETs
Outline the duodenal NETs
Gastrinoma - Zollinger-Ellison syndrome - G cells
Outline NETs of the gastrointestinal tract more broadly
VIP - vasoactive intestinal peptide
How are NETs diagnosed?
Biochemical assessment
Imaging
What biochemical assessments can confirm the presence of NETs?
Chromogranin A is a secretory product of NETs
Other gut hormones measure in fasting state
Other screening - calcium, PTH, prolacting, GH etc…
24 hr urinary 5-HIAA (serotonin metabolite)
What imaging methods can be used to confirm the presence of NETs?
Cross-sectional imaging (CT and/or MRI)
Bowel imaging (endoscopy, barium follow through, capsule endoscopy)
Endoscopic ultrasound
Somatostatin receptor scintigraphy
What is the treatment for NETs?
Curative resection
