Gastrointestinal cancers Flashcards
What is the anatomy of the stomach?
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What is gastric cancer? Types?
Gastric malignancy, most commonly adenocarcinoma, more rarely lymphoma or leiomyosarcoma (smooth muscle tissue).
What are the risk factors of gastric cancer? (x9)
Helicobacter pylori infection, atrophic gastritis (chronic inflammation of gastric mucosa), diet high in smoked, processed foods and nitrosamines (e.g. meat preservatives), smoking, obesity, Epstein-Barr virus, alcohol, pernicious anaemia, blood group A.
What is the epidemiology of gastric cancer: Where? UK incidence? Gender? Age?
Highest incidence in Asia, especially in Japan and China, 6th most common cancer in the UK (23 in 100 000 annual incidence), 2:1 male:female, age over 50 years.
What are the trends in location of gastric cancer in stomach anatomy? Possible explanation?
Cancer of antrum and body is becoming less common, while that of the cardia and gastro-oesophageal junction is increasing. Possible explanation: we have been very good in recent decades at treating and preventing H. pylori which typically causes non-cardia gastric cancer. Meanwhile, some have suggested that H. pylori is protective against cardia-related gastric cancers as it reduces proximal acid production; therefore, fall in H. pylori has promoted a rise in cardia cancers. In addition, smoking has been implicated in the rise of cardia cancers.
What are the symptoms of gastric cancer? (x9 – x3 sensation, x2 food, x3 blood, x1 swallowing)
o Initially asymptomatic and very non-specific
o Early satiety
o Epigastric discomfort
o Dyspepsia in patients over 55
o Weight loss and anorexia
o N&V
o Haematemesis
o Melaena (dark/black faeces)
o Symptoms of anaemia
o Dysphagia (when there are tumours of the cardia)
What are symptoms of metastatic gastric cancer? (x2)
Abdominal swelling (ascites) or jaundice (liver involvement)
What are the signs of gastric cancer? (x7)
o Physical examination may be normal. Note that if you observe these signs, it is likely that the disease is incurable.
o Epigastric mass
o Hepatomegaly
o Abdominal tenderness
o Signs of anaemia
o Virchow’s node/Troisier’s sign: lymphadenopathy in left supraclavicular fossa
o Sister Mary Joseph node: metastatic nodule on umbilicus
o Krukenberg’s tumour: ovarian metastases
What investigations are there for gastric cancer? (x8)
o UPPER GI ENDOSCOPY: with multi-quadrant biopsy of all gastric ulcers
o BLOODS: FBC for anaemia, LFT to assess liver compromise
o CT/MRI: staging of tumour and planning of surgery
o ULTRASOUND OF LIVER: staging of tumour
o BONE SCAN: staging of tumour
o ENDOSCOPIC ULTRASOUND: assess depth of invasion and lymph node spread
o LAPAROSCOPY: may be needed to determine if tumour is resectable.
o CYTOLOGY of PERITONEAL WASHINGS can help identify peritoneal metastases.
What is colorectal carcinoma?
Malignant adenocarcinoma of the large bowel
What is the aetiology of colorectal carcinoma?
Environmental and genetic factors have been implicated. A sequence of epithelial dysplasia leading to adenoma then carcinoma is thought to occur, involving accumulation of genetic changes in oncogenes (APC, K-ras) and tumour suppressor genes (p53 and DCC).
What is the distribution of colorectal carcinoma in the colon?
60% in the rectum and sigmoid colon, 15-20% in the ascending colon, remainder in the transverse and descending colon.
What are the risk factors of colorectal carcinoma? (x6)
Diet, obesity, smoking, diet (low fibre, red and processed meats), IBD, inherited conditions (familial adenomatous polyposis, hereditary nonpolyposis colorectal cancer (HNPCC)).
What is the epidemiology of colorectal carcinoma: Common? Deaths? Age? Gender?
Second most common cause of cancer death in the West. 20 000 deaths per year. Average age of diagnosis – 60-65 years. Equal gender distribution.
What is the ethnic and gender distribution of colorectal carcinoma anatomy?
Black women have more proximal neoplasms; white men have more distal neoplasms.
What are the specific symptoms of colorectal carcinoma: left-sided colon and rectum? (x3)
o Change in bowel habit
o Rectal bleeding or blood/mucous mixed with stool
o Rectal masses present as tenesmus (sensation of incomplete emptying after defecation)
What are the specific symptoms of colorectal carcinoma: right-sided colon? (x4)
Later presentation with symptoms of anaemia, weight loss, non-specific malaise, and rarely lower abdominal pain.
How may patients present with complications of colorectal carcinoma? (x3)
Pain and distension caused by large bowel obstruction, haemorrhage, or peritonitis as a result of perforation.
What are the signs of colorectal carcinoma? (x3)
o Anaemia may be the only sign, particularly in right-sided lesions
o Abdominal mass
o Low-lying rectal tumours may be palpable on rectal examination
What are the signs of metastatic colorectal disease? (x2)
HEPATOMEGALY, ‘shifting dullness’ of ASCITES.
What are the investigations for colorectal carcinoma? (x8)
o BLOODS: FBC for anaemia, LFT for liver compromise, tumour markers (CEA (carcino embryonic antigen) to monitor treatment response or disease recurrence).
o STOOL: occult (not visibly apparent) or frank blood in stool (can be used as a screening test)
o ENDOSCOPY: sigmoidoscopy, colonoscopy. Allows visualisation and biopsy. Polypectomy can also be performed if isolated small carcinoma in situ.
o BARIUM CONTRAST STUDIES: look for ‘apple core’ stricture on barium enema.
o ABDOMINAL USS: for hepatic metastases
o CXR: for staging
o CT/MRI: for staging
o ENDORECTAL ULTRASOUND: for staging
What does an apple core stricture look like on barium enema?
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What is the anatomy of the large intestine wall?
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What is Dukes’ staging for colorectal cancer?
Dukes’ stage A: limited to muscularis mucosae; B: breached muscularis mucosae, negative lymph nodes; C: breached serosa, positive lymph nodes; D: distant metastases.
What is the TNM staging of colorectal cancer?
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What is a colonic polyp?
A protuberance into the lumen from the normally flat colonic mucosa.
What are the two types of colonic polyp?
Neoplastic and non-neoplastic.
What are neoplastic colonic polyps? (x2)
Include adenomas and adenocarcinomas.
What are non-neoplastic polyps? (x3)
Include hyperplastic polyps, inflammatory pseudopolyps (islands of intact colonic mucosa resulting from mucosal ulceration and regeneration that occurs in IBD), and hamartomatous polyps (polyps which arise from a systemic genetic condition rather than from a single mutated cell)
What is an example of a disease that gives rise to hamaromatous polyps?
Peutz-Jeghers syndrome – autosomal dominant disorder presenting with polyps and mucocutaneous pigmentation of lips and gums
What conditions give rise to multiple colonic polyps? (x3)
Autosomal dominant conditions caused by mutations in the adenomatous polyposis coli (APC) gene. These give rise to: Familial adenomatous polyposis (FAP), and variants of FAP including Turcot’s syndrome (FAP associated with glioblastomas or medulloblastomas), and Gardner’s syndrome (FAP associated with osteomas, soft-tissue tumours and sebaceous cysts).
What is the epidemiology of colonic polyps: Prevalence?
Over 50% of those over 60 years old.
What is an oesophageal carcinoma?
Malignant tumour arising in the oesophageal mucosa.
What are the two main histological types of oesophageal carcinoma?
Squamous cell carcinoma (arising from squamous cell epithelium of the oesophagus) and adenocarcinoma (arising from glandular cells).
What is the cellular anatomy of the oesophageal lining?
Lined by squamous cell epithelium and mucus-secreting cells (adeno-).
!!! What is the aetiology of squamous cell carcinoma? (x13)
o Alcohol
o Tobacco
o Hot tea
o Certain nutritional deficiencies (vitamins, trace elements)
o HPV infection
o ACHALASIA
o Paterson-Kelly (Plummer-Vinson) syndrome (disease characterised by dysphagia, glossitis and iron-deficiency anaemia)
o Tylosis (Howel-Evans syndrome) (genetic condition of hyperkeratosis, associated with high lifetime risk of oesophageal cancer)
o Scleroderma (autoimmune connective tissue disorder)
o Coeliac disease
o Lye stricture
o History of previous thoracic radiotherapy or upper aerodigestive squamous cancer
o Dietary nitrosamines
!!! What is the aetiology of adenocarcinoma? (x2)
GORD and Barrett’s oesophagus (intestinal metaplasia of the distal oesophageal mucosa from squamous cell to columnar)
What is the anatomical stie of each type of oesophageal carcinoma?
Squamous cell is more common in the mid-upper oesophagus; adenocarcinoma more common in lower oesophagus or, increasingly, the gastro-oesophageal junction.
What is the typical spread of oesophageal carcinoma?
Spread is initially direct, and longitudinal via an extensive network of submucosal lymphatics to tracheobronchial, mediastinal, coeliac, gastric and cervical nodes.
What are other rare types of oesophageal tumour?
Lymphoma, melanoma, leiomyosarcoma.
What is the epidemiology of oesophageal carcinoma: Incidence? Gender? Epidemiology of each type? Geography? Age? Trend?
Eight most common malignancy in the UK, 3-4:1 male:female, most common type WORLDWIDE is squamous cell carcinoma (95%), adenocarcinoma is more common in WESTERN countries (65% of cases in the UK), high incidence in northern China, Iran and Southern Russia, 60-70 years old. Adenocarcinoma is rising.
What are the symptoms of oesophageal carcinoma? (x1 and x9)
o EARLY: reflux
o LATER: dysphagia, initially worse for solids. Regurgitation, vomiting blood, cough or choking after food, pain (odynophagia), retrosternal pain, weight loss, fatigue, voice hoarseness (may indicate recurrent laryngeal nerve palsy)
What does paroxysmal mean?
Sudden occurrence or exacerbation.
When may cough in oesophageal carcinoma be paroxysmal?
In aspiration pneumonia from a tumour found proximally.
What oesophageal symptoms are more relevant to proximal tumours? (x2)
Cough/choking after food intake and hoarseness.
What are the signs of oesophageal carcinoma? (x2 and x2)
No physical signs may be evident other than weight loss and respiratory signs related to aspiration or direct tracheobronchial (metastatic) involvement. With metastatic disease, there may be supraclavicular lymphadenopathy, hepatomegaly.
What are the investigations for oesophageal carcinoma? (x7)
o ENDOSCOPY (oesophagoscopy): tumour location and biopsy. Gold standard.
o BARIUM SWALLOW: detects occlusive tumour
o ENDOSCOPIC ULTRASOUND (EUS): for staging.
o CT: for staging.
o PET: can detect previously occult (no symptoms) distant metastases.
o BRONCHOSCOPY: if there is a risk of tracheobronchial invasion
o LAPAROSCOPY: if there is significant infra-diaphragmatic component
