4- Abdominal cancer Flashcards
Colorectal (bowel) cancer background
- 4th most prevalent cancer in UK (behind breast, prostate and lung)
- Anywhere from colon to rectum
- Small bowel and anal cancers less common
types of colorectal cancer
Types
- Adenocarcinomas (rarer types inc lymphoma, carcinoid (think flushing) and sarcoma)
- Adenomas may be present for 10 years before becoming cancerous
risk factors for colorectal cancer
Hereditary factors
- Family history of bowel cancer
- Familial adenomatous polyposis (FAP)
- Hereditary nonpolyposis colorectal cancer (HNPCC), also known as Lynch syndrome
- Inflammatory bowel disease (Crohn’s or ulcerative colitis)
- Increased age
Modifiable
- Diet (high in red and processed meat and low in fibre)
- Obesity and sedentary lifestyle
- Smoking
- Alcohol
Protective
- aspirin or NSAIDS
- HRT
- statin use
- physical activirty
- whole grains
- dietary fibre
- fish intake
- tree nuts
- vitamins D,C and others
- calcium supplements
presentation of colorectal cancer
- Change in bowel habit (usually to more loose and frequent stools)
- Unexplained weight loss
- Rectal bleeding
- Unexplained abdominal pain
- Iron deficiency anaemia (microcytic anaemia with low ferritin)
- Abdominal or rectal mass on examination
- Presenting with obstruction
o Tumour blocks passage through bowel- surgical emergency - Right side colon cancer: abdominal pain, iron def anaemia, palpable mass in RIF or on PR exam
- Left side colon cancer: rectal bleeding, change in bowel habit, tenesmus, palpable mass in LIF
Red flags for colorectal cancer
- Change in bowel habit (usually to more loose and frequent stools)
- Unexplained weight loss
- Rectal bleeding
- Unexplained abdominal pain
- Iron deficiency anaemia (microcytic anaemia with low ferritin)
- Abdominal or rectal mass on examination
referral for colorectal cancer
2- week wait
- Over 40 years with abdominal pain and unexplained weight loss
- Over 50 years with unexplained rectal bleeding
- Over 60 years with a change in bowel habit or iron deficiency anaemia
Familial adenomatous polyposis (FAP)
- Autosomal dominant condition involving malfunctioning of the tumour suppressor genes called adenomatous polyposis coli (APC).
- It results in many polyps (adenomas) developing along the large intestine.
- These polyps have the potential to become cancerous (usually before the age of 40).
Management
- Patients have their entire large intestine removed prophylactically to prevent the development of bowel cancer (panproctocolectomy).
Hereditary nonpolyposis colorectal cancer (HNPCC)
- Lynch syndrome.
- Autosomal dominant condition that results from mutations in DNA mismatch repair (MMR) genes.
- Patients are at a higher risk of a number of cancers, but particularly colorectal cancer.
- Unlikely FAP, it does not cause adenomas and tumours develop in isolation.
people with FAP or Lynch are offered
These patients offered FIT screening at regular intervals
classification for bowel cancer
Dukes’ Classification
Dukes’ classification is the system previously used for bowel cancer. It has now been replaced in clinical practice by the TNM classification, but you may come across it in older textbooks or question banks. A brief summary is:
* Dukes A – confined to mucosa and part of the muscle of the bowel wall
* Dukes B – extending through the muscle of the bowel wall
* Dukes C – lymph node involvement
* Dukes D – metastatic disease
Investigations for colorectal cancer
-
Bloods- FBC (microcytic – iron def anaemia), LFTs, clotting, carcinoembryonic antigen (CEA)- tumour marker
o CEA tumour marker for bowel cancer
o Not helpful in screening, but can be used for predicting relapse - Colonoscopy with biopsy- gold standard- biopsy if lesion found
- Sigmoidoscopy (if only features of rectal bleeding)
- CT colonography- pts less fit for colonoscopy- less detailed doesn’t allow for biopsy
- Staging CT scan
o CT thorax, abdomen and pelvis (CT TAP)
management of colorectal cancer
MDT approach
* Surgeons
* Oncologists
* Radiologists
* Histopathology
* Specialist nurse
Choice of managed depends on
* Clinical condition
* General health
* Stage
* Histology
* Patient wishes
Options (in any combination)
* Surgical resection
* Chemotherapy
* Radiotherapy
* Palliative care- stenting
Screening for colorectal cancer
Faecal Immunochemical Test (FIT) for asymptomatic
- Ages 60-74yo every 2 years
- If results positive –>colonoscopy
how does FIT testing work
- Faecal immunochemical tests (FIT) look very specifically for the amount of human haemoglobin in the stool.
- FIT replaced the older stool test called the faecal occult blood (FOB) test, which detected blood in the stool but could give false positives by detecting blood in food (e.g., from red meats).
how are FIT tests also used in GP
- FIT tests can be used as a test in general practice to help assess for bowel cancer in specific patients who do not meet the criteria for a two week wait referral, for example:
- Over 50 with unexplained weight loss and no other symptoms
- Under 60 with a change in bowel habit
surgical resection of colorectal cancer
Ideal to surgically remove entire tumour – potentially curative. Can also be used palliatively- reduce size of tumour and improve symptoms
- Laparoscopic surgery gives better recovery and few complications than open surgery
- Robotic surgery used increasingly
what does colorectal cancer surgery involve
- Identify tumour (may have been tattooed in endoscopy)
- Remove section of bowel containing tumour
- Creating an end-to- end anastomosis (sewing the remaining ends back together)
- Creating a stoma if end to end not possible
Complications of colorectal bowel resection
There is a long list of potential complications of surgery for bowel cancer:
- Bleeding, infection and pain
- Damage to nerves, bladder, ureter or bowel
- Post-operative ileus
- Anaesthetic risks
- Laparoscopic surgery converted during the operation to open surgery (laparotomy)
- Leakage or failure of the anastomosis
- Requirement for a stoma
- Failure to remove the tumour
- Change in bowel habit
- Venous thromboembolism (DVT and PE)
- Incisional hernias
- Intra-abdominal adhesions
Right hemicolectomy
involves removal of the caecum, ascending and proximal transverse colon.
left hemicolectomy
involves removal of the distal transverse and descending colon.
High anterior resection
involves removing the sigmoid colon (may be called a sigmoid colectomy).
Low anterior resection
involves removing the sigmoid colon and upper rectum but sparing the lower rectum and anus.
Abdomino-perineal resection (APR)
involves removing the rectum and anus (plus or minus the sigmoid colon) and suturing over the anus. It leaves the patient with a permanent colostomy.
reconstruction after gastrectomy
Roux-en-Y reconstruction
gives the best functional result, in particular with less bile reflux.
- Post-gastrectomy, distal oesophagus is end-to-end anastomosed directly to the small bowel, and the proximal small bowel is end-to-side anastomosed also to the small bowel
Location of pancreatic cancer
- Most occur in head of pancreas (as opposed to body or tail)
- Once large enough will press on bile duct- obstructive jaundice
- Tumours located in the body and tail are diagnosed later due to obstructive symptoms occurring later
pancreatic cancer investigations
Initial bloods
- FBC and LFTs
CA 19-9 (carbohydrate antigen) is a tumour maker raised in pancreatic cancer (also raised in cholangiocarcinoma)
Imaging
- Abdominal US
- Staging CT- CT TAP (Looks for metastasis and other cancers)
- Magnetic resonance cholangial pancreatography (MRCP)- assess biliary system
- Endoscopic retrograde cholangial-pancreatography (ERCP)- stent to relieve obstruction and biopsy tumour
- Endoscopic US for staging
Biopsy
- Through skin under US OR CT guidance
whipples procedure
A Whipple procedure (pancreaticoduodenectomy) is a surgical operation to remove a tumour of the head of the pancreas that has not spread. A Whipple procedure is a massive operation so patients need to be in good baseline health. It involves the removal of the:
- Head of the pancreas
- Pylorus of the stomach
- Duodenum
- Gallbladder
- Bile duct
- Relevant lymph nodes
