Bowel Cancer

Question 1

what is the most common type of colorectal cancer?

Answer 1

adenocarcinoma

Question 2

what is the chromosomal instability (CIN) pathway + how does it contribute to adenocarcinoma transitions?

Answer 2

• accounts for approximately 85% of adenocarcinoma transitions
• involves the suppression of tumour suppressor genes APC and TP53, activation of oncogenes BRAF and KRAS, and alterations in chromosome 18

Question 3

what are the genetic risk factors for colorectal cancer?

Answer 3

• hereditary non-polyposis colorectal cancer (HNPCC)/lynch syndrome
• familial adenomatous polyposis (FAP)

Question 4

what are the symptoms of colorectal cancer?

Answer 4

• change in bowel habit
• rectal bleeding
• abdominal pain
• abdominal bloating
• tenesmus
• weight loss
• fatigue

Question 5

what are the features of colorectal cancer on examination?

Answer 5

• rectal mass on PR
• abdominal mass
• cachexia
• anaemia
• lymphadenopathy

Question 6

NICE advises performing faecal immunochemical testing (FIT) in patients with which red flag features?

Answer 6

• change in bowel habit
• abdominal mass
• iron-deficiency anaemia
• age >40 with unexplained weight loss + abdominal pain
• age <50 with rectal bleeding + abdominal pain or weight loss
• age >50 unexplained rectal bleeding, abdominal pain or weight loss
• age >60 with anaemia

Question 7

what should be done if a FIT result is positive (>10 µg of haemoglobin/gram of faeces)?

Answer 7

urgent suspected cancer (two-week wait) referral pathway

Question 8

what tumour marker is used to monitor the treatment response for colorectal cancer?

Answer 8

carcinoembryonic antigen (CEA)

Question 9

what are the investigations for colorectal cancer?

Answer 9

• colonoscopy
• CT chest, abdomen + pelvis
• ? MRI pelvis

Question 10

how often is the NHS bowel cancer screening programme offered in the UK, and to whom?

Answer 10

every two years to people aged 60–74

Question 11

what is the difference in treatment approach between rectal cancer and colonic cancer?

Answer 11

rectal: patients typically receive chemoradiotherapy before surgery (neo-adjuvant)
colonic: patients typically receive chemotherapy after surgery (adjuvant)

Question 12

what are the long-term complications of colorectal cancer?

Answer 12

• metastasis
• bowel obstruction
• bowel perforation
• iron-deficiency anaemia
• fistula

Question 13

what is the most common site of metastasis for colorectal + rectal cancer?

Answer 13

colorectal: liver
rectal: thoracic organs + nervous system