Colorectal cancer

28th June 2014 by NASGP

Colorectal cancer

Aimee Lettis from the GP Update team gives us short, sharp nuggets of clinical information for sessional GPs.

Diagnosing colorectal cancer can be hugely challenging. Many patients come worried they have colorectal cancer and it can be difficult to determine who needs investigation. Focusing on colorectal cancer, survival is significantly better if detected early, but using 2WW guidelines alone will identify only 25% of cases. So what can we do? Well, an interesting article in the BMJ looked at why colorectal cancer is easily missed (BMJ 2013;346:f3172). Before we look at this, here’s a reminder of the 2WW criteria (NICE 2005 CG27):

Change in bowel habit and/or rectal bleeding

  • Age ≥40y with rectal bleeding AND change in bowel habit to looser stools/increased frequency for ≥6w.
  • Age ≥60y with rectal bleeding without anal symptoms OR change in bowel habit towards looser stools/increased frequency for ≥6w.

Mass

  • Patients of any age with a right iliac fossa (thought to be large bowel) or rectal mass.

Iron deficiency anaemia

  • Men of any age with unexplained iron deficiency anaemia AND Hb <110g/L.
  • Non-menstruating women with unexplained iron deficiency anaemia AND Hb <100g/L.

Why is colorectal cancer easily missed? BMJ 2013;346:f3172

Worryingly, 50% with colorectal cancer do not meet 2WW criteria at presentation. Audits suggest three groups of symptoms that are common presenting symptoms of colorectal cancer but where early diagnosis is missed because symptoms do not meet 2WW guidelines. These are:

Mild anaemia

  • Consider investigating earlier using higher cut-offs of ≤120g/L in men and ≤110g/L in women >60y (these patients have about a 4% risk of colorectal cancer).

Abdominal pain

  • The most typical symptom of colorectal cancer along with rectal bleeding, but is missing from referral guidelines because of its low predictive value of 1.1% (although this increases to 3% if reported twice).
  • Therefore, be wary of diagnosing IBS in patients >50y without considering other possibilities, e.g. colorectal/ovarian cancer, and whether colonoscopy is necessary before making the diagnosis.

Change in bowel habit

Read more

No credit card details needed – it takes two minutes.

Join free trial

Login

Already a member? Login to view this content.

Login

"NASGP came along way before people understood the need for sessional and small group practices to be valued by the system. On joining as a single-handed GP many years ago, I was welcomed into the team by initially wrote a few blogs for the organisation, which followed my understanding of yet another NHS reorganisation. It was only due to the vision and drive of Richard, your founder, that NASGP survived the large practice dominance. The inception of being a portal for the needs of GP locums was a masterstroke. Those who knew about it quickly realised the true meaning of networking. So here we are many years down the line and in footballing terminology NASGP now play in the Premier League.
"Well done to all as this is a just reward for the loyalty, dedication and hard work of your team. I have fond memories of working with NASGP and would urge every practice, large or small, to join this organisation, there are only gains and no losses."

Dr Tony Hall-Jones, retired GP

Dr Tony Hall-Jones, retired GP

See the full list of features within our NASGP membership plans

Membership