STEP 3: Diagnosis, staging and treatment planning

Diagnosis and staging

For colon and rectal cancer:

  • CT scan of the chest, abdomen and pelvis
  • MRI liver
  • PET-CT

For rectal cancer:

  • endorectal ultrasound

Genetic testing

Up to 5% of colorectal cancers are specifically inherited (familial adenomatous polyposis and lynch syndrome) and up to 25% may have some form of inherited component.

Find out more about colorectal cancer genetic testing.

Treatment planning

The multidisciplinary team should discuss all newly diagnosed patients within 2 weeks of diagnosis and staging.

Some cases of colorectal cancer present as emergencies and require appropriate acute care followed by management from a multidisciplinary team.

Research and clinical trials

Consider enrolment where available and appropriate. Search for a trial.


The lead clinician’s (1) responsibilities include:

  • discussing a timeframe for diagnosis and treatment options with the patient and/or carer
  • explaining the role of the multidisciplinary team in treatment planning and ongoing care
  • encouraging discussion about the diagnosis, prognosis, advance care planning and palliative care while clarifying the patient’s wishes, needs, beliefs and expectations, and their ability to comprehend the communication
  • providing appropriate information and referral to support services as required
  • communicating with the patient’s GP about the diagnosis, treatment plan and recommendations from multidisciplinary meetings (MDMs).

1: Lead clinician – the clinician who is responsible for managing patient care.

The lead clinician may change over time depending on the stage of the care pathway and where care is being provided.



Investigations should be completed within 2 weeks.