According to the Canadian Cancer Society, cancer is the leading cause of death for Canadians and is responsible for 30% of all deaths.  Canadian statistics indicate that one in two Canadians is likely to develop cancer during their lifetime and that one out of every four Canadians will likely die from cancer.  The most commonly diagnosed types of cancer in Canada are lung, breast, colorectal and prostate cancer.  Cancer can occur at any age, but typically affects those aged 50 and older.


In general, the earlier that a patient is treated, the better chances there are for a cure or recovery.  Many cancer treatments are most effective before the disease spreads.  Thus, the earlier that cancer is diagnosed the better the chances of surviving.  If a doctor fails to recognize symptoms which would lead a reasonable professional to diagnose cancer, the patient may be deprived of treatment options which could lead to a recovery. 

Cancers such as colon, lung, breast, prostate, cervical, testicle, kidney and non-small cell cancers respond well to early treatment.  However, other types of cancers such as small cell lung cancer, pancreatic cancer and ovarian cancer have a poor chance of recovery regardless of when the cancer is detected.

Given that there are so many types of cancers that are treatable, early diagnosis is key to preventing serious health consequences or even death.  Therefore, unreasonable delays in diagnosing a patient with the disease may result in unnecessary treatments, costs and a lower survival rate and may become the foundation for a medical malpractice claim.


In Canada, a plaintiff (the individual bringing a case against another in a court of law) must prove on the balance of probabilities that an earlier diagnosis would have changed the patient’s medical outcome.  In other words, the plaintiff would likely not have experienced the loss had he/she been diagnosed earlier.

The Ontario Court of Appeal clarified this burden by stating, “[i]t is not sufficient to prove that adequate diagnosis and treatment would have afforded a chance of avoiding the unfavourable outcome unless that chance surpasses the threshold of ‘more likely than not’.”  


When proceeding with a medical malpractice claim, the plaintiff must be able to prove causation.  The following are the components necessary to prove causation in the case of medical malpractice involving a delayed cancer diagnosis:

  1. The patient must prove that the cancer was present when the doctor examined the patient;
  2. The patient must prove that he/she would have been diagnosed at an earlier time if the doctor had met the standard of care; and
  3. The patient must prove that the outcome of his/her disease probably (not possibly) would have been more favourable with an earlier diagnosis.

Although scientific precision is not required in order to prove causation, the plaintiff must be able to prove that an earlier diagnosis probably would have changed the patient’s medical outcome.


There are a number of examples of ways in which a doctor may have failed to make an early diagnosis.  A doctor may have failed to take a proper individual or family history, failed to investigate the risk factors, failed to take the patient’s complaints seriously or neglected to order imaging, biopsies, blood tests or other diagnostic tests after reviewing the patient’s symptoms. 

The correct interpretation of various diagnostic tests including ultrasounds, mammograms, x-rays, CT scans, MRIs, biopsy samples and pathology slides are essential for a proper and early diagnosis.   The failure to examine and review these types of tests may delay the diagnosis and the availability of treatment options for the patient.

Communication errors may also result in a delayed cancer diagnosis.  Delays may occur if a doctor fails to communicate the test results to the patient or to follow-up on test results that have been ordered.  Doctors may also fail to recognize the significance of some of the symptoms or findings and fail to refer the patient to an appropriate specialist in a timely manner, thus delaying the diagnosis and treatment.


According to a report released by the Canadian Cancer Society, nearly half of all colorectal cancers in Canada are diagnosed after they have already spread to other parts of the body.  The statistics show that 49% of those diagnosed with colorectal cancers are diagnosed in Stage 3 or Stage 4, at which point they are most likely untreatable.

When colorectal cancer is diagnosed at Stage 1, the five-year survival rate is close to 90%.  However, when it is diagnosed at Stage 4, the survival rate drops below 15%. 

It is believed that many Canadians are not participating in the colorectal cancer screening programs, which are available in every province except Quebec.  The Canadian Cancer Society recommends having your stool screened every two years if you are 50 to 74 years of age and not at high risk of colorectal cancer.  The screening tests can help detect cancer early and result in a more positive outcome.

Medical malpractice claims related to a delayed cancer diagnosis are complicated legal claims that require the help of lawyers with experience and expertise.  If you or a loved one have suffered as a result of a doctor’s failure to diagnose cancer, the lawyers at Cuming Gillespie Lawyers can help you evaluate your legal options and help you decide whether to pursue a claim.  Contact our office at 403-571-0555 or online today to book a free consultation.