Delayed diagnosis of cancer: a global overview of loss of chance claims

In our interactive virtual conference we travelled across the world to review quantum in delay in diagnosis of cancer claims. For the purpose of this article, focusing on one of the key areas of discussion, we provide an overview of the differences in approach to loss of chance claims across nine jurisdictions - Australia, Canada, England and Wales, France, Ireland, Israel, Chile, Portugal, and Spain.

The impact of the pandemic on the number of delayed diagnosis claims, particularly in relation to loss of chance, is yet to be realised, but may be significant. In the jurisdictions explored in our conference, courts have not yet had to consider a COVID-19 resourcing defence. In England, allegations in delayed diagnosis of cancer claims that include elements relating to the pandemic, are starting to come through. This is despite cancer treatment being prioritised during the national lockdowns. 

Christopher Malla, Global Head of Healthcare


The current position in Australian law, following the High Court decision in Tabet v Gett [2010], is that a claimant in a medical negligence claim cannot recover damages based on a possible (less than 50%) ‘loss of a chance’ of a better medical outcome.

At first instance in this case the Court found that the loss of chance equated to 10% and awarded the claimant 10% of the total damages award. The defendant successfully appealed the decision to the Court of Appeal which held that adoption of the loss of chance analysis went beyond conventional tort law principles.

The plaintiff was then granted special leave to appeal to the High Court. The High Court dismissed the appeal, observing at paragraph 143 of the judgment that “the appellant could only succeed if the standard of proof is lower than the law presently requires.”

Policy considerations (see paragraph 102 of the judgment) were referred to as a factor against altering the standard of proof of causation, and included the potential for “encouraging defensive medicine, the impact of that on the Medicare system and private medical insurance schemes and the impact of any change to the basis of liability on professional liability insurance of medical practitioners”.

Contact: Anjali Woodford


In Canada, ‘loss of chance’ claims have been largely disregarded and, to date, have not been compensable.

In the early 1990s, the Supreme Court of Canada held that ‘lost chance’ was an inappropriate means of determining causation in cases where death or sickness had already occurred. Rather, a plaintiff must prove on the balance of probabilities that a delayed diagnosis caused or contributed to an unfavourable outcome.

In Ontario, the Court of Appeal has specified that it 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 (see Cottrelle v Gerrard [2003]).

Given the evidential hurdles, there has been a more recent push by the Plaintiff bar to implement loss of chance claims based on statistical evidence, however, no legislative reform in this respect appears to be on the horizon.

Contact: Jason Arcuri

England and Wales

The seminal case in England and Wales on loss of chance is Gregg v Scott [2005]. The claimant was diagnosed with non-Hodgkin’s lymphoma by the defendant doctor and his ten year survival rate was reduced from 42% to 25% as a result of the admitted negligent delay in diagnosis.  

The claimant sought to recover damages for the 17% reduction in his ten year survival rate. The House of Lords held that was not recoverable because had the defendant properly diagnosed the claimant at the time, the claimant would still have had a less than 50% chance of survival. Causation therefore remains to be tested/proved on the balance of probabilities test (i.e. the 50% test).

Distinguishing that from quantum, once the claimant has established breach of duty and causation, the courts can go on to consider the value of the claimant’s loss and can consider percentage attribution.

Therefore, whilst loss of chance may not apply in respect of causation, it can still be considered on quantum. For example, in circumstances where a claimant asserts a loss of chance to seek a promotion and a higher annual wage due to delay in their diagnosis.

Contact: Camilla Long


In cases of delayed diagnosis of cancer it is the loss of chance where the claimant has lost a positive opportunity, that is compensated.

Following a judgment by the Paris Court of Appeal (25 January 2018, n°16/20118)*, and a judgment by the Aix-en-Provence Court of Appeal (28 April 2016, n° 15/00220)**, a claimant bringing a delayed diagnosis of cancer claim may incur:

  • A loss of chance to obtain an earlier diagnosis of the pathology*
  • A loss of chance to benefit from a more effective and less burdensome treatment*
  • A loss of chance to limit the extent of the injury**
  • A loss of chance to prevent recurrence of cancer**

Loss of chance resulting from misdiagnosis is expressed in percentage terms, determined by the judge and applied to the damages award.

Courts do not detail the reasoning behind the assessment of that percentage. However, in some cases the loss of chance to recover or to survive, corresponds with the difference between the ‘Perte de chance de survie percentage (i.e. the rate of chance to recover without the delayed diagnosis) and the percentage chance of recovery after the delayed diagnosis.

The claimant is entitled to receive full compensation in circumstances where they have no chance of recovery because the pathology was detected too late.

Contact: Aurélia Cadain


There are two conflicting Supreme Court decisions in Ireland in relation to the recoverability of loss of chance.

The decision in Philp v Peter Ryan and the Bons Secours Health System [2004] concerned a missed diagnosis of prostate cancer. The trial judge held that the claimant could not prove, on balance, that his life expectancy had been reduced and determined that the eight month delay in diagnosis did not sound in damages. The case was appealed to the Supreme Court, which ultimately gave a unanimous decision in line with the later minority decision in Greg v Scott. The Supreme Court held that Mr Philp had been deprived of an opportunity, over a period of eight months, to discuss and decide upon his treatment options. For this the Court awarded Mr Philp €45,000.

The Supreme Court decision in Quinn (Minor) v Mid Western Health Board & AMP [2005], concerned causation of cerebral palsy, and was handed down six months after Philp. The trial judge (and later the Supreme Court) held that the claimant must discharge the burden of proof on the balance of probabilities and, ultimately, found that the claimant had failed, thus seemingly ruling out the possibility of a finding in favour of loss of chance. However, Quinn does not reference Philp.   

The supporters of the decision in Philp argue that damages should be awarded for loss of chance, where it can be shown on the balance of probabilities that the negligence caused the loss of chance. The supporters of the decision in Quinn  argue that the fundamental test for negligence still stands and that liability, and thereafter recovery of damages, should only follow if a claimant proves their case on the balance of probabilities. 

Clarity is required from the Supreme Court on the issue of the recoverability of loss of chance in Ireland.

Contact: Joanne O'Sullivan


The claimant must prove that because of the negligent treatment they suffered a loss of chance of recovery.

Where it is alleged that due to the medical practitioner’s negligent behaviour the claimant has suffered ‘evidential damage’, the burden of proof shifts to the medical practitioner.  For example, this approach applies in circumstances where due to an omission to refer for a biopsy, the claimant is unable to prove the exact stage they would have been diagnosed, but for the negligence.

The level of compensation depends on the percentage loss as a result of the negligent delay:

If the claimant is able to prove that but for the negligence, their chance of recovery was more than 50% at the time their disease should have been diagnosed, then they are entitled to be compensated for 100% of their damages.

Where the loss of chance is less than 50%, the claimant will be entitled to be compensated only for the actual percentage chance lost.


In the leading case on loss of chance (case nº 6112/15.9T8VIS.L1.S1, dated 23 June 2022), the Supreme Court sought to ascertain if the late communication of a cancer diagnosis was a breach of ‘legis artis’ of medical practice, namely that there was a real and effective loss. The Court also considered whether the nature of the condition was such that but for the late diagnosis, the requirement for invasive surgical treatment could have been prevented. 

In cases such as this, damages may have a material component (for example, medical expenses) and a non-material component (for example, moral damages) which will have to be quantified as a whole because from a legal standpoint, loss of chance is an independent form of loss/damage. In this particular case, quantification of the percentage loss was not possible and therefore the court applied an equity principle, awarding damages of €50,000.

Contact: Luís Paulino


Loss of chance is assessed with reference to two type of experts – an expert to provide an opinion on liability and an oncologist to determine the loss of chance by way of a percentage (known as loss of opportunities in Spain). The percentage at which the loss of chance is assessed is often contested by the claimant.

There is no binding scale for assessing damages in these types of claims. The scale is only binding for motor accident cases.

Where a claim is initially brought by the patient, if they pass away during the course of the claim there may be subsequent claims brought by members of the deceased’s family.

Contact: Alfonso De Ramos


One of the first cases in which loss of chance was recognised as a cause of compensation was in a case heard by the Court of Appeal of Valparaiso (near Santiago) on 11 December 2008 (Rol 776-2008). The case involved a claim for compensation for misdiagnosis of melanoma.

The Court held that the misdiagnosis was not causally linked to the death of the patient. However, because of the advanced stage of the cancer at the time of the correct diagnosis, the Court held that the misdiagnosis had prevented the claimant for more than a year from accessing treatment to improve their quality of life. Therefore, an award was granted of circa US$50,000 on the grounds of loss of chance.

In Chile, as in most Latin American countries, there is no mandatory jurisprudence. Therefore the decision of the court can vary from case to case and such decisions are not binding.  Whilst case law is often used as a reference, judicial discretion means the outcome of cases involving very similar facts/circumstances can differ.

The principle applied when calculating compensation in loss of chance claims is that it is partial – i.e. a proportion of the amount of compensation that would have been due if the negligence was the cause of the death of the claimant.

Contact: Gian Carlo Lorenzini

Read other items in Healthcare Brief - July 2023

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