Here's an uncomfortable reality about many diagnostic delay cases: even with timely diagnosis, some patients wouldn't have survived. Cancer can be aggressive regardless of when it's caught. Heart attacks can be massive despite prompt treatment. Some diseases are simply more powerful than medicine's ability to treat them.
Does that mean there's no case when a doctor's negligence delayed diagnosis of a condition that might not have been curable anyway? In many states, the answer is no—thanks to a doctrine called "loss of chance."
The Traditional Problem
Standard negligence law requires proving that the defendant's actions "more likely than not" caused your harm. In medical terms, you need to establish that proper diagnosis would have given you greater than 50% chance of a better outcome. This makes intuitive sense for many situations, but it creates harsh results in medical cases.
Consider two patients with the same type of cancer, both diagnosed late due to physician negligence. Patient A had a 60% chance of survival with timely diagnosis, reduced to 10% by the delay. Under traditional causation rules, this patient can pursue a claim because timely diagnosis "probably" would have saved her life. Patient B had a 40% chance of survival with timely diagnosis, reduced to 5% by the delay. Under the same rules, this patient gets nothing—even though the negligence affected both patients almost identically.
The delay destroyed most of both patients' survival chances. But because Patient A started above the 50% threshold and Patient B started below it, the law treats them completely differently. One recovers full damages; the other recovers nothing at all.
Loss of Chance Changes the Analysis
The loss of chance doctrine addresses this inequity by shifting the question. Instead of asking whether the patient probably would have survived with proper treatment, it asks how much survival probability the negligence destroyed.
In Patient B's case, the diagnostic delay reduced survival odds from 40% to 5%—destroying 35 percentage points of survival probability. Under loss of chance, the patient or estate can recover damages proportional to that lost chance. If full wrongful death damages would be $2 million, the loss of chance recovery would be approximately 35% of that amount—$700,000.
This isn't full compensation. But it recognizes that something valuable was taken. The patient had a real chance—not a certainty, but a genuine possibility of survival—and the doctor's negligence destroyed that chance. Loss of chance says that destruction is compensable harm.
State Variations
Not all jurisdictions recognize loss of chance, and those that do apply it differently. Some states allow loss of chance claims regardless of the original survival odds. Whether you had an 80% chance or a 20% chance, destroying that chance through negligence is actionable. Other states only apply the doctrine when original odds were below 50%—if you started with better than even odds, traditional causation rules apply and you either recover full damages or nothing. Still other states reject loss of chance entirely, maintaining the traditional all-or-nothing approach.
Your state's approach makes a significant difference to your case. An experienced attorney can explain how local law treats loss of chance and what that means for your specific situation.
How Lost Chance Gets Calculated
Loss of chance cases depend heavily on statistical evidence about survival rates at different disease stages. The analysis requires establishing what stage your cancer (or other condition) was at when finally diagnosed, what stage it would have been at proper diagnosis given when symptoms first appeared, what survival rates apply to each stage based on medical literature, and what percentage of survival probability was lost between those stages.
Expert witnesses—oncologists, cardiologists, other specialists depending on the condition—provide testimony about these survival statistics. They explain to juries what the numbers mean: that a patient diagnosed at Stage II had a specific likelihood of survival that dropped to a different likelihood when diagnosis was delayed until Stage IV. The difference between those likelihoods is the lost chance.
What Recovery Looks Like
Damages in loss of chance cases are typically calculated as a percentage of what full damages would have been. If the patient died and full wrongful death damages would have been $2 million, a 35% lost chance translates to roughly $700,000. If the patient survived but with worse outcomes, the lost chance percentage multiplies against the additional damages caused by the delayed diagnosis—the more aggressive treatment required, the reduced life expectancy, the additional pain and suffering.
This proportional approach means loss of chance recoveries are smaller than in cases where the negligence "probably" caused death or serious harm. But for patients whose chances were below 50% to begin with, proportional recovery is vastly better than the alternative under traditional rules: nothing at all.
The Practical Value
Loss of chance matters most for aggressive diseases where even prompt diagnosis offers uncertain prognosis. Pancreatic cancer patients rarely have better than 50% survival odds at any stage—under traditional rules, delayed diagnosis would almost never be actionable. Certain heart conditions, aggressive cancers, and other serious diseases create similar problems. Loss of chance ensures that diagnostic negligence in these cases carries consequences, even when the underlying disease made full recovery unlikely.
The doctrine also reflects a certain justice. A patient who had a 40% chance of survival and lost it to negligence suffered real harm. That chance, however uncertain, was theirs. They might have been in the 40% who survived. Destroying that possibility deserves recognition, even if it can't be proven that this particular patient probably would have beaten the odds.