Photo by National Cancer Institute on Unsplash

My mother had symptoms for months before her stage IV colon cancer diagnosis in the early 1990s. My father’s younger brother was a surgeon, we had medical expertise in the family, yet the cancer still went undetected until it was far advanced.

At the time, I chalked it up to the limitations of medicine in that era, before widespread screening protocols and more refined diagnostic criteria.

But a study published last month in JAMA Internal Medicine has made me reconsider what happened to my mother – and what continues to happen to thousands of patients today.

The Numbers

The researchers looked at over 55,000 patients with newly diagnosed colorectal or lung cancer across two major health systems. What they found was striking: between 59% and 78% of patients with advanced-stage cancers had identifiable missed opportunities for earlier diagnosis.

The median delay, from the first symptom or abnormal test to appropriate follow-up, ranged from one to twenty months.

Twenty months. Nearly two years of living with a persistent cough, unexplained fatigue, or abnormal bloodwork before the right test was ordered or the right specialist was consulted.

We Knew Delays Happened. We Just Didn’t Know How Often.

For years, we’ve known that diagnostic delays happen. But we lacked a systematic way to measure them.

Individual cases, like my mother’s, felt like unfortunate exceptions. We told ourselves these delays were inevitable. After all, cancer can be subtle, symptoms can be vague, and medicine is inherently uncertain.

But this new research suggests something more troubling, and also more hopeful: many of these delays follow patterns. Patterns we can now see and interrupt.

Where the Research Started

The study’s lead author, Dr. Hardeep Singh, started asking questions about missed diagnoses fifteen years ago. As a primary care physician in rural Texas, he kept encountering patients whose cancers weren’t diagnosed until late stages.

Rather than accepting these as isolated tragedies, he wondered whether they were signs of something bigger, systemic failure.

So, he and his team began developing tools to view the problem from a different perspective.

The Breakthrough: A Way to Measure Missed Chances

Singh’s team created something called digital quality measures – automated algorithms that scan electronic health records to flag potential missed opportunities for diagnosis.

These aren’t just theoretical models. They’re being tested in real-world health systems, including VA hospitals, and implemented in Epic.

Unlike traditional chart reviews, which are slow and labor-intensive, these digital tools can analyze tens of thousands of records to find signals clinicians might miss on their own.

They Took Hindsight Bias Seriously

Before accepting the study’s results, I wanted to understand how they defined a “missed opportunity.”

This wasn’t just a retrospective sweep where every symptom suddenly looks obvious in hindsight.

Instead, the team used strict, guideline-based criteria. A missed opportunity meant that a clinical signal, like a new cough lasting more than eight weeks, unexplained iron-deficiency anemia, or blood in the stool, should have prompted further evaluation, but didn’t.

And they set specific timelines: for example, if appropriate follow-up for a colorectal cancer signal didn’t happen within 60 days, it counted as a missed opportunity.

To limit bias, multiple physicians reviewed each case independently, using structured criteria. They reached strong agreement.

The Patterns They Found

For lung cancer, the most common breakdowns were related to test ordering and follow-up, like a suspicious shadow on a chest X-ray that never led to a CT scan, or an abnormal CT that never triggered a consult.

For colorectal cancer, the failures looked different. Iron-deficiency anemia often went uninvestigated, on average, for more than a year. Patients reporting blood in their stool sometimes waited months for colonoscopies. Positive fecal blood tests got lost in the system.

These were not cases of doctors making incorrect diagnoses. They were cases of systems failing to respond to well-known warning signs.

I Think About My Mother Differently Now

I wonder now which category my mother’s case would have fallen into. Were there signs that could have been recognized earlier? Or was it simply the reality of medicine at the time?

The distinction matters. It determines whether her late diagnosis was unavoidable or the kind of missed opportunity this research is trying to expose and prevent.

What This Means for My Work—and Yours

In supportive oncology, I hear this question all the time: “What if we had caught this earlier?”

Until recently, I would acknowledge the limits of what we can know, and try to focus on the care we can offer now.

But now I find myself answering differently. Because this research shows that in many cases, earlier diagnosis wasn’t just possible, it was likely achievable, with tools and systems we already have.

The failure wasn’t in our understanding of cancer biology. It was in how we execute the diagnostic process.

What We Can Do, Now

The encouraging news is that Singh’s team didn’t stop at identifying the problem. They built tools to help address it. These tools are already in use in some systems. But implementation is only part of the challenge.

Because the delays happen at many levels:

• A clinician not ordering the next test
• A result not being flagged for follow-up
• A referral lost in coordination
• A patient not knowing when—or how—to push back

Each of these gaps needs a different kind of fix.

For Clinicians:

• Track test results – even when they’re “probably nothing”
• Make your follow-up plans visible to patients and teams
• Document your reasoning, especially when you choose not to pursue a symptom

For Health Systems:

• Build systems that don’t lose abnormal results
• Assign responsibility for follow-up
• Don’t rely on busy humans to catch every red flag

For Patients and Families:

• Follow up on test results if you don’t hear back
• If something feels off, say so, again
• Keep asking: What happens next? Who’s following up?

This Isn’t About Blame. It’s About Building Something Better.

Not every late-stage cancer is preventable. Some tumors are biologically aggressive. Some symptoms are truly ambiguous.

But if 60–78% of advanced cases show missed opportunities for earlier detection, then we have enormous room to improve.

The goal isn’t diagnostic perfection, but a system that acts reliably when recognizable signs appear.

This study provides us with a new way to measure our progress. More importantly, it shows us we can do better.

For my mother, this knowledge comes too late. But for the patients we’ll see tomorrow, and next year, and in the decade to come, it might make all the difference.