A Third of Pancreatic Cancer Diagnoses Are Missed on Scans

2020 Türkiye Cancer Statistics recorded 8,392 new cases annually, making pancreatic cancer the 8th most common cancer. With 8,214 deaths annually, it ranked 3rd for cancer deaths. These figures show that pancreatic cancer is usually diagnosed at an advanced stage and remains a cancer with limited effective treatments. Early diagnosis is therefore an important oncology priority, but no approved screening method for early pancreatic cancer detection has yet been accepted.

In a new study, UK researchers say pancreatic cancer findings missed on earlier imaging represent “a major missed window of opportunity”.

In the study presented at United European Gastroenterology (UEG) Week 2022, researchers examined CT (computed tomography) and MRI (magnetic resonance) scans to determine the frequency and underlying causes of missed pancreatic cancer diagnoses.

The team studied 600 pancreatic cancer cases. Of these, 46 (7.7%) were classified as post-imaging pancreatic cancer: cases not detected on imaging performed 3-18 months before diagnosis.

They also reviewed 46 CT scans and 4 MRI scans performed in patients with pancreatic cancer missed on imaging.

1 in 3 Missed Cases Could Have Been Detected

Lead author Nosheen Umar, a gastroenterology research fellow at the University of Birmingham in the United Kingdom, said: “Detailed analysis showed that 36% of post-imaging pancreatic cancer cases were potentially avoidable.”

In 10% of patients with missed pancreatic cancer, associated findings such as dilated bile or pancreatic ducts were not recognised as such or investigated further. In 26% of scans, the radiologist did not detect signs of a mass lesion.

Pancreatic cancer can be operated on only at an early stage, and the window for detecting it then is very narrow. Carefully evaluating images that could identify early disease is therefore particularly important.

Details of Missed Imaging Findings

Nosheen Umar explained that the study aimed to identify the most plausible explanations for missed pancreatic cancer findings. She added that early diagnosis is vital to offer patients the best chance of survival.

The cases came from electronic records of adults diagnosed with pancreatic cancer between 2016 and 2021 at two National Health Service providers. An algorithm was developed to categorise post-imaging pancreatic cancers and assess possible reasons for missed diagnoses.

Post-imaging pancreatic cancer (PIPC) cases were categorised by type:

• Type 1: A focal lesion reported on previous imaging in the same pancreatic segment as the PIPC (0% of cases).

• Type 2: Previously reported imaging changes that could be associated with pancreatic cancer (20% of cases).

• Type 3: No lesion or imaging changes associated with pancreatic cancer reported previously in the same pancreatic segment as the PIPC, but lesions or changes identified on review after diagnosis (26% of cases).

• Type 4: No lesion or associated imaging changes reported previously in the same pancreatic segment, and none identified on review after PIPC diagnosis (54% of cases).

The study may raise awareness of common reasons pancreatic cancer is missed on earlier imaging. By helping standardise future research and guide quality improvement, it could improve the prospects of early diagnosis and patients’ chances of survival.