Routine blood tests may be a useful part of screening. Meanwhile the much hyped Galleri test is being called into question.
Flagging abnormal routine blood test results for patients with gut complaints could help find undiagnosed cancer, researchers say.
They estimate that an extra 16% of people with undiagnosed cancer would have been given urgent specialist referral if this were usual practice, compared to risk assessment based on symptoms, age and sex alone.
Data from people aged 30 or older in the UK between 2007-16 who had visited a GP for non-specific gastrointestinal issues and who had their blood tested within three months was analysed. More than 425,000 people attended for stomach pain and over 52,000 due to bloating, and two-thirds of the cohort were referred for blood tests.
Low serum albumin, high platelets, elevated C-reactive protein (CRP), high erythrocyte sedimentation rate (ESR) or elevated alkaline phosphatase (ALP) were most strongly predictive of cancer diagnosis.
The study looked at 19 total common blood tests, including haemoglobin, alanine transaminase (ALT), aspartate transaminase (AST), creatinine, urea, calcium, phosphate, sodium, potassium and carcinoembryonic antigen (CEA).
Each test alone, if outside the normal range, significantly increased the likelihood of cancer detection within 12 months compared to those with normal test results.
Professor Ian Olver, medical oncologist and cancer researcher at the University of Adelaide told The Medical Republic that clinicians should be made aware of this study to help underpin their decision to refer patients aged 30–59 as it can be more difficult to diagnose cancer in this group.
For those aged 60 and over, he said, the symptoms alone may be enough to warrant referral. But for the younger age bracket, the symptoms combined with abnormal blood tests may push patients to the risk level that justifies specialist referral.
The study found that among people aged 30 to 59 years with abdominal pain or bloating, anaemia, low albumin, raised platelets, abnormal ferritin or increased inflammatory markers strongly predicted a risk of undiagnosed cancer.
In women aged 50 to 59 with abdominal bloating, pre-blood test cancer risk of 1.6% increased to 10% with raised ferritin, 9% with low albumin, 8% with raised platelets, 6% with raised inflammatory markers and 4% with anaemia.
Risk of cancer was estimated to be 3.1% for men in their 60s reporting stomach pain, rising to 8.6% for men in their 80s with this symptom. For women, the risk was 3.1%, in their 60s, which doubled in their 80s.
Overall, bowel cancer was the most diagnosed cancer in the cohort in both men and women, followed by prostate and pancreatic cancer in men, and breast and ovarian cancer in women.
The study noted that half of all patients with as-yet-undetected cancer will first present with these symptoms, but it could be challenging to diagnose on that alone.
“Commonly used primary care blood test results can improve the detection of underlying cancer in patients consulting with nonspecific abdominal symptoms,” they wrote.
This revelation may be even more valuable at this time as the validity of the next generation cancer screening tool Galleri is being called into question.
Galleri is a world first, claiming the ability to detect over 50 types of cancer from a simple blood test. However, the BMJ says Galleri is facing mounting evidence against its implementation.
Related
In a recent investigative article, the BMJ say that there are serious concerns about the current NHS trial in the UK. Grail, the biotechnology company which created Galleri, is currently facing a class action lawsuit in the US which claims that the company exaggerated Galleri’s effectiveness to increase its share price.
According to the BMJ, eight months prior to announcement of the trial, Grail published data showing that in patients already known to have cancer, the test detected only 43.9% of stage I-III cancers.
Later, another Grail-funded study found that the test sensitivity for stage I cancers was only 16.8%. Many of the authors also declared fees, patents, or stock holdings with the company.
Galleri is currently available in the US for $US949 ($1444).
