The Red Flags for Low Back Pain – Can It Find Cancer Cases?
$28 million was awarded to a patient for a late diagnosis of a pelvic tumor, an osteosarcoma. This rare cancer presented as a case of low back pain and sciatica. The patient claimed that if the osteosacroma had been caught earlier that the subsequent surgery would have been avoided.
Could doctors have done better in diagnosing more quickly?
These cases strike fear into all primary care doctors. Which patient has a sinister pathology when the majority of patients with similar symptoms of back pain are due to benign non-life threatening causes?
Is the answer simply ordering more imaging like CT scans and MRIs? Though ordering more tests on more patients would be technically feasible, the truth is that CT scans or MRIs often find abnormalities which are not medically important. Once found, however, these abnormal findings require more work-up. This can cause unnecessary worry both psychologically and financially for patients. As more patients have less insurance coverage due to higher deductibles, many patients I see are choosing not to have an MRI even when in my medical judgment it is recommended.
So if more imaging alone may not be the answer, perhaps understanding when to do imaging might be better?
Are the Red Flags for Back Imaging Good Enough?
Would it have been possible to make the diagnosis sooner? Hindsight is always 20/20. What are the red flags for low back pain that would warrant imaging like a MRI?
According to Primary Care Medicine: Office Evaluation and Management of the Adult Patient (Primary Care Medicine ( Goroll )) – the history matters:
- The clinical presentation is one of insidious onset of back pain, gradually increasing in severity and aggravated by activity and lying down. Location can be anywhere in the spine, but occurrence in an area atypical for degenerative disk disease (e.g., the midback) is suggestive. A hallmark is back pain worsened by activity and worsened, or at least not relieved, by lying down.
- Unexplained weight loss, fever, abnormal serum protein electrophoresis pattern, history of malignant disease
When it comes to figuring out if the cause of back pain is due to cancer, these guidelines may not be that good. In the BMJ article –Red flags to screen for malignancy and fracture in patients with low back pain: systematic review noted:
- Some patients, however, present with low back pain as the initial manifestation of a more serious pathology, such as malignancy, spinal fracture, infection, or cauda equina syndrome. Spinal fracture and malignancy are the most common serious pathologies affecting the spine. In patients with low back pain presenting to primary care, between 1% and 4% will have a spinal fracture and in less than 1% malignancy, whether primary tumour or metastasis, will be the underlying cause.
- Through review of the literature, researchers found that the only red flag that was most likely to suggest malignancy was a prior history of cancer (post test probability of 7 percent). Looking at the American College of Physician guidelines, other minor risk factors included older age, weight loss, and failure to improve after 1 month (post test probability of less than 3 percent).
In other words, fewer than 1 out of 100 patients with back pain have a tumor.
The BMJ article concludes:
- While several red flags are endorsed in guidelines to screen for fracture or malignancy, only a small subset of these have evidence that they are indeed informative. These findings suggest a need for revision of many current guidelines.
A Faster Diagnosis?
- In August of 2008, at age 16, Anna Rahm began experiencing lower back pain. The pain began radiating down her right leg in January 2009. After unsuccessful chiropractic treatments in February 2009, her chiropractor urged her to go to Kaiser Permanente to get an MRI. Ms. Rahm and her mother went to Kaiser Permanente in Woodland Hills in March of 2009 and saw Ms. Rahm’s primary care physician and physical medicine specialist. Between March and June of 2009, The Rahm family repeatedly requested an MRI from their treating physicians at Kaiser Permanente.
- Because she was normal weight, 5 feet 4 and 125 pounds, Rahm was surprised at the diagnosis. She visited the nutritionist, tried acupuncture and yoga, but the pain only got worse.
Would a teenager with a body mass index of 22, considered normal weight, and pain for 2 months (January to March) warrant a MRI? Was there anything in the history or physical when matched up with the red flags for imaging that would have tipped doctors to diagnose more quickly?
The Choosing Wisely campaign has some insights on when to consider imaging for low back pain. It notes that “you probably don’t need an imaging test for at least several weeks after the onset of your back pain, and only after you’ve tried the self-care measures described…” Perhaps after several weeks, doctors might have considered imaging even without any red flags.
What is the natural history of osteosarcoma?
- Osteosarcoma is the most common type of bone cancer in children and teens.
- This cancer arises most often in the wide ends of long bones, such as the femur and tibia in the upper and lower leg, and the humerus in the upper arm.
- It can also occur in flat bones that support and protect vital organs, including the bones of the pelvis and the skull.
- In about 15 to 20% of patients, osteosarcoma has spread by the time it is diagnosed. It typically spreads to the lungs but sometimes to other bones (beyond the initial site).
Diagnosing Some Cancers Early or Late Makes Little Difference in Outcomes
So unfortunately it turns out some cancers are quite aggressive and no matter what we do, the outcome is the same. Ovarian cancer, lung cancer, renal cell cancer, and pancreatic cancer are ones that come to mind. Is this true of osteosarcoma? Researchers keep trying to find newer tests to detect these cancers sooner, better, and more accurately. Is it possible that earlier imaging would have made a difference? Medical experts on the case didn’t think so.
Though the medical experts in this case felt that the outcome may have made no difference, the jury did not agree. The standard often in legal cases is different than our scientific and medical standards. The legal standard is – “is it more likely than not XXXX then YYYY?” When it comes to the public and the law, perception is reality. Earlier detection may have made the patient feel better even if the resultant surgery was exactly the same as the diagnosis made later.
So What Can Doctors and Patients Do?
As doctors we need to do our best to listen and not prematurely form biases. It’s advice I share with my medical students and something I work hard on daily. Active unbiased listening can help diagnose more quickly and more accurately. One of the best book on this is How Doctors Think by Dr. Jerome Groopman.
What can patients do? Without knowing the full details of the case, it is hard to add more advice. It sounds like the patient and family did their best to express their concerns. The only piece of advice? If you feel like you are not being heard or listened to, find a new doctor. In this case, switching to a new primary care doctor. Sometimes a new face seeing your problem for the first time can remove unconscious bias your previous doctor had, provide a different level of insight and expertise due to experience, and more importantly get you the right care.