VAGUE ABDOMINAL SYMPTOMS? CAN THEY BE CANCER?

We’re all troubled from time to time by stomach or intestinal symptoms that cause us to wonder if we have something serious wrong. They become very worrisome when they keep occurring or get worse. We think to ourselves is this something for which I need to go to the ER or to my doctor? Hopefully, this question is answered somewhat by a study done in the United Kingdom and reported recently in a medical journal.

A team of nine researchers from medical centers in the United Kingdom and Denmark set out to determine how often certain symptoms were a sign of, or associated with, serious illnesses. The symptoms they studied were 

     dysphagia (difficult or painful swallowing)

     abdominal distension/bloating

     change in bowel habits

     rectal bleeding

     dyspepsia (indigestion)

     abdominal pain

The serious illnesses they were correlating were cancer and inflammatory bowel disease (IBD). The results were expressed in a statistic called the positive predictive value (PPV). In other words, they were able to predict what percentage of the time a specific symptom was caused by cancer or IBD. The higher the PPV the greater the possibility of correlation. 

They studied these symptoms in more than 1.9 million patients over an 18-year time period. That’s a lot of people, and a long time! The two symptoms with the highest positive predictive value were:

                  Changes in bowel habits in men and Dysphagia in men

Changes in bowel habits in men were associated with a cancer diagnosis in 4.64% of cases

Dysphagia in men was associated with cancer in 4.28% of cases, mainly esophageal cancer

In women, rectal bleeding was associated with cancer in 2.39% of cases and abdominal bloating and distension had the highest correlation with ovarian cancer.

Changes in bowel habits and rectal bleeding had the highest probability of being related  to colorectal cancer. 

Dysphagia (painful or difficult swallowing) was highest for esophageal cancer

Abdominal pain (in either sex) and abdominal bloating and distension (in men) correlated with non-cancerous conditions. 

What’s the message here? 

Some GI symptoms have a strong correlation to a cancer or inflammatory bowel disease and should be investigated.

In people over age 60, the risk of colorectal cancer is significant in patients, especially men, who complain of a change in bowel habits and/or who have rectal bleeding. These patients should be referred for colonoscopy and any other tests that seem appropriate to the situation.

In people over age 60, the possibility of esophageal cancer is significant in patients who complain of painful or difficult swallowing. They should be referred for upper GI endoscopy.

In women over age 60, the possibility of ovarian cancer is significant if they complain of abdominal distension and bloating. These women should be referred for pelvic ultrasound. 

In people over age 60, the possibility of serious intestinal problems was infrequent, or not at all, in patients who complained of dyspepsia (indigestion). 

Dr. G’s Opinion: GI symptoms should never be ignored, especially if they are recurrent or worsening. Change in bowel habits and rectal bleeding are “red flags” that demand attention. They always have been. It is now recommended that screening Colonoscopy begin at age 45 and I think compliance with this recommendation will save many lives. The same is true for persistent trouble swallowing. It demands evaluation and should not just be treated.

The percentages reported don’t seem very high, but they are when you consider the number of patients in the study and the length of time they were observed. The study reported here places emphasis on six symptoms and how frequently each can indicate serious disease. Looking at it from the endpoint backward, you find that most people with colorectal cancer will have a change in bowel habits and/or rectal bleeding. From that perspective, the positive predictive value is nearly 100%. The point is, one should evaluate these symptoms because of the likelihood they are caused by something serious.

Knowing what’s normal and abnormal for your body is the first step in being pro-active toward your health, as is having screenings when they are recommended. Don’t put off lifesaving tests that detect problems early, especially when you have symptoms. 

References: Patient-Oriented Advice That Matters: Predictive Values for Six Common Abdominal Symptoms Shaughnessy AF, Am Fam Phys March 2022;105(3):322.

Herbert A, Rafiq M, et al. Predictive values for different cancers and inflammatory bowel disease of 6 common abdominal symptoms among more than 1.9 million primary care patients in the UK: a cohort study. PLoS Med 2021 Aug 2 18(8):e1003708.