The three symptoms most often associated with cancer are breast lumps, urinary tract symptoms and changes in bowel habits. Photo / Getty Images
Worried about a swollen lymph node or change in bowel habits? Keep these red flags in mind.
As an oncologist, I’m often asked by family and friends about swollen lymph nodes. Even I find them concerning at times, wondering if they could be a sign of cancer.
I should know better. Most lymph nodes swell as a reaction to an underlying infection or inflammation and are nothing to worry about.
In a study conducted in England, investigators identified about 8000 people who were diagnosed with solid tumour cancers and pored over their medical records to determine the health complaints that led to their diagnoses. Ranked from most to least common, the top symptoms included:
Not surprisingly, the findings reflect incidence rates of the most prevalent cancers worldwide: breast, prostate, lung, skin and colorectal.
But these symptoms may also be due to relatively innocent causes. For example, a benign cyst can cause a breast lump, hemorrhoids can cause rectal bleeding, and normal age spots can look sinister.
Here are four symptoms that people often worry about - and the red flags that may signal an underlying cancer.
In a Dutch study, over 2500 people were evaluated by their doctors for swollen lymph nodes, and 10% were referred to a surgeon for a biopsy. Among patients with swollen lymph nodes, only about 1% were found to have cancer, though the likelihood was higher with advancing age.
In other words, your swollen lymph node most likely isn’t cancer. A lymph node that swells from an infection is often painful and shrinks after a few days, when the infection is gone. That is, unless you repeatedly press on it, in which case it will continue to swell and hurt - so avoid doing that.
Cancerous lymph nodes, on the other hand, are often painless, hard, fixed and continue to enlarge. Lymph nodes that are larger than about one inch (2.5cm) in diameter or increase rapidly in size are also more suspicious for being malignant. A lymph node that doesn’t go away and with any of these characteristics may need to be biopsied.
We all experience changes in our bowel habits, particularly if we’re taken out of our routines, like when we travel. And everyone has a different definition of “normal” when it comes to bowel movements. But symptoms related to cancer are often unusual, at least to us, and persist.
For example, the actor James Van Der Beek and the Brazilian singer Preta Gil, both of whom were diagnosed with colorectal cancer, revealed that they had bowel habit changes that were new to them, and that didn’t go away, before their diagnoses.
Researchers have found this scenario to be a common red flag. One study looked at 286 patients diagnosed with colorectal cancer under age 50 and investigated the symptoms that led to their diagnoses. Over half reported changes in their bowel habits (diarrhea more often than constipation) and over half had rectal bleeding, while 47% complained of abdominal pain.
Importantly, the vast majority reported two or more symptoms, and these symptoms lasted two months or longer.
An analysis of about 80 studies that included almost 25 million people with early-onset colorectal cancer came to similar conclusions about the frequency of these symptoms. On average, symptoms persisted for six months before cancer was diagnosed. My advice is to see a doctor if symptoms persist for two months or longer.
My weight will fluctuate 5 or 10 pounds (2.3-4.5kg) depending on the season and how much I’m exercising. This sort of slight variability in weight is nothing to worry about. But unintentional weight loss, or weight loss while dieting that far exceeds expectations, may be cause for concern.
In a study of over 150,000 health professionals followed for almost 30 years, those with a weight loss of 10% or more of their body weight had a 37% increased risk of a cancer diagnosis during the following 12 months compared with those without weight loss.
Cancers of the upper gastrointestinal tract, including of the esophagus, stomach, liver and pancreas, were particularly common among those with substantial weight loss.
It’s common for a cough to linger after a viral upper respiratory infection. In fact, I had a cough that lasted for weeks after a recent cold, putting me among the 25% of people who still have symptoms two weeks after a common cold.
That’s not the same as a chronic cough, which lasts eight weeks or longer and should be evaluated by a physician. A study of almost 10,000 people diagnosed with lung cancer in Spain found that cough was the most common symptom that led to a cancer diagnosis, present in about one-third of patients. Other estimates report cough in 55% of people with lung cancer.
Older adults with a chronic dry cough and a smoking history are more likely to be diagnosed with lung cancer. But overall, in patients with a chronic cough who see a primary care provider, lung cancer is diagnosed only 2% of the time or less.
The bottom line is that these symptoms are indeed associated with cancers, but most of the time, they won’t lead to a cancer diagnosis. If a symptom doesn’t get better, is unusual to you, or worsens over time, though, see your doctor just to be sure.