Lumps, blood in stools, sudden weight loss—most people know the major signs of cancer. However, many common cancers present with no symptoms or only vague, easily overlooked signs. With nearly one in two people expected to develop cancer in their lifetime, recognizing not only the obvious symptoms but also the subtle ones is crucial.
How Cancer Can Be Discovered Incidentally
The Princess of Wales recently revealed that her cancer was found after abdominal surgery for a non-cancerous condition. Similarly, King Charles was diagnosed with cancer following treatment for an enlarged prostate. Such cases are not uncommon; patients sometimes enter hospital with benign issues and leave with a cancer diagnosis. This happens because some cancers cause nonspecific symptoms often attributed to aging or everyday stress, such as persistent fatigue, explains Professor Mieke Van Hemelrijck, a cancer epidemiology expert at King's College London.
The Role of Rapid Diagnostic Centres
When general practitioners suspect cancer, patients are typically referred for urgent investigations within two weeks. However, vague symptoms make this process challenging. Rapid diagnostic centres (RDCs) address this by evaluating nonspecific symptoms like unexplained weight loss or extreme fatigue. Only about 7% of referrals to these centres turn out to be cancerous, but early detection is vital for those who are affected.
Why Some Cancers Are Difficult to Detect
Cancer develops over years as cells replicate and occasionally grow uncontrollably. Early-stage cancers may produce no symptoms or only subtle ones. Cancers in internal organs—such as the ovaries, lungs, or pancreas—are harder to detect because they don't create palpable lumps. In contrast, cancers near the skin surface, like breast or testicular cancer, are easier to notice.
Five Common Cancers with Vague Symptoms
Gastrointestinal Cancers
These include esophageal, gastric, liver, bile duct, pancreatic, and bowel cancers. Bowel cancer, the fourth most common in the UK, has a 90% five-year survival rate when caught early, dropping to 10% at later stages. Symptoms to watch for: unexplained weight loss, nausea, persistent abdominal pain, changes in bowel habits, reflux, difficulty swallowing, and jaundice.
Ovarian Cancer
Often called the silent killer, ovarian cancer mimics conditions like IBS or menopause. Early detection yields a 70% survival rate, versus 15% at advanced stages. Symptoms: abdominal pain, persistent bloating, feeling full quickly, loss of appetite, fatigue, frequent urination, postmenopausal bleeding, weight loss, and back pain.
Lung Cancer
The leading cause of cancer death in the UK, but early detection leads to a 60% five-year survival rate. Symptoms: a new or persistent cough, breathlessness, coughing up blood, chest or shoulder pain, recurrent chest infections, appetite loss, fatigue, night sweats, and weight loss.
Brain Cancer
Around 5,800 malignant brain tumours are diagnosed annually in the UK. Symptoms: headaches, seizures, limb weakness, stroke-like signs, nausea, drowsiness, vision changes, and personality or behaviour alterations.
Bladder Cancer
Bladder cancer is often mistaken for aging. Symptoms: blood in urine, recurrent UTIs, painful urination, frequent urination, incontinence, back or abdominal pain, fatigue, and weight loss.
The Promise of Liquid Biopsies
A revolutionary blood test called liquid biopsy analyses circulating tumour DNA to detect cancer before symptoms appear. While still in clinical trials, it offers non-invasive early detection. However, it may cause unnecessary anxiety for slow-growing cancers. Balancing benefits and drawbacks is key.
Red Flag Symptoms to Report
Half of adults with red-flag symptoms delay seeing a GP for six months or more. Report any of the following: unexplained lumps, weight loss, bowel habit changes, abdominal or anal pain, bleeding, persistent bloating, blood in stools or urine, changing moles, non-healing mouth ulcers, fatigue, unexplained pain, indigestion, itchy or yellow skin, anaemia, postmenopausal bleeding, or night sweats.
