Lung cancer

Lung cancer is one of the commonest malignant tumours and the leading cause of cancer death worldwide. Its defining feature is that the lung barely hurts: the tumour grows in tissue that has no pain endings, and for the first months, sometimes for years, a person feels much as usual. That is why the disease is so often found late, and why the small changes that are easy to blame on smoking and age matter so much. Treatment has changed more in the past decade than in the forty years before it, and in advanced disease the outlook is now often measured in years rather than months. But almost all of that gain depends on the stage at which the disease is caught.

Signs that are easy to blame on something else

There is no single symptom of lung cancer. What should raise concern is not that a complaint appears but that it persists: something that does not clear within three weeks and is not explained by a cold.

• A cough lasting more than three weeks, or a familiar smoker's cough that has changed — more frequent, harsher, different in sound.
• Blood in the sputum, even a few streaks, even once. This is the sign that always calls for investigation.
• Breathlessness building over weeks, and less tolerance of ordinary exertion.
• Repeated chest infections and pneumonias, particularly when the X-ray shows changes in the same place each time.
• Pain in the chest, shoulder or between the shoulder blades that is worse on breathing in and on coughing.
• Weight loss without dieting, loss of appetite, unexplained fatigue.

There are also less familiar signs, each with a definite anatomy behind it. A hoarse voice without a cold means the nerve running to the larynx has been affected. Swelling of the face and neck with prominent veins on the chest points to compression of the large vein in the mediastinum. Shoulder and arm pain with numbness, along with a drooping eyelid and a small pupil on that side, belongs to a tumour at the apex of the lung. Fingers whose tips become rounded like drumsticks, with curved nails, are a long-recognised sign that patients rarely know about. Sometimes the illness announces itself from a distance: seizures and weakness from a low sodium, confusion and thirst from a high calcium, striking muscle weakness. All of these are reasons to be investigated rather than to wait.

Who should be alert

Smoking remains the cause of most cases: tobacco smoke contains dozens of cancer-causing substances, and the risk depends both on how many cigarettes and on how many years. The important part is this: risk falls after stopping and keeps falling for decades, so giving up is worthwhile at any age and with any smoking history. E-cigarettes and heated tobacco are not regarded as a safe substitute — they are too recent for any judgement about cancer — and waterpipe smoking, or cannabis mixed with tobacco, raises the risk.

Besides smoking, what counts is:

• Radon, a natural radioactive gas that seeps out of the ground and collects in basements and ground-floor rooms. It is the second cause after tobacco and the leading one in people who have never smoked. Radon levels in a home can be measured and, if high, brought down with ventilation and sealing of the floor.
• Asbestos and occupational contact with arsenic, chromium, nickel, cadmium, silica, coal dust and diesel exhaust. Asbestos and smoking together multiply the risk rather than add to it.
• Second-hand smoke and years of living where the air is heavily polluted.
• Chronic obstructive pulmonary disease, previous tuberculosis, pulmonary fibrosis — scarred tissue raises the risk in its own right.
• Lung cancer in close relatives and previous radiotherapy to the chest.

Roughly one in ten of those who develop the disease has never smoked. They tend to be women and younger people, and their tumour is usually different in structure — precisely the kind in which modern targeted drugs work best. So "I don't smoke" is no argument against investigating persistent symptoms.

Why the type of tumour matters

Lung cancer is not one disease but several, and which one it is determines literally the whole of the treatment.

Non-small-cell cancer accounts for about four cases in five. It grows relatively slowly and at early stages can be removed surgically. Within it, adenocarcinoma (more often peripheral, more often in non-smokers), squamous cell carcinoma (closer to the large airways, more tightly linked to smoking) and rarer forms are distinguished.

Small-cell cancer makes up roughly one case in five and occurs almost only in smokers. It grows fast and spreads early, so surgery rarely fits, but the tumour is highly sensitive to chemotherapy and radiotherapy.

Today the name given under the microscope is no longer enough. The tumour sample is always tested for molecular faults — changes in the EGFR, ALK, ROS1, BRAF and KRAS genes among others — and for the PD-L1 protein. If a fault is found, tablets aimed squarely at it replace chemotherapy; they are tolerated far better and often work for years. If that testing was not done for you, it is worth asking about: it is not an optional extra but part of the modern diagnosis. Where there is little tissue, some of these changes can be found in a blood sample, from fragments of tumour DNA.

How the diagnosis is made

It usually starts with a chest X-ray. It is easy to obtain and quickly picks up large masses, but it has a weakness worth knowing: small tumours, and tumours hidden behind the heart or a rib, are missed. A normal film in someone with a persistent cough or blood in the sputum does not rule the diagnosis out — the next step should be a CT scan.

CT shows the size and position of the nodule and the state of the lymph nodes and neighbouring organs; to look for spread a PET-CT is done, and where the brain may be involved, an MRI of the head. Only examination of the cells, though, gives the final diagnosis. Tissue is obtained differently depending on where the tumour sits: through a bronchoscope if it is central, with a needle through the chest wall under CT guidance if it is peripheral, and from the mediastinal nodes with a bronchoscope carrying an ultrasound probe. Less often a surgical biopsy is needed. Any lung biopsy carries a risk of air leaking into the pleural cavity, so the person is monitored afterwards.

The stage is then worked out from the size and invasion of the tumour, whether there are cells in the lymph nodes, and whether there is spread to other organs. Early stages mean the disease is contained and removing it altogether can be attempted; late stages mean treatment will be systemic. Small-cell cancer is divided more simply: the tumour either fits inside a single radiotherapy field or has already gone beyond it.

Finding it early

This is where most can be gained. Regular low-dose CT scanning in people with a long smoking history has been shown to find tumours at an operable stage and to reduce mortality. A plain chest X-ray does not serve this purpose: trials have shown it does not lower mortality.

Exactly who should be scanned and how often is decided by national programmes, and these differ from country to country; the shared principle is mature age combined with many years of smoking, including those who stopped fairly recently. If that describes you, ask your doctor whether such a programme exists where you live. Scanning everyone makes no sense: in people without risk factors low-dose CT produces more false alarms and unnecessary procedures than benefit.

What treatment can offer

The plan is drawn up by a team — thoracic surgeon, oncologist, clinical oncologist in radiotherapy, radiologist and pathologist. This is not a formality: for one and the same tumour sitting on the border between stages, several reasonable approaches may exist.

• Surgery is the main chance of cure in early non-small-cell cancer. Usually a lobe is removed along with the nearby lymph nodes; for small tumours a segment may be enough, and a central tumour may require the whole lung. Many operations are now done through small incisions, with faster recovery. Living with one lung is possible; breathing reserve and heart function are checked beforehand.
• Radiotherapy. For someone who cannot have surgery, a small tumour is often treated instead with stereotactic radiotherapy — a few highly precise sessions, with results close to surgical ones. In locally advanced disease radiotherapy is combined with chemotherapy.
• Drug treatment. Chemotherapy is given before or after surgery, alongside radiotherapy or on its own. Immunotherapy teaches the body's own defences to recognise the tumour and has clearly extended life in advanced disease. Targeted drugs are used where a molecular fault has been found.
• Small-cell cancer is treated with chemotherapy together with immunotherapy; where the extent is limited, chest radiotherapy is added, and sometimes preventive radiotherapy to the head, because this type frequently spreads to the brain.
• Relief of symptoms. When the tumour blocks an airway or causes pain, a short course of radiotherapy, a stent in the bronchus and drainage of pleural fluid all help. Pain relief is built up in steps and at an adequate dose — there is no reason to endure pain.

One thing deserves separate mention because it rests with the person themselves. Stopping smoking after the diagnosis is not a belated gesture: it reduces surgical complications, improves tolerance of radiotherapy and chemotherapy, and lengthens survival. It is one of the few decisions a patient makes alone, and it genuinely affects the outcome.

When help is needed urgently

Lung cancer has situations measured in hours. Call an ambulance (in European countries, the single number 112) if:

• heavy coughing of blood begins — blood by the mouthful, or soaking one handkerchief after another;
• breathlessness worsens abruptly, there is severe chest pain, the lips turn blue, or the person cannot finish a sentence;
• there is loss of consciousness, a seizure, sudden weakness down one side or slurred speech;
• during chemotherapy the temperature rises to 38 °C or above with chills, confusion or fast breathing — with a low white cell count this is an emergency, and antibiotics are needed within the first hour.

The same day, without delay, contact the oncology team or go to hospital if the face and neck swell with prominent veins and a bursting sensation in the head; if back pain appears with increasing weakness in the legs, numbness or difficulty passing urine, because that is how spinal cord compression shows itself and whether walking is preserved depends on speed; if there is intense thirst, nausea, confusion and constipation, which can mean a dangerous rise in blood calcium; and likewise with a new severe headache, morning vomiting or double vision.

Life during treatment and afterwards

Breathlessness is the commonest complaint, and it is not tackled with medicines alone. Pursed-lip breathing helps, as does a stream of cool air from a fan onto the face, rearranging the home so the stairs are used less often, and breathing exercises with a physiotherapist. Where fluid in the pleural space, anaemia or infection lies behind the breathlessness, treating the cause achieves more than any exercise. Where oxygen levels stay low, home oxygen is considered.

Moderate physical activity during treatment is not forbidden but useful: it reduces fatigue and anxiety and eases recovery after surgery. Walking is the place to start, building up gradually. Holding weight matters, because losing muscle worsens tolerance of treatment, and with a poor appetite a dietitian is worth seeing. Vaccination against flu and pneumococcus is sensible: infections run a harder course in damaged lungs.

Anxiety, low mood and disturbed sleep with this diagnosis are not weakness but an ordinary part of the picture, and they respond to help: talking to a psychologist, medication where needed, support groups. Palliative care is also worth understanding: it is not "when nothing more can be done" but support brought in alongside the main treatment to keep pain, breathlessness and nausea under control — and the earlier it starts, the better both wellbeing and tolerance of therapy tend to be.

Online consultation

A remote appointment fits every stage except the procedures themselves. Before a diagnosis, the doctor will go through your symptoms, judge whether they sit within the usual picture for a smoker or call for a CT scan, and explain which test to start with so that weeks are not lost on the wrong one. After a diagnosis, they will help make sense of the discharge letter and the pathology report, explain what the stage and the molecular findings mean, and check whether molecular testing was requested — a question that often decides the treatment. During therapy, online is a convenient place to discuss side effects, skin and bowel reactions to immunotherapy, food and how much exertion is reasonable, and to work out what can wait at home and what means going to hospital. Support with stopping smoking and questions about vaccination belong here too. And separately, the doctor will name the signs that mean calling an ambulance rather than writing to the clinic.

This material is for information only and does not replace medical advice.