Mesothelioma

Mesothelioma is an uncommon tumour of the membranes that line the chest and the abdomen from the inside. Almost always there is asbestos behind it, breathed in decades before the first complaint, so a single sentence can change the whole direction of the investigation: "I worked with building materials", or "my father came home from work in dusty overalls". Say it to the doctor yourself, even if nobody asks.

What kind of tumour this is

The lungs, the heart and the organs of the abdomen are covered by a thin, slippery film called the mesothelium. It produces a small amount of fluid, thanks to which the lung glides freely inside the chest and loops of bowel move against one another. A tumour arising from the cells of that film is a mesothelioma.

Most often it starts in the pleura, the lining of the lung, and that accounts for the great majority of cases. Less often it involves the peritoneum, and very rarely the lining of the heart or of the testicle. It does not grow as a lump but as a sheet: it spreads across the surface, thickens the membrane and gradually squeezes whatever lies beneath. Hence its main effect, a build-up of fluid and increasing difficulty in breathing.

It comes in different types under the microscope, and this is not a formality: the epithelioid type behaves noticeably more gently and the sarcomatoid type more aggressively, and both treatment and expectations follow from that.

Asbestos and who is at risk

Asbestos is a group of natural minerals that split into extremely fine, strong fibres. They were prized for resisting fire and for decades were added to roofing sheets, pipes, insulation, brake linings and fireproof fabrics. An inhaled fibre settles deep in the lung, the body can neither dissolve nor clear it, and it keeps inflammation going around itself for decades.

The gap between breathing it in and falling ill is enormous, usually twenty to fifty years. That is why those affected are mostly over sixty while the cause reaches back to their youth. No safe threshold has been established: cases are known after relatively brief contact.

• builders, roofers, insulation fitters, plumbers and electricians who worked in older buildings;
• shipyard workers, boilermakers, engine drivers and railway staff;
• vehicle mechanics who changed brake pads and clutches;
• people employed in asbestos factories and quarries;
• family members who washed work clothes, known as household exposure.

Smoking does not cause mesothelioma, although together with asbestos it sharply raises the risk of lung cancer: these are two different diseases. There is also a rare inherited form linked to a fault in the BAP1 gene; in such families mesothelioma and melanoma of the eye turn up in several relatives, often at younger ages. If cases repeat in your family, mention it to the doctor.

Asbestos has been banned across the European Union since the mid-2000s, and earlier in some countries, but plenty remains in older buildings. Intact, undamaged material poses no danger; the danger is dust. Do not saw, drill or break up suspect panels yourself — licensed contractors do that work.

What should raise concern

The symptoms build up slowly over months and at first resemble almost anything.

• breathlessness that worsens week by week, at first on climbing stairs and later on level ground;
• a dull ache in one side of the chest or in the back, unrelated to movement and refusing to settle;
• a dry cough that does not respond to the usual treatment;
• night sweats, a low-grade temperature and unexplained tiredness;
• loss of weight and appetite with no dieting at all.

When the tumour sits in the peritoneum the picture differs: the abdomen swells and feels tight, with a dragging ache, nausea, a sense of fullness after a small meal, altered bowel habit and sometimes a hernia appearing for the first time. Weight is lost even as the abdomen grows, and that combination is highly characteristic.

None of these on its own means mesothelioma. But if they persist beyond three weeks and there was asbestos contact in the past, investigation should start without delay.

When waiting is not an option

Straight away, calling an ambulance on the single European number 112:

• rapidly worsening shortage of air, breathlessness at rest, inability to lie flat;
• severe chest pain, blue lips, confusion;
• coughing up blood;
• swelling of the face and neck with distended veins, a sign that a large vein in the chest is being compressed;
• with a tumour in the peritoneum, severe abdominal pain, vomiting and complete absence of stool and wind, which is how bowel obstruction presents.

A doctor is needed the same day or the next if breathlessness has worsened over a few days, if fever with chills appears, if the pain no longer responds to what usually works, or if a chest drain starts producing foul-smelling fluid and the skin around it turns red. Everything else calls for a planned appointment, but booked for the coming week rather than "whenever there is a slot".

How the diagnosis is made

It begins with a plain chest X-ray: it will show fluid in the pleural cavity or a thickened membrane, but it cannot tell mesothelioma apart from other causes. Next comes a computed tomography scan with contrast, which shows the thickness and the extent of the disease and indicates where a sample can be taken most safely.

Fluid from the pleura or the abdomen is drawn off through a needle: this relieves breathing at once, and the fluid is sent for analysis. Here comes an important caveat: examining cells from the fluid often gives no answer, and a negative result does not exclude mesothelioma. Stopping there is a mistake, and it is precisely at this step that months are most often lost.

The diagnosis rests on tissue. For that, a thoracoscopy is performed — inspecting the pleural cavity with a camera through a small incision and taking pieces of the abnormal membrane under direct vision; where the peritoneum is involved, the same is done laparoscopically. Sometimes a core needle biopsy of the thickened pleura under scan guidance is enough. The material obtained is always examined with immunohistochemistry: without it, mesothelioma is hard to separate from secondary deposits of another cancer, and the treatments differ.

To judge the extent, a positron emission tomography scan is added, and sometimes magnetic resonance imaging. Lung function is measured when surgery is under discussion. There is no proven screening programme for people who were exposed to asbestos: an X-ray taken just in case does not lengthen life, whereas coming forward with symptoms and naming the exposure straight away does.

How it is treated

The plan is drawn up by a team of specialists and depends heavily on where the tumour sits, which type it is and how much exertion the person can tolerate.

The backbone of drug treatment is chemotherapy and immunotherapy. A combination of two medicines that release the brakes on immune cells has shown an advantage over chemotherapy alone in pleural mesothelioma, particularly in the non-epithelioid types. Radiotherapy is used in a targeted way, most often to take away pain at a particular spot.

Surgery for pleural mesothelioma is possible only in a minority of patients, at an early stage and in specialist centres; its value is still debated, and an operation is never the only treatment. For mesothelioma of the peritoneum the picture is different and distinctly more hopeful: combining cytoreductive surgery with heated chemotherapy delivered into the abdomen gives selected patients years of life. It is worth asking about this if the tumour has been found in the abdomen.

Work on the symptoms matters no less. What gets in the way most is fluid re-forming, and there are two ways round it: putting talc into the pleural cavity so that the layers stick together and fluid stops collecting, or fitting a thin permanent catheter that allows it to be drained at home. Pain in mesothelioma can be stubborn and is treated by stepping up as needed, including opioid painkillers; enduring it is neither necessary nor useful. Bringing in the palliative care team early, rather than "at the very end", improves how people feel and does not shorten life.

Outlook and the practical side

Being straightforward about this is better than talking around it. Pleural mesothelioma is usually found late, and average survival after diagnosis is around a year to eighteen months. But an average is not a sentence passed on an individual: with the epithelioid type, good general condition and a response to immunotherapy, the count runs into years, and with peritoneal mesothelioma operated on in a specialist centre, into many years.

Practical matters are best settled early, while there is strength for them. In many countries mesothelioma is recognised as an occupational disease and carries an entitlement to payments or compensation; the procedure differs from place to place, but almost everywhere records of past employment and a written diagnosis will be needed. Gather your work history and write down where and when the asbestos contact occurred, because reconstructing it later is far harder.

And do not carry this alone. Talking to a psychologist, support groups for patients and their families, and help from a social worker are not luxuries; the illness weighs on more than the body, and those close to the patient sometimes find it harder than the patient does.

Online consultation

A remote appointment is useful at two points. Before diagnosis, to work out whether your symptoms fit a picture that needs investigating quickly and in what order to do it: the doctor goes through images and reports and explains why a fluid sample on its own is not enough and why a biopsy is worth insisting on. Have the radiology reports, discharge letters and a list of workplaces with approximate years to hand.

After diagnosis the conversation helps in reading the pathology report and the stage, understanding the proposed treatment and its side effects, weighing whether a second opinion or referral to a specialist centre makes sense, and adjusting pain relief between visits. The limits are obvious: nobody can examine you or obtain fluid and tissue through a screen, and a sudden worsening of breathlessness calls for an ambulance rather than a call.

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