Blood cancers: leukaemia, lymphoma and myeloma

What blood cancers are

Blood cancers happen when something goes wrong with the way the body makes blood cells. Most blood cells are made in the bone marrow, the spongy centre of our bones, and they include red cells that carry oxygen, white cells that fight infection, and platelets that help blood to clot. In blood cancer, cells grow abnormally and out of control, crowding out healthy cells and stopping the blood from doing its job properly. Because the problem is in the cells rather than a single organ, blood cancers usually do not form a lump you can feel in the way a breast or bowel cancer might. Understanding that these are cancers of the blood-making and infection-fighting systems helps make sense of the symptoms they cause and how they are treated.

Leukaemia, lymphoma and myeloma explained

The three main blood cancers affect different cells and parts of the system. Leukaemia mainly affects white blood cells and the bone marrow, where too many abnormal cells are made; it can be acute (fast-growing and needing urgent treatment) or chronic (slower and sometimes just monitored at first). Lymphoma affects the lymphatic system — the network of glands and vessels that helps fight infection — and often shows up as swollen lymph nodes; its two broad types are Hodgkin and non-Hodgkin lymphoma. Myeloma affects plasma cells, a type of white cell in the bone marrow, and often causes bone pain, kidney problems and tiredness. Each type has many sub-types, which is why specialist testing is needed to pin down exactly which one a person has and how best to treat it.

Symptoms to watch for

Blood cancer symptoms can be vague and easily mistaken for everyday illness, which is one reason diagnosis is sometimes delayed. Common warning signs include unexplained and persistent tiredness, repeated or unusual infections, unexplained bruising or bleeding, and unexplained weight loss. Some people notice drenching night sweats, fevers that come and go, or swollen but usually painless lumps in the neck, armpit or groin, which can be swollen lymph nodes. Myeloma often causes persistent bone or back pain. Individually these symptoms are far more likely to be caused by something harmless, but if they are unexplained, persistent, or several occur together, they should be checked by a GP. A simple blood test can often provide important early clues.

How they are diagnosed

Diagnosis usually begins with a GP who examines you and arranges blood tests, which can reveal abnormal numbers of blood cells or other clues. If blood cancer is suspected, you will be referred to a specialist, often on an urgent cancer pathway, for more detailed tests. These may include further blood tests, a bone marrow sample taken with a needle (usually from the back of the hip) to look at the cells directly, and a biopsy of a swollen lymph node for lymphoma. Scans such as CT or PET help show how far a cancer has spread. Specialist laboratory tests then identify the exact type and sub-type, which is essential because treatment differs greatly between them. Getting a precise diagnosis is the foundation for the right treatment plan.

Treatment and outlook

Treatment depends heavily on the type of blood cancer, how advanced it is, and the person's general health, so plans are highly individual. Options include chemotherapy, targeted therapies that home in on cancer cells, immunotherapy that harnesses the immune system, radiotherapy, steroids, and stem cell (bone marrow) transplants. Some slow-growing blood cancers may not need immediate treatment and are carefully monitored, an approach sometimes called "watch and wait". Care is provided by specialist teams and includes support for symptoms and wellbeing. Encouragingly, outcomes for many blood cancers have improved greatly thanks to better treatments and, in some, they can be cured or controlled for many years. The message is one of realistic hope: earlier diagnosis and modern treatment mean more people are living longer and living well.