Non-Hodgkin lymphoma (NHL) is a type of blood cancer that develops from the lymphatic system. This system is a network of vessels throughout your body that work as part of your immune system, carrying fluid containing infection-fighting white blood cells, called lymphocytes, to where they detect a threat. In NHL, these lymphocytes become dysfunctional and multiply out of control. They can then collect in different areas of the lymphatic system known as the lymph glands, and this can cause swelling you can see and feel in certain areas of the body. The consequence is that the lymphatic system becomes less able to fight infections. NHL can occur at any age, but your chance of developing the condition increases as you get older, with just over a third of cases diagnosed in people over 75. It’s fairly common in the UK, within the top 10 most common cancers and accounts for 4% of all cancers.
In most cases, we don’t know what causes NHL. There are certain factors that can put you at higher risk, such as having a weakened immune system, either from a condition such as cancer, or from medication such as chemotherapy. It can run in families and glandular fever, a common throat infection caused by the Epstein-Barr virus, may increase your risk.
You may notice swollen lymph glands – these sit in your neck, armpit and groin area. These swell when you have an infection, as part of lymphocyte production in defence, but healthy lymph nodes responding to infection will feel rather tender to touch, you may have other signs of infection, and they will shrink again after two weeks. In contrast, lymph nodes that are swollen due to NHL are usually painless and persistent. Other symptoms are more general for inflammatory processes, cancer or infection, such as night sweats, weight loss without trying, poor appetite, persistent fevers and itching all over the body. Abnormal cells in the bone marrow leads to fatigue, excessive bleeding and an increased risk of infections.
You should book an appointment urgently with your doctor if you notice any of these general signs or you have one or more lymph nodes that are swollen for more than a couple of weeks, especially if you weren’t unwell when it started. Your doctor will ask detailed questions about your symptoms, medical history and family history. They will examine your lymph glands looking for enlargement of these glands at particular points in your body. They will organise blood tests. If there are any concerns of blood cancer, they will refer you urgently to specialists called haematologists.
Treatment depends on the type of NHL, how much it has spread and your overall fitness and health. Chemotherapy is one option, where medications are designed to kill cancerous cells. Radiotherapy uses high energy radiation to damage cancerous cells and stop them growing. Targeted therapy is designed to seek and destroy vulnerable cancer cells. A combination of two or event three of these may be appropriate - treatment will be tailormade to each individual. NHL can be divided by how quickly it grows, and this guides treatment. High-grade NHL is where the cancer grows quickly and aggressively. Treatment will need to be initiated straight away, but it’s usually more effective and curable than low-grade NHL. This is where the cancer grows slowly, and symptoms may not present for some time. This one is harder to cure but may not require treatment straight away. With any cancer diagnosis, one of the first questions people ask is will I survive it? The chance of survival with NHL is good, with nearly 80% surviving after the first year, and around half are alive after 10 years. This is good, considering that most of those diagnosed are aged 70 and over.