Hodgkin lymphoma

Hodgkin lymphoma is an uncommon tumour of the lymphatic system: roughly two to three cases per hundred thousand people a year. It has an unusual spread across the ages — one peak between twenty and forty, another after seventy — and a reputation as one of the most rewarding diseases in cancer medicine. The word "cancer" frightens more here than the figures warrant: with modern treatment the great majority of people recover, including those whose tumour was found late. What matters far more is not missing the beginning, because it begins quietly, with a lump in the neck that causes no trouble at all.

What goes wrong in the lymphatic system

The lymphatic system is a network of fine vessels and nodes running through the whole body, serving at once as drainage and as a guard: lymph flows along the vessels, is filtered in the nodes, and the nodes house lymphocytes, the cells that recognise infection. The glands you can feel in the neck during a sore throat are that guard at work.

In Hodgkin lymphoma one B lymphocyte acquires a fault in its DNA and stops obeying the rules: it does not die on schedule and divides without restraint. Its descendants are large, misshapen cells that a pathologist recognises down the microscope at a glance, and it is by them that this disease is told apart from other lymphomas. Curiously, there are not many tumour cells in the node itself: the bulk is made up of ordinary inflammatory cells that the tumour recruits and persuades to defend it. The node grows for that reason and stops doing its own job at the same time.

At first the process stays within one group of nodes, most often in the neck or above the collarbone. It then spreads predictably from one group to the next, and only at late stages leaves the lymphatic system for the bone marrow, spleen, liver or lungs. That predictability is exactly what makes it so curable: there is time to catch it while it is still on the map.

The lump that does not go away

The main sign, and often the only one, is an enlarged node in the neck, above the collarbone, less often in the armpit or groin. It is painless, firm, moves under the fingers and is not inflamed; people find it by chance while shaving or doing up a collar. That is where its treachery lies: no pain, so it feels like nothing urgent.

Separate attention goes to what doctors call general symptoms, because their presence changes both the stage and the plan.

• a temperature above 38 °C with no infection to explain it, coming in waves towards evening;
• drenching night sweats — not "warm under the duvet" but a soaked nightshirt and a change of bedding;
• weight loss without dieting, and marked: around a tenth of body weight over six months;
• persistent itching of the whole skin with no rash, sometimes months before anything else;
• weakness and tiredness out of all proportion to what you have done.

There is also an uncommon clue worth knowing about: in some people the enlarged node starts to ache a few minutes after a glass of wine. It happens rarely but is so characteristic that it deserves a mention to the doctor.

If the tumour grows inside the chest, between the lungs, there is nothing to feel, and the first things to appear are a dry cough, a sense of pressure behind the breastbone and breathlessness on exertion. When the bone marrow is involved, pallor, repeated infections, bruising and bleeding are added. Nodes in the abdomen cause heaviness, dull pain and early fullness after eating.

One situation calls for immediate help: swelling of the face and neck, distended veins over the chest, a bluish colour and rising breathlessness. That is compression of the large vein returning blood from the head; it develops over hours and needs an ambulance (in Europe, 112), not an appointment.

When a swollen gland means nothing

Proportion matters here: almost everyone gets swollen glands at some point, and almost always for an innocent reason — tonsillitis, a bad tooth, a scratch, a viral infection. Such a gland is tender, soft, comes up quickly and settles just as quickly, within two or three weeks. Show a gland to a doctor if it lasts longer than a month without shrinking, if it is growing, hard and fixed to the surrounding tissue, if it sits above the collarbone, or if it arrived alongside fever, sweats and weight loss. Even with all of that the odds still favour something benign, but the checking should be prompt: the difference between waiting three weeks and waiting three months shows up in how much treatment is needed.

What raises the odds

The cause of the first fault in the cell is unknown, and no way of living brings it on. Only circumstances are known in which the risk is a little above usual:

• a past bout of glandular fever — the Epstein-Barr virus is found inside the tumour cells in some cases;
• weakened immunity: untreated HIV, medicines that suppress the immune system after an organ transplant, inherited immune deficiencies;
• lymphoma in a parent, sibling or child — the risk rises, although the disease is not directly inherited;
• smoking.

It is worth saying plainly: Hodgkin lymphoma is not contagious, and living alongside someone who has it is safe. Enormous numbers of people get glandular fever in their youth and only a handful develop lymphoma, so having had the infection is not a reason to be investigated just in case.

Only a biopsy makes the diagnosis

Blood tests, ultrasound and scans diagnose nothing; they only show where to look. Confirmation comes solely from a pathologist looking at node tissue under the microscope, and it is better if the whole node has been removed: a fine needle collects cells but not architecture, and here the architecture decides everything. It is a small operation, usually under local anaesthetic; a deep-lying node needs a general one.

Once confirmed, the next question is where else the disease has reached: blood tests including liver and kidney function, a CT scan of chest, abdomen and pelvis, and above all a PET scan combined with CT, which shows not the size of the nodes but their activity. It is precisely this that has replaced the separate bone marrow biopsy once performed on almost everybody.

One conversation belongs before the first infusion rather than after it. Chemotherapy and radiotherapy can damage fertility, sometimes permanently. Men are offered sperm banking, women the freezing of eggs, embryos or ovarian tissue. All of it happens beforehand, and if the doctor has not raised it, you should.

Stages, and why they are counted

The stage is set by how many groups of nodes are involved and on which side of the diaphragm — the muscular partition between chest and abdomen — they lie.

• Stage one — one group of nodes affected.
• Stage two — two or more groups, all on the same side of the diaphragm.
• Stage three — nodes both above and below the diaphragm.
• Stage four — the disease has left the lymphatic system for bone marrow, liver or lungs.

A letter is added to the number: A if there are no general symptoms, B if there is fever, night sweating or weight loss. Bulky tumour masses, usually in the chest, are noted separately.

The stage here does not mean what it means with most tumours. Stage four Hodgkin lymphoma is not a lost cause: it too is treated with cure in mind. The stage decides how long and how intensive treatment will be, not whether treatment is worth giving.

How it is treated

The backbone is chemotherapy: a combination of several medicines given in cycles with gaps between them, usually as an outpatient, over several months. In early stages radiotherapy is added to the affected area — nowadays at lower doses and over smaller fields than twenty years ago, precisely because the late consequences have been counted. Lymphoma is not removed surgically: the operating theatre is involved only for the biopsy.

The modern approach is built around an interim PET scan. It is done after the first cycles and the plan is adjusted by its result: if the tumour has gone quiet quickly, treatment is shortened and the most toxic components are dropped; if the response is poor, the regimen is intensified without waiting for the end. That adjustment on the move is the great change of recent years — treating less where one can and more where one must.

Disease that returns, or responds poorly to first-line treatment, is not the end of the road. High-dose chemotherapy with a transplant of the patient's own stem cells remains in reserve, along with newer medicines: antibodies that carry a drug directly into the tumour cell, and treatments that release the brake the tumour puts on the immune system.

Side effects are predictable: nausea, weakness, hair loss, mouth ulcers, falling blood counts. One rule is worth committing to memory. A temperature of 38 °C or above during chemotherapy is an emergency. White cells are low at that point, and an ordinary infection can turn dangerous within hours. Do not wait for morning and do not take something for the fever to see how it goes: contact the treating team at once or go to hospital.

Life after treatment

About eight or nine people in ten live for many years after treatment, and most are cured outright. For the first years appointments come every few months and then grow further apart, and the purpose of follow-up shifts: first it looks for the disease returning, later for the consequences of the treatment itself. Almost all of those are manageable, which is why knowing about them helps more than not knowing:

• the thyroid often becomes underactive after radiotherapy to the neck — a blood test finds it and one tablet makes up for it;
• the heart and arteries suffer from some of the drugs and from chest radiotherapy, so blood pressure, cholesterol, weight and smoking matter more here than for others of the same age;
• the lungs may become less elastic, and smoking multiplies that effect;
• second cancers are a rare but real consequence, usually ten years later or more; women irradiated to the chest when young start breast screening earlier than usual;
• immunity does not come back all at once, and live vaccines are not given in the first months after treatment; which vaccinations to repeat and when is decided with the doctor according to the national schedule.

Fatigue deserves a paragraph of its own. It lingers for months after the last cycle and takes people by surprise more than anything else. It does pass, but slowly, and moderate exercise speeds it up better than rest does.

Online consultation

Remote care covers the beginning and the end of this story well. At the beginning, when there is a lump that will not go and it is unclear whether to worry: the doctor will ask about timing, accompanying symptoms and general health, and will say whether an urgent face-to-face appointment is needed and which test to start with. At the end, when treatment is behind you and questions come up that hardly justify a journey: how to read follow-up blood tests, what to do about the fatigue, when to go back to work and to sport, which vaccinations are due, what a line in the discharge letter means. What cannot be done remotely is the diagnosis itself, which comes only from a biopsy. And with a swollen face and breathlessness, or a fever during chemotherapy, no consultation is waited for — urgent care is sought.

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