What's new in lymphoma treatment
Dr Lim ZiYi, Senior Consultant (haematology) at Parkway Cancer Centre, looks at the cutting edge in treating lymphoma.
Lymphoma is the most common form of blood cancers in adults – one in 50 people will develop lymphoma in their lifetime. As populations age, lymphoma will become increasingly common and indeed, the incidence of lymphoma has been steadily increasing over the past 15 years.
Stages of lymphoma
There are 4 main stages (Stage 1 to 4) as well as an A or B category as follows:
Stage 1: One group of affected lymph nodes on either side of the diaphragm.
Stage 2: Two or more groups of affected lymph nodes but still on only one side of the diaphragm.
Stage 3: At least two groups of affected lymph nodes but must be on both sides of the diaphragm.
Stage 4: If there is disease affecting an organ (e.g. bone marrow, liver) other than lymph nodes.
Stage A: Absence of recurrent fevers, night sweats or weight loss.
Stage B: Presence of any one of the above.
Lymphoma is usually detected at a more advanced stage, but even at Stage 4, the cure rates are about 50 per cent. Over the decades, treatment outcomes for people with lymphoma have improved. In the 1970s, the five-year survival rate for lymphoma was approximately 50 per cent. Today, it is over 70 per cent. This improvement in outcomes is largely due to significant advances in the treatment of lymphoma.
The main form of treatment for lymphoma has traditionally been chemotherapy and sometimes radiotherapy. However, in the last two decades, targeted therapy has made a significant difference to the way patients with lymphoma are treated.
Targeted therapies block the growth and spread of cancer by interfering with specific molecules that are involved in the growth, progression, and spread of cancer.
One important drug in the treatment of lymphoma is rituximab, which is a first-generation monoclonal antibody. These are engineered antibodies which target proteins on the cancer cell. In the United States, death rates from lymphoma dropped significantly from 1997, after rituximab was approved for use.
Other drugs have since emerged to target different types of lymphoma. These include brentuximab vedotin and ibrutinib.
Brentuximab vedotin targets the protein CD30, which is expressed in Hodgkin’s lymphoma and systemic anaplastic large cell lymphoma. Ibrutinib, on the other hand, is a drug that binds to a protein, Bruton’s tyrosine kinase (BTK), found in B cells which are a type of white blood cell. The drug is used on B-cell cancers such as mantle cell lymphoma as well as chronic lymphocytic leukaemia.
These drugs are part of a new wave of lymphoma therapies which are transforming the outcomes of patients.
However, while targeted therapies can be effective, they are not always a permanent solution as the cancer is able to evolve and become immune to the drug. That is where immunotherapy comes in.
Immunotherapy is a form of therapy where the patient’s own immune system is activated to fight the cancer cells within. It has been described as the fourth pillar of cancer treatment, together with chemotherapy, radiotherapy and targeted therapy.
In many advanced cancer patients, their immune system is often unable to recognise or fight the cancer effectively.
A new class of immunotherapy drugs targeting an important receptor (known as PD-1) have been shown to be highly effective in solid tumour cancers. New data has also shown that these drugs are highly effective in patients with resistant Hodgkin’s lymphoma with impressive results seen.
- There are more than 50 types of lymphoma but these can be generally classified into two categories: high grade and low grade.
- High grade lymphoma is fast growing and without treatment, many patients will die from the rapid disease progression. However, high grade lymphoma is potentially curable with chemotherapy.
- Low grade lymphoma grows over the years or decades, and often, in early stages, there is no need for treatment. However, it is generally incurable with chemotherapy and patients often require intermittent therapy.
- One of the signs of lymphoma is lymph node swelling, but most cases of swollen lymph nodes are not lymphoma. Patients should see a specialist if their lymph nodes have been persistently swollen, over four weeks or more, if they are increasing in size, if they are greater than 2 cm in size, if the enlarged nodes are widespread and if these are accompanied by the other symptoms.
- Other symptoms include a fever, night sweats, unexplained weight loss and pruritus, a severe itch. However, all these symptoms could be related to other causes including infections such as tuberculosis as well, so further investigation is necessary.
Tags: blood cancer, cancer drugs, immunotherapy, new ways to treat cancer, swollen lymph node, targeted therapy