50 years of CHOP chemotherapy A backbone of lymphoma treatment
Chemotherapy has long been a mainstay of cancer treatment and continues to be an important treatment option for many people with lymphoma. As well as 40 years of Lymphoma Action, 2026 also marks 50 years of the chemotherapy regimen CHOP.
What is CHOP?
The term ‘CHOP’ is an acronym representing a four-drug chemotherapy regimen used to treat some types of non-Hodgkin lymphoma.
C – cyclophosphamide
H – doxorubicin (or hydroxydaunorubicin)
O – vincristine (Oncovin®)
P – prednisolone
The drugs in CHOP work together to attack cancer cells in slightly different ways.
The history of CHOP
CHOP was first described fifty years ago in 1976 by Dr Eugene McKelvey and colleagues. Their studies showed CHOP to be an effective treatment for non-Hodgkin lymphoma and it became the most widely used treatment for aggressive large-cell lymphomas.
Alternative, more intensive, regimens were developed in the 1980s, but a pivotal study in 1993 by Dr Fisher confirmed CHOP to be the standard of care. Their randomised trial showed CHOP to be as effective as the newer regimens but with significantly less toxicity. CHOP has been a backbone of non-Hodgkin lymphoma treatment ever since.
When CHOP became R-CHOP
Another major milestone came in the early 2000s, with the addition of a targeted therapy called rituximab. Rituximab is an antibody that helps the immune system recognise and attack lymphoma cells. Clinical trials showed that adding rituximab significantly improved outcomes for many people with B cell lymphomas.
When rituximab is added to CHOP, the treatment is known as R-CHOP. R-CHOP quickly became the standard treatment for many people with diffuse large B-cell lymphoma (DLBCL) and remains widely used today.
When CHOP is still important
CHOP is still used today in the treatment of many T-cell lymphomas. Several modified CHOP regimens have been developed to optimise efficacy or reduce toxicity in specific patient populations. For example:
- mini-CHOP is a reduced-dose version of CHOP, reducing the toxicity, making it more suitable for frail or older people
- CVP doesn’t include the doxorubicin in CHOP for those with cardiovascular concerns.
Newer regimens are often related to CHOP, based on some of the same components. For example, Pola-R-CHP, often used in the treatment of DLBCL, replaces vincristine with an antibody-drug conjugate called polatuzumab vedotin. This improves effectiveness.
The CHOP chemotherapy regimen also continues to play a pivotal role in the development of lymphoma treatments. It is used in many clinical trials as a standard of care, against which many new treatments are tested and is the backbone to which new drugs are being added to improve outcomes.
Fifty years on, CHOP remains a backbone of many non-Hodgkin lymphoma treatment options. CHOP’s legacy is undeniable, illustrating the power of combination chemotherapy to treat lymphoma and laying the groundwork for modern treatments.
With thanks to Professor Andy Davies for reviewing this article.
