CHOP Regimen for Non-Hodgkin's Lymphoma
CHOP is a standard chemotherapy regimen for non-Hodgkin's lymphoma consisting of Cyclophosphamide, Hydroxydaunorubicin (doxorubicin), Oncovin (vincristine), and Prednisone. 1
Components and Dosing
CHOP is administered in cycles, typically every 21 days, with the following medications:
- Cyclophosphamide: 750 mg/m² intravenously on day 1
- Hydroxydaunorubicin (doxorubicin): 50 mg/m² intravenously on day 1
- Oncovin (vincristine): 1.4 mg/m² intravenously on day 1 (maximum total dose of 2 mg)
- Prednisone: 100 mg orally on days 1-5 2
Clinical Applications
CHOP is primarily used for:
- First-line treatment of diffuse large B-cell lymphoma (DLBCL)
- Treatment of various aggressive non-Hodgkin's lymphomas
- Often combined with rituximab (R-CHOP) for CD20-positive lymphomas 2
Treatment Variations
Several variations of the CHOP regimen exist:
- R-CHOP: Standard CHOP plus rituximab (375 mg/m² IV on day 1), which has become the standard of care for CD20-positive lymphomas 2
- R-CHOP-14: Administered every 14 days instead of 21 days, with G-CSF support 2
- R-miniCHOP: Attenuated doses for elderly patients (>80 years) 2
- Dose-adjusted CHOP: Modified dosing based on patient tolerance 3
Number of Cycles
The number of cycles depends on disease stage and patient factors:
- Early-stage disease: 3-4 cycles (may be combined with radiation therapy)
- Advanced disease: 6-8 cycles
- For young patients with favorable prognosis, 4 cycles of R-CHOP may be non-inferior to 6 cycles 4
Common Side Effects
Patients receiving CHOP commonly experience:
Hematologic toxicities:
- Neutropenia (may require G-CSF support)
- Thrombocytopenia
- Anemia
Non-hematologic toxicities:
- Alopecia (hair loss) - occurs in nearly all patients by cycle 3
- Fatigue (77% of patients)
- Taste changes (74% of patients)
- Nausea and vomiting
- Constipation (from vincristine)
- Peripheral neuropathy
- Increased risk of infection 5
Monitoring During Treatment
Patients receiving CHOP should be monitored for:
- Complete blood counts before each cycle
- Cardiac function (due to doxorubicin's cardiotoxicity)
- Neurological symptoms (due to vincristine's neurotoxicity)
- Tumor lysis syndrome, especially in patients with high tumor burden
- Response assessment typically after 3-4 cycles and at completion of therapy 2
Historical Context
CHOP was established as the standard treatment for aggressive non-Hodgkin's lymphoma in a landmark 1993 study that compared it with three more intensive regimens (m-BACOD, ProMACE-CytaBOM, and MACOP-B). The study found no significant differences in response rates or overall survival between CHOP and the more complex regimens, but CHOP had fewer fatal toxic reactions (1% vs 3-6%) 6.
Efficacy
CHOP alone produces complete response rates of approximately 60% in aggressive non-Hodgkin's lymphoma, with long-term disease-free survival in about 30-40% of patients. The addition of rituximab (R-CHOP) has significantly improved these outcomes, with 5-year overall survival rates now approaching:
- 60-70% for younger patients (<60 years)
- 43.5% for patients aged 60-80 years
- Lower rates for patients >80 years 2
CHOP remains a cornerstone of lymphoma treatment due to its established efficacy and manageable toxicity profile compared to more intensive regimens.