CHOP

CHOP is the acronym for a chemotherapy regimen used in the treatment of non-Hodgkin lymphoma. CHOP stands for Cytoxan, Hydroxydaunorubicin (Adriamycin), Oncovin (Vincristine), Prednisone/Prednisolone.

Uses and indications
CHOP consists of:
 * Cyclophosphamide
 * Hydroxydaunorubicin (alternative name) - doxorubicin
 * Oncovin&reg; (brand name) - vincristine
 * Prednisone or Prednisolone.

This regimen can also be combined with the monoclonal antibody rituximab if the lymphoma is of B cell origin (R-CHOP or CHOP-R). Typically, courses are administered at an interval of three weeks. A staging CT scan is generally performed after three cycles to assess whether the disease is responding to treatment.

In patients with a history of cardiovascular disease, the doxorubicin (which is cardiotoxic) is often deemed to be too great a risk and is omitted from the regimen. The combination is then referred to as COP or CVP.

Side-effects and complications
The combination is generally well tolerated. Chemotherapy-induced nausea and vomiting may require antiemetics (such as ondansetron), and hemorrhagic cystitis is prevented with administration of mesna. Alopecia (hair loss) is common.

Neutropenia generally develops in the second week. During this period, many clinicians recommend prophylactic use of ciprofloxacin. If a fever develops in the neutropenic period, urgent medical assessment is required for neutropenic sepsis, as infections in patients with low neutrophil counts may progress rapidly.

Allopurinol is typically co-administered prophylactically to prevent tumor lysis syndrome, the result of rapid death of tumor cells.

History
A pivotal study published in 1993 compared CHOP to several other chemotherapy regimens (e.g. m-BACOD, ProMACE-CytaBOM, MACOP-B). CHOP emerged as the regimen with the least toxicity but similar efficacy.