Page 744 - Withrow and MacEwen's Small Animal Clinical Oncology, 6th Edition

722 PART IV Specific Malignancies in the Small Animal Patient

TABLE 33.11 The CHOP-Based Chemotherapy Protocol TABLE 33.12 COP Protocol for Lymphoma in Cats
for Cats with Intermediate/High-grade Drug Frequency of Drug Delivery
VetBooks.ir Treatment Week Lymphoma Employed by the Author Cyclophosphamide: 250–300 Given every 3 weeks on the day after
Drug, Dosage, and Route
a
vincristine
2
mg/m , PO
1 Vincristine, 0.5–0.7 mg/m , IV Vincristine: 0.7 mg/m , IV Given weekly on weeks 1, 2, 3, and
2
2
l-Asparaginase, 400 Units/kg, SC 4, then given every 3 weeks
Prednisolone, 2.0 mg/kg, PO thereafter on the days before
2
2 Cyclophosphamide 200 mg/m , PO cyclophosphamide. Discontinue if
Prednisolone, 2.0 mg/kg, PO in remission at 1 year.
2
3 Vincristine, 0.5–0.7 mg/m , IV Prednisolone: 1–2 mg/kg, PO Given daily for 1 year.
Prednisolone, 1.0 mg/kg, PO
a Some divide the cyclophosphamide over 3 consecutive days.
4 Doxorubicin, 25 mg/m , IV Note: A complete blood count (CBC) should be performed before each chemotherapy. If neu-
2
Prednisolone, 1.0 mg/kg, PO a trophils are <1500 cells/μL, wait 5–7 days, repeat CBC, then administer the drug if neutro-
6 Vincristine, 0.5–0.7 mg/m , IV phils have risen above the 1500 cell/μL cutoff.
2
2
7 Cyclophosphamide 200 mg/m , PO
2
8 Vincristine, 0.5–0.7 mg/m , IV
predicting more durable responses. 488,527,534 The use of intraper-
2
9 b Doxorubicin, 25 mg/m , IV itoneal-delivered COP in a small number of cats (n = 26) was
reported; three-quarters achieved a CR with a MST of 1 year. 535
2
11 Vincristine, 0.5–0.7 mg/m , IV
This study included only three GI cases and did not histologi-
13 Cyclophosphamide 200 mg/m , PO cally or immunophenotypically subtype cases beyond saying all
2
were “large cell”; therefore larger, more controlled studies would
2
15 Vincristine, 0.5–0.7 mg/m , IV
be necessary to establish/confirm efficacy of this protocol.
2
17 Doxorubicin, 25 mg/m , IV Response rates and durability of response for cats with I/
19 Vincristine, 0.5–0.7 mg/m , IV HGAL treated with combination protocols are generally not as
2
good as in dogs with intermediate- or high-grade peripheral nodal
2
21 Cyclophosphamide 200 mg/m , PO lymphoma. Remission rates of 50% to 65% can be expected with
23 Vincristine, 0.5–0.7 mg/m , IV approximately one-third achieving CR. Remission and survival
2
are only durable in cases achieving a CR; MSTs for cats in CR are
2
25 c Doxorubicin, 25 mg/m , IV approximately 7 to 10 months with a subset living to 1 year or lon-
ger. 439,440,488,496,520–522,529,428,515,523–528 Rescue protocols involv-
CHOP, Combinations of cyclophosphamide (C), doxorubicin (H, hydroxydaunorubicin), vincris-
tine (O, Oncovin), and prednisolone (P); IV, intravenous; PO, by mouth; SQ, subcutaneous. ing alternate drugs (e.g., melphalan, lomustine, mechlorethamine,
a Prednisolone is continued (1 mg/kg, PO) every other day from this point on. actinomycin-D, cytarabine) or reinduction with CHOP generally
b If in complete remission at week 9, continue to week 11. do not result in durable subsequent remissions. 519,536,537
c If in complete remission at week 25, therapy is discontinued after this doxorubicin, and cat Several prognostic factors have been reported for cats with I/
is rechecked monthly for recurrence. HGAL; however, by far the most predictive is whether a CR is
Note: A complete blood count (CBC) should be performed before each chemotherapy. If neu- achieved. 439,440,487,488,491,496,520–522,529 Negative prognostic factors
trophils are <1500 cells/μL, wait 5–7 days, repeat CBC, then administer the drug if neutro- identified for I/HGAL include transmural extension, FeLV anti-
phils have risen above the 1500 cell/μL cutoff. genemia, weight loss, elevated LDH, hypoalbuminemia, hypo-

cobaliminemia, and bicavitary involvement, while stage I disease
(rare) is associated with a more favorable prognosis. Factors not
maintenance chemotherapy is used. Although data exist in dogs found to be prognostic were immunophenotype and various pro-
for a maintenance-free approach, similar comparative data do not liferation indices (e.g., PCNA, AgNOR, Ki67).
2
currently exist in the cat. DOX alone (25 mg/m every 3 weeks
2
for five total treatments), CCNU (lomustine; 40–50 mg/m PO Large Granular Lymphoma
q 3 weeks), 440 or palliative prednisone therapy is offered if clients Cats with LGL typically have the lowest reported response rates
decline more aggressive CHOP-based therapy. 440,530,531 Cats are and shortest response durations of any of the GI lymphomas.
generally less tolerant of DOX than are dogs; therefore a lower Approximately one-third of cases will experience a response and
2
dosage (25 mg/m or 1 mg/kg IV) is used (see Chapter 12). Car- MSTs in larger reports of cases were only 21 days; cats receiving
diac toxicity does not appear to be a clinically significant problem CHOP-based or CCNU-based protocols experienced MSTs of 45
in cats, although renal toxicity is more commonly encountered, 532 to 90 days. 438,488,500 That being said, a small subset (7% in this
and renal function should be monitored (i.e., serial blood urea report) enjoyed more durable (>6 month survivals) responses and,
nitrogen [BUN], creatinine, and urine specific gravity) closely in one small study (n = 6), a MST of 9 months was reported after
before and during therapy. The use of COP (i.e., CHOP without a variety of interventions. 498
the addition of DOX) is often used in cats in Europe, and one
compilation reported similar results to CHOP. 533 A COP (cyclo- The Role of Surgery in Cats with
phosphamide, vincristine, and prednisolone) protocol commonly Gastrointestinal Lymphoma
employed in cats is presented in Table 33.12; however, several Surgery is primarily reserved for I/HGAL that have discrete
studies have reported that the inclusion of DOX is important for lesions and in cats that are presented with intestinal perforation