Use of lomustine to treat cutaneous nonepitheliotropic lymphoma in a cat

Feline cutaneous lymphoma: an evaluation of disease presentation and factors affecting response to treatment

OBJECTIVES

The primary goal of this study was to characterize the clinical presentation of feline cutaneous lymphoma. The secondary aims included determining if treatment or initial response to treatment affected the overall survival of patients, and understanding if disease characteristics such as immunophenotype, cell size or the presence of epitheliotropism influenced response to treatment.

METHODS

Veterinary medical oncologists at four academic veterinary teaching hospitals submitted cases of feline patients with cutaneous lymphoma diagnosed by histopathology or cytology. Signalment, feline leukemia virus (FeLV)/feline immunodeficiency virus (FIV) status, physical examination findings, clinical signs, diagnostic tests, therapy, response and outcome, and necropsy findings, when available, were recorded.

RESULTS

Forty-one patients were identified and described. The majority of patients were domestic shorthair cats (n = 29). The median age at diagnosis was 12.3 years. Males were over-represented in the population (n = 30). In the majority of patients (n = 33), the FIV/FeLV status was unknown. Twenty patients were fully staged. Thirty-four patients were treated with a variety of modalities, including surgery, radiation, single-agent or combination chemotherapy, or prednisolone only. In multiple patients, surgery or radiation was combined with a systemic therapy. Of 34 patients treated with some form of therapy, 20 responded (achieving either a partial response or complete remission).

CONCLUSIONS AND RELEVANCE

Clinical signs and physical examination findings varied among patients. Response to therapy appeared to be associated with survival (P = 0.0025); however, this population was highly censored. Immunophenotype, cell size and the presence of epitheliotropism did not influence treatment response. Results were limited by small numbers of patients, heterogeneous disease manifestations and treatment protocols. Further studies are necessary to evaluate the effect of specific treatment modalities and disease subtype on prognosis.

LOPH: a novel chemotherapeutic protocol for feline high-grade multicentric or mediastinal lymphoma, developed in an area endemic for feline leukemia virus

OBJECTIVES

The aim of this study was to establish the safety and efficacy of a novel multidrug lomustine-based chemotherapeutic protocol for cats with high-grade multicentric or mediastinal lymphoma, in an area endemic for feline leukemia virus (FeLV).

METHODS

This prospective study included owned cats, diagnosed (cytologically) with multicentric or mediastinal lymphoma and treated with the LOPH (lomustine, vincristine [Oncovin; Antibióticos do Brasil], prednisolone and hydroxydaunorubicin [doxorubicin]) protocol. A complete blood count was performed before every chemotherapy session and any significant abnormalities recorded as possible related toxicities. Median survival time (MST) and disease-free interval were estimated by Kaplan-Meier curves.

RESULTS

Twenty-one cats were included in this study. Nineteen (90.5%) tested positive for FeLV and were therefore considered to have persistent viremia. Complete response was reported in 81% (n = 17/21), while three had partial remission and one had no response. Seven cats finished the induction protocol within 20-31 weeks (23.1 ± 4.5; median 20) and all seven received a maintenance protocol. The MST (lymphoma-related survival) for the 21 cats was 214 days. The MST was 214 days for cats with mediastinal lymphoma (n = 13), but it was not reached for multicentric lymphoma (n = 8; P = 0.9). The MST of cats with persistent FeLV antigenemia was 171 days. Grade I anorexia and vomiting occurred in 19% of the cats (n = 4/21). Hematologic toxicity was found in 100% of the cats at some point during their treatment, but it was mostly grade I or II. Neutropenia, thrombocytopenia and anemia occurred in 16/21, 21/21 and 15/21 cats, respectively.

CONCLUSIONS AND RELEVANCE

The LOPH protocol was well tolerated by cats with lymphoma and persistent FeLV viremia, and resulted in a better MST than similar studies with other protocols. Novel studies and controlled trials are necessary in order to evaluate the efficacy of different protocols according to the lymphoma subtype, anatomic form and FeLV status.

Multifocal cutaneous non-epitheliotropic B-cell lymphoma in a cat

Case summary

Skin tumours are the second-most common form of feline cancer after haematopoietic neoplasms and are often malignant. Cutaneous lymphoma is uncommon in cats and can be classified as epitheliotropic (typically of T-cell origin) or non-epitheliotropic (either of T-cell or B-cell origin). The present study describes a case of multifocal cutaneous non-epitheliotropic B-cell lymphoma. The skin nodules were multiple and variable in size; showed rapid progression; were alopecic and erythematous in appearance and pruritic and ulcerated; and were mostly located on the trunk. Nodule biopsies revealed the presence of uniform medium-to-large round neoplastic cells that infiltrated the dermis and subcutis. The neoplasias were consistent with a round cell cutaneous tumour and did not show evidence of epitheliotropism. Furthermore, immunohistochemical assessments indicated an immunophenotype characterised by round cells with a strong membrane and cytoplasmic positivity for the CD20 antigen, consistent with a lymphocyte of B-cell origin.

Relevance and novel information

Cutaneous non-epitheliotropic B-cell lymphoma in cats is rare and was previously reported to appear as single dermal and subcutaneous masses that are variable in size and generally develop in the tarsal region. To our knowledge, this is the first report to describe multifocal cutaneous non-epitheliotropic B-cell lymphoma in a cat.

Cutaneous non-epitheliotropic T-cell lymphoma associated with a fracture site in a cat

Case summary

A 7-year-old male neutered domestic shorthair cat presented for investigation of a swelling over the right forelimb. Radiographs of the right forelimb revealed significant lysis and soft tissue swelling surrounding a previously implanted surgical plate, used to repair a fracture of the distal radius 5 years prior. The implant was removed, and a biopsy was collected. Histopathological analysis and immunohistochemistry diagnosed a non-epitheliotropic T-cell cutaneous lymphoma. Staging confirmed multiple regional lymph node involvement. The cat was started on a CHOP-based protocol (vincristine, doxorubicin, cyclophosphamide and prednisolone). At week 4, the disease progressed both locally and within the regional lymph nodes. The primary lesion became severely ulcerated and the cat was euthanased, 42 days post-diagnosis.

Relevance and novel information

This is the first report of a cutaneous non-epitheliotropic lymphoma developing at the site of a previous traumatic fracture and metal implant. The cat's response to chemotherapy was poor and euthanasia was performed owing to progressive disease. More investigation is required to understand the role that malignant transformation could have at sites of chronic inflammation, bone fractures and surgical implants.

Low apparent risk of CCNU (lomustine)-associated clinical hepatotoxicity in cats

The purpose of this study was to evaluate the prevalence of serum alanine transaminase (ALT) increases in cats treated with 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea (CCNU, lomustine). The medical records of 95 cats treated with CCNU were reviewed, 29 of which met study criteria (at least one treatment with CCNU as a single agent, and at least one pretreatment and one post-treatment complete biochemical profile). Cats that received concurrent prednisone or dexamethasone were included, but those that received concurrent hepatoprotective or hepatotoxic medications were excluded. Cats included in the study were diagnosed with hepatic carcinoma, mammary carcinoma, lymphoma, mast cell tumor, plasma cell tumor and gastrointestinal leiomyoma. CCNU was given as a single agent at 31-60 mg/m(2), once every 4-8 weeks. Serum alanine transaminase (ALT) activity was measured after at least one dose of CCNU. Four cats (13.7%) had increased ALT activity above the reference interval before starting treatment. Two additional cats (6.8%) developed increased ALT activity above the reference interval 1 month after treatment with CCNU. One cat developed clinical signs potentially associated with hepatotoxicity, without a concurrent increase in ALT, 3 weeks following the final dose of CCNU. No association between dosing frequency, cumulative dose, initial starting dose or concurrent medications, and increases in ALT were found. Clinically significant hepatic injury is seemingly uncommon in cats treated with CCNU.

Evaluation of lomustine as a rescue agent for cats with resistant lymphoma

This retrospective study evaluated the use of lomustine as a rescue agent for 39 cases of resistant feline lymphoma. Parameters assessed included lymphocyte cell size, number of previous chemotherapy drugs and number of previous chemotherapy protocols received, time from lymphoma diagnosis to initiation of lomustine therapy, body weight and anatomic location of lymphoma. Cell size, number of previous chemotherapy drugs, number of previous chemotherapy protocols and anatomic location were all significant prognostic factors for the progression-free interval. Twenty-one cats (54%) received more than one dose of lomustine. The overall median progression-free interval (MPFI) was 39 days (range 7-708 days). The MPFI for large versus small and intermediate cell lymphomas was 21 versus 169 days, respectively. The MPFI for gastrointestinal versus non-gastrointestinal lymphomas was 180 versus 25.5 days, respectively. Lomustine has an acceptable efficacy and safety for use as a rescue agent in feline lymphoma.

Perforin expression in feline epitheliotropic cutaneous lymphoma

Cutaneous lymphomas are uncommon in people and companion animals. The tumors can be broadly categorized into epitheliotropic and nonepitheliotropic forms, which appear to have different biological behaviors. The present case describes a feline cutaneous epitheliotropic lymphoma. Masses in a 9-year-old cat were first identified on the tail. The cat was treated with chemotherapy, but additional skin masses developed on the flank, face, and ears. Local radiation induced transient tumor regression, but eventual dissemination prompted euthanasia 13 months after initial tumor appearance. Granular lymphocytes were consistently detected on blood smears, and histologically, the tumor involved the skin and superficial subcutis. Tumor lymphocytes expressed cluster of differentiation 3 (CD3) and perforin molecules, suggestive of a cytotoxic phenotype. Location, histopathological features, and perforin expression were similar to a distinct entity in human medicine designated primary cutaneous, CD8-positive, epidermotropic, cytotoxic, T-cell lymphoma.