Tumor Behaviour: Prognostic Factors in Canine Mast Cell Tumor, Melanoma and Osteosarcoma ▼
Izv. prof. dr. sc. Andrea Gudan Kurilj, dr. med. vet., DiplECVP
Zavod za veterinarsku patologiju, Veterinarski fakultet Sveučilišta u Zagrebu
e-mail: agudan@vef.hr
Trostupanjska histološka klasifikacija kožnih mastocitoma pasa, naročito u slučaju mastocitoma drugog stupnja malignosti čije biološko ponašanje varira u velikom broju slučajeva, veterinaru praktičaru otežava davanje točne prognoze. U cilju povećanja prognostičke sigurnosti predložena je dvostupanjska histološka klasifikacija mastocitoma, analiza stanične proliferacije, utvrđivanje mutacije c-Kit proteina pomoću PCR-a i imunohistokemijska analiza aberantne ekspresije c-KIT proteina.
Još jedna skupina tumora za koju je ponekad teško definirati točnu prognozu su melanomi, naročito oni koji nastaju u usnoj šupljini. Nedavna istraživanja su pokazala da podgrupa oralnih melanoma može imati povoljniju prognozu nego što se ranije mislilo. Predloženi prognostički panel za melanome uključuje imunohistokemijsku analizu Ki67 proteina u svrhu određivanja proliferacijskog indeksa, zatim procjenu mitotskog indeksa, procjenu atipije jezgri te stupnja pigmentacije.
Osteosarkomi u pasa predstavljaju histološki i klinički heterogene tumore. Stupanj malignosti osteosarkoma se najpreciznije može procijeniti određivanjem invazivnosti tumora u krvne žile, određivanjem mitotskog indeksa i razine alkalne fosfataze. Novija istraživanja su pokazala da i drugi biomarkeri (poput p53, ciklooksigenaze-2, epidermalnog receptora faktora rasta) mogu imati određeni prognostički značaj kod pasa sa osteosarkomima.
S razvojem veterinarske onkologije razvijati će se i novi prognostički markeri pomoću kojih će se preciznije moći utvrditi stupanj invazivnosti tumora, vjerojatnost ponovne pojave tumora nakon njegovog uklanjanja, interval bez znakova bolesti i duljina preživljavanja životinje koja boluje od malignog procesa.
Tumor Behaviour: Prognostic Factors in Canine Mast Cell Tumor, Melanoma and Osteosarcoma
Andrea Gudan Kurilj, DVM, PhD, DECVP
Department of Veterinary Pathology, Faculty of Veterinary Medicine, University of Zagreb, Croatia; e-mail: agudan@vef.hr
I n recent years, the incidence of various diseases in companion animals has increased along with their extended life expectancy. Among such diseases, the incidence of cancer in dogs seems to be increasing in particular. There is also an increasing need for more accurate diagnostic, prognostic and predictive markers in veterinary oncology because of an increasing number of treatment options, the increased financial costs associated with treatment, and the emotional stress experienced by owners in association with the diease and its treatment. Histopathology remains the gold standard method for cancer diagnosis, but today there are also an exclusive panels of tests that dramatically increase prognostic certainty for different forms of cancers.
The highly unreliable and variable nature of histologic grading for canine cutaneous mast cell tumors (MCT) has made it difficult for many veterinary practitioners to offer their clients an accurate prognosis. In order to increase prognostic certainty, a two-tier grading system is proposed as well as cell proliferation analysis, c-Kit PCR to detect internal tandem duplication mutations and KIT immunohistochemistry to analyze expression of this receptor.
Accuratelly determining the diagnosis and prognosis of melanocytic tumors is often difficult, especially those of the oral cavity. Recent evidence suggests that a subset of canine oral melanocytic tumors may have a more favorable prognosis than historically thought. A proposed prognostic melanocytic panel includes immunolabeling with Ki67, and assessment of nuclear atypia, mitotic index, and degree of pigmentation for prognostic information.
Canine osteosarcoma (OS) presents with heterogenous histologic and clinical features, of which tumor grade, best predicted by blood vessel invasion and mitotic index, and alkaline phosphatase levels seem to be most important for evaluating the prognosis for survival. Several other prognostic and predictive biomarkers (p53, cyclooxygenase-2, epidermal growth factor receptor) for canine OS have been investigated which could be used in prospective patient evaluation.
As veterinary oncology continues to advance, there will be an increasing need to identify novel prognostic markers associated with metastasis, recurrence, disease-free interval, and overall survival.