Oncology: Principles Flashcards
What are the most common cancers in dogs?
Lymphoma Leukaemia Mammary cancer Osteosarcoma Oral melanoma Mast cell tumours Prostate cancer Brain cancer
Most cancers are …….clonal
Poly
What are the two types of mutation that can cause cancer?
Point mutations: a change to one or a few of the bases in the DNA sequence
Chromosomal alterations: a change in the number or composition of the chromosomes
What happens to the DNA methylation and histones in cancer?
They are modified
What are the hallmarks of a cancer cell?
Self sufficiency in growth signals Insensitivity to anti-growth signals Limitless replicative potential Evading apoptosis Sustained angiogenesis Tissue invasion and metastasis
What are oncogenes?
Genes that promote cell proliferation
What are tumour supressor genes?
Genes that prevent aberrant cell proliferation
What are proto-oncogenes?
Viruses have genes that promote cancer (Oncogene: v-Src, protein tyrosine kinase)
Mammalian cells have equivalent genes (C-src) but the are normally regulated, so do not promote cancer
These genes are called proto-oncogenes (c-Src)
How do cancer cells look different on cytology?
Large nucleus
Cell becomes less specialised for function
Necrosis
A high mitotic index (How many metaphase cells there are)
What is the difference between the differentiation of benign and malignant cancers?
Benign:Well differentiated, similar to surrounding tissue, little or no anaplasia
Malignant:Lack of differentiation, atypical structure, variable anaplasia
What is the difference between the growth rate of benign and malignant cancers?
Benign: Slow or progressive, rare/normal mitotic figures
Malignant: Slow to rapid growth, Many/abnormal mitotic figures
What is the difference between the local invasion of benign and malignant cancers?
Benign: No invasion, cohesive growth, capsule often present
Malignant:local invasion, infiltrative growth, usually no capsule
What is the difference between the metastasis of benign and malignant cancers?
Benign: None
Malignant: Frequent
What is the difference between the host consequences of benign and malignant cancers?
Benign: Space occupying mass
Malignant: Life threatening
What is the difference between the host consequences of benign and malignant cancers?
Benign: Space occupying mass
Malignant: Life threatening
What are the characteristics of malignant cancer tissue?
Disorganisation of the tissue Increased nuclear or cell pleomorphism Large and/or multiple nuclei Increased amount of necrosis High cellularity and minimal stroma
Scirrhous or desmoplastic reaction: cancer cells secrete a lot of cytokines to the stroma and the stroma reacts with inflammation
What do you call a benign tumour of the fibrous connective tissue?
fibroma
What do you call a benign tumour of the fat?
Lipoma
What do you call a benign tumour of the glandular epithelium?
Adenoma