Patient Survival Periods and Death Causes Following Surgical Treatment of Mammary Gland Tumours Depending on Histological Type of Tumour: Retrospective Study of 221 Cases

Abstract

This retrospective study evaluated a canine patient group operated on for mammary neoplasms (221 females). After surgical treatment, the animals were divided based on histological findings into groups and subgroups according to the WHO system. In the individual groups and subgroups the length of their survival following a mammary tumour surgery and death causes were followed. Of their total number, 164 tumours were malignant, 39 were benign and 18 were mammary hyperplasias. With regard to malignant tumours, invasive tubular carcinoma (20.81%) was identified most frequently; fibroadenoma reached the highest occurrence (10.41%) as regards benign tumours. The length of survival in females with malignant tumours ranged from 12 to 37.4 months, depending on histological subtypes. In females with benign mammary neoplasms the length of survival ranged from 39.1 to 59.3 months and in animals with hyperplasia it was 50.2 months. As a result of mammary tumour, 41 females (25%) died in the malignant tumour group, none died in the benign tumour group and 2 females (11.1%) died in the hyperplasia group. The survival periods in surgically treated patients with mammary tumours were shorter for solid and complex carcinomas, compared to patients affected with the remainder of the histological subtypes. The longest survival period following operation was recorded in the group suffering from adenoma. The least favourable illness prognosis for patients with mammary tumours in respect to linking the death cause to the mammary tumour was for those having invasive papillary carcinoma. The most favourable illness prognosis was for patients with benign tumours and non-invasive tubular carcinoma. A frequent death cause in females with mammary tumours was another illness unrelated to mammary tumours.