One‐year conditional survival of dogs and cats with invasive mammary carcinomas: A concept inspired from human breast cancer

Abstract

Numerous studies have described the prognostic factors of canine and feline mammary carcinomas (MCs), that is, variables that predict patient survival after diagnosis. But how does survival estimation evolve in patients that escaped early death from their cancer? In human oncology, conditional survival (CS), the probability of surviving X further years when cancer patients have already survived Y years, is used to analyse cancer outcomes in a long‐term perspective. In this cohort of 344 dogs and 342 cats with surgically removed stage I to III invasive MCs, with a minimal follow‐up of 2 years, we calculated the 1‐year CS, that is, the probability for patients that have survived 1 year, to survive or to die from cancer during the subsequent year. The 1‐year conditional specific survival probabilities were 59% and 48% at diagnosis of invasive MC respectively in dogs and cats, and 80% and 52% in 1‐year surviving dogs and cats respectively, suggesting that 1‐year surviving dogs were relatively protected from cancer‐related death, whereas feline MCs remained life‐threatening cancers for longer periods of time. Among the most significant parameters associated with CS in surviving dogs and cats were the nodal stage and lymphovascular invasion, as well as patient age, cancer stage and margin status in surviving dogs. By comparison, tumour size and the histological grade did not significantly alter CS probabilities in surviving dogs and cats. Conditional survival may be considered a very interesting tool for veterinary practitioners to estimate the likely outcome of cancer survivors.

Correlation Analysis of Pathological Features and Axillary Lymph Node Metastasis in Patients with Invasive Breast Cancer

“…Invasive breast cancer referred to breast cancer with the ability to invade surrounding tissue, lymph node metastasis, or distant metastasis [18][19][20]. This study investigated the risk factors for axillary lymph node metastasis in patients with invasive breast cancer, and the results suggested that vascular tumor plug and left breast cancer were the risk factors for axillary lymph node metastasis in patients with invasive breast cancer.…”

Prognostic markers of canine mammary tumours: Retrospective study of 142 cases

“…In veterinary medicine, the conditional survival of bitches after mastectomy is proposed to be determined using such significant parameters as lymphatic and vascular invasions, aside from age of patients, stage and histological type of cancer and clinical status. At the same time, research has revealed that long-term prognosis to a greater degree depends on the presence of tumour emboli in lymph and blood vessels (Chocteau et al, 2021). Lymphatic invasion in case of mammary tumours in bitches with developed metastases in regional lymph nodes and remote tissues and the organs is accompanied by significant increase in cancer antigen (СА 15.3) content in blood, which is one of the most significant cancer markers in cases of this pathology (Campos et al, 2012).…”

Mammary carcinoma: Comparative oncology between small animals and humans—New therapeutic tools

“…In dogs and cats with MCs, ER, PR, HER2 and Ki‐67 are not routinely evaluated, but immunophenotypes similar to those described for human BCs (luminal‐A, luminal‐B HER2−, luminal‐B HER2+, HER2‐positive and triple‐negative) have been defined and significantly associated with prognosis: the two most common MC immunophenotypes in dogs and cats are luminal‐B HER2− and triple‐negative cancers, while only luminal‐A MCs are associated with better outcomes (Abadie et al, 2018; Chocteau et al, 2021; Maniscalco et al, 2013; Soares et al, 2016). Currently, such immunophenotypes are not routinely evaluated and have no predictive role, but recent studies demonstrate that HER2‐targeted therapies could be beneficial for cats with HER2‐positive MC (Gameiro, Almeida, et al, 2021; Gameiro, Nascimento, et al, 2021).…”

“…In this group of patients, it is estimated that RT reduced the 15‐year locoregional failure rate from 27% (mastectomy) to 4% (mastectomy + RT), and reduced the mortality rate from 57% to 48% (Overgaard et al, 2007). In dogs and cats with MCs, failure of locoregional control is a major cause of cancer‐related death: in a large study, euthanasia was motivated by inoperable locoregional cancer progression in 13% of dogs (24/181 cancer‐related deaths) and 10% of cats (23/226), and euthanasia was motivated by locoregional relapse that owners were not willing to treat in 20% of dogs (36/181) and 28% of cats (63/226) (Chocteau et al, 2021, supplementary data). Of note, in the same study in both dogs and cats, surgical reintervention after locoregional recurrence was associated with long survival: the median cancer‐specific survival was 44 months in dogs that benefited from second surgery compared to 6 months if locoregional recurrence was untreated, and 25 months in cats with reintervention compared to 11 months without (Chocteau et al, 2021, supplementary data).…”

“…In dogs and cats with MCs, failure of locoregional control is a major cause of cancer‐related death: in a large study, euthanasia was motivated by inoperable locoregional cancer progression in 13% of dogs (24/181 cancer‐related deaths) and 10% of cats (23/226), and euthanasia was motivated by locoregional relapse that owners were not willing to treat in 20% of dogs (36/181) and 28% of cats (63/226) (Chocteau et al, 2021, supplementary data). Of note, in the same study in both dogs and cats, surgical reintervention after locoregional recurrence was associated with long survival: the median cancer‐specific survival was 44 months in dogs that benefited from second surgery compared to 6 months if locoregional recurrence was untreated, and 25 months in cats with reintervention compared to 11 months without (Chocteau et al, 2021, supplementary data). Thus, a progress in canine/feline MC management can be expected by a better locoregional control, which can rely on margin‐free mastectomy with regional lymph node excision, new developments in RT for canine and feline MCs, and systematic reintervention in case of locoregional recurrence, or in case of positive margins.…”