This cohort study aimed to investigate the frequency, risk factors, and post-diagnosis survival associated with hemangiosarcoma in a large group of Golden Retrievers followed from puppyhood in the Golden Retriever Lifetime Study (GRLS).
The GRLS is a longitudinal cohort study designed to explore demographic, environmental, and lifestyle risk factors associated with hemangiosarcoma in Golden Retrievers.
The most consistently reported risk factors for canine hemangiosarcoma are breed and age. However, associations with other demographic factors, such as sex, neutering, or body weight, are less clear. While the link between neutering and hemangiosarcoma development is not fully understood, general cancer research suggests that the age of neutering may influence overall cancer risk.
Environmental exposures, health, and lifestyle factors are only beginning to be studied in veterinary oncology. Understanding these factors is important because they are modifiable during a dog’s life. A recent study found that physical activity intensity and frequency are significant predictors of overall cancer development in the GRLS cohort.
Survival times for dogs with hemangiosarcoma, particularly visceral forms, are historically short. This study hypothesized that older age and neutering status are associated with increased odds of hemangiosarcoma diagnosis, with visceral type having significantly shorter median survival times than those with cutaneous forms.
Key Findings
Hemangiosarcoma primarily affects middle-aged to older dogs, with Golden Retrievers at increased risk. In this study, 16.1% of the cohort was diagnosed with the disease:
- Age: The median age at first diagnosis was 9.73 years, consistent with previous reports across breeds. Large breed dogs have shorter lifespans than smaller breeds, meaning their peak risk for hemangiosarcoma may occur earlier in life.
- Sex: Males had 1.3 times higher odds of diagnosis compared to females. The reasons for this association are unclear but may involve androgens, immunologic differences, or sex-linked genetic factors. 80% of the GRLS cohort was neutered, which could influence these findings.
- Weight: Higher median adult weight was associated with increased odds of diagnosis. Overweight and obesity have been linked to cancer risk in both humans and animals, possibly due to chronic inflammation. However, interpreting weight alone is challenging without body condition score and sex-specific data.
- Prior Cancer Diagnosis: Dogs with a different cancer diagnosis within the five years before the study endpoint had reduced odds of hemangiosarcoma. This may reflect survival bias—dogs with earlier cancers may not live long enough to develop it.
- Chronic Gastrointestinal Disease: Among chronic inflammatory conditions, only gastrointestinal comorbidities were retained in the final model, showing increased odds of hemangiosarcoma diagnosis. Chronic inflammation has been theorized to promote carcinogenesis, but broader inflammatory conditions did not show significance in this study.
- Activity Levels: Dogs with moderate or high activity levels had reduced odds of diagnosis. Similar findings in human oncology suggest physical activity may lower cancer risk, but it remains unclear whether this is due to activity itself, lower body weight, or reduced inflammation.
- NSAID Use: Increased NSAID usage was unexpectedly associated with higher odds of diagnosis. This contrasts with prior research suggesting NSAIDs may reduce cancer risk through anti-inflammatory or anti-tumor effects. Differences in COX-2 expression or NSAID types may play a role, requiring further study.
While this study provides critical insights into haemangiosarcoma risk factors, its unexpected findings – particularly regarding NSAID use and prior cancer diagnoses – highlight crucial knowledge gaps that demand further investigation. Future research should specifically examine the roles of chronic inflammation, medication effects, and genetic susceptibility to better understand this disease’s mechanisms and develop more effective prevention and treatment strategies.
