Clinical and pathological features of renal tumours among women previously treated for breast carcinomas - the CanSeRe study.

INTRODUCTION

Renal cell carcinoma (RCC) and breast carcinoma (BC) are frequent tumours, yet their co-occurrence in the same patient is a unique scenario. Few studies explored the characteristics of such patients without specific focus on pathological data. In this retrospective study, we aimed to describe the clinico-pathological features of RCC patients with a history of BC and compare them to a control cohort of RCC women free of previous BC.

METHODS

All adult women treated for BC at a high-volume cancer institution between 2007 and 2020 and who subsequently developed a RCC were retrospectively included. Their clinical and pathological characteristics were compared to an independent cohort of consecutive women undergoing percutaneous kidney tumour biopsy for localized kidney cancer in a second high-volume cancer institution.

RESULTS

A total of 113 patients were identified from 2 different institutions. We observed a lower rate of clear cell RCC in the Kidney-breast (KB) group compared to the Kidney-only (KO) group, suggesting a potential association between breast cancer and non-ccRCC. The KB group had a higher proportion of locally advanced tumours and high-grade lesions. Although recurrence-free survival favored the KO cohort, no significant difference was found in cancer-specific survival and overall survival rates between the groups. Noteworthy, patients in the KB group had a higher prevalence of family history of cancer.

CONCLUSION

Our findings highlight the need for further research to elucidate the underlying mechanisms and clinical implications of RCC coexisting with breast carcinoma. Understanding the characteristics of this unique population can guide clinical strategies and improve patient outcomes.