Objective: This study is performed to explore the pathological characteristics and oncologic outcomes of T1 multifocal renal cell carcinoma (RCC).
Methods: The clinical data of 600 patients (442 males and 158 females) between the age of 29 and 73 years, diagnosed with T1 RCC were collected from three hospitals in China, out of which 421 cases had undergone nephron-sparing surgery (NSS) and 179 cases had undergone radical nephrectomy (RN) between December 2010 and January 2015.
Results: Tumor was identified with multifocality in 32 patients (5.33%), out of which 21 were set to receive NSS, and 11 to receive RN, respectively; 21 cases of clear cell tumor, 8 cases of papillary tumor, 1 case of chromophobe tumor and 2 cases of Xp.11.2 translocation RCC. Among 568 cases of monofocal tumors, 400 patients underwent NSS, and the remaining 168 patients underwent RN, respectively. After a median follow-up of 5 years, 13 patients were found with recurrent tumors out of those who had undergone NSS, 11 with monofocal tumors and 2 with multifocal tumors containing satellite tumor nodules (p = 0.13). Out of the 32 individuals with multifocal RCC, 4 cases were reported to have died of cancer, 2 of NSS and 2 of RN. From these findings, the cancer-specific survival for NSS and RN was estimated to be 90.48% and 81.82%, respectively (p = 0.48).
Conclusion: The findings from the study suggested that there were pathological differences in multifocal renal tumors, and that papillary carcinoma may be more common than clear cell carcinoma. The recurrence rate and survival rate of multifocal RCC were similar to monofocal tumors. Tumor recurrence may be related to satellite tumor nodules, which can only be detected once surgery is performed.
Keywords: Multifocality; Nephron-sparing surgery; Pathology; Renal cell carcinoma; T1 stage.