Long-term Outcomes of Follow-up for Initially Localised Clear Cell Renal Cell Carcinoma: RECUR Database Analysis

Background: Optimal follow-up (FU) strategy to detect potentially curable (PC) recurrences after treatment of localised clear cell renal cell carcinoma (ccRCC) is unclear. This study retrospectively analysed a large international database to determine recurrence patterns and overall survival (OS), as part of a wider project to issue recommendations on FU protocols. Objective: To analyse associations between RCC recurrences in patients with ccRCC, their risk group stratifications, treatments, and subsequent outcomes. Design, setting, and participants: Nonmetastatic ccRCC patients treated with curative intent between 1 January 2006 and 31 December 2011, with at least 4 yr of FU, were included. Patient, tumour and recurrence characteristics, Leibovich score, and management and survival data were recorded. Isolated local, solitary, and oligometastatic (three or fewer lesions at a single site) recurrences were considered PC, while all others were probably incurable (PI). Intervention: Primarily curative surgical treatment of ccRCC while at recurrence detection metastasectomy, systemic therapy, best supportive care, or observation. Outcome measurements and statistical analysis: Incidence, time to recurrence (TTR), and OS were measured. Competing risk analysis, Kaplan-Meier, and Cox regression models were used. Results and limitation: Of 1265 patients with ccRCC, 286 had a recurrence, with 131 being PC and 155 PI. Five-year cumulative risks of recurrence for low- (n = 53), intermediate- (n = 105), and high-risk (n = 128) patients were, respectively, 7.2%, 23.2%, and 61.6%, of whom 52.8%, 37.1%, and 30.5% were PC, respectively. Median TTR was 25.0 for PC patients versus 17.3 mo for PI patients (p = 0.004). Median OS was longer in PC compared with that in PI patients (p< 0.001). Competing risk analysis showed highest risk of ccRCC-related death in younger and high-risk patients. Limitations were no data on comorbidities, retrospective cohort, and insufficient data excluding 12% of cohort. Conclusions: Low-risk group recurrences are rare and develop later. Treatment of recurrences with curative intent is disappointing, especially in high-risk patients. An age- and risk score-dependent FU approach is suggested. Patient summary: We analysed data from eight European countries, and found that the incidence of the kidney cancer recurrence and patient survival correlated with clinical factors known to predict cancer recurrence reliably and age. We conclude that these factors should be used to design follow-up strategies. Renal cell carcinoma recurrences are rare in low-risk patients. Potentially curable recurrences are more frequent in high-risk patients, but local treatment is unlikely to be curative. Competing risk analyses suggest age and risk score as important factors in developing follow-up strategies.