Understanding Treatment Disconnect and Mortality Trends in Renal Cell Carcinoma Using Tumor Registry Data

Abstract

Background and Objectives The paradoxical rise in overall and cancer-specific mortality despite increased detection and treatment of Renal Cell Carcinoma (RCC) is termed “treatment disconnect.” We reassess this phenomenon by evaluating impact of missing data and rising incidence on mortality trends. Research Design, Subjects, and Measures Using Surveillance, Epidemiology, and End Results (SEER) data, we identified patients with RCC diagnosis from 1973–2011. We estimated mortality rates by tumor size after accounting for lags from diagnosis to death using multiple imputations for missing data from 1983. Mortality rates were estimated irrespective of tumor size after adjustment for prior cumulative incidence using ridge regression. Results 78,891 patients met inclusion criteria. Of 70,212 patients diagnosed since 1983, 10.4% had missing data. Significant attenuation in cancer-specific mortality was noted from 1983–2011 when comparing observed to imputed rates: Δobs0.05 versus Δimp0.10 (p=0.001, <2cm tumors); Δobs0.29 versus Δimp0.18 (p=0.005, 2–4cm tumors); Δobs0.46 versus Δimp-0.20 (p<0.001, 4–7cm tumors); Δobs0.93 versus Δimp-0.15 (p<0.001, >7 cm tumors). Holding incidence of RCC constant to 2011 rates, temporal increase in overall mortality for all patients was attenuated (p<0.001) when comparing observed estimates (3.9 to 6.8) to 2011 adjusted estimates (5.9 to 7.1), suggesting that rapidly rising incidence may influence reported overall mortality trends. These findings were supported by assessment of mortality to incidence ratio trends. Conclusions Missing data and rising incidence may contribute substantially to the “treatment disconnect” phenomenon when examining mortality rates in RCC using tumor registry data. Caution is advised when basing clinical and policy decisions on these data.

Partial nephrectomy is not associated with an overall survival advantage over radical nephrectomy in elderly patients with stage Ib‐II renal masses: An analysis of the national cancer data base

“…The increased detection of renal masses over the past 2 decades has contributed to a greater number of kidney surgeries being performed. 2 Although the uptake of NSS historically has been slow, 16 the current data corroborate prior findings 17 and demonstrate a trend toward increased use of PN in T1 and T2 tumors across all age groups, with >70% of patients with T1a tumors and 26% of those with T1b tumors receiving PN in 2014. Despite its increased use, it remains unclear whether the survival advantages associated with PN 18,19 are applicable to all patients who present with localized renal tumors, because selection biases (including unmeasured confounders) markedly limit prior conclusions.…”

“…1 In part because of the increased use of cross-sectional imaging, a rising incidence in RCC and its treatment has been observed. 2 Although ablation and active surveillance remain viable management strategies in select patients, existing guidelines recommend surgery as best practice for localized RCC in patients who have acceptable perioperative risk. 3,4 The decision to perform partial nephrectomy (PN) or radical nephrectomy (RN) in patients with T1 and T2 renal masses is complicated by controversial and contradictory evidence.…”

Trends in Renal-Cell Carcinoma Incidence and Mortality in the United States in the Last 2 Decades: A SEER-Based Study

“…Moreover, data on tumor size and stage were only available on certain years leading to a potential bias in the analysis and the results. In addition, the SEER database misses clinically important data as well as temporal follow up of patients (48). While the SEER database is not sensitive enough to compare outcomes conditioned on treatment or comparative effectiveness research, it certainly covers around 10-30% of the US population based on the registry.…”

The Importance of Nephropathology in Kidney Cancer

“…2 In fact, the 5-year survival rate exceeds 90% to 95% for stage I RCC, which accounts for the majority of cases. 3 Because a cure for localized RCC is attainable in most of these patients, management has begun to shift toward preservation of renal function in the 400,000 kidney cancer survivors in the United States. The most recent American Urological Association guidelines on localized renal cancer reflect the evolving management of kidney cancer patients by emphasizing the role of nephron-sparing procedures, such as partial nephrectomy and ablative therapies.…”

“…1 This is the result of many factors, including the earlier detection of small localized renal masses, which has resulted in a significant stage migration, 2 earlier intervention, and advances in surgical techniques. Given the increasing survival and excellent oncologic outcomes for most kidney cancer patients with localized disease, 3 attention has shifted toward the preservation of renal function, because renal cell carcinoma (RCC) patients typically are older and at increased risk for chronic kidney disease (CKD). 4 In fact, up to 26% of patients with RCC have CKD before nephrectomy, 5 and more will develop CKD after intervention because of the surgical loss of nephron mass.…”