How often are patients with diabetes or hypertension being treated with partial nephrectomy for renal cell carcinoma? A population-based analysis.

UNLABELLED: What's known on the subject? and What does the study add? We know that a major benefit of partial nephrectomy (PN) over radical nephrectomy (RN) is greater preservation of kidney function. Emerging evidence also suggests that chronic kidney disease (CKD) correlates with survival, likely as a result of increased cardiovascular morbidity. We also know that Diabetes Mellitus (DM) followed by Hypertension (HTN) are the two most frequent causes of end-stage renal disease (ESRD). Given the strong association between renal functional decline and the surgical treatment of small renal masses, one would expect utilization of PN in patients with HTN or DM to be high, however minimal data exist on PN use in these populations. We are thus unable to determine whether these patients are being managed optimally. Our large study demonstrates that PN is being underutilized in patients at risk for CKD, particularly patients with Diabetes Mellitus and Hypertension. Unlike previously published reports, our population-level study provides a description of the landscape of care for patients with renal masses in general practice, and does not simply reflect treatment patterns at tertiary referral centers. The finding of low PN use in patients at risk for CKD deserves further study. Future studies should focus on determining the specific factors contributing to PN underutilization in these susceptible patients, as well as developing clinical tools to reliably identify those patients in whom the benefits of PN outweigh the risks.

OBJECTIVE: • To determine partial nephrectomy (PN) use in patients at risk of chronic kidney disease (CKD), such as those with diabetes mellitus (DM) and hypertension (HTN).

PATIENTS AND METHODS: • We conducted a national, population-based, retrospective, observational study using the Canadian Institute for Health Information Discharge Abstract Database. • We included all patients treated surgically for renal cell carcinoma from 1 April 1998 to 31 March 2008. • Patients with DM and HTN were identified using specific diagnosis codes. • The proportions of patients treated with PN were compared in patients with and without DM and HTN using multivariable logistic regression adjusting for covariates.

RESULTS: • A total of 24,579 patients were treated for a renal mass; of these, 4292 (17.5%) underwent PN. • In our sample, 5613 (22.8%) patients were identified as having HTN, and 2738 (11.1%) were identified as having DM. • PN was used in 17.3% of patients with HTN compared to 17.5% of those without HTN, whereas, in patients with DM, PN was used in 18.6% compared to 17.3% of patients without DM. • After adjusting for covariates, neither HTN, nor DM were found to be independently associated with increased PN use (odds ratio, 1.07; 95% CI, 0.98-1.16 and odds ratio, 1.08; 95% CI, 0.96-1.20, respectively).

CONCLUSIONS: • In this contemporary national analysis, PN appears to be underutilized in DM and HTN, despite their known relationship with chronic renal failure. • Further studies are needed to elucidate the specific factors contributing to PN underutilization in these susceptible patients.