Small Renal Mass Surveillance: Histology-specific Growth Rates in a Biopsy-characterized Cohort.

BACKGROUND: Most reports of active surveillance (AS) of small renal masses (SRMs) lack biopsy confirmation, and therefore include benign tumors and different subtypes of renal cell carcinoma (RCC). OBJECTIVE: We compared the growth rates and progression of different histologic subtypes of RCC SRMs (SRMRCC) in the largest cohort of patients with biopsy-characterized SRMs on AS. DESIGN, SETTING, AND PARTICIPANTS: Data from patients in a multicenter Canadian trial and a Princess Margaret cohort were combined to include 136 biopsy-proven SRMRCC lesions managed by AS, with treatment deferred until progression or patient/surgeon decision. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Growth curves were estimated from serial tumor size measures. Tumor progression was defined by sustained size ≥4 cm or volume doubling within 1 yr. RESULTS AND LIMITATIONS: Median follow-up for patients who remained on AS was 5.8 yr (interquartile range 3.4-7.5 yr). Clear cell RCC SRMs (SRMccRCC) grew faster than papillary type 1 SRMs (0.25 and 0.02 cm/yr on average, respectively, p = 0.0003). Overall, 60 SRMRCC lesions progressed: 49 (82%) by rapid growth (volume doubling), seven (12%) increasing to ≥4 cm, and four (6.7%) by both criteria. Six patients developed metastases, and all were of clear cell RCC histology. Limitations include the use of different imaging modalities and a lack of central imaging review. CONCLUSIONS: Tumor growth varies between histologic subtypes of SRMRCC and among SRMccRCC, which likely reflects individual host and tumor biology. Without validated biomarkers that predict this variation, initial follow-up of histologically characterized SRMs can inform personalized treatment for patients on AS. PATIENT SUMMARY: Many small kidney cancers are suitable for surveillance and can be monitored over time for change. We demonstrate that different types of kidney cancers grow at different rates and are at different risks of progression. These results may guide better personalized treatment.

Hospitalizations to Manage Complications of Modern Prostate Cancer Treatment in Older Men.

OBJECTIVE: To assess rates of treatment-related hospitalizations following surgery and radiotherapy in the treatment of clinically localized prostate cancer, given the importance of hospitalizations in healthcare resource utilization. METHODS: We conducted a population-based retrospective cohort study of patients aged 65-79 years receiving radical prostatectomy (open or minimally invasive) or radiotherapy (brachytherapy or external beam) from 2001 to 2008 in the Surveillance, Epidemiology & End Results-Medicare linked databases. We assessed treatment-related hospitalizations. We analyzed the role of primary treatment on the number of complications per patient in each category using negative binomial regression. RESULTS: Among 60,476 men, 14,492 underwent primary surgery and 45,984 underwent primary radiotherapy. Over a median follow-up of 5.6 years, the surgery group had significantly lower rates of hospital admissions (8.9 vs 20.3/1000 person-years) than the radiation group. For both groups, admissions peaked within 2 years of treatment, but continued at a steady rate for 10 years. After adjustment for confounders, patients treated with radiation had higher incidence of hospital admissions (relative rate [RR] = 1.8, 95% confidence interval [CI]: 1.8-1.9, P < .0001), compared to those having surgery. Stratified analysis showed an increased rate of hospitalizations of 1 day and 2 or more days (RR 3.1, 95% CI: 2.7-3.7 and RR 1.6, 95% CI 1.4-1.8, respectively) for patients treated with radiotherapy. The use of adjuvant/salvage therapies significantly increased rates of hospitalization. The results were robust to analysis using propensity-score matching. CONCLUSION: Treatment-related hospitalizations are more common following radiotherapy than surgery in the treatment of clinically localized prostate cancer. Limitations include a lack of treatment detail and residual confounding due to observational study design.

New Rates of Interventions to Manage Complications of Modern Prostate Cancer Treatment in Older Men.

BACKGROUND: Interventions to treat complications from prostate cancer (PCa) treatment are common and affect the course of a patient's life. OBJECTIVE: To examine rates of complications other than urinary incontinence and impotence for older patients treated for PCa. DESIGN, SETTING, AND PARTICIPANTS: Population-based retrospective cohort study of patients aged 65-79 yr receiving radical prostatectomy or radiotherapy (RT) from 2001 to 2008 in the US Surveillance Epidemiology and End Results and Medicare linked databases. OUTCOME MEASURES AND STATISTICAL ANALYSIS: Complications were organised in three categories: urologic procedures, rectal-anal procedures, and major surgeries. We analysed the role of primary treatment on the number of complications using negative binomial regression. RESULTS AND LIMITATIONS: Among 60476 men, 14492 underwent primary surgery and 45984 underwent primary RT; 33418 (55%) experienced at least one complication (mean: 2.6 complications per patient). For both groups, complications peaked within 2 yr of treatment but continued at a steady rate for 10 yr. Patients treated with radiation had higher rates of urologic procedures (adjusted relative rate [aRR]: 1.25; 95% confidence interval [CI], 1.2-1.3; p<0.0001) and rectal-anal procedures (aRR: 1.4; 95% CI, 1.4-1.5; p<0.0001) but a lower rate of major surgeries (aRR: 0.9; 95% CI, 0.8-0.9; p<0.0001) compared with those having surgery. Because patients treated with RT were older and more comorbid, selection bias limits the strength of conclusions that can be drawn from this data. CONCLUSIONS: Complications are common following PCa cancer treatment and occur many years after treatment. The primary treatment is an important predictor of complication rates that may inform treatment decisions and long-term survivorship plans. PATIENT SUMMARY: We examined complications after prostate cancer treatment in a large American population. Patients treated with radiotherapy rather than surgery had higher rates of complications requiring urologic procedures and rectal-anal procedures but lower rates of open surgeries. However, we were only able to examine men aged >65 yr, and this, along with the observational study technique, means that these results may not apply to all patients and that factors beyond those that we could measure may have affected these results.