Predicting factors for death from other causes in patients with localized renal cell carcinoma

Prognostic Significance of Advanced Age in Patients with T1a Renal Cell Carcinoma Treated by Microwave Ablation: A 16-Year Experience

BACKGROUND

Previous studies have failed to investigate the specific effects of advanced age on survival outcomes by considering the Charlson Comorbidity Index (CCI) and age permutation in patients with T1a renal cell carcinoma (T1a RCC) treated by microwave ablation (MWA). Notably, RCC guidelines recommended radiofrequency ablation (RFA) and active surveillance (AS) are both treatment options for elderly T1a RCC, but whether MWA is superior to AS in light of higher heating efficiency and larger ablation zone compared with RFA is not clear. This study aimed to investigate the specific effects of advanced age on survival outcomes of T1a RCC patients stratified by CCI score and indicate better intervention for elderly T1a RCC between MWA and AS.

METHODS

This was a retrospective study. We retrospectively reviewed 237 patients with T1a RCC who had undergone MWA over the last 16 years. Data were analyzed by Cox regression and Landmark analysis. Interaction tests and propensity score matching were used to account for potential biases. We compared the overall survival (OS) and cancer-specific survival (CSS) rates of patients ≥75 years in our study with corresponding figures from 4251 counterparts undergoing AS in published articles.

RESULTS

Using patients ＜75 years with a CCI ≤2 as a reference, the hazard ratio (HR) and 95% confidence interval (CI) of OS for patients＜75 years with a CCI ≥3, patients ≥75 years with a CCI ≤2, and patients ≥75 years with CCI ≥3, were 2.954 (1.139-7.663), 3.48 (1.487-8.146), and 3.357 (1.162-9.698), respectively. The adverse effect of an age ≥75 years on OS was attenuated in patients with a CCI ≥3. The attenuation lasted for 62.5 months of follow-up (P = .017). Notably, advanced age exerted a protective effect on progression-free survival (PFS) in patients with a CCI ≥3, increasing the 8-year PFS from 67.8% to 100% (P = .049). Relative to 1-, 3-, 5-, and 8-year survival data for patients aged ≥75 undergoing AS, the OS rates for 5-year follow-up were always better in MWA. However, beyond 5 years, the OS rates dropped to levels that were similar to AS.

CONCLUSIONS

Advanced age exerts adverse effects and significantly protective effects on OS and PFS, respectively, in T1a RCC patients with a CCI ≥ 3. According to our study, elderly patients with T1a RCC underwent radical MWA may yield a better medium-term OS relative to AS.

Survival benefits analyses of T1a renal cell carcinoma patients treated with microwave ablation

PURPOSE

The individual decision-making reference of Microwave ablation (MWA) for T1a RCC treatment is not clear, and it may not benefit all the patients equally. Therefore, we quantitatively evaluated the distinct survival benefits of patients with T1a RCC stratified by survival predictors.

MATERIALS AND METHODS

A total of 237 patients with T1a RCC who underwent MWA over the last 16 years were retrospectively reviewed for survival benefit analysis. Cox proportional hazard models were used to control for the prognostic variables of OS, CSS, and PFS. Survival rates were calculated using the Kaplan-Meier method and compared by log-rank analysis. Linear extrapolation was used to compute median survival periods.

RESULTS

The OS benefit was significantly dependent on age (HR:2.499, 95% CI: 1.245-5.016, p = 0.010) and age-adjusted Charlson comorbidity index (CCI) score (HR:3.956, 95% CI, 1.409-11.110, p = 0.009). OS in patients aged <75 years or with an age-adjusted CCI score <7 was significantly prolonged (44.68, 65.55 months) compared to OS in patients aged ≥75 years or with CCI score ≥7 (p < 0.001 for both). PFS benefit was significantly dependent on age-adjusted CCI (HR:3.325, 95% CI, 1.390-7.956, p = 0.007), patient type (HR:0.4, 95% CI, 0.214-0.745, p = 0.004), and tumour growth pattern (HR:12.562, 95% CI, 1.552-101.696, p = 0.018). PFS in incipient patients was significantly prolonged (33.75 months) compared to that in the relapsed patients (p = 0.037). Patients with an age-adjusted CCI score <7 or without tumour protruding into the renal pelvis, lived free from recurrence or metastasis (55.69 or 101.61 months) longer than that in patients with an age-adjusted CCI score ≥7 or with tumour protruding into the renal pelvis (p < 0.01 for both). None of the variables was associated with CSS benefit.

CONCLUSIONS

The OS and PFS benefits from MWA were not equal for all T1a RCC patients. Age ≥75 years and age-adjusted CCI ≥ 7 significantly shortened OS. Age-adjusted CCI ≥ 7, relapsed RCC, and RCC protruding into the renal pelvis significantly shortened the PFS period. For a better survival prognosis, appropriate patient triage is still needed.

Cause-Specific Mortality Among Survivors From T1N0M0 Renal Cell Carcinoma: A Registry-Based Cohort Study

Objective

More T1N0M0 renal cell carcinoma (RCC) is detected and the prognosis has improved, but, the current focus on non-RCC-related mortality is superficial. We investigated cause-specific mortality and its temporal patterns after an RCC diagnosis.

Methods

In the Surveillance, Epidemiology, and End Results-18 database, patients with T1N0M0 RCC treated with partial nephrectomy (PN) or radical nephrectomy (RN) during 2000-15 were identified. Standardized mortality ratios (SMRs) for cause of death were calculated. Risk predictors for each cause-specific mortality were investigated using the Fine and Gray sub-distribution model.

Results

In all, 68,612 eligible patients were pooled. A total of 14,047 (20.5%) patients had died (cardiovascular disease [CVD], 28.3%; other non-cancer-related diseases, 20.3%; RCC, 18.7%; other cancer types, 16.3%; non-disease events, 16.1%) during follow-up. Heart disease, diabetes mellitus, and cerebrovascular disease were the primary causes of non-RCC-related mortality within 1 year after the diagnosis. The greatest proportion of death (39.0%) occurred within 1-5 years after the diagnosis, mostly due to RCC itself, followed by heart disease. However, >5 years after the diagnosis, heart disease became the leading cause of death. Compared with the general US population, a 21% (SMR, 1.21; 95%CI 1.19-1.23) increased risk of all-mortality was observed; RCC patients had a higher risk of heart disease-related death within 5-10 years (SMR, 1.10; 95%CI 1.04-1.17) and >10 years (1.12; 1.02-1.22) after the diagnosis. Older age and RN increased the death risk of CVD and RCC-specific mortality. Although a larger tumor diameter increased the risk of RCC-specific death, this was not a significant predictor for CVD. Moreover, for T1N0M0 RCC tumors of diameter >4 cm, there was no significant difference in CVD incidence for RN vs. PN.

Conclusions

RCC-specific mortality is a common challenge for the prognosis. Importantly, a large proportion and higher SMRs of other non-RCC-related diseases (especially CVD) should not be disregarded for the better holistic management of survivors of local RCC. Targeted prevention strategies for non-RCC-related death could lead to significant reductions in mortality for RCC survivors.

Acute kidney injury after nephron sparing surgery and microwave ablation: focus on incidence, survival impact and prediction

Purpose: To compare acute kidney injury (AKI) incidence between nephron sparing surgery (NSS) and microwave ablation (MWA) for T1a RCC patients, reveal the effect of AKI on survival prognosis, construct AKI nomogram and use Law of Total Probability for survival probability (SP) prediction.Materials and methods: Patients were studied retrospectively after NSS (n = 1267) or MWA (n = 210) from January 1, 2011 to June 30, 2017. Using one to one Propensity Score Matching (PSM), 158 pairs of patients were identified for the cohort study. AKI incidence, risk factors and impact on survival outcomes were analyzed using Chi-square test, logistic and cox regression analysis. AKI risk and SP were predicted by nomogram and Law of Total Probability. The performance of the nomogram was assessed with respect to its discrimination, calibration, and clinical usefulness.Results: AKI occurred more commonly in NSS (27.85%) cohort, when compared to MWA (17.72%) cohort (p = 0.032), but treatment modality was not independently predictive of AKI occurrence (odds ratio [OR]: 0.598; 95% confidence interval [CI]: 0.282-1.265; p = 0.178). The 5-yr overall survival (OS) was lower in AKI patients (73.5%) compared with non-AKI patients (94.8%; p < 0.001). AKI was an independent risk factor for all-cause mortality in RCC patients (hazard ratio [HR]: 2.820; 95% confidence interval [CI]: 1.110-7.165; p = 0.029). Predictors for both NSS- and MWA-related AKI included tumor diameter, baseline eGFR and CCI score. RENAL score and tumor blood supply can predict AKI after NSS and MWA, respectively. The AKI normograms demonstrated good discrimination, with AUCs >0.86, excellent calibration and net benefits at the decision curve analysis with probabilities ≥5%. SP predicted by Law of Total Probability was comparable to actual OS.Conclusion: AKI was an early indicator for poor overall survival in RCC patients. It can be predicted by several oncological parameters. Nomogram and Law of Total Probability can accurately predict AKI risk and SP.

Prognostic indicators of pulmonary metastasis in patients with renal cell carcinoma who have undergone radical nephrectomy

The aim of the present study was to validate prognostic indicators of pulmonary metastasis in patients with renal cell carcinoma (RCC) that have undergone nephrectomy treatment. The data from 356 patients who underwent nephrectomy were investigated and subsequently divided into 2 groups, according to the pulmonary metastasis status. The risk factors for pulmonary metastasis were examined in all patients. In the subgroup analysis, the risk factors were additionally verified in patients with pulmonary nodules using univariate and multivariate logistic regression analyses. The status of pulmonary nodules and pulmonary metastasis were confirmed through preoperative chest radiography by two radiologists. Pulmonary metastasis was observed in 33 (9.3%) patients with a median follow-up time of 54.4 months (interquartile range, 38.8-71.8). Patients with pulmonary nodules indicated significantly increased rates of pulmonary metastasis, compared with patients without pulmonary nodules (24.2 vs. 6.1%; P<0.001). In multivariate analysis, the presence of pulmonary nodules [hazard ratio (HR)=3.15; P=0.0262], albumin (HR=0.42; P=0.0490) and pTstage (HR=3.63; P=0.0475) were indicated to be independent prognostic markers for pulmonary metastasis. In subgroup analysis, pTstage was the only independent prognostic indicator for pulmonary metastasis in these patients (HR=9.81; P=0.0033). In patients with RCC, the presence of pulmonary nodules was associated with pulmonary metastasis. Furthermore, pTstage is a negative prognostic indicator in patients with pulmonary nodules. Therefore, a chest radiologic short-term follow-up is required for these patients.

Differences in peritumoral pseudocapsule characteristics according to clinicopathological factors in clinical T1a renal tumors

OBJECTIVES

To evaluate the status of peritumoral pseudocapsules in renal tumors and the effects of clinicopathological factors on their formation.

METHODS

From January 2011 to December 2012, 258 patients with solitary clinical stage T1a renal tumors who underwent partial nephrectomy were analyzed. Status of pseudocapsule was re-evaluated by a pathologist.

RESULTS

The mean long diameter (± SD) of the tumor and the width of the safety margin were 2.17 (± 0.94) cm and 3.2 (± 2.4) mm, respectively. A complete pseudocapsule was identified in 152 (58.9%) tumors, an incomplete pseudocapsule was identified in 69 (26.7%) tumors, and no pseudocapsule was identified in 37 (14.3%) tumors. Out of 152 tumors with complete pseudocapsules, 45 (29.6%) were confirmed to directly invade the renal parenchyma. In a multivariable analysis, age (odds ratio [OR], 1.045; 95% confidence interval [CI], 1.021-1.070, P < 0.001) and histologic subtype (chromophobe type: OR, 19.455; 95% CI, 4.233-89.471, P < 0.001; oncocytoma: OR, 11.307; 95% CI, 1.357-94.198, P = 0.025) were significant factors for an incomplete or absent pseudocapsule.

CONCLUSIONS

Peritumoral pseudocapsules are absent or incomplete in a significant portion of renal tumors. Old age as well as chromophobe and oncocytoma histologic subtypes were significant risk factors for an incomplete or absent peritumoral pseudocapsule.

Influence of body mass index, smoking, and blood pressure on survival of patients with surgically-treated, low stage renal cell carcinoma: a 14-year retrospective cohort study

The association of body mass index, smoking, and blood pressure, which are related to the three well-established risk factors of renal cell carcinoma, and survival in patients with renal cell carcinoma is not much studied. Our objective was to evaluate this association. A cohort of 1,036 patients with low stage (pT1 and pT2) renal cell carcinoma who underwent radical or partial nephrectomy were enrolled. We retrospectively reviewed medical records and collected survival data. The body mass index, smoking status, and blood pressure at the time of surgery were recorded. Patients were grouped according to their obesity grade, smoking status, and hypertension stage. Survival analysis showed a significant decrease in overall (P = 0.001) and cancer-specific survival (P < 0.001) with being underweight, with no differences of smoking status or perioperative blood pressure. On multivariate analysis, perioperative blood pressure ≥ 160/100 mmHg (HR, 2.642; 95% CI, 1.221-5.720) and being underweight (HR, 4.320; 95% CI, 1.557-11.984) were independent predictors of overall and cancer-specific mortality, respectively. Therefore, it is concluded that being underweight and perioperative blood pressure ≥ 160/100 mmHg negatively affect cancer-specific and overall survival, respectively, while smoking status does not influence survivals in patients with renal cell carcinoma.