Cause-specific mortality of low and selective intermediate-risk prostate cancer patients with active surveillance or watchful waiting

Clinical characteristics and prostate-cancer-specific mortality of competitive risk nomogram in the second primary prostate cancer

Background

With the development of early diagnosis and treatment, the second primary malignancy (SPM) attracts increasing attention. The second primary prostate cancer (spPCa) is an important class of SPM, but remains poorly understood.

Methods

We retrospectively analyzed 3,322 patients with spPCa diagnosed between 2004 and 2015 in the Surveillance, Epidemiology, and End Results (SEER) database. Chi-square test was applied to compare demographic and clinical variables and analyze causes of death. Multivariate competitive risk regression model was used to identify risk factors associated with prostate-cancer-specific mortality (PCSM), and these factors were enrolled to build a nomogram of competitive risk. The C-index, calibration curve, and decision curve analysis (DCA) were employed to evaluate the discrimination ability of our nomogram.

Results

The median follow-up (interquartile range, IQR) time was 47 (24-75) months, and the median (IQR) diagnosis interval between the first primary cancer (FPC) and spPCa was 32 (16-57) months. We found that the three most common sites of SPM were the urinary system, digestive system, and skin. Through multivariate competitive risk analysis, we enrolled race (p < 0.05), tumor-node-metastasis (TNM) stage (p < 0.001), Gleason score (p < 0.05), surgery (p = 0.002), and radiotherapy (p = 0.032) to construct the model to predict the outcomes of spPCa. The C-index was 0.856 (95% CI, 0.813-0.899) and 0.905 (95% CI, 0.941-0.868) in the training and validation set, respectively. Moreover, both the calibration curve and DCA illustrated that our nomogram performed well in predicting PCSM.

Conclusion

In conclusion, we identified four risk factors associated with the prognosis of spPCa and construct a competing risk nomogram, which performed well in predicting the 3-, 5-, and 10-year PCSM.

Prostate cancer mortality rates in low- and favorable intermediate-risk active surveillance patients: a population-based competing risks analysis

PURPOSE

To determine prostate cancer (PCa) and other-cause mortality rates in low- and favorable intermediate-risk (FIR) active surveillance (AS) patients.

METHODS

The SEER Prostate with Watchful Waiting database was used to identify men diagnosed with NCCN low or FIR PCa, between 2010 and 2015, managed with AS. FIR patients were subdivided into three subgroups, based on their intermediate risk factor: grade group two (GG2), PSA 10-20 ng/ml or cT2b-c disease. Cumulative incidence function curves with other-cause mortality as the competing risk were utilized. Predictors of PCa mortality were assessed using multivariable regression analysis with semi-parametric proportional hazards modeling.

RESULTS

Among 70,871 patients, 48,127 (67.9%) had low and 22,744 (32.1%) had FIR disease. Median patient age was 64.0 years, and median PSA was 5.70 ng/ml. Median follow-up was 49.0 months. There were 166 (0.2%) PCa and 3,176 (4.48%) other-cause mortalities. The 5-year mortality rates in the low and FIR cohorts overall were 0.29% and 0.28%, respectively (p = 0.64). Within the FIR cohort, the corresponding rates were highest in the PSA 10-20 ng/ml subgroup at 0.73%, followed by 0.32% for GG2 FIR and 0.052% for cT2b-c FIR disease (p < 0.001). Older age at diagnosis (sHR 2.38, p = 0.006), Medicaid insurance (sHR: 2.58, p < 0.001), low socioeconomic (sHR 1.39, p = 0.032), and non-married statuses (sHR: 2.58, p < 0.001) were associated with increased PCa mortality.

CONCLUSION

Intermediate-term PCa mortality rates in FIR PCa patients are non-significantly different to those with low-risk PCa. However, there is significant within-group heterogeneity, with PCa mortality rates significantly higher in the PSA 10-20 subgroup.

Variance of Tumor Grade at Radical Prostatectomy With Assessment of Each Tumor Nodule Versus Global Grading

CONTEXT.—

Multifocal prostate cancer at radical prostatectomy (RP) may be graded with assessment of each individual tumor nodule (TN) or global grading of all TNs in aggregate.

OBJECTIVE.—

To assess case-level grade variability between these 2 grading approaches.

DESIGN.—

We reviewed 776 RPs with multifocal prostate cancer with 2 or more separate TNs of different Grade Groups (GGs). Two separate grades were assigned to each RP: one based on the TN with the highest grade and a global grade based on the Gleason pattern volumes for all TNs. We then compared the results of these 2 methods.

RESULTS.—

The case-level grade changed by 1 or more GGs between the 2 grading methods in 35% (132 of 374) of GG3 through GG5 cases. Twelve percent (37 of 309) of GG2 cases with Gleason pattern 4 more than 5% based on individual TN grading decreased their Gleason pattern 4 to less than 5% based on the global approach. Minor tertiary pattern 5 (Gleason pattern 5 <5%) was observed in 6.8% (11 of 161) of GG4 (Gleason score 3 + 5 = 8 and 5 + 3 = 8) and GG5 cases with global grading. The risk of grade discrepancy between the 2 methods was associated with the highest-grade TN volume (inverse relationship), patient age, and number of TNs (P < .001, P = .003, and P < .001, respectively).

CONCLUSIONS.—

The global grading approach resulted in a lower grade in 35% of GG3 through GG5 cases compared with grading based on the highest-grade TN. Two significant risk factors for this discrepancy with a global grading approach occur when the highest-grade TN has a relatively small tumor volume and with the higher number of TNs per RP. The observed grade variability between the 2 grading schemes most likely limits the interchangeability of post-RP multi-institutional databases if those institutions use different grading approaches.