Evaluation of clinical staging of the American Joint Committee on Cancer (eighth edition) for prostate cancer

Analysis of the surgical approach in prostate cancer staging: results from the surveillance, epidemiology and end results program

Surgery is not used as a criterion for staging prostate cancer, although there is evidence that the number of analyzed and affected lymph nodes have prognosis value. The aim of this study was to determine whether there are significant differences in staging criteria in patients who underwent prostatectomy compared to those who did not, and whether the number of affected and analyzed lymph nodes (LN) plays a prognostic role. In this retrospective study, a test cohort consisting of 404,210 newly diagnosed men with prostate cancer, between 2004 and 2010, was obtained from the 17 registries (Nov 2021 submission); a validation consisting of 147,719 newly diagnosed men with prostate cancer between 2004 and 2019 was obtained from the 8 registries (Nov 2021 submission). Prostate cancer-specific survival was analyzed by Kaplan-Meier curves, survival tables and Cox regression; overall survival was analyzed only to compare Harrell's C-index between different staging criteria. In initial analyses, it was observed that the prognostic value of lymph node metastasis changes according to the type of staging (clinical or pathological), which is linked to the surgical approach (prostatectomy). Compared with T4/N0/M0 patients, which are also classified as stage IVA, N1/M0 patients had a shorter [adjusted HR: 1.767 (1429-2184), p < 0.0005] and a longer [adjusted HR: 0.832 (0.740-0.935), p = 0.002] specific survival when submitted to prostatectomy or not, respectively. Analyzing separately the patients who were submitted to prostatectomy and those who were not, it was possible to obtain new LN metastasis classifications (N1: 1 + LN; N2: 2 + LNs; N3: > 2 + LNs). This new (pathological) classification of N allowed the reclassification of patients based on T and Gleason grade groups, mainly those with T3 and T4 disease. In the validation group, this new staging criterion was proven to be superior [specific survival C-index: 0.908 (0.906-0.911); overall survival C-index: 0.788 (0.786-0.791)] compared to that currently used by the AJCC [8th edition; specific survival C-index: 0.892 (0.889-0.895); overall survival C-index: 0.744 (0.741-0.747)]. In addition, an adequate number of dissected lymph nodes results in a 39% reduction in death risk [adjusted HR: 0.610 (0.498-0.747), p < 0.0005]. As main conclusion, the surgery has a major impact on prostate cancer staging, mainly modifying the effect of N on survival, and enabling the stratification of pathological N according to the number of affected LN. Such a factor, when considered as staging criteria, improves the prognosis classification.

Modified the 8th AJCC staging system for patients with advanced prostate cancer: a study based on SEER database

Background

The American Joint Committee on Cancer (AJCC) 8th staging system of prostate cancer may be insufficient in predicting the prognosis of some staged patients. This study aimed to modify the AJCC 8th staging system in patients with advanced prostate cancer.

Methods

Data of patients with advanced prostate cancer from the Surveillance, Epidemiology, and End Results (SEER) database between 2004 and 2016 were enrolled in this cohort study. All patients were divided into the training set and the testing set with a ratio of 6:4. Multivariate Cox survival model was utilized to obtain the nomogram score for each stage variable. The modified staging system was based on the total nomogram score. The C-index and Kaplan-Meier (K-M) curves were used to show the prognostic prediction effect of patients with different staging systems.

Results

A total of 28,006 patients were included for analysis. T stage, N stage, M stage, primary Gleason pattern score, secondary Gleason pattern score, and PSA level were included as stage variables. Patients with AJCC stage III C [hazard ratio (HR) = 4.17, 95% confidence interval (CI), 3.39–5.13] and AJCC stage IV B (HR = 3.19, 95%CI, 1.79–5.69) were associated with worse prognosis compared with those of AJCC stage III B, while no statistical significance was found in patients with stage IV A (P > 0.05). In terms of the modified staging system, patients with modified stage III C (HR = 2.06, 95%CI, 1.46–2.92), modified stage IV A (HR = 6.91, 95%CI, 4.81–9.94), and modified stage IV B (HR = 21.89, 95%CI, 14.76–32.46) were associated with a poorer prognosis compared with patients with modified stage III B. The prognostic ability (C-index) of the modified staging system (0.789; 95%CI, 0.777–0.801) was better than that of the AJCC 8th edition system (0.762; 95%CI, 0.748–0.776) (0.789 vs. 0.762, P = 0.004). The K-M curves indicated that the modified staging system may be distinguished prognostic differences in patients with different stages.

Conclusion

Modified staging system may be better than AJCC 8th staging system for predicting prognosis in prostate cancer patients. The AJCC 8th staging system should be further optimized.

The homogeneous and heterogeneous risk factors for the morbidity and prognosis of bone metastasis in patients with prostate cancer

Purpose

Using the Surveillance, Epidemiology, and End Results database (SEER) to assess the incidence and risk factors of morbidity and prognosis for bone metastases in initial metastatic prostate cancer.

Patients and methods

The records of 249,331 prostate cancer patients in the SEER database, diagnosed between 2010 and 2014, were obtained were obtained to investigate the risk factors for developing bone metastasis, and the records of 9925 of them who registered before 2013 were retrieved (with at least 1 year follow up) to explore the prognostic factors for bone metastasis. Multivariate logistic and Cox regression were used to identify risk factors and prognostic factors for bone metastases, respectively.

Results

In total, 12,794 patients (5.1%) were diagnosed with bone metastases at the initial diagnosis. Older age, unmarried status, lymph node metastasis, poor tumor differentiation grade (Gleason grade), metastases at lung, brain, and liver were all positively associated with risk for the morbidity and prognosis of bone metastasis in prostate cancer. Black race and higher T stage were positively associated with bone metastasis development; however, they were not associated with a prognosis of bone metastasis.

Conclusion

The incidence of bone metastasis in prostate cancer was approximately 5% with poor survival. The prostate cancer has homogeneous and heterogeneous risk factors for incidence and prognosis of bone metastasis, which may provide potential guidelines for the screening and preventive treatment for the bone metastasis of prostate cancer.