Nomograms Predict Survival in Rare Prostate Cancer

RARE prostate cancer nomograms showed strong performance in predicting one-, three-, and five-year overall survival (OS) and cancer-specific survival (CSS), according to a study using data from the Surveillance, Epidemiology, and End Results database.

Developing Rare Prostate Cancer Nomograms

The study included 3,538 patients with rare histological variant prostate cancer diagnosed between 2000 and 2021. Researchers randomly divided the cohort into a training group of 2,476 patients and a validation group of 1,062 patients.

Clinicopathological and prognostic data were assessed to identify independent factors associated with survival. Univariate and multivariate Cox regression analyses identified age, marital status, Gleason score, tumour grade, summary stage, chemotherapy, surgery, and histology as independent prognostic factors for both OS and CSS, with all associations reaching statistical significance at P<0.05.

The researchers subsequently developed nomograms to estimate individual one-, three-, and five-year survival probabilities.

Strong Predictive Performance

The rare prostate cancer nomograms demonstrated favourable discrimination in both cohorts. For OS, the concordance index (C-index) was 0.831 in the training cohort and 0.821 in the validation cohort. For CSS, the corresponding values were 0.873 and 0.868.

Receiver operating characteristic analysis also indicated strong predictive performance. For OS, the one-, three-, and five-year areas under the receiver operating characteristic curve (AUCs) were 0.918, 0.908, and 0.892 in the training cohort, compared with 0.913, 0.902, and 0.882 in the validation cohort.

For CSS, AUCs were 0.929, 0.940, and 0.930 in the training cohort and 0.933, 0.932, and 0.921 in the validation cohort. Calibration curves showed close agreement between predicted and observed survival probabilities.

The researchers also reported that receiver operating characteristic curves, AUC, C-index, net reclassification improvement, integrated discrimination improvement, and decision curve analysis indicated better prognostic discrimination than the TNM staging system within the study cohort.

Implications For Clinical Management

The findings suggested that rare prostate cancer nomograms could provide clinicians with more individualised estimates of OS and CSS than TNM staging alone within this SEER-derived cohort.

The tools incorporated multiple clinicopathological characteristics and treatment-related factors, potentially supporting personalised prognostic assessment and clinical management.

However, the study’s validation was internal. The researchers therefore highlighted the need for further external validation before the nomograms can be established as reliable tools for broader clinical application.

Reference

Long Q et al. Prognostic factors and nomograms predicting overall survival and cancer specific survival for patients with rare histological variant prostate cancer. Sci Rep. 2026;DOI: https://doi.org/10.1038/s41598-026-73583-8.

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