The study was conducted as a cross-sectional analysis of men with histologically confirmed prostate cancer enrolled in two prospective registries: the International Registry for Men with Advanced Cancer (IRONMAN) and the African Cancer Genomic Registry (ACGR). Participants were recruited at two tertiary hospitals in Nairobi—Kenyatta National Hospital, a national public referral center, and MP Shah Hospital, a private tertiary facility. The sample size was calculated using Cochran’s formula, with a minimum required number of 162 patients based on a 95% confidence interval, a 5% margin of error, and an estimated population proportion of 0.88 representing patients presenting with advanced disease in Kenya.

Eligible participants were men aged 40 years or older with histologically confirmed prostate adenocarcinoma. The IRONMAN registry enrolled patients with locally advanced and metastatic prostate cancer, while the ACGR registry enrolled all patients with prostate cancer irrespective of stage. Patients included in the study from both registries were enrolled once to avoid potential overlap and duplication. Tumour stage was derived from clinical records and categorized as localized disease (T1-2, N0, M0) or advanced disease (T3-4 irrespective of N and M stage). PSA level at diagnosis was grouped into clinically meaningful, data-driven categories: ≤10, 11–20, 21–50, and >50 ng/mL. Gleason scores were obtained from diagnostic pathology reports and summarized according to individual WHO/ISUP Grade Groups.

Of the 170 men included in the stage-stratified analysis, only 26 (15.3%) presented with localized disease, while 144 (84.7%) had locally advanced or metastatic disease at diagnosis. The majority of patients were 70 years and older, and 85.9% (n=146) were recruited from the public hospital. More than half of the cohort (54.1%, n=92) had PSA values above 50 ng/mL, and WHO/ISUP grade group 5 dominated the histological patterns at 49.4%. These figures align with multi-country analyses documenting advanced-stage presentation among approximately 78%–85% of men with prostate cancer across sub-Saharan Africa.

PSA levels exhibited a strong, progressive gradient across tumour stages. Men with localized disease were predominantly concentrated within the lower PSA ranges, particularly below 20 ng/mL. As PSA levels increased, the distribution shifted progressively toward advanced-stage presentation. Men with PSA values between 21 and 50 ng/mL were already more likely to present with advanced disease than with localized disease. This trend became even more pronounced at higher thresholds: among men with PSA values over 50 ng/mL, 81 out of 92 (88%) had advanced disease at diagnosis.

Multivariable logistic regression analysis confirmed these associations. Compared with men with PSA ≤10 ng/mL, those with PSA levels of 11–20 ng/mL had significantly higher odds of advanced-stage disease (AOR=9.61, 95% CI: 1.61–57.26; p=0.013). Similarly, PSA levels >50 ng/mL were associated with significantly higher odds of advanced-stage disease (AOR=9.26, 95% CI: 2.12–40.34; p=0.003). Although men with PSA levels of 21–50 ng/mL also had higher odds of advanced-stage disease, the association did not reach statistical significance (AOR=3.99, 95% CI: 0.79–19.97; p=0.093). In a separate analysis treating PSA category as an ordinal variable, each increase in PSA category was associated with 59% higher odds of advanced-stage disease after adjustment for age (AOR=1.59, 95% CI: 1.05–2.41; p=0.029). Age was not independently associated with advanced-stage disease (AOR=1.00, 95% CI: 0.94–1.06; p=0.956). The authors caution that the wide confidence intervals around the category-specific estimates indicate considerable uncertainty and warrant cautious interpretation.

ISUP grade groups demonstrated a parallel association with tumour stage. Among the 168 men with available grade groups and stage data, 25 (15%) had localized disease, while 143 (85%) had advanced disease. Lower-grade tumours were more frequently observed among men with localized disease, whereas higher-grade tumours predominated among men with advanced-stage cancer. Notably, the ISUP grade 3 pattern was strongly associated with advanced disease, with 28 of 34 cases (82.4%) occurring among men with advanced-stage tumours. High-grade tumours (WHO/ISUP grade groups 4 and 5) constituted the majority of advanced-stage cases at 54.7%. Advanced disease predominated across all grade groups, ranging from 82.4% among patients with WHO/ISUP grade 3 disease to 86.9% among those with grade 5 disease. However, there was no statistically significant association between ISUP grade group and disease stage at diagnosis (Pearson χ²(1)=0.39, p=0.53), and in the multivariable analysis, advanced-stage disease was associated with 31% higher adjusted odds of having a higher grade group, an association that was not statistically significant (OR=1.31; 95% CI: 0.55–3.14; p=0.543).

Interestingly, each one-category increase in PSA was associated with 44% higher odds of having a higher ISUP grade after adjustment for age (OR=1.44; 95% CI: 1.02–2.04; p=0.040). Compared with men with PSA ≤10 ng/mL, PSA >50 ng/mL had 3.23 times the odds of high-grade group, although this did not reach statistical significance (95% CI: 0.79–13.09, p=0.101). Age was not significantly associated with the grade group category (AOR 1.01; 95% CI 0.97–1.06; p=0.682). Taken together, the PSA and ISUP grade distributions reveal a consistent clinicopathological profile: men diagnosed with localized disease represented a minority and were largely characterized by lower PSA values and lower-grade tumours, while advanced-stage disease predominated and was associated with markedly elevated PSA levels and a higher-grade histological pattern.

The authors suggest that both late diagnosis and aggressive tumour biology contribute to the predominance of advanced-stage prostate cancer in this cohort. Beyond health system constraints, emerging evidence points to biological and genetic factors that may contribute to the aggressive clinicopathological profile of prostate cancer among men of African ancestry, including ancestry-associated differences in tumour behavior, disease aggressiveness, and PSA-related risk stratification. However, the authors note that this relationship cannot be concluded from the present study due to the absence of molecular and genetic data. An additional observation was that advanced-stage disease predominated across all age categories, including men younger than 60 years, suggesting that delayed diagnosis is not restricted to a particular demographic but likely reflects broader challenges within the prostate cancer care pathway, including delayed health-seeking behavior, limited access to early diagnostic evaluation, and barriers to timely referral and specialist care.

A central, clinically actionable finding is that the strong association between PSA level and tumour stage supports the continued clinical utility of PSA as a clinical marker in resource-limited settings. The authors suggest that PSA values, particularly those above 50–100 ng/mL, may have potential utility as a pragmatic indicator for prioritizing expedited urological referral and staging at primary and secondary care levels, especially where specialist evaluation is not immediately accessible. However, given the cross-sectional nature of the study, these findings do not establish a referral threshold, and prospective studies would be required to validate the clinical utility of such PSA-based triage. The study has two main limitations: recruitment was primarily conducted at tertiary referral hospitals, which may preferentially capture patients with more advanced or complex disease and limit generalizability, and the cross-sectional design limits assessment of temporal relationships and precludes causal inference. Nevertheless, the combination of markedly elevated PSA, high-grade histology, and advanced-stage presentation highlights the need for earlier diagnosis and more efficient referral pathways in Kenya. Strengthening early detection, public awareness, and context-appropriate referral pathways may help reduce advanced-stage presentation and improve prostate cancer outcomes. Future research should explore the development and validation of pragmatic, data-driven approaches to prostate cancer risk assessment, referral, and early detection, and evaluate their feasibility and effectiveness within Kenyan and other sub-Saharan African healthcare settings.

Subject of Research: Prostate cancer in Kenya: registry analysis of PSA, stage, and ISUP grade at diagnosis

Article Title: Advanced stage at diagnosis and aggressive histology dominate prostate cancer presentation in Kenya: a registry analysis

Article References: Waihenya, C., Ojuka, D. K., Ragin, C., Zeigler-Johnson, C., Mbugua, R. W., & Thumbi, S. M. (2026). Advanced stage at diagnosis and aggressive histology dominate prostate cancer presentation in Kenya: a registry analysis. Frontiers in Cancer Control and Society, 4, Article 1946844. https://doi.org/10.3389/fcacs.2026.1946844

Image Credits: AI Generated

DOI: 10.3389/fcacs.2026.1946844

Keywords: prostate cancer, Kenya, PSA, WHO/ISUP grade groups, early detection, health systems, IRONMAN registry, ACGR, sub-Saharan Africa, cancer control, Advanced, stage