Prostate Cancer Cases Are Growing More Serious

Abdullah Hashmi, MD

July 07, 2022

The study covered in this summary was published on as a preprint and has not yet been peer reviewed.

Key Takeaways

  • In the past decade, the incidence of T1a/b prostate cancer has remained stable, but clinically significant T1a/b disease has increased over time. 

  • Across all risk groups and accounting for age and comorbidity status, patients diagnosed with T1a/b prostate cancer are more likely to enter active surveillance/watchful waiting and are less likely to be treated definitively with surgery or radiation.

Why This Matters

  • The changing recommendations regarding prostate cancer screening in the U.S. during the last decade have led to changes in incidence patterns of prostate cancer, and the appropriate management of T1a/b prostate cancer is not well defined. 

  • Only a few studies have previously addressed the incidence of T1a/b prostate cancer. It has remained unclear which patients with T1a/b disease benefit from definitive treatment or expectant management.

  • This is the largest study examining trends in incidence, clinical significance, and treatment patterns for T1a/b prostate cancer regardless of risk group, age, and comorbidity status.

Study Design

  • Using the National Cancer Database, the study looked at a dataset of 24,679 patients diagnosed with T1a/b prostate cancer between 2010 and 2017. 

  • Patients with missing data for pathological T stage, prostate specific antigen (PSA), or Gleason score were removed from analysis.

  • Clinically significant disease was defined as Gleason grade group ≥ 2.

  • Treatment modalities were assessed for primary treatment after diagnosis only.  To reduce treatment bias, a second analysis of treatment modality proportions for patients between 62 and 68 years of age was completed. Patients in this age group were eligible for all treatment modalities. 

Key Results

  • Of the 24,679 patients identified, 15,186 had T1a disease and 9493 had T1b disease.

  • T1a/b prostate cancer represented 3.5% of all prostate cancer without a change in incidence over time.

  • The likelihood of T1a/b prostate cancer being clinically significant increased over time, from 38.8% in 2010 to 44.1% in 2017 (P < .001). Similarly, the chance of being diagnosed with T1a/b non-clinically significant disease decreased from 61.3% in 2010 to 55.9% in 2017.

  • Patients diagnosed with T1a/b disease were significantly older (mean age 72.2 ± 9.6 vs 64.2 ± 8.1; P < .001) than patients diagnosed with T1c disease.

  • Accounting for age and risk, patients with diagnosed T1a/b disease were less likely to be treated definitively with surgery or radiation compared with patients with T1c disease (low risk — 6.9% [T1a] vs 17.6% [T1b] vs 67.5% [T1c]; P < .001); (intermediate risk — 21.6% [T1a] vs 30.4% [T1b] vs 86.2% [T1c]; P < .001); (high risk — 28.4% [T1a] vs 26.3% [T1b] vs 78.2% [T1c]; P < .001).

  • Across all risk groups, patients with T1a/b disease were more likely to enter active surveillance/watchful waiting compared with T1c patients. In comparison to T1b, patients with T1a disease across all risk groups were more likely to enter active surveillance/watchful waiting.


  • Variations between institutions for the National Cancer Database reporting and coding may have affected the analyzed dataset.

  • Long-term oncological outcomes and functional outcomes were not obtained because the data was not coded in the National Cancer Database.

  • The National Cancer Database only included data for Commission on Cancer-accredited facilities and may not have been generalizable to other countries.


  • The study received no commercial funding.

  • The authors disclosed no relevant financial relationships.

This is a summary of a preprint research study, “Trends in Diagnosis and Treatment of T1a, T1b Prostate Cancer in the United States, 2010-2017,” led by Eyal Kord, MD, MPH,  Virginia Mason Medical Center, Seattle, Washington, and published on This study has not yet been peer reviewed. The full text can be found on

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