Aim:

It is a known fact that a particular number of prostate cancer (PCa) patients diagnosed in the PSA era have T1c tumors. The aim of this review is to investigate the unique characteristics and natural history of T1c tumors and compare them to other clinical stages of PCa.

Materials and methods:

Thirty-one studies including the comparison of T1c cancers with cancers of other clinical stages are reviewed. The questions regarding the debates about the definition and clinical significance of T1c tumors, their differences from insignificant cancers, the zones of the prostate that they tend to develop from, tendency for grade progression and why they may not be palpable during digital rectal examination are investigated.

Results:

Almost 80% of T1c cancers are clinically significant and require radical treatment. If untreated, 20% may experience grade progression. There are some uncertainties regarding the definition of T1c cancers in the TNM system. Most of the T1c cancers develop from the peripheral zone, some develop from transitional zone while some of them develop from both peripheral and transitional zones. T1c tumors show some similarities with T2a tumors.

Conclusions:

An important proportion of T1c cancers are clinically significant and require treatment. Treatment outcomes of T1c cancers are similar to those of T2a cancers in some aspects. A safe threshold PSA value for biopsy decision is yet to be defined instead, PSA progression over time remains to be a more important criteria in deciding for a biopsy. It is still debateful if a positive transrectal ultrasound finding is sufficient to discriminate T1c from T2a tumors.