The prognostic role of the pathological T2 subclassification for prostate cancer in the 2002 Tumour‐Nodes‐Metastasis staging system

Abstract

OBJECTIVE To evaluate the prognostic role of the 2002 Tumour‐Nodes‐Metastasis (TNM) pT2 subclassification for biochemical recurrence (BCR) after radical prostatectomy (RP) for prostate cancer. PATIENTS AND METHODS The 1997 TNM staging system is based on one subdivision for organ‐confined prostate tumours (T2a, unilateral; T2b, bilateral involvement). The 2002 TNM staging system subdivides unilateral involvement into T2a (half of one lobe or less) and T2b (more than one half of one lobe), while bilateral involvement is classified as T2c. In all, 542 patients were treated with RP at our institute; the RP specimens were completely embedded and histopathologically evaluated for Gleason grade, tumour volume and anatomical extent, and were staged according to the 2002 TNM staging criteria. Patients were followed for a median of 39.5 months. BCR was defined as two subsequent increasing prostate‐specific antigen (PSA) levels of >0.10 ng/mL. Kaplan‐Meier and proportional hazards regression analyses were used to evaluate the univariable and multivariable prognostic effect of tumour stage. RESULTS According to the 2002 TNM staging system, 360 specimens were found to have pT2 tumours; 79 (22%) of the RP specimens were staged as pT2a and 281 (78%) as pT2c; no pT2b specimens were identified. Patients with unilateral involvement (pT2a) had a 5‐year risk of BCR of 13%, while those with bilateral involvement (pT2c) had a risk of 23% (log rank test, P = 0.056). Patients with pT2c disease were more likely to have a larger tumour volume (Mann–Whitney U‐test P < 0.001) and positive surgical margins (Fishers’ exact test, P = 0.001)than those with pT2a tumours. Mann–Whitney U‐tests showed no differences between the groups for preoperative PSA levels (P = 0.167). Also, the RP Gleason score was no different between groups (Pearson chi‐square, P = 0.807). In the multivariable analyses, positive surgical margins appeared to increase the risk of BCR (hazard ratio 4.4, 95% confidence interval 2.5–7.9); pT2c vs pT2a had only a marginally (insignificant) additional effect (1.3, 0.6–2.7). CONCLUSION The absence of a true unilateral pathological T2b tumour in a series of 360 pT2 RP specimens questions the relevance of substaging unilateral disease. The limited differences in BCR and in pathological features of unilateral vs bilateral pT2 prostate cancer justify modifying the TNM staging system to one with no subclassification of pT2 disease, or at most as only one subdivision into unilateral (T2a) and bilateral (T2b) disease, combining the T2b and T2c substages.

International Society of Urological Pathology (ISUP) Consensus Conference on Handling and Staging of Radical Prostatectomy Specimens. Working group 1: specimen handling

“…In contrast, patients with a biopsy positive for cancer, but with no cancer in the radical prostatectomy specimen, have no increased risk of tumor recurrence or progression. 50,[56][57][58][59] European urologists have suggested that in these cases, pT2 could be further characterized as pT2(À), where (À) indicates that cancer was not detected in the surgical specimen. Another alternative is to grade these tumors as pT2 ( þ bx/Àrp) to indicate the special situation of a positive biopsy ( þ bx) with no cancer detected in the radical prostatectomy specimen (Àrp).…”

Pathological T2 sub‐divisions as a prognostic factor in the biochemical recurrence of prostate cancer

“…Although clinical prostate cancer (PCa) T2 sub‐stage evaluation appears to be a useful independent predictor of biochemical disease‐free survival (bDFS) [1], there is growing evidence that pathological T2 sub‐staging does not have the same value [2–8]. After its introduction in 1992, the American Joint Committee on Cancer/International Union Against Cancer (AJCC/UICC) tumour, node, metastases system became the standard method in which PCa is clinically and pathologically staged [9].…”

Is substaging necessary in patients with pathological stage T2 prostate cancer?

“…Biyokimyasal nüksü öngörmede T2 alt sınıflamasının katkısının değerlendirildiği başka bir çalışmada, ameliyat öncesi PSA ve patolojik Gleason skorunun 7 ve 8-10 olması biyokimyasal nüks bakımından öngörücü iken, patolojik T2 alt gruplarının herhangi bir katkısının olmadığı bulunmuştur. [19] 2002 TNM sınıflamasına göre pT2b tümörlerin saptanma oranı çalışmaların çoğunda çok düşüktür, [20][21][22] hatta bazı çalışmalarda hiç saptanmamıştır. [14] Farklı olarak bir çalışmada prostata sınırlı tümörlerin %61.1'inin pT2b olduğu bulunmuştur.…”