[807] The Significance of Midline Crossing in Organ Confined pT2c Prostate Carcinoma

Alena Bartakova, Patrick H Sweet, Ahmed S Shabaik. UCSD, San Diego, CA; ULB, Brussels, Belgium

Background: In the seventh edition of the American Joint Committee on Cancer (AJCC) cancer staging manual, organ confined prostatic adenocarcinoma (PCa) pT2 is substaged into pT2a in which carcinoma involves one half or less of one side, pT2b, with more than one half of one side, and pT2c with both sides involvement. Frequently, pT2c cases consist of two unrelated tumor nodules with one nodule in each side. In this study we investigated the difference in outcome in pT2c cases in which a dominant tumor nodule crossed the midline to involve both sides of the prostate, against cases that involved both sides with two separate unrelated nodules.
Design: We reviewed the slides of 65 cases of pT2c PCa resected in 2006-2007. We divided the cases in two groups: those where the tumor crossed the midline (group 1), and those presenting with bilateral foci of independent tumors without histologic evidence of crossing of the midline (group 2). We compared the pathologic and clinical findings and the outcome of both groups.
Results: Our results are presented in table 1:

Table 1: Cases review
  GR 1: 49 casesGR 2: 16 cases
AGE (y)Mean61.359.3
 Median [Range]61.0 [42-74]58.5 [41-76]
PRE-OP PSA (ng/ml)Mean5.65.1
 Median [Range]5.1 [0.02-23]4.5 [0.9-12.5]
GLAND VOLUME (cc)Mean68.885.7
 Median [Range]68.4 [31.5-109]64.0 [27.5-216]
 Median [Range]6 [6-9]7 [6-9]
TUMOR VOLUME (%) 13.44.0
POST-OP PSA (ng/ml)Mean0.040.05
 Median,[Range]0.01 [0.01-0,06]0.02 [0.01-0.42]
RFS 5y (%) 87.893.8
GS 5y (%) 93.9100
Group 1: large bilateral tumor, crossing the midline; Group 2: bilateral foci of independent tumors; PSA: prostate-specific antigen; RFS: recurrence-free survival; GS: global survival

Conclusions: This pilot study found a difference in global and recurrence-free survival between group 1 and group 2 pT2c PCa. Although this may be attributed to chance because of the small sample size, it merits a larger series to assess whether there is a statistically significant difference. Interestingly, if this difference is born out, it would suggest that the biologic behavior is indeed different for these two types of presentation and pT2a or pT2b categories may suit better to cases that are pT2c because of bilateral separate nodules. Indeed, our recurrence-free survival for group 2 patients is comparable to pT2a-pT2b data published previously (Caso et al., 2010). Alternatively the organ-confined tumors may better be subdivided into two subclasses rather than three based on crossing of the midline by the index tumor.
Category: Genitourinary (including renal tumors)

Wednesday, March 6, 2013 9:30 AM

Poster Session V # 131, Wednesday Morning


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