Discontinuous foci of cancer in a single core of prostatic biopsy: when it occurs and performance of quantification methods in a private-practice setting.

In addition to clinical data, prostatic biopsy (Bx) reports orient urologists in outlining the patient's treatment options. Discontinuous involvement of a core by multiple foci of cancer is not infrequent; however, there is currently no consensus as to which method of quantification should be the standard. We applied 2 distinct approaches to quantify the length of cancer foci in the Bx and compared the results to prostatectomy (RP) parameters. All patients with matched Bx and RP treated by the same medical team between 2006 and 2010 were consecutively included in the study. Tumor extent in the Bx was estimated by multiple approaches, and the length was measured in millimeters. The subset of cases with discontinuous foci of cancer in a single core was initially reported by adding each foci and ignoring the benign intervening prostatic tissue, which was designated as additive quantification (AQ). Upon slide review, these foci were reassessed as a single focus and measured by linear quantification (LQ). RPs were partially embedded according to the International Society of Urological Pathology recommendations, and the percentage of tumor was evaluated with graphic precision. Mean percentage of the tumor in RP (%RP) and in the Bx were arbitrarily classified as limited (<6%) and nonlimited (≥6%). Bx parameters were then correlated with %RP and margin status. All methods of quantification of the tumor in the Bx obtained excellent correlation with %RP. LQ and AQ diverged in 14/38 patients, with a mean total length of cancer of 5.8 mm more than the length obtained by LQ in the same population, accurately upgrading 6/14 cases to nonlimited. This subset (LQ>AQ) was more often seen in Bx with significantly more positive cores (P=0.003) of predominantly Gleason score 7 and associated with positive surgical margins in RP (P=0.034) independent of %RP (21% vs. 19% in the margin-negative cases). However, in the subset of Bx in which the tumor infiltration was continuous (AQ=AL) positive margins were indeed associated with tumor extent (31% vs. 6% in margin-negative cases). Discontinuous foci of cancer in a single core were most often seen in Bx sampling nonlimited disease, and this event was associated with positive surgical margins. LQ of cancer improved the performance of the Bx in predicting RP tumor extent relative to the traditional millimetric sum. Our findings support the idea that discontinuous foci may represent undersampling of a larger irregular nodule; however, this study is based on routine reports and does not directly access tumor biology.

Iatrogenic and non-iatrogenic positive margins: incidence, site, factors involved, and time to PSA progression following radical prostatectomy.

INTRODUCTION: There are conflicting data regarding the incidence, site and prognostic significance of positive margins resulting from iatrogenic incision into the prostate (pT2+) or non-iatrogenic inability to excise extraprostatic extension (EPE) of tumor. MATERIALS AND METHODS: The surgical specimens were whole-mount processed. Nerve-sparing, tumor extension and Gleason score were considered possible factors involved in positive margins. Time to PSA progression was studied using a Kaplan-Meier product-limit analysis. RESULTS: Positive margins resulted from iatrogenic incision in 61/230 (26.52%) prostates and from EPE in 34/230 (14.78%) prostates. The site most frequently involved in pT2+ prostates was the posterolateral quadrants (40.98%); in cases with EPE both anterolateral and posterolateral quadrants (67.65%) were most frequently involved. Positive margins occurred equally in patients with and without nerve-sparing in both groups. Tumors were significantly more extensive and with higher Gleason score in patients with EPE. Time to PSA progression was similar in patients with pT2+ versus EPE and no invasion of the seminal vesicle, but was significantly shorter in patients with EPE and invasion of the seminal vesicle. CONCLUSION: The frequency of positive margins in our institution was similar to others with large experience in performing radical prostatectomies. The higher frequency of posterolateral quadrants in iatrogenic positive margins is probably related to the preservation of adjacent vital structures and not to nerve-sparing surgery. A trend for a decreasing frequency of non-iatrogenic surgical margins may be explained by the marked increase of clinical stage T1c in recent years. More-extensive tumors and higher Gleason scores seem to influence only non-iatrogenic positive margins. Biochemical (PSA) progression in EPE must be studied by stratifying the patients into two groups: with and without seminal vesicle invasion.

Are prostate carcinoma clinical stages T1c and T2 similar?

PURPOSE: A recent study has found that PSA recurrence rate for clinical T1c tumors is similar to T2 tumors, indicating a need for further refinement of clinical staging system. To test this finding we compared clinicopathologic characteristics and the time to PSA progression following radical retropubic prostatectomy of patients with clinical stage T1c tumors to those with stage T2, T2a or T2b tumors. MATERIALS AND METHODS: From a total of 186 consecutive patients submitted to prostatectomy, 33.52% had clinical stage T1c tumors, 45.45% stage T2a tumors and 21.02% stage T2b tumors. The variables studied were age, preoperative PSA, prostate weight, Gleason score, tumor extent, positive surgical margins, extraprostatic extension (pT3a), seminal vesicle invasion (pT3b), and time to PSA progression. Tumor extent was evaluated by a point-count method. RESULTS: Patients with clinical stage T1c were younger and had the lowest mean preoperative PSA. In the surgical specimen, they had higher frequency of Gleason score < 7 and more organ confined cancer. In 40.54% of the patients with clinical stage T2b tumors, there was extraprostatic extension (pT3a). During the study period, 54 patients (30.68%) developed a biochemical progression. Kaplan-Meier product-limit analysis revealed no significant difference in the time to PSA progression between men with clinical stage T1c versus clinical stage T2 (p = 0.7959), T2a (p = 0.6060) or T2b (p = 0.2941) as well as between men with clinical stage T2a versus stage T2b (p = 0.0994). CONCLUSION: Clinicopathological features are not similar considering clinical stage T1c versus clinical stages T2, T2a or T2b.

Are prostate carcinoma clinical stages T1C and T2 similar?

PURPOSE: A recent study has found that PSA recurrence rate for clinical T1c tumors is similar to T2 tumors, indicating a need for further refinement of clinical staging system. To test this finding we compared clinicopathologic characteristics and the time to PSA progression following radical retropubic prostatectomy of patients with clinical stage T1c tumors to those with stage T2, T2a or T2b tumors. MATERIALS AND METHODS: From a total of 186 consecutive patients submitted to prostatectomy, 33.52 percent had clinical stage T1c tumors, 45.45 percent stage T2a tumors and 21.02 percent stage T2b tumors. The variables studied were age, preoperative PSA, prostate weight, Gleason score, tumor extent, positive surgical margins, extraprostatic extension (pT3a), seminal vesicle invasion (pT3b), and time to PSA progression. Tumor extent was evaluated by a point-count method. RESULTS: Patients with clinical stage T1c were younger and had the lowest mean preoperative PSA. In the surgical specimen, they had higher frequency of Gleason score < 7 and more organ confined cancer. In 40.54 percent of the patients with clinical stage T2b tumors, there was extraprostatic extension (pT3a). During the study period, 54 patients (30.68 percent) developed a biochemical progression. Kaplan-Meier product-limit analysis revealed no significant difference in the time to PSA progression between men with clinical stage T1c versus clinical stage T2 (p = 0.7959), T2a (p = 0.6060) or T2b (p = 0.2941) as well as between men with clinical stage T2a versus stage T2b (p = 0.0994). CONCLUSION: Clinicopathological features are not similar considering clinical stage T1c versus clinical stages T2, T2a or T2b.