Theresa Y. Chan

Telomere Length Abnormalities Occur Early in the Initiation of Epithelial Carcinogenesis

Purpose: Telomeres help maintain chromosomal integrity. Dysfunctional telomeres can cause genetic instability in vitro and an increased cancer incidence in telomerase knock out mouse models. We recently reported that telomere shortening was a prevalent alteration in human prostate, pancreas, and breast cancer precursor lesions. In the present study, we address whether the previous findings are broadly applicable to human epithelial cancer precursors in general. Experimental Design: Surgical specimens of epithelial cancer precursor lesions from the urinary bladder, esophagus, large intestine, oral cavity, and uterine cervix were examined using a recently developed technique for direct in situ telomere length assessment in formalin-fixed human tissue specimens. Results: Widespread telomere length abnormalities were nearly universal (97.1% of cases) in the preinvasive stages of human epithelial carcinogenesis in all sites examined in this series, with telomere shortening the predominant abnormality (88.6% of cases). Conclusions: Telomere length abnormalities appear to be one of the earliest and most prevalent genetic alterations acquired in the multistep process of malignant transformation. These findings support a model whereby telomere dysfunction induces chromosomal instability as an initiating event in many, perhaps most, human epithelial cancers. Together with previous findings from the prostate and pancreas, the percentage of intraepithelial neoplasia lesions showing telomere length abnormalities is 95.6%. The implications of these findings include the potential that telomere length assessment in situ may be a widely useful biomarker for monitoring disease prevention strategies and for improved early diagnosis.

Prognostic significance of Gleason score 3+4 versus Gleason score 4+3 tumor at radical prostatectomy

OBJECTIVES To determine the clinical significance of Gleason score 3+4 versus 4+3 on radical prostatectomy. METHODS Of 2390 men who underwent radical prostatectomy by a single surgeon, 570 had Gleason score 7 tumors without lymph node metastasis, seminal vesicle invasion, or tertiary Gleason pattern 5. Patients were evaluated for biochemical recurrence (prostate-specific antigen progression) and distant metastases. RESULTS Eighty percent of patients had Gleason score 3+4, 20% had 4+3. The rate of established extraprostatic extension at radical prostatectomy for Gleason score 3+4 and 4+3 tumors was 38.2% and 52.7%, respectively (P = 0.008). With a mean follow-up of 4.6 years for men without progression, Gleason score 4+3 tumors had an increased risk of progression independent of stage and margin status (P <0.0001). The 5-year actuarial risk of progression was 15% and 40% for Gleason score 3+4 and 4+3 tumors, respectively. The mean time to progression was 4.4 years for Gleason score 3+4 tumors and 3.2 years for Gleason score 4+3 tumors. We stratified the patients into four prognostic groups on the basis of organ-confined status, margin status, and Gleason score (3+4 versus 4+3). The 5-year actuarial risk of progression was 10%, 35%, 45%, and 61%, with 10-year progression rates of 29%, 42%, 69%, and 84%, for the four groups. 3.9% of patients with Gleason score 3+4 and 10. 5% with Gleason score 4+3 tumors developed metastatic disease within a mean of 5.7 and 5.6 years, respectively. A Gleason score of 4+3 versus 3+4 was predictive of metastatic disease (P = 0.002) but not local recurrence. CONCLUSIONS Gleason score 7 tumors are heterogeneous in their biologic behavior. The differences in prognosis for patients with Gleason scores 3+4 and 4+3 tumors at radical prostatectomy are significant. Although the assessment of the percentage of pattern 4 at radical prostatectomy is not likely to be reproducible, the distinction between Gleason score 3+4 and 4+3 should be easier for pathologists to perform.

Follow-up of atypical prostate needle biopsies suspicious for cancer

OBJECTIVES To determine both how the diagnosis of an atypical biopsy influences a urologists decision to repeat the biopsy and the outcome of rebiopsy. METHODS Of 200 atypical biopsies that we confirmed from outside consultations to the Johns Hopkins Hospital from 1992 to 1993, we were able to retrieve follow-up information for 144 cases. Each atypical biopsy was evaluated for the reason for atypia (atrophic glands, rule out [r/o] adenosis, atypical not otherwise specified [NOS; insufficient cytologic and/or architectural atypia], r/o prostatic intraepithelial neoplasia [PIN], inflammation, crush artifact) and a favored diagnosis (cancerous, benign, and undetermined). RESULTS Of the 144 atypical biopsies, 92 were rebiopsied (63.9%). The time from the initial atypical biopsy to rebiopsy ranged from 0.5 months to 3 years (63% less than 6 months; 39% less than 3 months). Rebiopsy revealed carcinoma in 48.9%, benign in 38%, atypical in 8.7%, and PIN in 4.4%. The median prostate-specific antigen (PSA) value was lower in men who did not undergo a repeat biopsy (6 versus 7.8) (rank sum analysis, P = 0.04). No correlation was found between PSA level and results of the rebiopsy. Of the atypical biopsies in which cancer was favored, 61% were cancerous on rebiopsy versus 33% where a benign process was favored. The three reasons for atypical biopsies that seemed to correlate with outcome of rebiopsy were atypical NOS (68% cancer on rebiopsy); inflammation (63% cancer on rebiopsy); and r/o adenosis (36% cancer on rebiopsy). CONCLUSIONS Although 48.9% of the rebiopsied cases were cancerous, only 63% of men underwent rebiopsy, raising a concern that cancers are being missed in those cases not rebiopsied after an atypical diagnosis. Although there was a trend for serum PSA to correlate with outcome of rebiopsy, this correlation was not significant, and even men with serum PSA less than 4 ng/mL had a 33% risk of cancer on rebiopsy. Although histologic features of the atypical foci may be useful as factors in determining the urgency for rebiopsy, they also were not statistically significant in predicting outcome. Men with atypical diagnoses should undergo rebiopsy regardless of serum PSA levels and regardless of why the lesions were atypical.

Does increased needle biopsy sampling of the prostate detect a higher number of potentially insignificant tumors

PURPOSE Several studies have documented that increased biopsy sampling, that is 6 versus 12 biopsy cores, can detect more prostate cancer. It is unknown whether increased sampling of the prostate will detect a higher number of potentially insignificant tumors. MATERIALS AND METHODS We searched the surgical pathology files at The Johns Hopkins Hospital for patients in whom prostate needle biopsy was performed by a single urologist between April 1993 and April 2000, and subsequently underwent radical prostatectomy. Patients who underwent radical prostatectomy and had 8 core biopsies or less between March 1994 and August 1999 were also studied. Clinically significant tumors were defined as those with volume greater than 0.5 cc, Gleason score 7 or greater or nonorgan confined disease. RESULTS A total of 297 patients with a mean age of 60 years (range 36 to 75) were evaluated. Group 1 consisted of 107 men with 8 core biopsies or less, including 51 with 6, and group 2 comprised 190 men with 9 cores or greater, including 145 with 12. The 2 groups were equal in regard to prostate specific antigen, age, digital rectal examination and transrectal ultrasound gland volume at biopsy. The only difference between the groups was a higher number of cores with cancer in group 2 (mean 2.8 versus 2.1, p = 0.0006). Of the patients who underwent radical prostatectomy 59.6% had Gleason score 6 or less, 26.3% 3+4, 6.7% 4+3 and 7.4% 8 to 9. There were 12.4% of patients with positive margins, 36.4% extraprostatic extension, and 5.4% seminal vesicle invasion and/or lymph node metastasis. Tumor volumes averaged 1.1 cc (range 0.01 to 10.7) and 60.9% of tumors were greater than 0.5 cc. Clinically significant tumors were seen in 77.4% of patients in group 1 and 74.6% in group 2. There was no significant difference in Gleason score, margin status, tumor volume, seminal vesicle invasion, or lymph node metastasis between groups 1 and 2, or in a subset analysis of men with 6 versus 12 core biopsies. However, patients in whom cancer was diagnosed with 9 core biopsies or greater were more likely to have organ confined disease (p = 0.02). CONCLUSIONS Although increased sampling of the prostate does not increase the detection of potentially insignificant tumors, it does appear to detect earlier stage cancer.

Prognostic assessment of nonmetastatic renal cell carcinoma: A clinically based model

OBJECTIVES Determining the recurrence risk in patients treated for renal cell carcinoma (RCC) is important for providing prognostic information and planning potential surveillance strategies. The pathologic stage has been the most widely used single prognostic variable. However, with minimally invasive treatment modalities, the pathologic stage may not be readily available. We developed a biostatistical prognostic model for postoperative RCC that is independent of the pathologic stage. METHODS The records of 296 patients who underwent open nephrectomy for RCC at Johns Hopkins Hospital between 1990 and 1999 were reviewed. Cox proportional hazards regression analysis was used to generate a prognostic model. RESULTS The recurrence risk (R(rec)) was determined from this model: R(rec)=1.55 x presentation (0-1)+0.19 x clinical size (in centimeters). Using this equation, 79% of patients were identified as low risk compared with 45% of patients considered low risk by pathologic stage (pT1). Moreover, the separation between the high and low-risk survival curves increased. CONCLUSIONS This model is the first to our knowledge that uses purely clinical variables to assess the postoperative prognosis in patients with RCC. These results, although not validated, provide substantial evidence that preoperative clinical variables may be used instead of the pathologic stage to determine the risk of recurrence. Uncoupling the reliance on pathologic stage for prognostic information removes a potential barrier to novel minimally invasive treatments for renal malignancy and provides a standard to which observation protocols can be compared. In the future, this model may facilitate selection of appropriate patients for less toxic adjuvant or neoadjuvant therapies.

Florid von Brunn nests mimicking urothelial carcinoma: a morphologic and immunohistochemical comparison to the nested variant of urothelial carcinoma.

Florid von Brunn nests may mimic the nested variant of urothelial carcinoma. We examined formalin-fixed, paraffin-embedded tissue from 21 cases of florid von Brunn nests and 11 cases of nested variant of urothelial carcinoma. Morphologic features were recorded in detail. Also, cases were stained with monoclonal antibodies against MIB-1, p53, p27, and cytokeratin 20. Percentage positivity was calculated by counting 300 to 500 cells from each case. Clinical follow-up information was also obtained. Florid von Brunn nests from the bladder were comprised of large nests with regular spacing, and all the nests extended to the same horizontal level at the base of the proliferation. Central lumen formation was often seen within florid von Brunn nests, at times with cystic dilatation, such that there was a spectrum from proliferating von Brunn nests to cystitis glandularis to cystitis cystica. Small, crowded nests with variable spacing and an infiltrative base characterized nested variant of urothelial carcinoma. Four cases showed detrusor muscle invasion on biopsy with an additional case showing detrusor muscle invasion at cystectomy. One additional patient with nested variant of urothelial carcinoma had distant metastases and another had prostatic invasion. Nine of 21 florid von Brunn nests cases were from either the ureter or renal pelvis, whereas all cases of nested variant of urothelial carcinoma arose in the bladder. The ureteral and pelvic florid von Brunn nest cases showed smaller, more variable nests with irregular spacing closely mimicking nested variant of urothelial carcinoma but had a noninfiltrative base and often areas with either a lobular or linear array. Immunohistochemical studies showed nested variant of urothelial carcinoma to have higher MIB-1 expression (8.8% vs. 2.8%, P = 0.01). Nested variant of urothelial carcinoma had nonsignificantly higher p53 positivity (4.2% vs. 1.5%, P = 0.06) and lower p27 positivity (4.7% vs. 7.8%, P = 0.22). Cytokeratin 20 staining was not discriminatory. However, staining with each antibody was widely variable. Wide variation in staining for MIB-1, p53, p27, and cytokeratin 20 was seen in both florid von Brunn nests and nested variant of urothelial carcinoma, such that except for a few cases, a specific cutoff value could not be determined for diagnostic purposes. The findings underscore the importance of morphologic assessment in the distinction of florid von Brunn nests and nested variant of urothelial carcinoma.

A neural network predicts progression for men with Gleason score 3+4 versus 4+3 tumors after radical prostatectomy

OBJECTIVES To determine the significance of Gleason scores 3+4 (GS3+4) versus 4+3 (GS4+3) with respect to biochemical recurrence in a retrospective review of a series of men with clinically localized prostate cancer who underwent radical retropubic prostatectomy (RRP) and to develop and test an artificial neural network (ANN) to predict the biochemical recurrence after surgery for this group of men using the pathologic and clinical data. METHODS From 1982 to 1998, 600 men had pathologic Gleason score 7 disease without lymph node or seminal vesicle involvement. We analyzed the freedom from biochemical (prostate-specific antigen) progression after RRP on 564 of these men on the basis of their GS3+4 versus GS4+3 (Gleason 7) status. The Cox proportional hazards model was used to determine the importance of Gleason 7 status as an independent predictor of progression. In addition, an ANN was developed using randomly selected training and validation sets for predicting biochemical recurrence at 3 or 5 years. Different input variable subsets, with or without Gleason 7 status, were compared for the ability of the ANN to maximize the prediction of progression. Standard logistic regression was used concurrently on the same random patient population sets to calculate progression risk. RESULTS A significant recurrence-free survival advantage was found in men who underwent RRP for GS3+4 compared with those with GS4+3 disease (P <0.0001). The ANN, logistic regression, and proportion hazard models demonstrated the importance of Gleason 7 status in predicting patient outcome. The ANN was better than logistic regression in predicting patient outcome, in terms of prostate-specific antigen progression, at 3 and 5 years. CONCLUSIONS A simple modification of the Gleason scoring system for men with Gleason 7 disease revealed a difference in the patient outcome after RRP. ANN models can be developed and used to better predict patient outcome when pathologic and clinical features are known.

Malignant solitary fibrous tumor of the kidney : Report of a case and comprehensive review of the literature

Renal solitary fibrous tumors (SFTs) have been reported infrequently. We report a 76-year-old man with a left renal mass that had previously been shown radiographically to be stable, but was now growing. Grossly, the mass measured 12 cm, was poorly circumscribed, and invaded beyond the renal capsule. Approximately 10% of the neoplasm consisted of haphazardly arranged spindle cells admixed with dense collagenous bands, which is typical of benign SFT. However, the remainder of the mass was composed of pleomorphic, spindled sarcoma cells with frequent mitoses and foci of necrosis. Immunohistochemically, we observed CD34 labeling in the benign SFT component with loss of expression in the sarcomatous component, focal labeling for Bcl-2 protein in both areas, and absence of labeling for cytokeratin, renal cell carcinoma marker, S100 protein, CD117, and muscle markers in both areas. To our knowledge, this is the first reported case of malignant renal SFT, likely representing transformation from a histologically documented benign SFT component.

Immunohistochemical staining of prostate cancer with monoclonal antibodies to the precursor of prostate-specific antigen.

OBJECTIVES To characterize the immunohistochemical staining (IHS) of precursor forms of prostate-specific antigen (pro-PSA) forms in prostate cancer, high-grade prostatic intraepithelial neoplasia (HGPIN), and benign tissue from the peripheral and transition zones. Pro-PSA have previously been shown to be more concentrated in prostate cancer tissue extracts than in benign tissue. METHODS Prostate needle biopsies showing HGPIN (22 sections, 11 patients) and adenocarcinoma (30 sections, 21 patients) and 17 radical prostatectomy and 3 open prostatectomy specimens were identified from the surgical pathology files of Johns Hopkins Hospital. IHS was performed on formalin-fixed, paraffin-embedded sections using one monoclonal antibody (mAB) against pro-PSA with a truncated pro-leader peptide containing two amino acids, [-2]pPSA, and a second mAB against native pro-PSA ([-5/-7]pPSA). RESULTS The mABs were specific for both benign and malignant prostatic glandular tissue and did not stain stromal, vascular, or colonic tissue when present in the specimens. All sections with HGPIN and/or adenocarcinoma showed staining with both mABs. HGPIN was strongly positive in most cases (66.1%). The native pro-PSA mAB showed little differential between cancer and benign glands, and the mAB to the truncated [-2]pPSA stained cancer tissue more strongly than benign tissue. Benign atrophic glands often showed negative or weak/patchy staining. No difference was found in the staining pattern between benign glands in the peripheral zone and transition zone. CONCLUSIONS This study is the first to demonstrate that mABs to pro-PSA can be used as specific IHS for benign and malignant prostatic tissue. [-2]pPSA appears to be preferentially more concentrated in cancer tissue than in benign glands, correlating with previous tissue extract studies. Unlike previous studies with PSA staining, the IHS for pro-PSA remained uniform among the different tumor grades. Therefore, pro-PSA may be a useful marker in differentiating high-grade prostate adenocarcinoma from other non-prostate carcinomas.

Radiation or chemotherapy cystitis with "pseudocarcinomatous" features.

Background:The features of radiation or chemotherapy cystitis mimicking invasive urothelial cancer are not widely known. Design:A search of the consultation files from our institution between January 1996 and September 2003 identified 20 patients with bladder biopsies showing cystitis mimicking invasive urothelial cancer. Results:The mean age at diagnosis was 69 years (range, 40–85 years); 80% were males. Complete history was not available in 1 patient. Seventeen patients had a history of pelvic irradiation (15 prostate cancer and 2 endometrial cancer). Two patients had systemic chemotherapy (1 metastatic colon cancer and 1 mixed connective tissue disease). All patients presented with hematuria. The mean time from radiation and/or chemotherapy to presentation was 27 months (range, 0–84 months). All cases showed epithelial proliferation that mimicked invasive cancer within the lamina propria, with marked proliferation seen in 45% of cases. Mild to moderate nuclear pleomorphism was seen in all cases. A characteristic feature was the presence of pseudoinvasive urothelial nests wrapping around the vessels associated with fibrin deposition. Most cases did not show any mitoses (75%). Ulceration was seen in 39% of cases. All cases showed some degree of hemorrhage, fibrin deposition and fibrin thrombi, fibrosis, and acute and chronic inflammation, with hemosiderin identified in 60% of cases. Edema and vascular congestion were common features (95% and 80%, respectively). Thickened vessels and vascular changes associated with radiation injury were identified in 75% of cases. Seventeen patients were followed for a mean of 9 months (range, 0.25–37 months), and none developed bladder cancer. Conclusions:Radiation or chemotherapy cystitis can show epithelial proliferations that may be confused with invasive urothelial carcinomas. Other findings characteristic of radiation or chemotherapy cystitis, such as hemorrhage, fibrin, and vascular changes, are often seen in association with the epithelial proliferations and are helpful in distinguishing it from invasive cancer. Pathologists must be aware that these changes may be seen with a remote radiation or chemotherapy history, where this information may not be provided or known at the time of the biopsy evaluation.