Affiliations of authors: K. Sato, M. M. Lieber (Department of Urology), J. Qian, D. G. Bostwick, R. B. Jenkins (Department of Laboratory Medicine and Pathology), J. M. Slezak, E. J. Bergstralh (Section of Biostatistics), Mayo Clinic, Rochester, MN.
Correspondence to: Robert B. Jenkins, M.D., Ph.D., Department of Laboratory Medicine and Pathology, Mayo Clinic, 200 First St., S.W., Rochester, MN 55905 (e-mail: jenkins.robert{at}mayo.edu).
![]() |
ABSTRACT |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
![]() |
INTRODUCTION |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
The development of a fluorescence in situ hybridization (FISH) technique has allowed the investigation of numerical chromosomal anomalies and genetic alterations on a cell-by-cell basis within a region of interest (12,13). For the detection of numerical chromosome alterations in solid tumors, FISH analysis of interphase cells has been proven to be a more sensitive and reliable method than Southern blot hybridization (14) and polymerase chain reaction (15-17).
Clinically aggressive behavior is associated with an accumulation of genetic aberrations in solid tumors, such as colon cancer (18) and urinary bladder cancer (19). Similar multiple genetic changes may occur in prostate carcinoma. Prostate cancer is a leading cause of death of men in the United States, so the identification of patients whose tumor is destined to progress rapidly is a major goal of current research. Unfortunately, within a cohort of men with a single grade and stage of prostate cancer, there are few markers of clinical aggressiveness. High-stage prostate carcinoma often has multiple genetic abnormalities, often involving 8p and 8q. To determine whether 8p loss and/or 8q24 gain predict a poor prognosis in prostate cancer, we used dual-probe FISH to investigate the copy number changes of 8p22, 8cen (centromere 8), and c-myc in a large cohort of high-grade stage III prostate carcinoma.
![]() |
MATERIALS AND METHODS |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
A comprehensive analysis of allelic imbalance of chromosome arms 7q, 8p, 16q, and 18q has been previously performed on a large cohort of high-grade stage III prostate carcinomas (20). All 227 patients underwent radical prostatectomy and pelvic lymphadenectomy during the period from 1966 through 1987, and metastases were not identified. Thus, all patients had pathologic stage T3N0M0 (tumor-node-metastasis) cancer (21). One hundred fifty-seven specimens from this cohort contained an adequate number of tumor cells in the paraffin blocks for FISH analysis. The overall mean age of these patients at surgery was 66 years (range, 53-79 years). The order of patients in the list was randomized, and FISH analyses were performed on these 157 tumor specimens by individuals who did not have knowledge of the clinicopathologic findings and survival data of the patients.
As described below, FISH was successfully performed on 144 (91.7%) specimens. The FISH data on these patients were compared with the corresponding Gleason scores. We divided the tumors into three Gleason score groups of 4-6, 7, and 8-10, as reported previously (10). Because we selected predominantly high-grade tumors, only 16 (11.1%) of the 144 prostate carcinomas had a Gleason score of 4-6. Of the remaining 128 tumors, 64 (44.4% of 144 patients) had a Gleason score of 7 and 64 (44.4% of 144 patients) had a Gleason score of 8-10. Seminal vesicle involvement was observed in 90 (62.5%) patients. Surgical margins were positive for carcinoma in 58 (40.3%) patients. Thirty-one (21.5%) and 24 (16.7%) patients postoperatively received adjuvant hormonal therapy and radiotherapy, respectively, whereas two patients (1.4%) received both therapies. Standard flow cytometry DNA ploidy analysis was possible for 133 samples; 45 (33.8%) were diploid, 70 (52.6%) were tetraploid, and 18 (13.5%) were aneuploid. The preoperative serum concentration of prostate-specific antigen (the assay for which became available in 1987) was not included.
Follow-up data were obtained by a nurse who contacted the patients annually by telephone or in writing as a part of the formal, ongoing Mayo Clinic Radical Prostatectomy Tumor Registry (22). Briefly, systemic prostate carcinoma progression and prostate carcinoma-specific death were used as clinical endpoints. Systemic progression was defined as clinical evidence of distant metastatic cancer and was ascertained by positive findings on bone scan or other radiologic imaging tests. Whether the patient's death was caused by prostate cancer was ascertained at the time of the patient's death by a combination of death certificate review, contact with the primary physician, and discussion with the patient's family, if necessary. The mean follow-up of these patients was 7.7 years (median = 7.5 years).
Of the 144 patients on whose samples FISH was successful, 14 received hormonal therapy before prostatectomy. These patients were excluded from the prognostic studies. Among the remaining 130 patients, 35 (26.9%) had systemic disease progression and 28 (21.5%) died of prostate cancer.
We compared the distribution of clinical variables between the patients whose samples provided FISH results and the patients whose paraffin blocks were not available or whose samples did not provide FISH results. There was no statistically significant difference in DNA ploidy status, pathologic stages, postsurgical adjuvant treatment, 10-year progression-free survival, or 10-year overall survival between these two groups of patients (data not shown).
Informed consent was obtained from all of the patients for the use of their follow-up information. This study was approved by the Mayo Clinic Institutional Review Board.
Tissue Preparation
For each patient, a surgical pathologist previously had identified a single prostate specimen block that contained the highest (worst) histologic grade of prostate carcinoma. Fifteen tissue sections (5 µm thick) were sliced from each paraffin-embedded tumor block and mounted on glass slides. The first tissue section was stained with hematoxylin-eosin to ascertain the region of interest.
Dual-Probe FISH With Centromere 8 and Locus-Specific Probes
FISH is described elsewhere (11). Briefly, tissue sections were deparaffinized, dehydrated, treated with microwave radiation in 10 mM citric acid (pH 6.0) for 10 minutes, digested with pepsin (4 mg/mL in 0.9% NaCl [pH 1.5]) for 12 minutes at 37 °C, rinsed in 2x standard saline citrate (SSC) (pH 7.2) at room temperature, and air-dried. Dual-probe hybridization then was performed with a centromere 8 probe (chromosome enumeration probe 8 [CEP8]; Vysis, Inc., Downers Grove, IL) and with a locus-specific probe, either an 8p22 probe (LPL gene; Vysis, Inc.) or an 8q24.1 probe (c-myc; Vysis, Inc.). Probes and target DNA were codenatured at 80 °C for 2 minutes, annealed at 50 °C for 30 minutes, and then incubated at 37 °C overnight. After hybridization, samples were washed in a solution of 1.5 M urea and 0.1x SSC (pH 7.2) at 45 °C for 30 minutes. Tissue sections were equilibrated in 2x SSC for 5 minutes at room temperature. Nuclei were then counterstained with 4,6-diamidino-2-phenylindole and antifade compound p-phenylenediamine.
Three hundred nonoverlapping interphase nuclei from a focus of benign epithelium and adenocarcinoma were counted for each probe with a Diaplan microscope (Leitz, Wetzlar, Germany) equipped with a triple-pass filter. By use of the hematoxylin-eosin-stained slide of the adjacent section as a reference, the same dominant tumor focus was evaluated for each probe. In some cases, there were variations in FISH findings within one tumor focus. In these samples, the cancer focus with the primary Gleason pattern was evaluated. Nuclei from stromal elements were not enumerated. Locus-specific probe (8p22 or c-myc) and CEP8 signals were enumerated for each nucleus.
Criteria for FISH Anomalies
A normal value study was performed by enumerating 8p22, c-myc, and CEP8 signals in histologically normal prostatic epithelial nuclei of 10 patients, as described previously (11) (data not shown). With the use of results from the normal value study and an inspection of the distribution of each FISH signal among the carcinoma foci, we categorized the 8p22, c-myc, and CEP8 copy number status of a tumor focus as normal, gain, and loss. In addition, the category of additional increase (AI) of c-myc copy number relative to the centromere copy number was also used. This category contains overrepresentation (e.g., duplication, triplication, etc.) and amplification of c-myc. The threshold values for these categories were chosen to minimize the detection of false-positive changes. The normal category required less than 10% of epithelial nuclei with three or more signals and less than 55% of epithelial nuclei, with zero or one signal for an applied probe. The gain category required 10% or more of epithelial nuclei with three or more signals for an applied probe. The category of loss of CEP8 required 55% or more of epithelial nuclei with zero or one signal for CEP8. The category of loss of 8p22 required the overall mean 8p22/CEP8 ratio of less than 0.85. The category of loss of c-myc required the overall mean c-myc/CEP8 ratio of less than 0.90. The AI category was applied only to c-myc and required the overall mean c-myc/CEP8 ratio of more than 1.3 and 10% or more of epithelial nuclei with three or more signals for c-myc.
Statistical Analysis
The frequency and distribution of FISH anomalies in prostate carcinoma were compared by
use of the Pearson 2 test and Student's t test. The
relationships of FISH anomalies with Gleason scores were evaluated with the Pearson
2 test. Kaplan-Meier curves and the logrank test were used to estimate systemic
progression-free survival or cause-specific death. Univariate comparisons of survival curves were
done with the logrank test. All risk ratios for disease progression and survival were estimated by
use of the multivariate Cox proportional hazards model. Variables in the model included findings,
Gleason score, seminal vesicle involvement, surgical margin status, use of postoperative adjuvant
therapy, and aneuploid flow cytometry ploidy pattern. All statistical tests were two-sided with an
level of 0.05. A P value of less than .05 is considered statistically significant in all
tests.
![]() |
RESULTS |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
Of 157 tumors subjected to FISH analysis, FISH was performed successfully on 144 (91.7%) for c-myc/CEP8 and 143 (91.1%) for 8p22/CEP8.
By applying the cutoff values described in the "Materials and Methods" section, we defined 78 (54.2%) of 144 prostate carcinomas as having a gain of c-myc gene copy number. Of these 78 tumors, 50 (34.7% of 144) had a gain of 8cen and an equivalent gain of c-myc and 28 (19.4% of 144) had an AI of c-myc. Among the 28 tumors with an AI of c-myc, 16 (11.1% of 144) had a gain of 8cen and an AI of c-myc and 12 (8.3% of 144) had an AI of c-myc alone. The group with an AI of c-myc alone contained two tumors that had loss of 8cen and 10 tumors that had no apparent anomaly of 8cen. No loss of c-myc was found in this study. Two carcinomas (1.4%) designated as having loss of 8cen had a high c-myc/CEP8 ratio due to loss of 8cen, without an actual increase (three or more) of c-myc signals per nucleus.
Tumors with loss of 8p22 were clearly separated from those with no loss of 8p22 by the 8p22/CEP8 ratio cutoff of 0.85. One hundred nine (76.2%) of 143 prostate carcinomas were defined as having 8p22 abnormalities. Among those tumors, 89 (62.2% of 143) had a loss of 8p22 and 20 (14.0% of 143) had a gain of 8p22. We observed no apparent homozygous deletion of 8p22 in this study.
A similar CEP8 copy number status for c-myc and 8p22, defined in the dual-probe hybridization experiments, was observed, and the CEP8 FISH classifications were concordant between the two experiments. Sixty-six (45.8%) of the 144 patients had tumors with a gain of 8cen, and four (2.8%) had tumors with a loss of 8cen.
Table 1, A, summarizes 8p22, 8cen, and c-myc FISH results for all
144 patients. We classified FISH anomalies as one of 11 patterns, which represent all of the
genetic alterations of chromosome 8 that occurred in this cohort of patients. The first pattern
normal-normal-normal (i.e., normal FISH findings for 8p22-8cen-c-myc) was observed in 31
(21.5%) tumors. Results from 113 (78.5%) tumors with abnormal FISH findings
were distributed among the other 10 patterns.
|
Table 1, B, shows that there was no statistically significant
association between Gleason score and loss of 8p22 (P = .11).
However, the Gleason score was statistically significantly associated
with a gain of 8p22, a gain of 8cen, a gain of c-myc, and an AI of
c-myc (P = .01, P<.01, P = .03, and
P = .02, respectively). When we considered the combined FISH
results for 8p22, 8cen, and c-myc, the percentage of tumors with a
Gleason score of 8-10 increased from 29.0% to 36.4% to 50.0% to
63.6% for the dominant FISH anomaly patterns normal-normal-normal,
loss-normal-normal, loss-gain-gain, and loss-gain-AI, respectively.
Association With Systemic Cancer Progression and Patient Survival
Alterations in 8p22 were not statistically significantly associated
with systemic cancer progression (P = .63) (Fig.
1, A) or patient death (P = .14) (Fig. 1,
B). Ten-year progression-free survival rates for the groups with a
normal 8p22, a loss of 8p22, and a gain of 8p22 were 77.1%, 72.9%,
and 69.7%, respectively. Similarly, 10-year cause-specific survival
rates for the groups with a normal 8p22, a loss of 8p22, and a gain of
8p22 were 90.3%, 76.4%, and 94.1%, respectively.
|
Multivariate analysis indicated that an AI of c-myc was a statistically significant independent predictor of systemic progression but was of only borderline statistical significance for cause-specific death. The risk ratio for an AI of c-myc was 2.4 (95% confidence interval [CI] = 1.1-5.1; P = .021) for systemic progression and was 1.8 (95% CI = 0.8-4.2; P = .14) for cause-specific death when adjusted for Gleason grade, seminal vesicle involvement, margin positivity, and adjuvant therapy (data not shown). Further adjustment for DNA content was done by use of the 119 tumors for which ploidy data were available: 35% of tumors were diploid, 52% were tetraploid, and 13% were aneuploid. Risk ratios for an AI of c-myc, adjusted also for ploidy, increased to 2.9 (95% CI = 1.3-6.4; P = .008) for systemic progression and 2.3 (95% CI = 1.0-5.7; P = .064) for cause-specific death (data not shown).
Previous studies (6-9) and biologic rationale suggest that specific
patterns or combinations of 8p22 and c-myc anomalies might be related to disease outcome. This
hypothesis was supported by a statistically significant interaction between an 8p22 loss and an AI
of c-myc with respect to cause-specific death (P = .03; Cox model; data not
shown), suggesting that patients with both alterations have a poor prognosis. Ten-year
progression-free survival was 45.5% for patients with the pattern loss-any 8cen-AI (Table
1, A; groups 7, 8, and 9) and from 60.8% to 85.7% for
patients with all other patterns (P = .009) (Fig. 1,
E).
Similarly, 10-year cause-specific survival was 47.1% for patients with loss-any 8cen-AI and
was from 82.0% to 100.0% for patients with all other patterns (P =
.013) (Fig. 1,
F).
Multivariate analyses demonstrated that the pattern loss-any 8cen-AI was a statistically
significant predictor for systemic progression and cause-specific survival, with risk ratios of 3.3
(95% CI = 1.5-7.3; P = .003) and 2.9 (95% CI =
1.3-6.9; P = .013), respectively. The pattern loss-any 8cen-AI was independent of
Gleason score, seminal vesicle involvement, surgical margin status, and use of postoperative
adjuvant therapy in predicting systemic progression and cause-specific survival (Table 2, model 1).
|
![]() |
DISCUSSION |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
On the basis of the frequency of FISH anomaly patterns observed in this study, we
hypothesize that the accumulation of gene aberrations in prostate carcinoma occurs primarily in
three steps (Fig. 2, thick arrows). In the first step, 8p22 is deleted.
Mutation or a small deletion of a gene or genes on 8p that is not detectable by the 8p22 FISH
probe also may take place. Previous studies of 8p loss in prostate intraepithelial neoplasia and in
prostate carcinoma (2,20,23,24) support this idea. Second, a whole
chromosome 8 is gained (perhaps the chromosome 8 that suffered the first 8p22 loss). Third, 8q is
gained [possibly one of the chromosome 8 undergoes isochromosome 8q formation, which
will simultaneously delete 8p and gain 8q (6-9,11,12)]. A smaller
region, including the c-myc gene, may also be overrepresented or amplified.
|
This study suggests that the c-myc gene is a marker for the malignant potential of a prostate carcinoma. Overexpression of the c-myc gene has been found in prostate carcinoma (25,26), and we have previously shown (11) that substantial amplification of the c-myc gene is strongly associated with immunohistochemical evidence of the c-myc protein overexpression. Overexpression of c-myc protein has been hypothesized to cause degradation of p27kip1, leading to activation of cyclin E/cyclin-dependent kinase 2 and cell proliferation (27,28). It has recently been shown (29-32) that the level of p27kip1 is associated with Gleason score, tumor recurrence, and patient survival with prostate carcinoma. A study with the use of in vivo transduction of prostate cancer cells with antisense c-myc (33) demonstrated that tumor growth was reduced by suppressing c-myc protein. Thus, these observations suggest that overexpression of c-myc deregulates the control of cell growth, resulting in proliferation of prostate carcinoma cells. This overexpression is most often mediated through an increased c-myc gene copy number (11).
Of 130 patients with a follow-up, 35 had systemic progression and 28 died of prostate cancer
after a curative surgical operation. This result suggests that these patients already had clinically
undetectable metastases before the surgery. The patients whose tumor had an AI of c-myc had
rapid progression and died early of cancer, indicating that the AI of c-myc enhanced the
proliferation of the metastasized tumor cells. If this is the case, it is natural to speculate that the
late systemic progressions at 10-12 years, observed in the patients whose prostate carcinoma had
a gain of c-myc (see Fig. 1, C and D), may result from an AI of
c-myc that occurred as a new genetic event in the metastatic tumor cells. Unfortunately, it is
difficult to obtain specimens from late metastatic lesions to test this hypothesis. Van Den Verg et
al. (8) observed amplification of 8q DNA sequences, including 8q24, in
three (75%) of four metastatic lymph node lesions, but they observed this amplification in
four (9%) of 44 primary prostate carcinomas. Our previous study (11) reported more frequent amplification of the c-myc gene in metastatic foci
(21%) than in primary foci (8%). Thus, c-myc gene status may predict whether a
metastatic prostate cancer focus progresses or not.
In addition, some patients whose tumor had a normal or a gain of c-myc had systemic progression, suggesting that metastasis of prostate carcinoma could occur without amplification of the c-myc gene and that there may be other genes involved in triggering metastasis (34).
Management of stage III prostate carcinoma is still a major clinical challenge (35). As previous studies (36,37) indicated, our study also demonstrated the superiority of FISH to flow cytometry in identifying a subset of tumors with an aggressive nature. A FISH study with c-myc may allow early cancer detection for a patient whose prostate carcinoma, especially a possible metastatic focus, is destined to progress rapidly. Postoperative systemic adjuvant therapy may benefit the patient with prostate carcinoma positive for an AI of c-myc.
We selected the c-myc probe because c-myc is overexpressed and 8q24.1 is often amplified in prostate cancer (6,11). It is possible that another gene of importance for prostate carcinoma progression lies within 8q24. For example, prostate stem cell antigen is frequently overexpressed in high-grade and high-stage prostate cancer. The prostate stem cell antigen gene has been recently cloned and is mapped to 8q24 (38). There may be other genes in 8q24 that are critical for prostate carcinogenesis. Even so, our study strongly suggests that the pattern loss-any 8cen-AI anomaly is a useful marker for prostate carcinoma progression. Because we had only 20 (13.9%) patients with this pattern, additional studies with larger sample sizes are necessary to confirm our results.
In conclusion, our FISH results suggest that genetic alterations of chromosome 8 are statistically significantly associated with clinicopathologic characteristics of stage III prostate carcinoma. Substantial amplification of the c-myc gene, especially with loss of 8p22, appears to predict systemic progression and poor patient prognosis and may justify an early adjuvant treatment for these patients.
![]() |
NOTES |
---|
![]() |
REFERENCES |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
1 Bova GS, Carter BS, Bussemakers MJ, Emi M, Fujiwara Y, Kyprianou N, et al. Homozygous deletion and frequent allelic loss of chromosome 8p22 loci in human prostate cancer. Cancer Res 1993;53:3869-73.[Abstract]
2 Macoska JA, Trybus TM, Benson PD, Sakr WA, Grignon DJ, Wojno KD, et al. Evidence for three tumor suppressor gene loci on chromosome 8p in human prostate cancer. Cancer Res 1995;55:5390-5.[Abstract]
3 Kagan J, Stein J, Banaian RJ, Joe YS, Pisters LL, Glassman AB, et al. Homozygous deletions at 8p22 and 8p21 in prostate cancer implicate these regions as the sites for candidate tumor suppressor genes. Oncogene 1995;11:2121-6.[Medline]
4 Crundwell MC, Chughtai S, Knowles M, Takle L, Luscombe M, Neoptolemos JP, et al. Allelic loss on chromosomes 8p, 22q and 18q (DCC) in human prostate cancer. Int J Cancer 1996;69:295-300.[Medline]
5 Emmert-Buck MR, Vocke CD, Pozzatti RO, Duray PH, Jennings SB, Florence CD, et al. Allelic loss on chromosome 8p12-21 in microdissected prostatic intraepithelial neoplasia. Cancer Res 1995;55:2959-62.[Abstract]
6 Cher ML, MacGrogan D, Bookstein R, Brown JA, Jenkins RB, Jensen RH. Comparative genomic hybridization, allelic imbalance, and fluorescence in situ hybridization on chromosome 8 in prostate cancer. Genes Chromosomes Cancer 1994;11:153-62.[Medline]
7 Visakorpi T, Kallioniemi AH, Syvanen AC, Hyytinen ER, Karhu R, Tammela T, et al. Genetic changes in primary and recurrent prostate cancer by comparative genomic hybridization. Cancer Res 1995;55:342-7.[Abstract]
8 Van Den Berg C, Guan XY, Von Hoff D, Jenkins R, Bittner M, Griffin C, et al. DNA sequence amplification in human prostate cancer identified by chromosome microdissection: potential prognostic implications. Clin Cancer Res 1995;1:11-8.[Abstract]
9
Nupponen NN, Kakkola L, Koivisto P, Visakorpi. Genetic
alterations in hormone-refractory recurrent prostate carcinomas. Am J Pathol 1998;153:141-8.
10 Depinho RA, Schreiber-Agus N, Alt FW. myc family oncogenes in the development of normal and neoplastic cells. Adv Cancer Res 1991;57:1-46.[Medline]
11 Jenkins RB, Qian J, Lieber MM, Bostwick DG. Detection of c-myc oncogene amplification and chromosomal anomalies in metastatic prostatic carcinoma by fluorescence in situ hybridization. Cancer Res 1997;57:524-31.[Abstract]
12 Qian J, Bostwick DG, Takahashi S, Borell TJ, Herath JF, Lieber MM, et al. Chromosomal anomalies in prostatic intraepithelial neoplasia and carcinoma detected by fluorescence in situ hybridization. Cancer Res 1995;55:5408-14.[Abstract]
13 Ried T. Interphase cytogenetics and its role in molecular diagnostics of solid tumors. Am J Pathol 1998;152:325-7.[Medline]
14 Pauletti G, Godolphin W, Press MF, Slamon DJ. Detection and quantitation of HER-2/neu gene amplification in human breast cancer archival material using fluorescence in situ hybridization. Oncogene 1996;13:63-72.[Medline]
15 Macoska JA, Trybus TM, Sakr WA, Wolf MC, Benson PD, Powell IJ, et al. Fluorescence in situ hybridization analysis of 8p allelic loss and chromosome 8 instability in human prostate cancer. Cancer Res 1994;54:3824-30.[Abstract]
16 Deubler DA, Williams BJ, Zhu XL, Steele MR, Rohr LR, Jensen JC, et al. Allelic loss detected on chromosomes 8, 10, and 17 by fluorescence in situ hybridization using single-copy P1 probes on isolated nuclei from paraffin-embedded prostate tumors. Am J Pathol 1997;150:841-50.[Abstract]
17 Jenkins RB, Qian J, Lee HK, Huang H, Hirasawa K, Bostwick DG, et al. A molecular cytogenetic analysis of 7q31 in prostate cancer. Cancer Res 1998;58:759-66.[Abstract]
18 Vogelstein B, Fearon ER, Hamilton SR, Kern SE, Preisinger AC, Leppert M, et al. Genetic alterations during colorectal-tumor development. N Engl J Med 1988;319:525-32.[Abstract]
19 Orntoft TF, Wolf H. Molecular alterations in bladder cancer [editorial]. Urol Res 1998;26:223-33.[Medline]
20 Jenkins R, Takahashi S, DeLacey K, Bergstralh E, Lieber M. Prognostic significance of allelic imbalance of chromosome arms 7q, 8p, 16q, and 18q in stage T3N0M0 prostate cancer. Genes Chromosomes Cancer 1998;21: 131-43.[Medline]
21 Schroder FH, Hermanek P, Denis L, Fair WR, Gospodarowicz MK, Pavone-Macaluso M. The TNM classification of prostate cancer. Prostate Suppl 1992;4:129-38.[Medline]
22 Zincke H, Oesterling JE, Blute ML, Bergstralh EJ, Myers RP, Barrett DM. Long-term (15 years) results after radical prostatectomy for clinically localized (stage T2c or lower) prostate cancer. J Urol 1994;152:1850-7.[Medline]
23 Bova GS, Isaacs WB. Review of allelic loss and gain in prostate cancer. World J Urol 1996;14:338-46.[Medline]
24 Prasad MA, Trybus TM, Wojno KJ, Macoska JA. Homozygous and frequent deletion of proximal 8p sequences in human prostate cancers: identification of a potential tumor suppressor gene site. Genes Chromosomes Cancer 1998;23:255-62.[Medline]
25 Buttyan R, Sawczuk IS, Benson MC, Siegal JD, Olsson CA. Enhanced expression of the c-myc protooncogene in high-grade human prostate cancers. Prostate 1987;11:327-37.[Medline]
26 Fleming WH, Hamel A, MacDonald R, Ramsey E, Pettigrew NM, Johnston B, et al. Expression of the c-myc protooncogene in human prostatic carcinoma and benign prostatic hyperplasia. Cancer Res 1986;46:1535-8.[Abstract]
27 Steiner P, Philipp A, Lukas J, Godden-Kent D, Pagano M, Mittnacht S, et al. Identification of a Myc-dependent step during the formation of active G1 cyclin-cdk 7complexes. EMBO J 1995;14:4814-26.[Abstract]
28 Bouchard C, Staller P, Eilers M. Control of cell proliferation by Myc. Trends Cell Biol 1998;8:202-6.[Medline]
29 Cheville JC, Lloyd RV, Sebo TJ, Cheng L, Erickson L, Bostwick DG, et al. Expression of p27kip1 in prostatic adenocarcinoma. Mod Pathol 1998;11:324-8.[Medline]
30
Cote RJ, Shi Y, Groshen S, Feng AC, Cordon-Cardo C, Skinner
D, et al. Association of p27Kip1 levels with recurrence and survival in patients with
stage C prostate carcinoma. J Natl Cancer Inst 1998;90:916-20.
31
Cordon-Cardo C, Koff A, Drobnjak M, Capodieci P, Osman I,
Millard SS, et al. Distinct altered patterns of p27KIP1 gene expression in benign
prostatic hyperplasia and prostatic carcinoma. J Natl Cancer Inst 1998;90:1284-91.
32 Tsihlias J, Kapusta LR, DeBoer G, Morava-Protzner I, Zbieranowski I, Bhattacharya N, et al. Loss of cyclin-dependent kinase inhibitor p27Kip1 is a novel prognostic factor in localized human prostate adenocarcinoma. Cancer Res 1998;58:542-8.[Abstract]
33 Steiner MS, Anthony CT, Lu Y, Holt JT. Antisense c-myc retroviral vector suppresses established human prostate cancer. Hum Gene Ther 1998;9:747-55.[Medline]
34 Dong JT, Lamb PW, Rinker-Schaeffer CW, Vukanovic J, Ichikawa T, Isaacs JT, et al. KAI1, a metastasis suppressor gene for prostate cancer on human chromosome 11p11.2. Science 1995;268:884-6.[Medline]
35 Bostwick DG, Myers RP, Oesterling JE. Staging of prostate cancer. Semin Surg Oncol 1994;10:60-72.[Medline]
36 Takahashi S, Qian J, Brown JA, Alcaraz A, Bostwick DG, Lieber MM, et al. Potential markers of prostate cancer aggressiveness detected by fluorescence in situ hybridization in needle biopsies. Cancer Res 1994;54:3574-9.[Abstract]
37 Persons DL, Gibney DJ, Katzmann JA, Lieber MM, Farrow GM, Jenkins RB. Use of fluorescent in situ hybridization for deoxyribonucleic acid ploidy analysis of prostatic adenocarcinoma. J Urol 1993;150:120-5.[Medline]
38
Reiter RE, Gu Z, Watanabe T, Thomas G, Szigeti K, Davis E, et
al. Prostate stem cell antigen: a cell surface marker overexpressed in prostate cancer. Proc
Natl Acad Sci U S A 1998;95:1735-40.
Manuscript received March 3, 1999; revised July 9, 1999; accepted July 29, 1999.
This article has been cited by other articles in HighWire Press-hosted journals:
![]() |
||||
|
Oxford University Press Privacy Policy and Legal Statement |