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979 PREVALENCE AND PROGNOSTIC ROLE OF COMMON TUMOR SUPPRESSOR GENE DELETIONS IN PROSTATE CANCER
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THE JOURNAL OF UROLOGY姞
978 PTEN DELETION AND MUTATION IN CLINICALLY INSIGNIFICANT AND SIGNIFICANT PROSTATE CANCER: AN ANALYSIS BY MATE-PAIR NEXT GENERATION AND SANGER SEQUENCING R. Jeffrey Karnes*, john cheville, george vasmatzis, william sukov, Rochester, MN INTRODUCTION AND OBJECTIVES: Deletion of PTEN is associated with worse prognosis in prostate cancer. However, little is known about the impact of PTEN mutations, and there is limited data regarding the frequency and clinical impact of deletion and mutation in clinically insignificant tumors compared to significant tumors. METHODS: We identified 40 prostatectomy cases with adenocarcinoma consisting of 9 clinically insignificant tumors (defined as GS6 and tumor volume ⬍0.5 cm3), 7 cases of large volume (⬎1.0 cm3) GS6, 23 cases of GS7, and 1 case of GS8) and performed massively parallel mate-pair next generation sequencing (NGS) on whole genome-amplified DNA extracted from laser capture microdissected tumor tissue. Sequence analysis of exonic regions was performed using standard Sanger methodology. Follow-up information was available for 31 patients. Tumor-free survival from date of prostatectomy was assessed using the Kaplan-Meier method and the log-rank test. RESULTS: PTEN deletion detected by mate-pair NGS occurred in 10 cases and three of these cases showed additional deleterious mutations (2 nonsense and 1 frameshift) in the remaining PTEN allele by Sanger sequencing. Although not mutually exclusive, alterations in PTEN occurred more frequently in the setting of ERG rearrangements (70%). PTEN abnormalities were absent in clinically insignificant GS6, and large volume GS6 but were common in GS7 or higher tumors (10 of 23 cases; 43%)(p⫽0.032). Radiographic or biochemical recurrence occurred in 5 patients with PTEN abnormalities (HR⫽4.65, p⫽0.036), including metastatic recurrences in 2 of the 3 patients with confirmed bi-allelic loss of PTEN. The overall 5-year tumor-free survival rate among patients with Gleason 7-8 tumors was 57% with PTEN abnormalities and 79% in the remaining cases (p⫽0.039). CONCLUSIONS: PTEN abnormalities were absent in clinically insignificant and large volume GS6 tumors, but occurred in a significant number of GS7 cases, Although our series is small, patients that had PTEN deletion and mutation has a significantly worse outcome.. These results suggest that PTEN abnormalities identify a subset of prostatic adenocarciomas at higher risk for progression, for which molecular and cytogenetic testing for PTEN abnormalities may provide significant prognostic information. Source of Funding: None
979 PREVALENCE AND PROGNOSTIC ROLE OF COMMON TUMOR SUPPRESSOR GENE DELETIONS IN PROSTATE CANCER Thorsten Schlomm*, Martinia Kluth, Pierre Tennstedt, Guido Sauter, Lia Burkhardt, Anje Krohn, Jovisa Gjoni, Thomas Hass, Rami Galal, Ronald Simon, Sarah Minner, Hamburg, Germany INTRODUCTION AND OBJECTIVES: A variety of chromosomal deletions are known to occur frequently in prostate cancer. Target genes and clinical significance of most of these deletions are unknown. To learn more about epidemiology, association with tumor phenotype, relevance for PSA recurrence and associations with other molecular features, several relevant deletions were analyzed on a large-scale tissue microarray platform in this project. METHODS: For the purpose of this study, a tissue microarray containing 11,156 prostate cancers was analyzed by fluorescence in situ hybridization (FISH). All cancers were analyzed with dual-labeling probes including PTEN (10q23), TP53 (17p13.1), FOXP1 (3p14.1), CHD1 (5q21) and MAP3K7 (6q15) together with their respective centromere probes. In addition, ERG fusion status and tumor cell proliferation (Ki67 labeling index) of all cancers were determined by immunohistochemistry.
Vol. 189, No. 4S, Supplement, Monday, May 6, 2013
RESULTS: Deletions were seen for PTEN in 17.9% of 6,122, TP53 in 14.7% of 7,604, FOXP1 in 9.2% of 6,059, CHD1 in 9.9% of 7,026, and for MAP3K7 in 18.7% of 3,528 interpretable cases. All deletions were strongly linked to the ERG status (p⬍0.0001 each). In ERG positive/negative cancers, the deletion frequency was 27%/11% for PTEN, 22%/9% for TP53, 22%/7% for FOXP1, 6%/18% for CHD1, and 11%/28% for MAP3K7. The frequency of all these deletions increased significantly with tumor stage and grade. This was most prominently true for TP53, PTEN and MAP3K7 (p⬍0.0001 each). In addition, there was a significant association of most deletions with the likelihood of PSA recurrence (PTEN, TP53, MAP3K7, CHD1: p⬍0.0001; FOXP1: p⫽0.1486). The combination of deletion information provided even better prognostic information. There was a dose dependent relationship between the number of deletions and PSA recurrence. Tumors with no deletion had the best clinical outcome followed by cancers, with one, two, and three or more deletions (p⬍0.0001). Particular strong prognostic information was obtained by combining PTEN and p53 deletions. Patients with none of these alterations had 17% PSA recurrence while the respective figure was 40% on patients with both deletions. CONCLUSIONS: In summary, these data show, that chromosomal deletions are tightly linked with ERG status in prostate cancer and that most of these deletions have clinical relevance. Combinatorial analysis of genomic alterations in prostate cancer might provide clinically relevant information. Source of Funding: German Cancer Aid (grant #109505) and Sander Foundation (2012-023.1).
980 GENOMIC ABERRATIONS OF PTEN ARE HIGHLY HETEROGENEOUS AND DEVELOP SUBSEQUENT TO ERG FUSION IN PROSTATE CANCER Thorsten Schlomm*, Anje Krohn, Pierre Tennstedt, Fabian Freudenthaler, Martinia Kluth, Maria Christina Tsourlakis, Hueseyin Sirma, Guido Sauter, Ronald Simon, Sarah Minner, Hamburg, Germany INTRODUCTION AND OBJECTIVES: Prostate cancer is often heterogeneous and multifocal. TMPRSS2:ERG fusion, in combination with deletion of the PTEN tumor suppressor have been suggested to cooperatively drive tumor progression in prostate cancer. We utilized a novel heterogeneity tissue microarray format to study the intrafocal heterogeneity of PTEN deletions and rearrangements as well as ERG fusions, and to determine the sequel of occurrence. METHODS: The heterogeneity TMA was made from 189 entirely archived prostatectomy specimens, each of which that been dissected into 50-70 tissue blocks. From each prostate, 10 tumor containing blocks were selected for TMA construction, and one 0.6 mm punch was taken from each block. RESULTS: PTEN alterations were found in 48/123 (39%) analyzable individual tumor foci, including 40 foci with deletions, 7 with deletion and rearrangement, and 1 focus with rearrangement only. PTEN was homogeneously aberrant in only 4 (8.3%) and heterogeneously in 44 (91.7%) of the foci. We found a specific sequel of molecular events from PTEN breakage followed by deletion of DNA sequences flanking the breakpoint, resulting in homozygous deletion. The observation that 16 of 19 foci with homogeneous ERG positivity had focal PTEN alterations but none of 10 foci with PTEN alterations had focal ERG positivity (p⬍0.0001) suggests that PTEN alterations typically develop subsequent to ERG fusions. In conclusion, we demonstrate a high level of intratumoral heterogeneity of PTEN alterations with deletions and rearrangements that challenges potential PTEN routine diagnosis testing in biopsies. CONCLUSIONS: The observation that PTEN alterations develop subsequent to ERG fusion strongly suggests that ERG expression might directly drive development of PTEN aberrations. Source of Funding: German Cancer Aid (grant #109505) and Sander Foundation (2012-023.1).
THE JOURNAL OF UROLOGY姞
978 PTEN DELETION AND MUTATION IN CLINICALLY INSIGNIFICANT AND SIGNIFICANT PROSTATE CANCER: AN ANALYSIS BY MATE-PAIR NEXT GENERATION AND SANGER SEQUENCING R. Jeffrey Karnes*, john cheville, george vasmatzis, william sukov, Rochester, MN INTRODUCTION AND OBJECTIVES: Deletion of PTEN is associated with worse prognosis in prostate cancer. However, little is known about the impact of PTEN mutations, and there is limited data regarding the frequency and clinical impact of deletion and mutation in clinically insignificant tumors compared to significant tumors. METHODS: We identified 40 prostatectomy cases with adenocarcinoma consisting of 9 clinically insignificant tumors (defined as GS6 and tumor volume ⬍0.5 cm3), 7 cases of large volume (⬎1.0 cm3) GS6, 23 cases of GS7, and 1 case of GS8) and performed massively parallel mate-pair next generation sequencing (NGS) on whole genome-amplified DNA extracted from laser capture microdissected tumor tissue. Sequence analysis of exonic regions was performed using standard Sanger methodology. Follow-up information was available for 31 patients. Tumor-free survival from date of prostatectomy was assessed using the Kaplan-Meier method and the log-rank test. RESULTS: PTEN deletion detected by mate-pair NGS occurred in 10 cases and three of these cases showed additional deleterious mutations (2 nonsense and 1 frameshift) in the remaining PTEN allele by Sanger sequencing. Although not mutually exclusive, alterations in PTEN occurred more frequently in the setting of ERG rearrangements (70%). PTEN abnormalities were absent in clinically insignificant GS6, and large volume GS6 but were common in GS7 or higher tumors (10 of 23 cases; 43%)(p⫽0.032). Radiographic or biochemical recurrence occurred in 5 patients with PTEN abnormalities (HR⫽4.65, p⫽0.036), including metastatic recurrences in 2 of the 3 patients with confirmed bi-allelic loss of PTEN. The overall 5-year tumor-free survival rate among patients with Gleason 7-8 tumors was 57% with PTEN abnormalities and 79% in the remaining cases (p⫽0.039). CONCLUSIONS: PTEN abnormalities were absent in clinically insignificant and large volume GS6 tumors, but occurred in a significant number of GS7 cases, Although our series is small, patients that had PTEN deletion and mutation has a significantly worse outcome.. These results suggest that PTEN abnormalities identify a subset of prostatic adenocarciomas at higher risk for progression, for which molecular and cytogenetic testing for PTEN abnormalities may provide significant prognostic information. Source of Funding: None
979 PREVALENCE AND PROGNOSTIC ROLE OF COMMON TUMOR SUPPRESSOR GENE DELETIONS IN PROSTATE CANCER Thorsten Schlomm*, Martinia Kluth, Pierre Tennstedt, Guido Sauter, Lia Burkhardt, Anje Krohn, Jovisa Gjoni, Thomas Hass, Rami Galal, Ronald Simon, Sarah Minner, Hamburg, Germany INTRODUCTION AND OBJECTIVES: A variety of chromosomal deletions are known to occur frequently in prostate cancer. Target genes and clinical significance of most of these deletions are unknown. To learn more about epidemiology, association with tumor phenotype, relevance for PSA recurrence and associations with other molecular features, several relevant deletions were analyzed on a large-scale tissue microarray platform in this project. METHODS: For the purpose of this study, a tissue microarray containing 11,156 prostate cancers was analyzed by fluorescence in situ hybridization (FISH). All cancers were analyzed with dual-labeling probes including PTEN (10q23), TP53 (17p13.1), FOXP1 (3p14.1), CHD1 (5q21) and MAP3K7 (6q15) together with their respective centromere probes. In addition, ERG fusion status and tumor cell proliferation (Ki67 labeling index) of all cancers were determined by immunohistochemistry.
Vol. 189, No. 4S, Supplement, Monday, May 6, 2013
RESULTS: Deletions were seen for PTEN in 17.9% of 6,122, TP53 in 14.7% of 7,604, FOXP1 in 9.2% of 6,059, CHD1 in 9.9% of 7,026, and for MAP3K7 in 18.7% of 3,528 interpretable cases. All deletions were strongly linked to the ERG status (p⬍0.0001 each). In ERG positive/negative cancers, the deletion frequency was 27%/11% for PTEN, 22%/9% for TP53, 22%/7% for FOXP1, 6%/18% for CHD1, and 11%/28% for MAP3K7. The frequency of all these deletions increased significantly with tumor stage and grade. This was most prominently true for TP53, PTEN and MAP3K7 (p⬍0.0001 each). In addition, there was a significant association of most deletions with the likelihood of PSA recurrence (PTEN, TP53, MAP3K7, CHD1: p⬍0.0001; FOXP1: p⫽0.1486). The combination of deletion information provided even better prognostic information. There was a dose dependent relationship between the number of deletions and PSA recurrence. Tumors with no deletion had the best clinical outcome followed by cancers, with one, two, and three or more deletions (p⬍0.0001). Particular strong prognostic information was obtained by combining PTEN and p53 deletions. Patients with none of these alterations had 17% PSA recurrence while the respective figure was 40% on patients with both deletions. CONCLUSIONS: In summary, these data show, that chromosomal deletions are tightly linked with ERG status in prostate cancer and that most of these deletions have clinical relevance. Combinatorial analysis of genomic alterations in prostate cancer might provide clinically relevant information. Source of Funding: German Cancer Aid (grant #109505) and Sander Foundation (2012-023.1).
980 GENOMIC ABERRATIONS OF PTEN ARE HIGHLY HETEROGENEOUS AND DEVELOP SUBSEQUENT TO ERG FUSION IN PROSTATE CANCER Thorsten Schlomm*, Anje Krohn, Pierre Tennstedt, Fabian Freudenthaler, Martinia Kluth, Maria Christina Tsourlakis, Hueseyin Sirma, Guido Sauter, Ronald Simon, Sarah Minner, Hamburg, Germany INTRODUCTION AND OBJECTIVES: Prostate cancer is often heterogeneous and multifocal. TMPRSS2:ERG fusion, in combination with deletion of the PTEN tumor suppressor have been suggested to cooperatively drive tumor progression in prostate cancer. We utilized a novel heterogeneity tissue microarray format to study the intrafocal heterogeneity of PTEN deletions and rearrangements as well as ERG fusions, and to determine the sequel of occurrence. METHODS: The heterogeneity TMA was made from 189 entirely archived prostatectomy specimens, each of which that been dissected into 50-70 tissue blocks. From each prostate, 10 tumor containing blocks were selected for TMA construction, and one 0.6 mm punch was taken from each block. RESULTS: PTEN alterations were found in 48/123 (39%) analyzable individual tumor foci, including 40 foci with deletions, 7 with deletion and rearrangement, and 1 focus with rearrangement only. PTEN was homogeneously aberrant in only 4 (8.3%) and heterogeneously in 44 (91.7%) of the foci. We found a specific sequel of molecular events from PTEN breakage followed by deletion of DNA sequences flanking the breakpoint, resulting in homozygous deletion. The observation that 16 of 19 foci with homogeneous ERG positivity had focal PTEN alterations but none of 10 foci with PTEN alterations had focal ERG positivity (p⬍0.0001) suggests that PTEN alterations typically develop subsequent to ERG fusions. In conclusion, we demonstrate a high level of intratumoral heterogeneity of PTEN alterations with deletions and rearrangements that challenges potential PTEN routine diagnosis testing in biopsies. CONCLUSIONS: The observation that PTEN alterations develop subsequent to ERG fusion strongly suggests that ERG expression might directly drive development of PTEN aberrations. Source of Funding: German Cancer Aid (grant #109505) and Sander Foundation (2012-023.1).