Genetic alterations associated with prostate cancer progression
Prostate cancer is the second most commonly diagnosed cancer among men in the United States. In this study, evidence is presented to support the hypothesis that specific chromosomal aberrations (involving one or more chromosomal regions) are associated with prostate cancer progression from organ-confined to locally advanced tumors and that some aberrations seen in high frequency in metastatic tumors may also be present in a subset of primary tumors. To determine the appropriate approach to address this hypothesis, I have established a modified CGH protocol by microdissection and DOP-PCR for use in detecting chromosomal changes in clinical prostate tumor specimens that is more sensitive and accurate than conventional CGH methods. I have successfully performed the improved CGH protocol to screen for genetic changes of 24 organ confined (pT2) and 21 locally advanced (pT3b) clinical prostate cancer specimens without metastases (N0M0). Comparisons of tumors by stage or Gleason scores following contingency table analysis showed that seven regions of the genome differed significantly between pT2 and pT3b tumors or between low and high Gleason tumors suggesting that these regions may be important in local prostate cancer progression. These included losses on 6p21–25, 6q24–27, 8p, 10q25–26, 15q22–26, and 18cen–q12 as well as gain of 3p13–q13. Multivariate analyses showed that loss of 8p (step1) and loss of 6q25–26 (or 6p21–25 or 10q25–26) (step 2) were predictive of pathologic stage or Gleason groups with 80% accuracy. Additional 5–7 steps in the multivariate model increased the predictive value to 91–95%. Comparison of the CGH data from the primary prostate tumors of this study with those obtained from published literature on metastases and recurrent tumors showed that the clinically more aggressive stage pT3b tumors shared more abnormalities in high frequency with metastases and recurrent tumors than less aggressive stage pT2 tumors. Furthermore, loss of 11cen–q22 was shared only between the primary tumors and metastases while gain of Xcen–q13 and loss of 18cen–q12 were in common between primary and recurrent tumors. These analyses suggest that the multistage model of prostate cancer progression is not linear and that some early primary tumors may be predisposed to metastasize or evolve into recurrent tumors due to the presence of specific genetic alterations.
Chu, Lisa Wey-Lan, "Genetic alterations associated with prostate cancer progression" (2001). Texas Medical Center Dissertations (via ProQuest). AAI3004450.