title: Tracking tumor evolution via prostate-specific antigen: an individual post-operative study.
abstract: BACKGROUND
  The progress of the prostate-specific antigen (PSA) level after radical prostatectomy is observed for a patient in order to extract information about the mode of tumor cell growth. Although PSA values are determined routinely to find the doubling time of the prostate marker, to our knowledge, this analysis is the first in the literature.
  
  
  RESULTS
  The prostate tumor marker values were determined regularly after the surgery and plotted on a logarithmic scale against time. An initial rapid-growth mode changed to a slower power-law regime within two years of surgery. Our analysis associates this observation with a transition in the growth mode from unrestricted growth of dispersed cells to their clumping into macroscopic structures.
  
  
  CONCLUSIONS
  Such studies may help determine the appropriate time window for postoperative therapies in order to increase the life expectancy of the patient.
authors.affiliation: Laboratory for Solid State Physics, ETH Zurich, CH-8093 Zurich, Switzerland. erbudak@phys.ethz.ch
authors.forename: Mehmet
authors.initials: M
authors.lastname: Erbudak
authors.forename: Ayşe
authors.initials: A
authors.lastname: Erzan
mesh_terms: D049109:Cell Proliferation; D006801:Humans; D008297:Male; D011182:Postoperative Care; D017430:Prostate-Specific Antigen / Q000378:metabolism*; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000378:metabolism* / Q000473:pathology* / Q000601:surgery; D013997:Time Factors
chemical_list: D017430:Prostate-Specific Antigen