Quantifying the ki-67 heterogeneity profile in prostate cancer.
BACKGROUND
Ki-67 is a robust predictive/prognostic marker in prostate cancer; however, tumor heterogeneity in prostate biopsy samples is not well studied.


METHODS
Using an MRI/US fusion device, biopsy cores were obtained systematically and by targeting when indicated by MRI. Prostate cores containing cancer from 77 consecutive men were analyzed. The highest Ki-67 was used to determine interprostatic variation. Ki-67 range (highest minus lowest) was used to determine intraprostatic and intralesion variation. Apparent diffusion coefficient (ADC) values were evaluated in relation to Ki-67.


RESULTS
Interprostatic Ki-67 mean ± standard deviation (SD) values for NCCN low (L), intermediate (I), and high (H) risk patients were 5.1 ± 3.8%, 7.4 ± 6.8%, and 12.0 ± 12.4% (ANOVA P = 0.013). Intraprostatic mean ± SD Ki-67 ranges in L, I, and H risk patients were 2.6 ± 3.6%, 5.3 ± 6.8%, and 10.9 ± 12.3% (ANOVA P = 0.027). Intralesion mean ± SD Ki-67 ranges in L, I, and H risk patients were 1.1 ± 0.9%, 5.2 ± 7.9%, and 8.1 ± 10.8% (ANOVA P = 0.22). ADC values at Ki-67 > and <7.1% were 860 ± 203 and 1036 ± 217, respectively (P = 0.0029).


CONCLUSIONS
High risk patients have significantly higher inter- and intraprostatic Ki-67 heterogeneity. This needs to be considered when utilizing Ki-67 clinically.
UC Irvine School of Medicine, 1001 Health Sciences Road, 252 Irvine Hall, Irvine, CA 92697-3950, USA.
Shane
S
Mesko
Patrick
P
Kupelian
D Jeffrey
DJ
Demanes
Jaoti
J
Huang
Pin-Chieh
PC
Wang
Mitchell
M
Kamrava