Quantifying the Ki-67 Heterogeneity Profile in Prostate Cancer

Abstract EN

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.