Tumour growth fraction measured by immunohistochemical staining of Ki67 is an independent prognostic factor in preoperative prostate biopsies with small‐volume or low‐grade prostate cancer

Abstract

Accurate prognostic parameters in prostate biopsies are needed to better counsel individual patients with prostate cancer. We evaluated the prognostic impact of morphologic and immunohistochemical parameters in preoperative prostate cancer biopsies. A consecutive series of prostate biopsies of 279 men (72% with clinical stage T1c and 23% with T2) who subsequently underwent radical prostatectomy was prospectively analysed for Gleason score, number and percentage of positive cores (NPC, PPC), total percentage of biopsy tissue with tumour (TPT), maximum tumour percentage per core (MTP), and expression of Ki67, Bcl‐2 and p53. All biopsy features were significantly associated with at least one feature of the radical prostatectomy specimen. pT stage was independently predicted by PSA, seminal vesicle invasion by Ki67 LI, positive margins by PSA and MTP, large tumour diameter by PSA and PPC, and Gleason score by biopsy Gleason score, MTP, and Ki67 LI, respectively. Biopsy Gleason score, NPC (1 vs. >1), TPT (<7 vs. ≥7%), and Ki67 LI (<10 vs. ≥10%) were significant predictors of biochemical recurrence after radical prostatectomy (p < 0.01, each). KI67 LI was the only independent prognostic factor in case of a low TPT (<7%) or low Gleason score (<7), the hazard ratio being 6.76 and 6.44, respectively. In summary, preoperative Gleason score, NPC, TPT and Ki67 LI significantly predict the risk of recurrence after radical prostatectomy, and Ki67 is an independent prognosticator in biopsies with low‐volume or low‐grade prostate cancer. Analysis of Ki67 LI in these biopsies may help to better identify patients with clinically insignificant prostate cancer. © 2008 Wiley‐Liss, Inc.

Is the improved prognosis of p16 positive oropharyngeal squamous cell carcinoma dependent of the treatment modality?

“…This corresponds to the vast majority of publications, confirming significantly improved overall survival of HPV induced p16 positive OPSCC only. 15,28,31,32,[34][35][36] Focusing on OSCC, most tumors in our TMA were localized in the palatal tonsils or in the base of the tongue. As reported by others, p16 expression did not differ between the four different localizations nor did it correlate with clinicopathological parameters cT and cN classification or tumor grade.…”

The impact of the number of cores on tissue microarray studies investigating prostate cancer biomarkers

“…For Ki67, the data support the prognostic relevance of tumor cell proliferation (14) and that the proliferative activity even has importance if small biopsy samples are analyzed (29). Given the heterogeneity of tumor cell proliferation within cancers, it has earlier been discussed whether proliferation hot spots or randomly selected areas better reflect tumor proliferation properties (14,30).…”

A patient‐derived explant (PDE) model of hormone‐dependent cancer

“…Ki67 proliferative index is an independent predictor of prostate cancer outcomes (Fisher et al ., 2013; Pollack et al ., 2004; Zellweger et al ., 2009); however, the wide range of Ki67 expression naturally observed in clinical prostate tumors and a lack of consensus on appropriate cutoff points have prevented utilization of Ki67 as a marker in the clinic (Penault‐Llorca and Radosevic‐Robin, 2017). Similarly, we observed wide variation in baseline Ki67 expression in PDE tissues, reflecting the diverse genetic heterogeneity of prostate tumors (Barbieri et al ., 2013).…”