Evaluating normal-looking tissue adjacent to prostate tumors using digitized prostatectomy specimens may improve prediction of biochemical recurrence for prostate cancer (PCa) patients, according to a preliminary study.
Compared with Gleason score alone, adding the tumor plus adjacent benign signature (TABS) provided better stratification for recurrence-free survival, researchers reported. It was also better than the Kattan and Stephenson nomograms alone. TABS is a combination of the top 10 features identified as most predictive of recurrence within both benign and cancerous regions of pathology images. Investigating benign fields next to the tumor added new information not found in other prognostic models.
For the study, Anant Madabhushi, PhD, of Case Western Reserve University in Cleveland, and colleagues examined 140 tissue microarray cores from 70 PCa patients who underwent radical prostatectomy between 2000 and 2004. Over 14 years of follow-up, 22 patients experienced biochemical recurrence, local or distant recurrence, or cancer death; 48 did not.
Using Cox regression models, the investigators determined that tumor-adjacent benign field features predicted recurrence. Combining TABS with Gleason sum was even more predictive. Tumor-field nuclear shape descriptors and benign-field local nuclear arrangement were the most telling features in TABS.
In summary, the researchers found that both tumor and benign regions contain features capable of distinguishing recurrent from non-recurrent patients; that the arrangement of nuclei in the benign regions provides a majority of the contribution; and that the size and shape of nuclei in tumor regions are primary components, according to a report in European Urology Focus.
Cancer cell invasion is necessary for PCa recurrence, and the morphology of benign tissue surrounding the tumor may provide clues about a potential invasion, they explained.
As the work is preliminary, the investigators plan to conduct future studies with larger numbers of patients to reproduce the findings. If confirmed, the tool may help clinicians decide which PCa patients need closer monitoring or treatment after surgery.
1. Lee G, Veltri RW, Zhub G, Alia S, Epstein JI, and Madabhushia A. Nuclear Shape and Architecture in Benign Fields Predict Biochemical Recurrence in Prostate Cancer Patients Following Radical Prostatectomy: Preliminary Findings. Eur Urol Focus. doi:10.1016/j.euf.2016.05.009. [Epub ahead of print]