Artificial intelligence for diagnosis and Gleason grading of prostate cancer: the PANDA challenge

Artificial intelligence (AI) has shown promise for diagnosing prostate cancer in biopsies. However, results have been limited to individual studies, lacking validation in multinational settings. Competitions have been shown to be accelerators for medical imaging innovations, but their impact is hindered by lack of reproducibility and independent validation. With this in mind, we organized the PANDA challenge—the largest histopathology competition to date, joined by 1,290 developers—to catalyze development of reproducible AI algorithms for Gleason grading using 10,616 digitized prostate biopsies. We validated that a diverse set of submitted algorithms reached pathologist-level performance on independent cross-continental cohorts, fully blinded to the algorithm developers. On United States and European external validation sets, the algorithms achieved agreements of 0.862 (quadratically weighted κ, 95% confidence interval (CI), 0.840–0.884) and 0.868 (95% CI, 0.835–0.900) with expert uropathologists. Successful generalization across different patient populations, laboratories and reference standards, achieved by a variety of algorithmic approaches, warrants evaluating AI-based Gleason grading in prospective clinical trials.

Significant Inter- and Intralaboratory Variation in Gleason Grading of Prostate Cancer: A Nationwide Study of 35,258 Patients in The Netherlands

Purpose: Our aim was to analyze grading variation between pathology laboratories and between pathologists within individual laboratories using nationwide real-life data. Methods: We retrieved synoptic (n = 13,397) and narrative (n = 29,377) needle biopsy reports from the Dutch Pathology Registry and prostate-specific antigen values from The Netherlands Cancer Registration for prostate cancer patients diagnosed between January 2017 and December 2019. We determined laboratory-specific proportions per histologic grade and unadjusted odds ratios (ORs) for International Society of Urological Pathologists Grades 1 vs. 2–5 for 40 laboratories due to treatment implications for higher grades. Pathologist-specific proportions were determined for 21 laboratories that consented to this part of analysis. The synoptic reports of 21 laboratories were used for analysis of case-mix correction for PSA, age, year of diagnosis, number of biopsies and positive cores. Results: A total of 38,321 reports of 35,258 patients were included. Grade 1 ranged between 19.7% and 44.3% per laboratory (national mean = 34.1%). Out of 40 laboratories, 22 (55%) reported a significantly deviant OR, ranging from 0.48 (95% confidence interval (CI) 0.39–0.59) to 1.54 (CI 1.22–1.93). Case-mix correction was performed for 10,294 reports, altering the status of 3/21 (14%) laboratories, but increasing the observed variation (20.8% vs. 17.7%). Within 15/21 (71%) of laboratories, significant inter-pathologist variation existed. Conclusion: Substantial variation in prostate cancer grading was observed between and within Dutch pathology laboratories. Case-mix correction did not explain the variation. Better standardization of prostate cancer grading is warranted to optimize and harmonize treatment.

Squamous cell carcinoma transformed from the prostatic adenocarcinoma with endocrine therapy: a case report and literature review

BackgroundSquamous cell carcinoma (SCC) of the prostate is a very rare and highly aggressive tumor, which is insensitive to multiple treatments, prone to metastasis, and has a worse prognosis than adenocarcinoma of the prostate. However, a transformation of prostatic adenocarcinoma into squamous cell carcinoma is rarer and may occur after endocrine or radiotherapy. By now, there are few cases in the world about the transformation from adenocarcinoma into squamous cell carcinoma after treatment. To our knowledge, our case is the first reported in China.Case presentationA 67-year-old man with metastatic adenocarcinoma of the prostate for 2 years, was not suitable for radical prostatectomy due to the disease classified T4N1M1. Endocrine therapy using Luteinizing Hormone-Releasing Hormone (LHRH) analog (leuprorelin) and antiandrogen agent (bicalutamide) was started, and serum prostate-specific antigen (PSA) level gradually decreased to a nadir of 0.04ng/ml. 2 years after treatment, he complained of worsening of lower urinary tract symptoms, and then he underwent transurethral resection of the prostate (TURP). Histopathological examination confirmed most of the tissue areas were accompanied by poorly differentiated keratinizing squamous cell carcinoma. Now, the patient started docetaxel treatment. He has received 2 times of systemic chemotherapy. The patient's current general condition is fair.ConclusionsProstatic adenocarcinoma transformed into squamous cell carcinoma after endocrine therapy is very rare. However, the serum PSA of this tumor is probably normal, PSA and the Gleason grading system are of limited value in the diagnosis of SCC, histopathological can help its diagnosis. The transformation is silent and we cannot know it. The question of whether prostatic adenocarcinoma or SCC of the prostate requires more definitive research to answer.