Gleason scores from prostate biopsies obtained with 18-gauge biopsy needles poorly predict Gleason scores of radical prostatectomy specimens.

OBJECTIVES: Prostate cancer is the most frequent cancer among men in the US. Histological grading is an important part of the diagnostic evaluation aside from clinical staging and serum PSA. The most commonly used grading system is the one described by Gleason. From a prognostic point of view, it is of considerable interest to know how accurate the needle biopsy Gleason score is in predicting the final score of the radical prostatectomy specimen. From an outcome research point of view, it is important to recognize that a stratification of patients by Gleason score may prove correct in patients undergoing radical prostatectomy, while in patients undergoing radiation or conservative management some of the well-differentiated cancers could actually be moderately and poorly differentiated, and some of the moderately differentiated might be poorly differentiated, thus favoring radical prostatectomy in a direct comparison of treatment efficacy. We aimed to determine (1) whether such undergrading exists, (2) what the magnitude of the bias is, and (3) whether it is common and similar in different institutions. MATERIALS AND METHODS: We retrospectively reviewed the records of 415 patients who underwent radical prostatectomy in three Dallas area hospitals, excluding patients who received neoadjuvant therapy prior to surgery. Data of Gleason grades and score were collected from the needle biopsy and the radical prostatectomy specimen. Analysis was done using three categorization schemes for mild, moderate and poor differentiation for the three individual hospitals and the entire group. RESULTS: The most common Gleason score by needle biopsy and prostatectomy was five. 37.2% of all patients had no change in score assignment, while 12.7% were 'overgraded' and 50.1% 'undergraded' by needle biopsy. The most common undergrading was by 1 or 2 score points. Only 23.7% of the category 'well' cancers remained so after surgery. Between 65.0 and 88.4% of the category 'moderate' cancers remained so after surgery. To determine the degree of agreement between needle biopsy and surgery category, kappa statistics were employed. The kappa value ranged from 0.148 to 0.328 for all categories and classification schemes indicating poor reproducibility. Serum prostate-specific antigen was not helpful in predicting Gleason score upgrading. CONCLUSIONS: Independent of the setting, about 50% of all Gleason score assignments made on needle biopsy specimen are revised in the direction of a worse score/category. It is important for clinicians to realize this phenomenon when consulting with patients regarding treatment choices if the grade is taken into consideration. For outcome research purposes, it is important to realize that this introduces a bias into direct comparisons between surgical and nonsurgical (radiation and watchful waiting) series favoring the outcomes of surgical series as the nonsurgical series suffer from a less favorable patient mix.

Radical retropubic prostatectomy for localized carcinoma of the prostate in a large metropolitan hospital: changing trends over a 10-year period (1984-1994). Dallas Outcomes Research Group for Urological Disorders.

OBJECTIVES: To analyze changing trends in the surgical treatment for localized carcinoma of the prostate in a large metropolitan community hospital over a 10-year period from 1984 to 1994. METHODS: The records of all 428 patients who underwent radical prostatectomy for localized carcinoma of the prostate from January 1, 1984, to January 1, 1994, at a large metropolitan community hospital (Baylor University Medical Center, Dallas, Tex) were retrieved and data abstracted in a predefined computerized database by a urology resident who was not part of the patient's surgical team. The abstracted data included attending surgeon, date of surgery, patient's age, clinical stage at presentation and pathologic stage, prostate-specific antigen (PSA), perioperative events, such as duration of surgery, blood loss, transfusion, duration of hospital stay, comorbidities according to the Charlson comorbidity index, and others. The data were analyzed in regard to changes over the 10-year period and stratified by a variety of parameters. RESULTS: The number of radical prostatectomies performed increased by fourfold from 1984 to 1993. The distribution of clinical stage and the incidence of pathologic upstaging noted in the 428 cases were similar to other series reported in the literature. The average age of patients decreased from 67 to 63 years over the 10 years (average calculated in increments of 15 cases in ascending order). Similarly, over time the average duration of surgery, average blood loss, average use of transfusion, and the average duration of hospital stay decreased. When the cases were grouped by individual attending surgeon, whose numerical surgical experience during that time period ranged from 1 to 76 cases, no correlation was noted between the numerical experience and these outcomes. CONCLUSIONS: As opposed to the national Medicare experience recently reported by the Prostate Patients Outcome Research Team, the increase in the number of cases performed was mostly due to patients under the age of 70 years, considered reasonable candidates for radical prostatectomy. Independent of numerical experience of individual attending surgeons, duration of surgery, blood loss, transfusion rates, and duration of hospital stay decreased during this period. This might indicate a learning effect due to continuing education, exchange of ideas, published technical improvements in the surgical procedure, and other factors, ultimately benefiting the patient by improving outcomes.