Importance of the amount of Gleason 4 in a Gleason sum of 7

[Guest guest]

The recent abstract below adds to the growing literature on the importance

of determining how much Gleason 4 cancer is found in a biopsy with

a Gleason sum of 7 (which can be 3+4 or 4+3).

This study found a three-fold increase in prostate cancer death for

patients with a Gleason score of 4+3 compared to 3+4.

Clearly, the amount of biopsy tissue graded as Gleason 4 is

an important predictor of ultimate prostate cancer survival.

Hopefully pathology labs will start reporting actual percentages

of tissue with Gleason 4, not just the relative amounts

reflected in a reported Gleason 7 sum as 3+4 vs 4+3.

(Dr. Strum has been preaching this lesson for years.......)

The Best to You and Yours!

Jon in Nevada

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Gleason Score and Lethal Prostate Cancer: Does 3 + 4 = 4 + 3? - Abstract

Stark JR, Perner S, Stampfer MJ, Sinnott JA, Finn S, Eisenstein AS, Ma J,

Fiorentino M, Kurth T, Loda M, Giovannucci EL, Rubin MA, Mucci LA.F

Departments of Epidemiology, Biostatistics, and Nutrition, Harvard School

of Public Health; Channing Laboratory and Division of Preventive

Medicine, Department of Medicine, Brigham and Women's Hospital; Center

for Molecular Oncologic Pathology, Dana-Farber Cancer Institute, Boston,

MA. Department of Pathology and Laboratory Medicine, Weill Medical College,

Cornell University, New York, NY.

Gleason grading is an important predictor of prostate cancer (PCa)

outcomes. Studies using surrogate PCa end points suggest outcomes for

Gleason score (GS) 7 cancers vary according to the predominance of

pattern 4. These studies have influenced clinical practice, but it is

unclear if rates of PCa mortality differ for 3 + 4 and 4 + 3 tumors.

Using PCa mortality as the primary end point, we compared outcomes in

Gleason 3 + 4 and 4 + 3 cancers, and the predictive ability of GS from a

standardized review versus original scoring.

Three study pathologists conducted a blinded standardized review of 693

prostatectomy and 119 biopsy specimens to assign primary and secondary

Gleason patterns. Tumor specimens were from PCa patients diagnosed

between 1984 and 2004 from the Physicians' Health Study and Health

Professionals Follow-Up Study. Lethal PCa (n = 53) was defined as

development of bony metastases or PCa death. Hazard ratios (HR) were

estimated according to original GS and standardized GS. We compared the

discrimination of standardized and original grading with C-statistics

from models of 10-year survival.

For prostatectomy specimens, 4 + 3 cancers were associated with a

three-fold increase in lethal PCa compared with 3 + 4 cancers (95% CI,

1.1 to 8.6). The discrimination of models of standardized scores from

prostatectomy (C-statistic, 0.86) and biopsy (C-statistic, 0.85) were

improved compared to models of original scores (prostatectomy

C-statistic, 0.82; biopsy C-statistic, 0.72).

Ignoring the predominance of Gleason pattern 4 in GS 7 cancers may

conceal important prognostic information. A standardized review of GS can

improve prediction of PCa survival.

Reference: J Clin Oncol. 2009 May 11. Epub ahead of print. doi:10.1200/JCO.2008.20.4669PubMed Abstract PMID:19433685 Make your summer sizzle with fast and easy recipes for the grill.