Gleason score – predicting the future in metastatic prostate cancer

The authors aimed to evaluate the use of Gleason scores in predicting the outlook of metastatic prostate cancer.

The Gleason grading system is from 2-10. It describes how different the cancer cells look from  normal cells and predicts the likelihood of the tumor spreading. The lower the score, the less likely it is that the tumor will spread. Gleason score is the most common factor used to estimate outlook in localised prostate cancer (tumor confined to the prostate).

It is also used to estimate cancer outlook in metastatic prostate cancer (cancer that has spread). It is useful in castrate-sensitive (cancer treatable with hormone therapy that targets testosterone) and castrate-resistant diseases (patients becomes resistant to hormone therapy and cancer grows/progresses despite treatment). Metastatic prostate cancer usually has a score of 8 – 10. Previous studies have mostly evaluated outcomes based simply on whether a Gleason score is less than 7 or greater than 8, and not differentiated between individual scores. 

The aim of this study was to evaluate the outlook associated with Gleason scores in metastatic prostate cancer patients with a score of 6-10. 4,654 patients were evaluated who averaged 71 years of age.

The 4-year overall survival rates were as follows: score of 6 – 51%, score of 7 – 45%, score of 8 – 34%, score of 9 – 25% and score of 10 – 14.6%. 

The 4-year prostate cancer-specific survival (the percentage of patients who did not die of prostate cancer) were as follows: score of 6 – 69%, score of 7 – 57%, score of 8 – 44%, score of 9 – 33% and score of 10 – 21%.

Gleason pattern refers to how abnormal the cells look under a microscope, with 1 being the most normal and 5 being the most abnormal. Cleason scores are made up of the two most common patterns found in the tumor (for example Gleason score 7 could be made up of pattern 3 + pattern 4). Both Gleason score 8 and Gleason score 9 patients showed significantly reduced overall and prostate cancer-specific rates when Gleason pattern 5 was present as one of the patterns in their score. 

2,197 patients with Gleason pattern 5  were compared to 2,402 patients who had no Gleason pattern 5. The overall survival rates for those with Gleason pattern 5 present were 23.5% compared to 42.1% for those with no Gleason pattern 5 present. The prostate cancer-specific survival rates for those with Gleason pattern 5 present were 31.3% compared to 54% for those with no Gleason pattern 5 present.

Gleason score is an important prognostic factor in metastatic prostate cancer. Gleason pattern 5 is also a strong individual predictor for survival rates in patients. 

There was no information available on the types of treatment that were undertaken by the patients.  

If you would like information on your current Gleason scores please consult your doctor.