A group of Japanese researchers has suggested that it may be beneficial to subdivide the D’Amico “high risk” patient group into two subgroups.
D’Amico and his colleagues defined men with localized prostate cancer at high risk for progressive disease as those who met any one or more of the following criteria:
- A clinical stage higher than T2b
- A Gleason score of 8 or higher
- A PSA level of > 20 ng/ml
In a new paper by Kita et al. (written in Japanese but with an English abstract), the authors report that, based on their series of 208 patients treated surgically between 1997 and 205, men in the high-risk category according to the D’Amico risk criteria consisted of patients with a range of prognoses. They therefore suggest that it might be beneficial to subdivide the current D’Amico high-risk patient group into the following two subgroups:
- A semi-high-risk group of patients that met only one of the three criteria listed above
- A very high-risk group of patients that met two or more of the three criteria listed above
When Kita et al. reclassified their own patients according to these criteria, they were able to show that men in the very high-risk group had prostate cancer recurrence at a significantly higher rate than those in the semi-high-risk group (p＝0. 021).
Now we do need to be careful about this recommendation. The number of men in the high-risk category in the study by Kita et al. is small (n = 50) and it does appear as though Kita et al. may have been including men with Gleason 7 disease as being at high risk (which does not, in fact, comply with the original D’Amico risk criteria). On top of that, the overall series of patients assessed by Kita et al. (n = 208) is small for an 8-year series.
However, there may be some possible benefit to this extension of the D’Amico classification. It would need to be re-examined in a much larger series of high-risk men from a more contemporary cohort of surgical patients (e.g., from 2000 to 2010, perhaps). The possibility is that one could show that men in the very high-risk subgroup were, de facto, going to need immediate adjuvant radiation therapy with hormone therapy after primary surgery … but this will take some time to explore.