THE "NEW" PROSTATE CANCER INFOLINK

We now have data from an eighth randomized clinical trial of hypofractionated radiation therapy. There are no surprises: it showed that oncological and toxicity outcomes were not significantly different between the two regimens. We last looked at it here. This trial is unusual because of the long length of follow-up.

Arcangeli et al. reported the 10-year outcomes of their study covering 168 high-risk patients treated using 3D-CRT (not IMRT) at the Regina Elena Cancer Institute in Rome between 2003 and 2007. The details of the treatments were as follows:

• Half (85 patients) received conventionally fractionated (Conv) 80 Gy in 40 fractions
• Half (83 patients) received hypofractionated (Hypo) 62 Gy in 20 fractions

After a median of 9 years of follow-up:

• 10-year freedom from biochemical failure was 72 percent for the Hypo group vs. 65 percent for the Conv group.(no statistically significant difference)
• 10-year prostate cancer -specific survival was 95 percent for the Hypo group vs. 88 percent for the Conv group (no statistically significant difference)
• 10-year overall survival was 75 percent for the Hypo group vs. 64 percent for the Conv group (no statistically significant difference)
• Hypofractionation was a significant variable in determining prostate cancer-specific survival in multivariate analysis
• There were no differences in late-term grade 2 or higher urinary or rectal toxicity between the 2 groups.

There are a couple of caveats. For those who insist on rigorous analysis, the Hypo group had worse oncological and toxicity outcomes on an intention-to-treat basis. It was only after the patients were analyzed according to the treatment they actually received that the lack of statistically significant difference became apparent. James Yu, in an accompanying editorial, points out that blood in urine was 16.5 percent for the Hypo group vs. 3.6 percent for the Conv group. This may be a caution that hypofractionation should not be attempted using 3D-CRT. In the US, where IMRT is widely available, this should not be an issue.

Here’s the table summarizing all eight randomized clinical trials:

References: 1. The PROFIT trial (Catton et al.). 2. The Fox Chase trial (Pollack et al.). 3. The CHHiP trial (Dearnaley et al.). 4. The M. D. Anderson trial (Hoffmann et al.). 5. The RTOG 0415 trial (Lee et al.). 6. The HYPRO trial (Incrocci et al.). 7. The HYPRO trial (Aluwini et al.). 8. The Cleveland Clinic trial (Kupelian et al.). 9. The Regina Elena trial (Arcangeli et al.).

Editorial note: This commentary was written by Allen Edel for The “New” Prostate Cancer InfoLink.

Filed under: Diagnosis, Management, Risk, Treatment | Tagged: hypofractionation, outcomes, radiation |