5-year survival of high-risk patients after EBRT + brachytherapy

Long-term data on survival of high-risk patients after treatment with a combination of external beam radiation therapy (EBRT) and brachytherapy (radioactive seed implantation), with or without neoadjuvant and adjuvant androgen deprivation therapy (ADT), are not well established as yet.

A new paper by a Japanese clinical research team, just published in the journal Radiation Oncology, has provided us with some helpful data in this area. Both the provisional abstract and the provisional full text of the article are available on line.

Between 2003 and 2009, Ohashi et al. treated a total of 206 patients with high-risk prostate cancer with a combination of 125I (iodine-125) permanent prostate brachytherapy and EBRT. About half of their patients also received neoadjuvant ADT but none of them received adjuvant (follow-up) ADT after completion of the radiation therapy. Patients were defined as being high-risk if they met any one of the following criteria: PSA level > 20 ng/ml; a Gleason score of 8 to 10; and/or clinical stage T3 or higher. The authors defined biochemical failure according to the standard Phoenix criteria: a rise in the PSA post-treatment from the lowest (nadir level) to the nadir level + 2 ng/ml.

Here are the basic results reported in their paper:

  • Average (median) follow-up was 60 months (5 years).
  • 8/206 patients (3.9 percent) died during the follow-up period; 2/206 patients (1.0 percent) died of prostate cancer.
    • The 5-year overall survival rate was 97.6 percent.
    • The 5-year prostate cancer-specific survival rate was 98.7 percent.
  • 30/206 patients (14.6 percent) had biochemical failure during the follow-up period.
    • The median time to biochemical failure among these 30 patients was 37.2 months.
    • The 5-year, actuarial rate of biochemical progression-free survival (bPFS) was 84.8 percent.
    • Among men with less than half their biopsy cores positive for cancer, the bPFS was 89.3 percent.
    • Among men with half or more than half their biopsy cores positive for prostate cancer, the bPFS was 78.2 percent.
    • For men with only one of the three risk factors for high-risk disease, the bPFS was 86.1 percent.
    • For men with two or three of the three risk factors for high-risk disease, the bPFS was 73.6 percent.
    • The use of neoadjuvant ADT had no evident impact on 5-year, actuarial bPFS.
  • With respect to side effects associated with treatment
    • 12/206 patients (5.8 percent) experienced acute grade 2 gastrointestinal (GI) toxicity
    • 20/206 patients (14.6 percent) experienced acute grade 2 genitourinary (GU) toxicity.
    • 18/206 patients (8.8 percent) experienced late grade 2 GI toxicity (primarily rectal bleeding).
    • 21/206 patients (10.2 percent experienced late GU toxicity (primarily urinary urgency or retention).
    • No patients experienced Grade 3 or Grade 4 acute or late toxicity.

These data appear to indicate that the combination of 125I-based brachytherapy with EBRT is an effective treatment, at least in men with only one risk factor for high-risk disease, over a median 5-year follow-up period. Data on 10-year follow-up would clearly be more compelling, of course.

4 Responses

  1. I presume 30/206 patients reported Grade 2 GU toxicity, not 20? (14.6% is more difficult to mis-transcribe. 20/206 is about 9.7%)

  2. Only anecdotal, I know, but I had brachytherapy and radiation, followed by ADT in 2001. I am still here to tell the tale, although my PSA is now 1,400 … after last 2 years on chemotherapy (docetaxel, abiraterone, enzalutamide, EcarboF [epirubicin + carboplatin + 5-fluorouracil], and most recently cabazitaxel).

    None of the wonder drugs did me any good at all, and PSA/tumours have continued to develop in liver, bladder, and now bones. Just hoping cabazitaxel may work; failing that, does anyone have any experience of radium-223 (Xofigo)?

  3. Dear Chedley:

    These are the precise numbers reported in the paper. I can only report what the paper reports.

    It is possible that you are correct about there being 30 patients with acute GU toxicity as opposed to 20, and that there is a typo in the paper. The alternative is that it is the 14.5% that is incorrect and it was only 10 patients (although that seems less likely to me).

  4. Dear Sitemaster:

    I have some high risk values and shall do my best to comment on this later. I do not know if my comments will be relevant, as I have had high dose rate (HDR) brachytherapy, not implantation. All I can say right now, is that at (I think) nearly 3 years after treatment, the results are very, very good (except perhaps for that Oxford Comma, in this sentence).

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