Prostate cancer is
treated with surgery, radiation, chemotherapy and hormonal therapy. Since
hormones like testosterone and dihydrotestosterone, which are chemically
androgens, promote the growth of prostate cancer, prostate cancer benefits from
androgen-deprivation therapy. Androgen deprivation can be brought about either
by surgical removal of the testes or medications like
. In due
course of the cancer, patients stop responding to androgen-deprivation
treatment and require other therapeutic options.
‘Abiraterone with prednisone may soon be used at an earlier stage of prostate cancer, when it is sensitive to androgen-deprivation therapy.’
Abiraterone
acetate
Abiraterone acetate is a drug that is
emerging as a possible vital addition to the androgen-deprivation therapy for
advanced prostate cancer. Abiraterone prevents the production of androgens in
the body, and is currently approved along with the corticosteroid prednisone
for patients with advanced prostate cancer, who do not respond to
androgen-deprivation therapy. Thus,
abiraterone
is currently being used only when the standard hormonal treatment fails.
The
Systemic Therapy in Advancing or Metastatic Prostate Cancer: Evaluation
of Drug Efficacy (STAMPEDE) is a large trial which evaluated the addition
of treatments for prostate cancer that has locally advanced or spread to
distant sites in patients who did not receive prior hormonal treatment. It has
come up with several important findings which, if introduced into clinical
practice, could possibly improve the survival of patients with advanced
prostate cancer.
The
STAMPEDE study compared the use of ADT plus abiraterone and prednisolone, to
the use of ADT alone for a period of two years or until disease progression. The study
included patients who had localized disease as well as those in whom the cancer
had spread, and who may have undergone surgery or radiotherapy. Fifty-two
percent patients had metastatic cancer, that is, cancer that had spread to
other sites of the body. Radiotherapy was administered along with hormonal
treatment as and if necessary. The researchers found that, with respect to the
group that received the standard treatment, the group taking abiraterone
experienced:
- An improvement in
overall survival by 37%
- An improvement in
the failure-free survival by 71%
- A reduction in
the symptomatic skeletal events by 55%
- More
cardiovascular and liver related-side effects, with 47% patients in the
abiraterone group and 33% patients in the standard treatment group
suffering serious adverse effects with grades 3 to 5
The
LATITUDE Trial, conducted in 34 countries, evaluated the effects of abiraterone
and prednisone along with ADT as opposed to ADT with placebos in the treatment
of newly diagnosed metastatic, hormone-sensitive prostate cancer, that is, in
cases where the patient did not receive
any earlier treatment. The
researchers found that as compared to the group administered only ADT, the
group taking abiraterone and prednisone along with ADT:
- Had an overall survival
of 66% at the end of 3 years while the comparison group registered an
overall survival of 49%
- Had a median
radiographic progression free-survival in patients of 33 months, as
compared to 14.8 months in the control group
- Showed slower
progression of other parameters assessed, like pain and next symptomatic
skeletal event, and the need for chemotherapy and subsequent prostate
cancer therapy
- More commonly
caused side effects of high blood pressure, low blood potassium levels and
increase in liver enzymes
Thus,
the earlier use of abiraterone, along with androgen-deprivation therapy,
instead of after it, if approved, could benefit hundreds of men with advanced
prostate cancer.
References :- James ND et al. Abiraterone for Prostate Cancer Not Previously Treated with
Hormone Therapy. NEJM; DOI: 10.1056/NEJMoa1702900
- Fizazi K et al. Abiraterone plus Prednisone in Metastatic, Castration-Sensitive Prostate Cancer. NEJM; DOI: 10.1056/NEJMoa1704174
Source: Medindia
