UCLA Journal of Radiation Oncology January 1, 2022 - Flipbook - Page 35
UCLA RADIATION ONCOLOGY JOURNAL
International Meta-Analysis
Quantifies Impact of Three
Prostate Cancer Therapy
Intensification Strategies
Individual patient data analysis from
the Meta-Analysis of Randomized Trials
in Cancer of the Prostate (MARCAP)
Consortium may be the strongest evidence
to date on androgen deprivation therapy use
and duration
FINDINGS
An individual patient data (IPD) metaanalysis of randomized, controlled clinical
trials provides strong evidence for the
addition of androgen deprivation therapy
(ADT) to definitive radiotherapy (RT) for
the treatment of prostate cancer, with the
projection that adding ADT to the treatment
of 10-15 men would prevent the development
of distant metastasis in one man. Similarly,
if ADT has been added, prolonging the
portion of it that follows the radiation (called
“adjuvant ADT”) to 18-36 months provides
a similar benefit in terms of preventing
metastatic disease. The benefits of adding
ADT and of prolonging adjuvant ADT were
identified regardless of patient age, RT dose
(high vs. low), or prostate cancer risk group
(high vs. intermediate risk). In contrast,
prolongation of ADT that begins before
radiation (called “neoadjuvant ADT”) beyond
two to three months did not improve any
cancer outcome, according to the study,
prompting researchers to conclude that the
latter treatment should not routinely be
employed.
The analysis was conducted through the
MARCAP Consortium, a group formed in
2020 to serve as a data repository from
international trial groups. The MARCAP
consortium was co-founded by Dr. Amar
Kishan, associate professor and vice chair
of clinical and translational research in
the department of Radiation Oncology
at UCLA and researcher at the UCLA
Jonsson Comprehensive Cancer Center,
and Dr. Daniel Spratt, the chairman of
the Department of Radiation Oncology at
University Hospitals Seidman Cancer Center.
The MARCAP consortium has data from
multiple trials across the world and is the
first consortium group of its kind for prostate
cancer. Kishan will be presenting the results
at ASTRO 2021, the annual meeting of the
American Society for Radiation Oncology.
“Individual patient data meta-analyses
provide the highest levels of evidence
in oncology, allowing us to quantify
treatment effects,” said Kishan, Chief of
the Genitourinary Oncology Service for the
Department of Radiation Oncology at the
David Geffen School of Medicine at UCLA
and the UCLA Jonsson Comprehensive
Cancer Center. “The approach has been used
to assess therapies in breast cancer and head
and neck cancers, but this is the first such
effort for prostate cancer.”
According to Spratt, "MARCAP represents
the first international collaboration of all
radiotherapy clinical trial groups to assess
the true impact of the many treatment
strategies we have to offer in prostate cancer.
The results from MARCAP will be practicechanging and benefit patients around the
world."
Prostate cancer is the most common cancer
in men other than skin cancer, and it’s the
second-leading cause of cancer death in
men, according to the American Cancer
Society. Each year, about 248,000 new cases
are diagnosed, but most men diagnosed with
the disease survive.
BACKGROUND
Because the male hormone testosterone
is a known contributor to prostate cancer
development, androgen deprivation is a
strategy often considered among treatment
options – especially for patients at high risk
of recurrence and/or metastasis – as an
adjunct to radiation therapy (RT). ADT can be
given for short courses of four to six months
or long courses of 18-36 months. Since the
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