UCLA Journal of Radiation Oncology_SS 2025_FOR PRINT - Flipbook - Page 26
UCLA RADIATION ONCOLOGY JOURNAL
STUDY LED BY DR. AMAR KISHAN ESTABLISHES
the link between early side effects from prostate cancer
radiation and long-term side effects
Men undergoing radiation therapy for prostate cancer
causing acute and late-term side e昀昀ects.
who experience side e昀昀ects early in treatment may face
Acute toxicity refers to side e昀昀ects that occur during
a higher risk of developing more serious long-term
treatment or within the 昀椀rst three months after it ends,
and they are typically temporary. Common urinary side
urinary and bowel health issues, according to a new study
e昀昀ects include increased frequency of urination, di昀케culty
led by investigators from the UCLA Health Jonsson
urinating and discomfort during urination. Bowel-related
Comprehensive Cancer Center.
side e昀昀ects may include softer stools or diarrhea, as well as
The study found that patients who experienced moderate
rectal discomfort during bowel movements.
acute urinary side e昀昀ects in the 昀椀rst three months after
Late toxicity, on the other hand, can appear months or even
years later and can last for years. Late urinary toxicities
include narrowing of the urethra and having blood in the
radiation were nearly twice as likely to develop late urinary
complications years later compared to those without early
urine. Late bowel toxicities include having blood in the
symptoms. Similarly, patients with early bowel side e昀昀ects
stool or having an ulcer in the wall of the rectum. These
had nearly double the risk of chronic bowel issues.
issues often can have a bigger impact on a person’s quality
of life compared to acute side e昀昀ects.
The 昀椀ndings, published in the Lancet Oncology, highlight
the importance of developing strategies to better manage
acute toxicities to help improve long-term outcomes and
quality of life for patients.
While both acute and late toxicities are caused by
radiation’s e昀昀ect on healthy tissues, the connection between
"Men with prostate cancer are living longer than ever,
scale data.
the two hasn’t been well-studied, particularly using large-
and our goal is to reduce the risk of late toxicities, such as
To better understand this relationship, the researchers
di昀케culty urinating or rectal bleeding, that can impact a
analyzed data from over 6,500 patients from six randomized
patient’s quality of life for years," said Dr. Amar Kishan,
phase 3 clinical trials that shared detailed, individual-level
Executive Vice Chair of Radiation Oncology at the David
data on short-term and long-term side e昀昀ects a昀昀ecting the
Ge昀昀en School of Medicine at UCLA and senior author
urinary and bowel systems.
of the study. “This study highlights innovations we’re
The researchers found patients with moderate or worse
developing, such as using smaller treatment margins in
early side e昀昀ects were more likely to experience severe late
prostate radiation to minimize early side e昀昀ects, that can
e昀昀ects, even years after treatment. Men with early urinary
lead to lasting bene昀椀ts by also reducing the risk of long-
or bowel issues were also more likely to report signi昀椀cant
term complications for patients.”
drops in their ability to manage daily activities and overall
Prostate cancer is the most common cancer among men,
quality of life.
with radiation therapy often serving as a key treatment for
For urinary toxicity, experiencing acute toxicity increased
localized prostate cancer, often involving higher doses to
the rate of late toxicity from 7.5% to 12.5%, and for bowel
better control the disease. While this approach e昀昀ectively
toxicity, experiencing acute toxicity increased the
controls cancer, it can also harm nearby healthy tissues,
26
