Healthcare (Commonwealth Union) – Men undergoing radiation therapy for prostate cancer who experience early side effects may be at an increased risk of developing long-term urinary and bowel complications, according to a new study by researchers at UCLA Health Jonsson Comprehensive Cancer Center.
The study revealed that patients who had moderate urinary side effects within the first three months of treatment were nearly twice as likely to face chronic urinary issues in later years compared to those without early symptoms. Likewise, those who experienced bowel-related side effects early on had nearly double the risk of long-term bowel complications.
Published in The Lancet Oncology, the findings underscore the need for improved management of acute toxicities to enhance long-term outcomes and quality of life for patients.
Dr. Amar Kishan, who is executive vice chair of radiation oncology at the David Geffen School of Medicine at UCLA and senior author of the study indicated that with prostate cancer patients living longer than ever, their goal is to minimize late toxicities—such as urinary difficulties or rectal bleeding—that can affect quality of life for years.
Dr. Kishan further indicated that this research highlights innovations like using smaller treatment margins in prostate radiation to lower early side effects, which can lead to lasting benefits by bringing down the risk of long-term complications.
Prostate cancer is the most frequently diagnosed cancer in men, with radiation therapy being a primary treatment for localized cases. Higher radiation doses are often used to improve cancer control, but this approach can also damage surrounding healthy tissues, leading to both short-term and long-term side effects.
Researchers of the study indicated that short-term, or acute, side effects emerge during treatment or within the first three months after it concludes and are usually temporary. Common urinary symptoms include increased urgency, difficulty urinating, and discomfort, while bowel-related effects may involve diarrhea, softer stools, or rectal irritation.
Long-term, or late, side effects can develop months or even years later and may persist indefinitely. Urinary complications may include urethral narrowing and blood in the urine, while bowel issues can involve rectal bleeding or ulcer formation in the rectal wall. These chronic effects often have a greater impact on a patient’s quality of life than acute symptoms.
Although both types of toxicities result from radiation exposure to healthy tissues, the relationship between early and late side effects has not been extensively studied, particularly in large-scale research.
To gain deeper insight into this connection, the researchers examined data from more than 6,500 patients across six randomized phase 3 clinical trials. These studies provided comprehensive, individual-level information on both short-term and long-term urinary and bowel side effects.
Their analysis revealed that patients who experienced moderate or more severe early side effects were at a higher risk of developing serious late complications, even years later following the treatment. Men who had early urinary or bowel problems were also more likely to face significant declines in their ability to perform daily tasks and maintain their overall quality of life.
Regarding urinary toxicity, those who developed acute symptoms saw their likelihood of late toxicity rise from 7.5 percent to 12.5 percent. Similarly, for bowel toxicity, the incidence of late toxicity increased from 12.7 percent to 22.5 percent among those who experienced acute effects.
Men with moderate acute urinary toxicity were 1.4 times more likely to suffer a meaningful decline in urinary quality of life, while those with moderate acute bowel toxicity faced 1.5 times higher odds of experiencing a substantial drop in bowel-related quality of life.
“These results show that acute toxicities following prostate radiotherapy are associated with late toxicities months and years later,” explained Dr. John Nikitas, who is a resident in the department of radiation oncology at UCLA Health, and first author of the study. “This underscores the importance of measures that reduce the risk of acute toxicities because they may also potentially improve long-term outcomes and quality of life for patients.”
