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ASTRO 2016: Cervical and Endometrial Cancer Patients Report Fewer Side Effects and Better Quality of Life With IMRT

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Key Points

  • Patients in the intensity-modulated radiation therapy (IMRT) arm experienced significantly fewer bowel-related toxicities than patients who received standard radiation therapy did, as indicated by smaller average declines in their EPIC bowel domain scores. Analysis of subscales within the EPIC determined that IMRT patients experienced less severe declines in bowel function, but not bowel bother.
  • IMRT patients also experienced fewer high-level adverse events following treatment, including less diarrhea and fecal incontinence. Moreover, roughly one in five women in the standard radiation therapy group (20.4%) reported taking four or more antidiarrheal medications daily, compared to 7.8% of women in the IMRT group.
  • Urinary side effects at 5 weeks from treatment start were less prevalent among patients who received IMRT, as indicated by significantly smaller declines in average EPIC urinary domain scores for the IMRT arm.

Patients with cervical and endometrial cancer have fewer gastrointestinal and genitourinary side effects and experience better quality of life when treated with intensity-modulated radiation therapy (IMRT) than with conventional radiation therapy, according to research presented by Klopp et al at the 58th Annual Meeting of the American Society for Radiation Oncology (ASTRO). Women receiving IMRT reported significantly fewer bowel and bladder problems than those receiving conventional radiation treatment.

Many women diagnosed with cervical or endometrial cancer receive radiation therapy following surgery to remove their tumors, but questions remain as to which form of pelvic radiation therapy delivery can most effectively eliminate the tumor while minimizing the impact of radiation on surrounding healthy tissue.

This multicenter, international study assessed this impact by evaluating patient-reported acute toxicities in the gastrointestinal and genitourinary systems following IMRT, an advanced form of external beam radiation therapy that delivers precise radiation doses highly tailored to patients’ individual tumors, vs standard four-field radiation therapy.

“The way that radiation therapy is performed has a major impact on the risk of side effects from treatment,” said Ann H. Klopp, MD, PhD, lead author of the study and Associate Professor in the Department of Radiation Oncology at the University of Texas MD Anderson Cancer Center. “We know that IMRT reduces the amount of normal tissue irradiated, so we suspected that it would have fewer side effects. This was one of the first studies, however, to rigorously ask this question using patient questionnaires to ensure that the lower doses resulted in meaningful differences in patients’ experiences during treatment.”

Study Details

A total of 278 patients with cervical or endometrial cancer who received pelvic radiation therapy postoperatively at cancer centers in the U.S., Canada, Japan, and Korea were evaluated to determine if pelvic IMRT for cervical and endometrial cancer resulted in fewer patient-reported gastrointestinal and genitourinary side effects and improved patients’ quality of life. Patients were stratified based upon radiation dose (45 Gy or 50.4 Gy); use of chemotherapy (no chemotherapy or five cycles of weekly cisplatin at 40 mg/m2); and disease site. The patients were then randomly assigned to receive standard radiation therapy or IMRT.

Acute gastrointestinal and genitourinary toxicities and quality of life were measured via multiple patient questionnaires. Instruments included the Expanded Prostate Cancer Index Composite (EPIC) to measure bowel and urinary toxicities; the Patient-Reported Outcomes version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) to assess gastrointestinal- and genitourinary-related adverse events (eg, diarrhea); and the Functional Assessment of Cancer Therapy–General with cervix subscale (FACT-Cx) to track health-related quality of life. Researchers compared changes in average scores on these instruments from baseline to 5 weeks following RT start using two-way t-tests.

Study Findings

Patients in the IMRT arm experienced significantly fewer bowel-related toxicities than patients who received standard radiation therapy did, as indicated by smaller average declines in their EPIC bowel domain scores (-18.6 vs -23.6, P = .048). Analysis of subscales within the EPIC determined that IMRT patients experienced less severe declines in bowel function, but not bowel bother.

IMRT patients also experienced fewer high-level adverse events following treatment, including less diarrhea (frequency: 33.7 vs 51.9%, P = .01) and fecal incontinence (frequency: 1.1 vs 9.3, P = .01). Moreover, roughly one in five women in the standard radiation therapy group (20.4%) reported taking four or more antidiarrheal medications daily, compared to 7.8% of women in the IMRT group (P = .04).

Urinary side effects at 5 weeks from treatment start were less prevalent among patients who received IMRT, as indicated by significantly smaller declines in average EPIC urinary domain scores for the IMRT arm (-5.6 vs -10.4, P = .03).

Furthermore, IMRT regime negatively impacted patients’ quality of life less substantially than the conventional radiation therapy regime did. FACT-Cx trial outcome index scores demonstrated less decline in health-related quality of life following IMRT compared to standard RT (-8.8 vs -12.8, P = .06). Patients treated with IMRT had less change in physical well-being (-4.2 vs -6.1, P = .03) and addition concerns (-2.7 vs -4.9, P = .01).

“Many radiation oncologists already use IMRT for women undergoing pelvic radiation, but this research provides data that using IMRT, which is a more resource-intensive treatment, makes a real difference to patients receiving radiation therapy to the pelvic area,” said Dr. Klopp. “When performed by an experienced radiation oncology team, IMRT reduces the risk of short-term bowel and bladder side effects for patients with endometrial and cervical cancer.”

The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.


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