BARCELONA – Vaginal brachytherapy for high-intermediate risk endometrial cancer is associated with significantly less diarrhea and fewer bowel symptoms that limit patients’ daily activities, compared with pelvic external beam radiation therapy, according to 5-year follow-up data from a phase III trial.
Dr. Remi A. Nout
The latest findings from the open-label, randomized PORTEC-2 (Postoperative Radiation Therapy for Endometrial Carcinoma–2) trial also show that, compared with standard pelvic radiotherapy, vaginal brachytherapy results in better overall social functioning and does not significantly affect sexual activity.
These data further support vaginal brachytherapy as the preferred form of adjuvant radiotherapy for high-intermediate risk endometrial cancer, said Dr. Remi A. Nout, a radiation oncologist at Leiden (the Netherlands) University Medical Center. He presented the updated quality of life findings Sept. 15th at the biennial meeting of the European Society for Therapeutic Radiation and Oncology (ESTRO 29).
“From the first PORTEC trial [Lancet 2000;355:1404-11], we learned that high-intermediate risk patients showed the largest benefit in terms of locoregional control” from the addition of EBRT after surgery, Dr. Nout explained. “The locoregional recurrence risk dropped from approximately 20% in the nonirradiated group to 5% in the patients who received external beam radiotherapy, and the major decrease was seen in vaginal recurrences which accounted for approximately 75% of the locoregional recurrences.”
The use of postoperative EBRT was associated with increased treatment morbidity, however, and the aim of PORTEC-2 was to determine whether vaginal brachytherapy could achieve similarly good efficacy results, but with less overall toxicity, and perhaps beneficial effects on quality of life. The primary outcome data of the trial were reported recently, and showed similar rates of vaginal recurrence (1.8% with EBRT vs. 1.6% with brachytherapy), locoregional relapse (2.1% vs. 5.1%, respectively), and overall survival (79.6% vs. 84.8%, respectively) at a median follow-up of 3.75 years (Lancet 2010;375:816-23).
Quality of life during the trial was assessed before and after radiotherapy, and then every 6 months for the first 2 years and thereafter annually until 5 years’ follow-up had been achieved. Several instruments were used to assess both cancer-specific and symptom-related quality of life. Of the 427 women in the PORTEC-2 trial, 349 completed the quality of life questionnaires, giving an overall initial response rate of 82%.
The 2-year quality of life findings from the study have been previously reported (J. Clin. Oncol. 2009;27:3547-56), and Dr. Nout presented an updated quality of life analysis after a median follow-up of 4.4 years. The results showed significantly higher rates of diarrhea following EBRT than vaginal brachytherapy at all assessment points (P less than .001). The greatest difference in EORTC QLQ-C30 (European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire C330) diarrhea scores occurred after radiotherapy. Diarrhea scores following vaginal brachytherapy were comparable with those from the age-matched Dutch general population, whereas those for EBRT were substantially worse.
“In addition to this increased rate of diarrhea, we also saw an increased rate of fecal leakage and a need to remain close to the toilet” in the EBRT vs. the brachytherapy groups, Dr. Nout observed. He added, “If we look at the limitation in daily activities due to bowel problems, we can also see a clear increase which persists over time until 5 years, which is highly significant [P less than .001] in favor of brachytherapy.”
Social functioning scores were lowest at baseline and rose after both EBRT and brachytherapy, although scores were significantly higher (P less than .001) in women who underwent brachytherapy, and were again in line with the age-matched general population data.
With regard to sexual activity, there was no difference between the two types of radiotherapy, and an overall increase from baseline values. The sexual activity decreased over time, which reflected changes in sexual activity of the age-matched general population.
Considering these long-term quality of life data together with the prior efficacy findings, “vaginal brachytherapy is the adjuvant treatment of choice for women with high-intermediate risk endometrial carcinoma,” Dr. Nout said.
A grant from the Dutch Cancer Society supported PORTEC-2 trial. Dr. Nout had no conflicts of interest.