Long term toxicity of WPRT for endometrial cancer (results of PORTEC 1)

In the JCO

Long term toxicity data for the PORTEC 1 trial sees manuscript publication (previously presented at ASTRO 2 years ag0). Worth a read, as the investigators find significant long term toxicity from WPRT. These results should be taken with some caveats however, as the surveys were sent out after the fact (only 351 surveys were sent out, of 714 in the full trial, and there was a 70% responsed rate for those 351). This raises the question of recall and selection bias. One can easily speculate that the patients continuing in followup were those that had complications. Additionally, one could also speculate that one is more likely to answer a QOL survey if one has significant symptoms.

That said, this should give the practicing radiation oncologist pause when recommending WPRT if there are alternatives (VBT) or a low risk of recurrence even in the absence of adjuvant therapy.

Link and Abstract:

Long-Term Outcome and Quality of Life of Patients With Endometrial Carcinoma Treated With or Without Pelvic Radiotherapy in the Post Operative Radiation Therapy in Endometrial Carcinoma 1 (PORTEC-1) Trial [Gynecologic Cancer]: "Purpose

To determine the long-term outcome and health-related quality of life (HRQL) of patients with endometrial carcinoma (EC) treated with or without pelvic radiotherapy in the Post Operative Radiation Therapy in Endometrial Carcinoma 1 (PORTEC-1) trial.

Patients and Methods

Between 1990 and 1997, 714 patients with stage IC grade 1 to 2 or IB grade 2 to 3 EC were randomly allocated to pelvic external-beam radiotherapy (EBRT) or no additional treatment (NAT). HRQL was evaluated with the Short Form 36-Item (SF-36) questionnaire; subscales from the European Organisation for Research and Treatment of Cancer (EORTC) PR25 module for bowel and bladder symptoms and the OV28 and CX24 modules for sexual symptoms; and demographic questions. Analysis was by intention-to-treat.

Results

Median follow-up was 13.3 years. The 15-year actuarial locoregional recurrence rates were 5.8% for EBRT versus 15.5% for NAT (P < .001), and 15-year overall survival was 52% versus 60% (P = .14). Of the 351 patients confirmed to be alive with correct address, 246 (70%) returned the questionnaire. Patients treated with EBRT reported significant (P < .01) and clinically relevant higher rates of urinary incontinence, diarrhea, and fecal leakage leading to more limitations in daily activities. Increased symptoms were reflected by the frequent use of incontinence materials after EBRT (day and night use, 42.9% v 15.2% for NAT; P < .001). Patients treated with EBRT reported lower scores on the SF-36 scales "physical functioning" (P = .004) and 'role-physical' (P = .003).

Conclusion

EBRT for endometrial cancer is associated with long-term urinary and bowel symptoms and lower physical and role-physical functioning, even 15 years after treatment. Despite its efficacy in reducing locoregional recurrence, EBRT should be avoided in patients with low- and intermediate-risk EC.

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