जर्नल ऑफ़ क्लिनिकल एपिजेनेटिक्स खुला एक्सेस

अमूर्त

A Comparison of Post-treatment Quality of Life Outcomes for Endoluminal Brachytherapy and Chemoradiation for the Treatment of Localized Rectal Cancer

Azah A Althumairi

Keywords: Endoluminal brachytherapy (EBT); Neoadjuvant chemoradiation (CRT) Rectal cancer;
Quality of life (QOL); EORTC QLQ-C30; EORTC QLQ-CR29
Introduction
The current standard of care established in large randomized phase III trials for locally advanced distal
rectal cancer (stage II and III) is neoadjuvant chemoradiation (CRT) with 5-fluorouracil (5-FU) based
chemotherapy and external beam radiation with a total dose of 50.4 Gy delivered in 28 fractions over 5-6
weeks. Neoadjuvant treatment is then followed with total mesorectal excision (TME) by either a low
anterior resection (LAR) or abdominoperineal resection (APR) in 6 – 8 weeks [1]. This regimen has been
shown to be associated with tumor pathological complete response (pCR) rates of 8.0% – 19.0%, and
local recurrence (LR) rates and overall survival (OS) rates at 10 years of 6.0% – 11.7% and 50.7% –
68.0%, respectively [2-5]. However, this current approach is associated with significant risk of adverse
effects on short-term and long-term quality of life (QOL) [6]. In particular, strong associations with poor
social and emotional functioning, poor body image and sexuality, defecatory dysfunction, and pain have
been demonstrated following treatment for rectal cancer [7-9]. In an attempt to improve QOL by
decreasing treatment side effects, long term effects, and shortening the duration of therapy, investigators
at McGill University have investigated high dose rate endorectal brachytherapy (EBT) as a neoadjuvant
monotherapy for locally advanced rectal cancer [10]. This treatment consists of 4 fractions of 6.5 Gy
given over 4 consecutive days followed by surgery (TME) in 4 - 8 weeks [10]. With this technique, a
focused high dose of ionizing radiation is delivered to the tumor only, limiting the dose of radiation to
adjacent normal structures including small bowel, bladder, prostate and skin [10,11]. In the McGill series
of 47 patients, the pathologic CR rate was 32.0%, the 5 year LR rate was 5.0%, and the DFS was 65.0%
[10]. This neoadjuvant monotherapy delivered over short periods of time and resulting in high pCR rates
is a very attractive modality but little is known about the treatment related toxicity and its impact on
patient related QOL. At our institution, we performed the first prospective trial to examine the changes in
symptoms and QOL of rectal cancer patients undergoing EBT for locally advanced disease. Our
objectives were to assess post-treatment symptoms and QOL using validated questionnaires given prior
to, during and after EBT monotherapy and compare these results to the same QOL questionnaires that
were prospectively collected from rectal cancer patients treated with conventional CRT.