Abstract
Azah A Althumairi
Abstract
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.