J Cancer 2017; 8(16):3114-3121. doi:10.7150/jca.21237

Research Paper

A phase II trial of preoperative concurrent chemotherapy and dose escalated intensity modulated radiotherapy (IMRT) for locally advanced rectal cancer

Jeremy Tey1✉, Cheng Nang Leong1, Wai Kit Cheong3, Tay Guan Sze4, Wei Peng Yong2, Ivan Weng Keong Tham1, Khai Mun Lee5

1. Department of Radiation Oncology, National University Cancer Institute, Singapore;
2. Department of Medical Oncology, National University Cancer Institute, Singapore;
3. Department of Colorectal Surgery, National University Hospital, Singapore;
4. Department of Colorectal Surgery, Tan Tock Seng Hospital, Singapore;
5. Department of Radiation Oncology, Farrer Park Hospital, Singapore.

Abstract

Objectives: To determine the pathological response rates and toxicity and in patients with locally advanced rectal cancer treated with concurrent capecitabine and dose escalated intensity modulated radiotherapy (IMRT)

Methods: Patients with stage II or III adenocarcinoma of the rectum were treated with preoperative concurrent capecitabine and IMRT. Dose of capecitabine was 825mg/m2, 5 days a week for 5 weeks. IMRT was used to deliver a dose of 45Gy in 25 fractions (1.8Gy per fraction daily, 5 days a week over 5 weeks) to the regional lymphatics and areas at risk of harbouring microscopic disease. A concomitant synchronous integrated boost (SIB) to the gross tumour with a margin to a total dose of 55Gy in 25 fractions was also delivered in the same period. TME surgery was performed 8 weeks after preoperative therapy. The primary endpoint is pathological complete response rate (pCR) and the secondary endpoint was downstaging rates, Sphincter preservation rates (SPR), disease free survival (DFS) at 2 years and toxicity graded using the CTCAE v3.0.

Results: Twenty three patients were enrolled. Three were not evaluable; one did not complete treatment due to logistic issues and two declined surgery. The remaining 20 patients completed preoperative chemoIMRT followed by TME surgery.

At a median follow-up of 38.2 months (17.5-53.2 months), 90% (18 of 20) patients were alive. The 2 year overall survival and DFS were 90% and 90% respectively. 35%(7/20) of patients had a pCR. 65% (13 of 20) patients had successful downstaging of their rectal tumours. There was no local recurrence. Sphincter preservation rate was 85%. Treatment was well tolerated with only one patient (5%) having Grade 3 radiation proctitis.

Conclusions: Preoperative concurrent capecitabine and dose escalated IMRT is well tolerated and results in high rates of pCR. A randomized trial comparing this regimen with standard 3D conformal chemoradiotherapy is warranted.

Keywords: rectal Cancer, IMRT, preoperative, chemoradiotherapy, capecitabine

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How to cite this article:
Tey J, Leong CN, Cheong WK, Sze TG, Yong WP, Tham IWK, Lee KM. A phase II trial of preoperative concurrent chemotherapy and dose escalated intensity modulated radiotherapy (IMRT) for locally advanced rectal cancer. J Cancer 2017; 8(16):3114-3121. doi:10.7150/jca.21237. Available from http://www.jcancer.org/v08p3114.htm