Sequential short-course radiation therapy and chemotherapy in the neoadjuvant treatment of rectal adenocarcinoma

• Published in: Radiation oncology (London, England) Vol. 14; no. 1; p. 147
• Main Authors: Jia, Angela Y, Narang, Amol, Safar, Bashar, Zaheer, Atif, Murphy, Adrian, Azad, Nilofer S, Gearhart, Susan, Fang, Sandy, Efron, Jonathan, Warczynski, Tam, Hacker-Prietz, Amy, Meyer, Jeffrey
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 19.08.2019; BioMed Central; BMC
• Subjects: Adenocarcinoma; Adenocarcinoma - pathology; Adenocarcinoma - therapy; Adjuvant chemotherapy; Adult; Aged; Analysis; Antineoplastic Combined Chemotherapy Protocols - therapeutic use; Cancer treatment; Capecitabine - administration & dosage; Care and treatment; Chemoradiotherapy, Adjuvant - methods; Chemotherapy; Colorectal cancer; Female; Fluorouracil - administration & dosage; Gastrointestinal diseases; Humans; Leucovorin - administration & dosage; Male; Middle Aged; Neoadjuvant Therapy - methods; Neoplasm Recurrence, Local - pathology; Neoplasm Recurrence, Local - therapy; Oxaliplatin - administration & dosage; Proctitis; Radiation (Physics); Radiotherapy; Rectal cancer; Rectal Neoplasms - pathology; Rectal Neoplasms - therapy; Retrospective Studies; Short-course chemoradiotherapy; Surgery; Toxicity; Treatment Outcome; Tumors; Watch and wait; Short-course chemoradiotherapy; Rectal cancer; Watch and wait
• ISSN: 1748-717X; 1748-717X
• DOI: 10.1186/s13014-019-1358-1

There is continued debate regarding the optimal combinations of radiation therapy and chemotherapy in the preoperative treatment of locally advanced rectal adenocarcinomas. We report our single-institution experience of feasibility and early oncologic outcomes of short-course preoperative radiation therapy (5 Gy X 5 fractions) followed by consolidation neoadjuvant chemotherapy. We reviewed the records of 26 patients with locally advanced rectal adenocarcinoma. All patients underwent short course radiotherapy (5 Gy X 5 fractions) followed by chemotherapy [either modified infusional and bolus 5-fluorouracail and oxalipatin (mFOLFOX6) or capecitabine and oxaliplatin] prior to consideration for surgery. A full course of chemotherapy was defined as at least 8 weeks of chemotherapy. There were five clinical (c) T2, 16 cT3, and five cT4 rectal tumors, with 88% cN+. Twenty-five patients received a median of 4 cycles (range 3 to 8) of mFOLFOX6 (with one cycle defined as a two-week period); one patient received 3 cycles of capecitabine and oxaliplatin. All patients completed SCRT; 81% completed the full course of neoadjuvant chemotherapy with 19% requiring dose reductions in chemotherapy, most commonly due to neuropathy. Nineteen patients underwent post-treatment endoscopic evaluation, and nine patients were noted to achieve a complete clinical response (CCR). Six of the nine patients who achieved CCR opted for a non-operative approach of watch-and-wait. Twenty patients underwent surgical resection; pathologic complete response was observed in seven (35%) of these twenty. The main radiation-associated toxicity was proctitis with CTCAE Grade 2 proctitis observed in seven patients (27%). Post-operative Clavien-Dindo Grade 3 complications within 30 days of surgery were identified in six patients (30%), with no Grade 4 or 5 adverse events. Median length of hospital stay was 4.5 days (range 2-16 days); three patients were readmitted within a 30 day period. Short course preoperative radiotherapy followed by neoadjuvant chemotherapy was well-tolerated and achieved oncologic outcomes that compare favorably with short-course radiation therapy alone or long-course chemoradiotherapy. This regimen is associated with high rates of clinical and pathologic complete response.