Analysis of bevacizumab-based preoperative radiochemotherapy in patients with locally advanced rectal cancer on surgery-associated spectrum of complications

Adding Adjuvants to Fluoropyrimidine-based Neoadjuvant Chemoradiotherapy for Locally Advanced Rectal Cancer: An Option Worthy of Serious Consideration

The application of fluoropyrimidine-based neoadjuvant chemoradiotherapy (Fu-nCRT) of locally advanced rectal cancer (LARC) has become a common therapeutic regimen. In order to improve the efficacy and enable more patients to benefit from this treatment, an accumulation of studies have been carried out on the auxiliary use of other drugs with Fu-nCRT. However, due to specific challenges and the potential opportunities that coexist in this field, a more reasonable approach to the mode of treatment remains to be explored. In this review, we have summarized the results of the studies on the combination of Fu-nCRT with cytotoxic drugs, anti-tumor angiogenesis, and anti-EGFR agents, as well as the status of the application of immune checkpoint inhibitors in the neoadjuvant therapy of LARC patients.

Neoadjuvant radiotherapy in rectal cancer

SUMMARY 

In the treatment of rectal cancer, neoadjuvant (chemo)radiotherapy is used to decrease the locoregional recurrence risk. The most common treatment consists of neoadjuvant radiotherapy to a dose of 45–50 Gy, combined with 5-fluorouracil or capecitabine-based chemotherapy. In parts of Europe, a short-course radiotherapy schedule of 5 × 5 Gy in 1 week is practiced for patients in whom no downstaging is required to achieve a radical resection. With the increased interest in organ preserving strategies, indications for chemoradiotherapy are changing and the focus has changed from achieving radical resections toward maximal downstaging. In this review, indications for and types of neoadjuvant treatment in rectal cancer are discussed, as well as new aspects related to organ preservation.

Neoadjuvant capecitabine, bevacizumab and radiotherapy for locally advanced rectal cancer: results of a single-institute Phase I study

The aim of this Phase I clinical trial was to assess the feasibility and safety of capecitabine-based preoperative chemoradiotherapy (CRT) combined with bevacizumab and to determine the optimal capecitabine dose for Japanese patients with locally advanced rectal cancer. Patients with cT3/T4 rectal cancer were eligible. Bevacizumab was administered at 5 mg/kg intravenously on Days 1, 15 and 29. Capecitabine was administered on weekdays concurrently with pelvic radiotherapy at a daily dose of 1.8 Gy, totally to 50.4 Gy. Capecitabine was initiated at 825 mg/m(2) twice daily at Dose Level 1, with a planned escalation to 900 mg/m(2) twice daily at Dose Level 2. Within 6.1-10.3 (median, 9.4) weeks after the completion of the CRT, surgery was performed. Three patients were enrolled at each dose level. Regarding the CRT-related acute toxicities, all of the adverse events were limited to Grade 1. There was no Grade 2 or greater toxicity. No patient needed attenuation or interruption of bevacizumab, capecitabine or radiation. All of the patients received the scheduled dose of CRT. All of the patients underwent R0 resection. Two (33.3%) of the six patients had a pathological complete response, and five (83.3%) patients experienced downstaging. In total, three patients (50%) developed postoperative complications. One patient developed an intrapelvic abscess and healed with incisional drainage. The other two patients healed following conservative treatment. This regimen was safely performed as preoperative CRT for Japanese patients with locally advanced rectal cancer. The recommended capecitabine dose is 900 mg/m(2) twice daily.