Phase II trial of neoadjuvant chemotherapy with XELOX plus bevacizumab for locally advanced rectal cancer

Phase 2 study of perioperative chemotherapy with SOX and surgery for stage III colorectal cancer (SOS3 study)

This phase 2 study evaluated the safety and efficacy of perioperative chemotherapy with S-1 plus oxaliplatin (SOX) for stage III colorectal cancer (CRC). Patients with stage III CRC received surgery after neoadjuvant chemotherapy (NAC; SOX 4 cycles) and adjuvant chemotherapy (AC; SOX 4 cycles). The primary endpoints were response rate and safety. We enrolled 30 patients. Their median age was 62 years (range: 43-87 years); 53% were women. They received a median of 4 cycles (range: 1-4) of NAC and a median 4 cycles (range: 0-4) of AC. Five patients interrupted NAC treatment because of toxicity (grade 3 diarrhoea [n = 1], grade 3 ileus [n = 1], and grade 3-4 thrombocytopenia [n = 3]). Patients' responses were complete responses: n = 2 (6.6%), partial responses: n = 21 (70%), stable disease: n = 6 (20.0%), and progressive disease: n = 1 (3.3%; response rate: 73.3%). Curative resection was performed in 29 patients. No patients showed anastomotic leakage. Five-year overall survival and disease-free survival were 83.3% and 76.7%, respectively (median follow-up time: 48 months). NAC using SOX regimen is safe and effective, and may lead to reduced local recurrence and distant metastasis. Long-term outcomes are awaited to evaluate further the efficacy of this strategy (UMIN000006790).

Postoperative XELOX therapy for patients with curatively resected high-risk stage II and stage III rectal cancer without preoperative chemoradiation: a prospective, multicenter, open-label, single-arm phase II study

Background

Preoperative 5-FU-based chemoradiation is currently a standard treatment for advanced rectal cancer, particularly in Western countries. Although it reduced the local recurrence, it could not necessarily improve overall survival. Furthermore, it can also produce adverse effects and long-term sphincter function deficiency. Adjuvant oxaliplatin plus capecitabine (XELOX) is a recommended regimen for patients with curatively resected colon cancer. However, the efficacy of postoperative adjuvant therapy for rectal cancer patients who have not undergone preoperative chemoradiation remains unknown. We aimed to evaluate the efficacy of surgery and postoperative XELOX without preoperative chemoradiation for treating rectal cancer.

Methods

We performed a prospective, multicenter, open-label, single arm phase II study. Patients with curatively resected high-risk stage II and stage III rectal cancer who had not undergone preoperative therapy were treated with a 120 min intravenous infusion of oxaliplatin (130 mg/m²) on day 1 and capecitabine (2000 mg/m²/day) in 2 divided doses for 14 days of a 3-week cycle, for a total of 8 cycles (24 weeks). The primary endpoint was 3-year disease-free survival (DFS).

Results

Between August 2012 and June 2015, 60 men and 47 women with a median age was 63 years (range: 29–77 years) were enrolled. Ninety-three patients had Eastern Cooperative Oncology Group performance status scores of ‘0’ and 14 had scores of ‘1’. Tumors were located in the upper and lower rectums in 54 and 48 patients, respectively; 8 patients had stage II disease and 99 had stage III. The 3-year DFS was 70.1% (95% confidence interval, 60.8–78.0%) and 33 patients (31%) experienced recurrence, most commonly in the lung (16 patients) followed by local recurrence (9) and hepatic recurrence (7).

Conclusions

Postoperative XELOX without preoperative chemoradiation is effective for rectal cancer and provides adequate 3-year DFS prospects.

Trial registration

This clinical trial was registered in the University Hospital Medical Information Network registry system as UMIN000008634 at Aug 06, 2012.

Feasibility of Neoadjuvant FOLFOX Therapy Without Radiotherapy for Baseline Resectable Rectal Cancer

BACKGROUND/AIM

The combination of oxaliplatin, leucovorin and fluorouracil (FOLFOX) has been established as postoperative adjuvant chemotherapy for stage III colon cancer. However, the safety and efficacy of neoadjuvant FOLFOX in patients with rectal cancer are still controversial. This prospective pilot study aimed to evaluate the feasibility of neoadjuvant FOLFOX therapy without radiation for baseline resectable rectal cancer (RC).

PATIENTS AND METHODS

The study included 30 patients with clinical stage II/III RC between February 2012 and December 2015. The patients were treated with six cycles of FOLFOX followed by elective surgery. The primary endpoint was the R0 resection rate. The secondary endpoints were the scheduled treatment completion rate, adverse events, pathological response and the disease-free survival (DFS) rate.

RESULTS

All the patients underwent elective R0 resection after neoadjuvant FOLFOX therapy. The completion rate of the 6-cycle regimen was 93.3% (28/30 patients). Grade 3-4 adverse events occurred in seven patients (23.3%). Pathological complete response was noted in two patients (6.7%). The 3-year DFS rate was 77.5% (95% confidence interval, 61.4%-93.7%).

CONCLUSION

Neoadjuvant FOLFOX therapy without radiation is a feasible therapeutic strategy for baseline resectable RC.

BACCHUS: A randomised non-comparative phase II study of neoadjuvant chemotherapy (NACT) in patients with locally advanced rectal cancer (LARC)

BACKGROUND

Chemoradiation (CRT) or short-course radiotherapy (SCRT) are standard treatments for locally advanced rectal cancer (LARC). We evaluated the efficacy/safety of two neoadjuvant chemotherapy (NACT) regimens as an alternative prior to total mesorectal excision (TME).

METHODS/DESIGN

This multi-centre, phase II trial in patients with magnetic resonance imaging (MRI) defined high-risk LARC (>cT3b, cN2+ or extramural venous invasion) randomised patients (1:1) to FOLFOX + Bevacizumab (Arm 1) or FOLFOXIRI + bevacizumab (Arm 2) every 14 days for 6 cycles prior to surgery. Patients were withdrawn if positron emission tomography (PET) standardised uptake value (SUV) after 3 cycles failed to decrease by >30% or increased compared to baseline. Primary endpoint was pathological complete response rate (pCR). Secondary endpoints included adverse events (AE) and toxicity. Neoadjuvant rectal (NAR) scores based on "T" and "N" downstaging were calculated.

FINDINGS

Twenty patients aged 18-75 years were randomised. The trial stopped early because of poor accrual. Seventeen patients completed all 6 cycles of NACT. One stopped due to myocardial infarction, 1 poor response on PET (both received CRT) and 1 committed suicide. 11 patients had G3 AE, 1 G4 AE (neutropenia), and 1 G5 (suicide). pCR (the primary endpoint) was 0/10 for Arm 1 and 2/10 for Arm 2 i.e. 2/20 (10%) overall. Median NAR score was 14·9 with 5 (28%), 7 (39%), and 6 (33%) having low, intermediate, or high scores. Surgical morbidity was acceptable (1/18 wound infection, no anastomotic leak/pelvic sepsis/fistulae). The 24-month progression-free survival rate was 75% (95% CI: 60%-85%).

INTERPRETATION

The primary endpoint (pCR rate) was not met. However, FOLFOXIRI and bevacizumab achieved promising pCR rates, low NAR scores and was well-tolerated. This regimen is suitable for testing as the novel arm against current standards of SCRT and/or CRT in a future trial.

Role of bevacizumab in neoadjuvant chemotherapy and its influence on microvessel density in rectal cancer

BACKGROUND

The role of bevacizumab (Bev) in neoadjuvant chemotherapy (NAC) without radiotherapy for rectal cancer has not been fully discussed. The purpose of this study is to assess the clinicopathological benefit of Bev in NAC for rectal cancer and to investigate its influence on microvessel status in cancerous tissue.

METHODS

Data on 47 patients with rectal cancer, who received NAC with or without Bev between August 2008 and November 2012, were analyzed retrospectively. The objective response was evaluated using the maximum tumor diameter. Tumor regression grade 3/4 was classified as a pathological response.

RESULTS

Thirty-one patients (66 %) received NAC that included Bev and the other 16 patients were treated without Bev. The objective response rate was significantly higher in the Bev group than in the non-Bev group (64.5 vs. 25.0 %, p = 0.015). The rate of pathological response was much higher in the Bev group (41.9 %) than in the non-Bev group (12.5 %), but did not reach significant difference (p = 0.052). Microvessel density (MVD) in the resected cancerous tissue was significantly lower in the Bev group than in the non-Bev group.

CONCLUSIONS

We have confirmed that objective and pathological responses were better in patients treated with NAC that included Bev than in those who received NAC without Bev. Additionally, MVD in tumor tissues was inhibited in the patients treated with Bev. To investigate the impact of Bev in NAC on long-term survival, further follow-up is required.

Anti-EGFR and anti-VEGF agents: Important targeted therapies of colorectal liver metastases

Colorectal liver metastasis (CLM) is common worldwide. Targeted therapies with monoclonal antibodies have been proven effective in numerous clinical trials, and are now becoming standards for patients with CLM. The development and application of anti-epidermal growth factor receptor (anti-EGFR) and anti-vascular endothelial growth factor (anti-VEGF) antibodies represents significant advances in the treatment of this disease. However, new findings continue to emerge casting doubt on the efficacy of this approach. The Kirsten rat sarcoma viral oncogene (KRAS) has been proven to be a crucial predictor of the success of anti-EGFR treatment in CLM. Whereas a recent study summarized several randomized controlled trials, and showed that patients with the KRAS G13D mutation significantly benefited from the addition of cetuximab in terms of progress-free survival (PFS, 4.0 mo vs 1.9 mo, HR = 0.51, P = 0.004) and overall survival (OS, 7.6 mo vs 5.7 mo, HR = 0.50, P = 0.005). Some other studies also reported that the KRAS G13D mutation might not be absolutely predictive of non-responsiveness to anti-EGFR therapy. At the same time, “new” RAS mutations, including mutations in neuroblastoma RAS viral (v-ras) oncogene homolog (NRAS) and exons 3 and 4 of KRAS, have been suggested to be predictors of a poor treatment response. This finding was first reported by the update of the PRIME trial. The update showed that for patients with non-mutated KRAS exon 2 but other RAS mutations, panitumumab-fluorouracil, leucovorin, and oxaliplatin (FOLFOX)4 treatment led to inferior PFS (HR = 1.28, 95%CI: 0.79-2.07) and OS (HR = 1.29, 95%CI: 0.79-2.10), which was consistent with the findings in patients with KRAS mutations in exon 2. Then, the update of the PEAK trial and the FIRE-III trial also supported this finding, which would reduce candidates for anti-EGFR therapy but enhance the efficacy. In first-line targeted combination therapy, the regimens of cetuximab plus FOLFOX was called into question because of the inferior prognosis in the COIN trial and the NORDIC-VII trial. Also, bevacizumab plus oxaliplatin-based chemotherapy was questioned because of the NO16966 trial. By the update and further analysis of the COIN trial and the NORDIC-VII trial, cetuximab plus FOLFOX was reported to be reliable again. But bevacizumab plus oxaliplatin-based chemotherapy was still controversial. In addition, some trials have reported that bevacizumab is not suitable for conversion therapy. The results of the FIRE-III trial showed that cetuximab led to a significant advantage over bevacizumab in response rate (72% vs 63%, P = 0.017) for evaluable population. With the balanced allocation of second-line treatment, the FIRE-III trial was expected to provide evidence for selecting following regimens after first-line progression. There is still no strong evidence for the efficacy of targeted therapy as a preoperative treatment for resectable CLM or postoperative treatment for resected CLM, although the combined regimen is often administered based on experience. Combination therapy with more than one targeted agent has been proven to provide no benefit, and even was reported to be harmful as first-line treatment by four large clinical trials. However, recent studies reported positive results of erlotinib plus bevacizumab for maintenance treatment. The mechanism of antagonism between different targeted agents deserves further study, and may also provide greater understanding of the development of resistance to targeted agents.

A complete response to mFOLFOX6 and panitumumab chemotherapy in advanced stage rectal adenocarcinoma: a case report

BACKGROUND

Pathological complete remission of advanced stage rectal adenocarcinoma by chemotherapy alone is rare. A case of advanced stage, low-lying rectal adenocarcinoma in which a complete response to treatment was obtained with mFOLFOX6 and panitumumab (Pmab) is reported.

CASE PRESENTATION

A 53-year-old man was referred to Shiga University of Medical Science hospital Shiga, Japan, complaining of bloody stool. Gastrointestinal endoscopy was performed, and advanced stage rectal adenocarcinoma was diagnosed. Computed tomography (CT) revealed regional lymph node metastases in the mesorectum. Neoadjuvant chemotherapy (NAC) with mFOLFOX6 and Pmab was planned.Endoscopy following four courses of chemotherapy revealed that the rectal cancer had been markedly reduced, and the results of biopsies of the rectal tumor were negative for cancer. On CT, the mesorectal lymph node metastases had disappeared. Total intersphincteric resection (ISR) with a handsewn coloanal anastomosis was performed. Histological examination showed a complete response to mFOLFOX6 and Pmab in advanced stage rectal cancer.

CONCLUSION

The result seen in this case suggests that short-term NAC with mFOLFOX6 and Pmab was effective for low-lying rectal adenocarcinoma.

MRI and FDG-PET for assessment of response to neoadjuvant chemotherapy in locally advanced rectal cancer

BACKGROUND

The purpose of this study was to assess the value of magnetic resonance imaging (MRI) and additional (18)F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) for tumor response to neoadjuvant chemotherapy (NAC) in patients with locally advanced rectal cancer (LARC).

METHODS

Data on 40 patients with LARC, who were treated with NAC and underwent MRI and FDG-PET/CT before and after NAC, were analyzed retrospectively. Surgery was performed at a median of 6 weeks after NAC and the images were compared with the histological findings. The tumor regression grade 3/4 was classified as a responder.

RESULTS

Sixteen patients were pathological responders. Receiver operating characteristic (ROC) analysis revealed that MRI total volume after NAC (MRI-TV2) and ΔMRI-TV had the highest performance to assess responders (area under the ROC curve [AUC] 0.849 and AUC 0.853, respectively). The reduction rate of the maximum standardized uptake value (ΔSUVmax) was also an informative factor (AUC 0.719). There seems no added value of adding FDG-PET/CT to MRI-TV2 and ΔMRI-TV in assessment of NAC responders judging from changes in AUC (AUC of ΔSUVmax and MRI-TV2 was 0.844, and AUC of ΔSUVmax and ΔMRI-TV was 0.846).

CONCLUSIONS

MRI-TV2 and ΔMRI-TV were the most accurate factors to assess pathological response to NAC. Although ΔSUVmax by itself was also informative, the addition of FDG-PET/CT to MRI did not improve performance. Patients with LARC who were treated by induction chemotherapy should receive an MRI examination before and after NAC to assess treatment response. A more than 70 % volume reduction shown by MRI volumetry may justify the omission of subsequent radiotherapy.

Neoadjuvant therapy before surgical treatment

Neoadjuvant treatment in terms of preoperative radiotherapy reduces local recurrence in rectal cancer, but this improvement has little if any impact on overall survival. Currently performed optimal quality-controlled total mesorectal excision (TME) surgery for patients in the trial setting can be associated with very low local recurrence rates of less than 10% whether the patients receive radiotherapy or not. Hence metastatic disease is now the predominant issue. The concept of neoadjuvant chemotherapy (NACT) is a potentially attractive additional or alternative strategy to radiotherapy to deal with metastases. However, randomised phase III trials, evaluating the addition of oxaliplatin at low doses plus preoperative fluoropyrimidine-based chemoradiotherapy (CRT), have in the main failed to show a significant improvement on early pathological response, with the exception of the German CAO/ARO/AIO-04 study. The integration of biologically targeted agents into preoperative CRT has also not fulfilled expectations. The addition of cetuximab appears to achieve relatively low rates of pathological complete responses, and the addition of bevacizumab has raised concerns for excess surgical morbidity. As an alternative to concurrent chemoradiation (which delivers only 5-6 weeks of chemotherapy), potential options include an induction component of 6-12 weeks of NACT prior to radiotherapy or chemoradiation, or the addition of chemotherapy after short-course preoperative radiotherapy (SCPRT) or chemoradiation (defined as consolidation chemotherapy) which utilises the "dead space" of the interval between the end of chemoradiation and surgery, or delivering chemotherapy alone without any radiotherapy.

Postoperative complications following neoadjuvant bevacizumab treatment for advanced colorectal cancer

PURPOSES

Attempts have been made to use bevacizumab (BEV) in an adjuvant or neoadjuvant setting. However, BEV is known to cause various adverse events, and the safety of neoadjuvant BEV has not yet been fully evaluated. This study assessed the postoperative complications in patients receiving neoadjuvant BEV for colorectal cancer.

METHODS

The data for 78 patients with resectable advanced or metastatic colorectal cancer who received neoadjuvant BEV followed by surgical resection were retrospectively analyzed.

RESULTS

The median interval between the last BEV dose and surgery was 9 weeks. The most common postoperative complication was pelvic sepsis, which occurred in 11 patients (14 %). A biliary fistula developed in four of 23 patients who underwent liver resection. Anastomotic leakage occurred in six of 24 patients with a colorectal anastomosis, four of whom required re-laparotomy. In a univariate analysis, male gender and a greater intraoperative blood loss were associated with postoperative complications of any grade. Colorectal anastomosis was a risk factor for major complications. In a multivariate analysis, intraoperative blood loss was an independent risk factor for postoperative complications of any grade (HR 6.338; P = 0.003). With regard to major postoperative complications, colorectal primary anastomosis was the only independent predictive risk factor (HR 8.285; P = 0.013).

CONCLUSIONS

In patients with colorectal cancer who underwent elective surgery after BEV treatment, the interval between BEV and surgery was not a risk factor for postoperative complications (based on a median interval of 9 weeks). Colorectal primary anastomosis was the only independent risk factor for major postoperative complications.

Neoadjuvant oxaliplatin and capecitabine and bevacizumab without radiotherapy for poor-risk rectal cancer: N-SOG 03 Phase II trial

OBJECTIVE

This Phase II trial was designed to evaluate the safety and efficacy of neoadjuvant oxaliplatin and capecitabine and bevacizumab without radiotherapy in patients with poor-risk rectal cancer.

METHODS

Patients with magnetic resonance imaging-defined poor-risk rectal cancer received neoadjuvant oxaliplatin and capecitabine and bevacizumab followed by total mesorectal excision or more extensive surgery.

RESULTS

Between February 2010 and December 2011, 32 patients were enrolled in this study. The completion rate of the scheduled chemotherapy was 91%. Reasons for withdrawal were refusal to continue therapy in two patients and disease progression in one, with two of these three patients not undergoing surgery. Among the 29 patients who completed the scheduled chemotherapy, one refused surgery within 8 weeks after the completion of chemotherapy, which was the period stipulated by the protocol, and another had rectal perforation, requiring urgent laparotomy. As a result, the completion rate of this experimental treatment was 84%. Of the 30 patients who underwent surgery, the R0 resection rate was 90% and a postoperative complication occurred in 43%. A pathological complete response was observed in 13% and good tumor regression was exhibited in 37%.

CONCLUSIONS

Neoadjuvant oxaliplatin and capecitabine plus bevacizumab for poor-risk rectal cancer caused a high rate of anastomotic leakage and experienced a case with perforation during chemotherapy, both of which were bevacizumab-related toxicity. Although the short-term results with the completion rate of 84.4% and the pathological complete response rate of 13.3% were satisfactory, we have to reconsider the necessity of bevacizumab in neoadjuvant chemotherapy (UMIN number, 000003507).

Progress in rectal cancer treatment

The dramatic improvement in local control of rectal cancer observed during the last decades is to be attributed to attention to surgical technique and to the introduction of neoadjuvant therapy regimens. Nevertheless, systemic relapse remains frequent and is currently insufficiently addressed. Intensification of neoadjuvant therapy by incorporating chemotherapy with or without targeted agents before the start of (chemo)radiation or during the waiting period to surgery may present an opportunity to improve overall survival. An increasing number of patients can nowadays undergo sphincter preserving surgery. In selected patients, local excision or even a "wait and see" approach may be feasible following active neoadjuvant therapy. Molecular and genetic biomarkers as well as innovative imaging techniques may in the future allow better selection of patients for this treatment option. Controversy persists concerning the selection of patients for adjuvant chemotherapy and/or targeted therapy after neoadjuvant regimens. The currently available evidence suggests that in complete pathological responders long-term outcome is excellent and adjuvant therapy may be omitted. The results of ongoing trials will help to establish the ideal tailored approach in resectable rectal cancer.

Neoadjuvant chemotherapy in MRI-staged high-risk rectal cancer in addition to or as an alternative to preoperative chemoradiation?

BACKGROUND

For patients with resectable rectal cancer chemoradiation (CRT) or short-course preoperative radiotherapy (SCPRT) reduces locoregional failure, without extending disease-free survival (DFS) or overall survival (OS). Compliance to postoperative adjuvant chemotherapy is poor. Neoadjuvant chemotherapy (NACT) offers an alternative strategy.

METHODS

A systematic computerised database search identified studies exploring NACT alone or NACT preceding/succeeding radiation. The primary outcome measure was pathological complete response (pCR). Secondary outcome measures included acute toxicity, surgical morbidity, circumferential resection margin, locoregional failure, DFS and OS.

RESULTS

Four case reports, 12 phase I/II studies, 4 randomised phase II and one randomised phase III study evaluated chemotherapy before CRT. Four prospective studies reviewed chemotherapy after CRT. Three phase II studies investigated chemotherapy using FOLFOX plus bevacizumab without radiotherapy. In 24 studies of 1271 patients, pCR varied from 7% to 36%, but with no impact on metastatic disease.

CONCLUSIONS

NACT before CRT delivers does not compromise CRT but has not increased pCR rates, R0 resection rate, improved DFS or reduced metastases. NACT following CRT is an interesting strategy, and the utility of NACT alone could be explored compared with SCPRT or CRT in selected patients with rectal cancer where the impact of radiotherapy on DFS and OS is marginal.