Induction FOLFOX followed by preoperative hyperfractionated radiotherapy plus bolus 5-fluorouracil in locally advanced rectal carcinoma: single arm phase I–II study

Total Neoadjuvant Therapy in Rectal Cancer: A Systematic Review and Meta-analysis of Treatment Outcomes

BACKGROUND

The addition of induction chemotherapy to concomitant neoadjuvant chemoradiation in locally advanced rectal cancer could increase pathological downstaging and act on occult micrometastatic disease, leading ultimately to a better outcome. A systematic review was carried out of the existing literature on the treatment outcomes of total neoadjuvant therapy (TNT) on locally advanced rectal cancer. TNT was defined as chemotherapy using cycles of induction and/or consolidation in conjunction with standard chemoradiotherapy prior to surgery.

METHODS

A systematic search of PubMed, Embase, and the Cochrane Library was performed according to the PRISMA statement up until January 2019. The primary endpoints were complete pathologic response (pCR), disease-free survival, and overall survival rates.

RESULTS

A total of 28 studies (3 retrospective and 25 prospective for a total of 3579 patients) were included in the final analysis (n = 2688 treated with TNT and n = 891 with neoadjuvant chemoradiotherapy therapy). The pooled pCR rate was 22.4% (95% CI 19.4%-25.7%) in all patients treated with TNT (n = 27 studies with data available). In n = 10 comparative studies with data available, TNT was found to increase the odds of pCR by 39% (1.40, 95% CI 1.08-1.81, P = 0.01).

CONCLUSIONS

The addition of induction or consolidation chemotherapy to standard neoadjuvant chemoradiotherapy results in a higher pCR rate. Given that the comparative analysis was derived from few randomized publications, large confirmatory trials should be carried out before a strong recommendation is made in favor of TNT.

Pre-operative hyperfractionated concurrent radiochemotherapy for locally advanced rectal cancers: a phase II clinical study

OBJECTIVE

The study was prospectively designed as a single-arm, single-institution prospective trial of pre-operative concomitant hyperfractionated radiotherapy (HART) with co-administration of chemotherapy based on 5-fluorouracil (5FU) in patients with T2/N+ or T3/any N resectable mid-low primary rectal cancer. The aim of the study was to assess the safety and efficacy of accelerated HART with concurrent 5FU-based chemotherapy in patients with locally advanced rectal cancer.

METHODS

Patients with resectable locally advanced (≥T3 or N+) rectal cancer were eligible. The patients received total dose 42 Gy in 28 fractions of 1.5 Gy, two times daily, with at least 8 h of interval, with concurrent chemotherapy: 325 mg m^-2 of 5FU (bolus) on Days 1-3 and Days 16-18 (except for cN0 patients for whom only one cycle on Days 1-3 was prescribed). The primary end point included tolerance, post-operative complication rate and pathological response rate. The secondary end points included locoregional relapse-free survival, metastasis-free survival and overall survival.

RESULTS

Out of 53 enrolled patients; 2 did not undergo surgery. Of the 51 patients evaluable for pathological response, there were 8 (15.6%), 20 (39.3%), 18 (35.3%) and 5 (9.8%) patients with tumour regression grade 0, 1, 2 and 3, respectively. Downstaging of the primary tumour and lymph nodes was observed in 22 (43%) and 25 (49%) patients, respectively. The primary tumour ypCR (ypT0) rate was 15% (8/51). The nodal ypCR rate for cN+ patients was 60% (21/35). The total ypCR (ypT0N0M0) rate was 11% (6/51). Toxicity included: Grade 3 diarrhoea (4/51, 7.8%), Grade 2 diarrhoea (22/51, 43.1%), Grade 2 leukopenia (7/51, 13.7%), Grade 2 neutropenia (6/51, 11.7%) and Grade 1 thrombocytopenia (3/51, 5.9%). No Grade 4 toxicity was reported. Nine patients (18%) presented with post-operative complications (during the 3 months after surgery). There were 6 locoregional relapses (11.8%) and distant metastasis occurred in 11 patients (21.6%). The 2-year cumulative locoregional relapse-free survival, metastasis-free survival and overall survival was 87%, 79% and 89%, respectively.

CONCLUSION

The proposed pre-operative HART with co-administration of 5FU had acceptable toxicity profile and provided satisfactory rate of ypCR. This created rationale to initiate a Phase III randomized study that was registered under ClinicalTrials.gov Identifier: NCT01814969. Advances in knowledge: The results of this research show that responders to pre-operative radiochemotherapy have favourable outcome. Tumour regression grade as prognostic clinical feature holds the promise of better classifying patients at high risk of local and systemic recurrence and this issue may be an interesting objective for future research.