mFOLFOXIRI versus mFOLFOX6 as neoadjuvant chemotherapy in locally advanced rectal cancer: A Propensity Score Matching Analysis

Brazil-TNT: A Randomized Phase 2 Trial of Neoadjuvant Chemoradiation Followed by FOLFIRINOX Versus Chemoradiation for Stage II/III Rectal Cancer

BACKGROUND

Neoadjuvant radiation and oxaliplatin-based systemic therapy (total neoadjuvant therapy-TNT) have been shown to increase response and organ-preservation rates in localized rectal cancer. However, trials have been heterogeneous regarding treatment protocols and few have used a watch-and-wait (WW) approach for complete responders. This trial evaluates if conventional long-term chemoradiation followed by consolidation of FOLFIRINOX increases complete response rates and the number of patients managed by WW.

METHODS

This was a pragmatic randomized phase II trial conducted in 2 Cancer Centers in Brazil that included patients with T3+ or N+ rectal adenocarcinoma. After completing a long-course 54 Gy chemoradiation with capecitabine patients were randomized 1:1 to 4 cycles of mFOLFIRINOX (Oxaliplatin 85, irinotecan 150, 5-FU 2400)-TNT-arm-or to the control arm, that did not include further neoadjuvant treatment. All patients were re-staged with dedicated pelvic magnetic resonance imaging and sigmoidoscopy 12 weeks after the end of radiation. Patients with a clinical complete response were followed using a WW protocol. The primary endpoint was complete response: clinical complete response (cCR) or pathological response (pCR).

RESULTS

Between April 2021 and June 2023, 55 patients were randomized to TNT and 53 to the control arm. Tumors were 74% stage 3, median distance from the anal verge was 6 cm, 63% had an at-risk circumferential margin, and 33% an involved sphincter. The rates of cCR + pCR were (31%) for TNT versus (17%) for controls (odds ratio 2.19, CI 95% 0.8-6.22 P = .091) and rates of WW were 16% and 9% (P = ns). Median follow-up was 8.1 months and recurrence rates were 16% versus 21% for TNT and controls (P = ns).

CONCLUSIONS

TNT with consolidation FOLFIRINOX is feasible and has high response rates, consistent with the current literature for TNT. This trial was supported by a grant from the Brazilian Government (PROADI-SUS - NUP 25000.164382/2020-81).

Organ Preservation in MSS Rectal Cancer

Rectal cancer is a heterogeneous disease with complex genetic and molecular subtypes. Emerging progress of neoadjuvant therapy has led to increased pathological and clinical complete response (cCR) rates for microsatellite stable (MSS) rectal cancer, which responds poorly to immune checkpoint inhibitor alone. As a result, organ preservation of MSS rectal cancer as an alternative to radical surgery has gradually become a feasible option. For patients with cCR or near-cCR after neoadjuvant treatment, organ preservation can be implemented safely with less morbidity. Patient selection can be done either before the neoadjuvant treatment for higher probability or after with careful assessment for a favorable outcome. Those patients who achieved a good clinical response are managed with nonoperative management, organ preservation surgery, or radiation therapy alone followed by strict surveillance. The oncological outcomes of patients with careful selection and organ preservation seem to be noninferior compared with those of radical surgery, with lower postoperative morbidity. However, more studies should be done to seek better regression of tumor and maximize the possibility of organ preservation in MSS rectal cancer.

MRI-based pre-Radiomics and delta-Radiomics models accurately predict the post-treatment response of rectal adenocarcinoma to neoadjuvant chemoradiotherapy

Objectives

To develop and validate magnetic resonance imaging (MRI)-based pre-Radiomics and delta-Radiomics models for predicting the treatment response of local advanced rectal cancer (LARC) to neoadjuvant chemoradiotherapy (NCRT).

Methods

Between October 2017 and August 2022, 105 LARC NCRT-naïve patients were enrolled in this study. After careful evaluation, data for 84 patients that met the inclusion criteria were used to develop and validate the NCRT response models. All patients received NCRT, and the post-treatment response was evaluated by pathological assessment. We manual segmented the volume of tumors and 105 radiomics features were extracted from three-dimensional MRIs. Then, the eXtreme Gradient Boosting algorithm was implemented for evaluating and incorporating important tumor features. The predictive performance of MRI sequences and Synthetic Minority Oversampling Technique (SMOTE) for NCRT response were compared. Finally, the optimal pre-Radiomics and delta-Radiomics models were established respectively. The predictive performance of the radionics model was confirmed using 5-fold cross-validation, 10-fold cross-validation, leave-one-out validation, and independent validation. The predictive accuracy of the model was based on the area under the receiver operator characteristic (ROC) curve (AUC).

Results

There was no significant difference in clinical factors between patients with good and poor reactions. Integrating different MRI modes and the SMOTE method improved the performance of the radiomics model. The pre-Radiomics model (train AUC: 0.93 ± 0.06; test AUC: 0.79) and delta-Radiomcis model (train AUC: 0.96 ± 0.03; test AUC: 0.83) all have high NCRT response prediction performance by LARC. Overall, the delta-Radiomics model was superior to the pre-Radiomics model.

Conclusion

MRI-based pre-Radiomics model and delta-Radiomics model all have good potential to predict the post-treatment response of LARC to NCRT. Delta-Radiomics analysis has a huge potential for clinical application in facilitating the provision of personalized therapy.

Neoadjuvant chemotherapy for treatment patients with rectal cancer with adverse prognostic factors: A review

Rectal cancer (RC) is one of the leading tumor location in the structure of the incidence of malignant neoplasms in the Russian Federation and the world. And the standard approach to the treatment of patients with locally advanced forms of RC is preoperative chemo-radiotherapy (CRT) with delayed surgery. The use of such sort of approach in the recent decades has led to the reduction of the frequency of local recurrence up to 10% and even less. However, approximately a third of patients die of distant metastases. In this regard, one of the main tasks in the treatment of patients with locally advanced forms of RC with adverse prognostic factors is the prevention of distant metastasis formation. Early initiation of the systemic therapy before surgery is aimed at solving this issue. Conducting neoadjuvant chemotherapy (NCT) instead of CRT in RC treatment allows to avoid radiation reactions and injuries, occurring in some patients. Two-component oxaliplatin-containing regimens are the most well studied types of NCT in the treatment of patients with non-metastatic RC. In this connection, despite the differences in the treatment regimens and the number of cycles, a good tolerability of the method as well as no effect on the frequency of postoperative complications and in general a satisfactory results comparable to the effects of CRT were observed. The use of NCT in combination with targeted treatment modalities as well as three-component chemotherapy regimens are promising and encouraging treatment options for patients with RC with adverse prognostic factors.

Evaluation of the ability of fatty acid metabolism signature to predict response to neoadjuvant chemoradiotherapy and prognosis of patients with locally advanced rectal cancer

Neoadjuvant chemoradiotherapy (nCRT) is widely used to treat patients with locally advanced rectal cancer (LARC), and treatment responses vary. Fatty acid metabolism (FAM) is closely associated with carcinogenesis and cancer progression. In this study, we investigated the vital role of FAM on the gut microbiome and metabolism in the context of cancer. We screened 34 disease-free survival (DFS)-related, FAM-related, and radiosensitivity-related genes based on the Gene Expression Omnibus database. Subsequently, we developed a five-gene FAM-related signature using the least absolute shrinkage and selection operator Cox regression model. The FAM-related signature was also validated in external validation from Fujian Cancer Hospital for predicting nCRT response, DFS, and overall survival (OS). Notably, patients with a low-risk score were associated with pathological complete response and better DFS and OS outcomes. A comprehensive evaluation of the tumor microenvironment based on the FAM-related signature revealed that patients with high-risk scores were closely associated with activating type I interferon response and inflammation-promoting functions. In conclusion, our findings indicate the potential ability of FAM to predict nCRT response and the prognosis of DFS and OS in patients with LARC.

The Evolving Neoadjuvant Treatment Paradigm for Patients with Locoregional mismatch Repair Proficient Rectal Cancer

OPINION STATEMENT

The standard of care for locally advanced rectal cancer (LARC) has included preoperative chemoradiation, total mesorectal excision surgery and post operative adjuvant chemotherapy based on histopathology. The current therapeutic landscape in LARC has many different options with different directions of travel - depending on the goal of treatment. Enthusiasm for delivering total neoadjuvant therapy (TNT) for patients with locally advanced rectal cancer (LARC) is increasing in the light of recently published randomised phase III trials - RAPIDO and PRODIGE-23. There is a wide diversity of different potential schedules and a multitude of approaches, which include induction neoadjuvant chemotherapy (NACT) with a range of chemotherapy options (CAPEOX, FOLFOX, FOLFOXIRI) and a varying duration of 6-18 weeks, or consolidation NACT. These schedules either precede or follow short-course preoperative radiation therapy (SCPRT) using 5 × 5Gy or long-course chemoradiation (LCCRT) using 45-60Gy respectively. The different strategies of induction and consolidation neoadjuvant chemotherapy have been compared and have similar long-term outcomes, but consolidation chemotherapy may facilitate organ-sparing. The results are driving novel paradigms with both intensification and de-intensification treatment strategies. The ideal combination, sequence or duration of such a TNT approach remains undefined. As yet, there are no robust clinical, genetic, molecular, immune or imaging features (alone or integrated), which either direct or aid these choices. Currently, the selection of neoadjuvant treatment is driven by the impact on avoidance or feasibility of surgery or reducing the risk of metastases rather than prevention of local recurrence. Most believe that TNT will improve overall survival, despite the present lack of evidence. Both the inherent heterogeneity in LARC and the observed range of different responses underline the need for response biomarkers to individually tailor therapy rather than 'a one size fits all' approach.