Comparison of Capecitabine (Xeloda) vs. Combination of Capecitabine and Oxaliplatin (XELOX) as Neoadjuvant CRT for Locally Advanced Rectal Cancer

Results of phase Ib/II trial of PEP503 (NBTXR3, radioenhancer) with chemoradiotherapy in patients with rectal cancer

AIM

To evaluate the efficacy, recommended phase II dose (RP2D), dose-limiting toxicity (DLT), and safety profiles of PEP503 (NBTXR3) in combination with concurrent chemoradiotherapy (CCRT) in patients with locally advanced or unresectable rectal adenocarcinoma.

METHODS

A single administration of intratumor injection of PEP503 (NBTXR3) (multiple punctures) was applied, followed by radiotherapy in combination with capecitabine or 5-fluorouacil (5-FU). Surgery was performed 8 to 12 weeks after completion of CCRT.

RESULTS

Thirty-two patients were enrolled (one dropped out before CCRT), comprising 20 in phase Ib and 12 in phase II. The disease control rate was 100% (n = 31). One (3.2%) and 19 (61.3%) patients achieved clinical complete response and partial response, respectively. Twenty-five patients underwent surgery, of whom 24 (96%) had R0 resection and 5 (20%) had pathological complete response. Most of the adverse events were grade 1/2 events.

CONCLUSION

Intratumor injection of PEP503 (NBTXR3) in patients with locally advanced or unresectable rectal adenocarcinoma is safe and effective. Addition of PEP503 (NBTXR3) to fluoropyrimidine-based neoadjuvant CCRT does not engender increased toxicity. The strong safety profile and encouraging efficacy of PEP503 (NBTXR3) in combination with neoadjuvant CCRT in locally advanced or unresectable rectal cancer warrant further examination in clinical studies.

CLINICAL TRIAL REGISTRATION

This study was registered on ClinicalTrials.gov Identifier: NCT02465593.

Short-term and long-term oncological outcomes of chemoradiotherapy for rectal cancer patients with or without oxaliplatin: a propensity score-matched retrospective analysis

BACKGROUND/AIM

Current approaches for locally advanced rectal cancer (LARC) typically recommend neoadjuvant chemoradiotherapy (nCRT) with 5-fluorouracil (5FU) or its oral analogs followed by surgery as the standard of care. However, the question of whether intensifying concurrent chemotherapy by adding oxaliplatin to the 5FU-based backbone can yield better outcomes remains unresolved. This study aimed to investigate the benefits of incorporating oxaliplatin into fluoropyrimidine-based chemoradiotherapy (CRT) to increase locoregional control and survival.

METHODS

Among 290 patients with LARC admitted to the Iran Cancer Institute's radiation oncology department between January 2008 and December 2019, 29 received CAPEOX (capecitabine 625 mg/m²/bid on RT days and weekly oxaliplatin 50 mg/m²), whereas 293 received capecitabine (825 mg/m² twice daily or rarely 5FU in the first 4 days and last week of radiotherapy (RT)). Variables potentially affecting treatment outcomes were used for propensity score matching. Kaplan‒Meier and log-rank tests were employed for overall survival (OS) and disease-free survival (DFS) analyses and were adjusted with propensity score matching.

RESULTS

Data from 29 patients who received CAPEOX and 216 patients who received capecitabine were analyzed after propensity score matching without replacement. After propensity score matching, in the multivariate analysis, CAPEOX significantly increased the likelihood of achieving a pathologic complete response (pCR) by 4.38 times (CI: 1.90-10.08, p value < 0.001). However, CAPEOX did not demonstrate any statistically significant predictive value for DFS (P = 0.500) or OS (P = 0.449).

CONCLUSION

The addition of oxaliplatin resulted in a significantly higher rate of pCR without any translation into long-term survival outcomes.

The incidence rate of allergic reactions induced by oxaliplatin is higher in patients with rectal cancer compared with colon cancer

AIM

To explore the diverse profiles of adverse reactions caused by oxaliplatin between colon and rectal cancer, we investigated the toxicity of oxaliplatin in patients with colon and rectal cancer.

METHODS

From January 2017 to December 2021, 200 cases of sporadic CRC patients with adverse reactions after oxaliplatin were collected from Harbin Medical University Cancer Hospital, Harbin, China. All patients received a chemotherapy regimen containing oxaliplatin (100 colon cancer and 100 rectal cancer). We reviewed the adverse reactions induced by oxaliplatin in patients with colon and rectal cancer.

RESULTS

We found there was no significant difference in gastrointestinal toxicity, hematotoxicity, neurotoxicity, hepatotoxicity, respiratory toxicity, and cardiotoxicity caused by oxaliplatin between patients with colon cancer and patients with rectal cancer, but patients with rectal cancer were more prone to allergic reactions than patients with colon cancer after oxaliplatin. In addition, we found neutrophil-to-lymphocyte ratios (NLR) and platelet-to-lymphocyte ratios (PLR) were higher in patients with colon cancer than in patients with rectal cancer. This may reflect differences in immune status and inflammatory responses between colon cancer and rectal cancer, which might be the reason for more allergic reactions caused by oxaliplatin in colon cancer patients compared to rectal cancer patients.

CONCLUSION

Except for a higher incidence of allergic reactions in patients with rectal cancer, no significant difference in the incidence of adverse drug reactions associated with oxaliplatin was noted between patients with colon cancer and rectal cancer. Our results suggested more attention should be paid to the allergic reaction caused by oxaliplatin in patients with colon cancer.

Role of Oxaliplatin in the Neoadjuvant Concurrent Chemoradiotherapy in Locally Advanced Rectal Cancer: a Review of Evidence

The treatment of locally advanced rectal cancer (LARC) is a challenging situation for radiation oncologists and colorectal surgeons. Most current approaches recommend neoadjuvant fluorouracil or capecitabine-based chemoradiotherapy followed by surgery as a standard of care. Intensification of concurrent chemotherapy by adding oxaliplatin to fluorouracil or capecitabine backbone to get better outcomes is the matter that has remained unresolved. In this review, we searched Medline and Google Scholar databases and selected 28 prospective phase II and III clinical trials that addressed this question. We discussed the potential advantages and drawbacks of incorporating oxaliplatin into concurrent chemoradiation therapy. We tried to define whether adding oxaliplatin to concurrent chemoradiation with excellent performance and high-risk features benefits some subpopulations. The available literature suggests that by adding oxaliplatin there are some benefits in enhancing response to neoadjuvant chemoradiotherapy, however, without any translated improvements in long-term outcomes including overall and disease-free survival.

Radiotherapy in the preoperative neoadjuvant treatment of locally advanced rectal cancer

Radiotherapy and chemotherapy are effective treatments for patients with locally advanced rectal cancer (LARC) and can significantly improve the likelihood of R0 resection. Radiotherapy can be used as a local treatment to reduce the size of the tumor, improve the success rate of surgery and reduce the residual cancer cells after surgery. Early chemotherapy can also downgrade the tumor and eliminate micrometastases throughout the body, reducing the risk of recurrence and metastasis. The advent of neoadjuvant concurrent radiotherapy (nCRT) and total neoadjuvant treatment (TNT) has brought substantial clinical benefits to patients with LARC. Even so, given increasing demand for organ preservation and quality of life and the disease becoming increasingly younger in its incidence profile, there is a need to further explore new neoadjuvant treatment options to further improve tumor remission rates and provide other opportunities for patients to choose watch-and-wait (W&W) strategies that avoid surgery. Targeted drugs and immunologic agents (ICIs) have shown good efficacy in patients with advanced rectal cancer but have not been commonly used in neoadjuvant therapy for patients with LARC. In this paper, we review several aspects of neoadjuvant therapy, including radiation therapy and chemotherapy drugs, immune drugs and targeted drugs used in combination with neoadjuvant therapy, with the aim of providing direction and thoughtful perspectives for LARC clinical treatment and research trials.

Combination chemotherapy against colorectal cancer cells: Co-delivery of capecitabine and pioglitazone hydrochloride by polycaprolactone-polyethylene glycol carriers

BACKGROUND

Colorectal cancer causes numerous deaths despite many treatment options. Capecitabine (CAP) is the standard chemotherapy regimen for colorectal cancer, and pioglitazone hydrochloride (PGZ) for diabetic disease treatment. However, free drugs do not induce effective apoptosis. This work aims to co-encapsulate CAP and PGZ and evaluate cytotoxic and apoptotic effects on HCT-119, HT-29 colorectal cancer cells, and human umbilical vein endothelial cells (HUVECs).

METHOD

CAP, PGZ, and combination treatment nano-formulations were prepared by triblock (TB) (PCL-PEG-PCL) biodegradable copolymers to enhance drugs' bioavailability as anti-cancer agents. The Ultrasonic homogenization method was used for preparing nanoparticles. The physicochemical characteristics of nanoparticles were studied using 1H NMR, FTIR, DLS, and FESEM techniques. The zeta potential, entrapment efficiency, drug release, and storage stability were studied. Also, cell viability and apoptosis were examined by using MTT, acridine orange (AO), and propidium iodide (PI), respectively.

RESULT

The smaller hydrodynamic size (236.1 nm), polydispersity index (0.159), and zeta potential (-20.8 mV) were observed in nanoparticles. Nanoparticles revealed a proper formulation and storage stability at 25 °C than 4 °C in 90 days. The synergistic effect was observed in (CAP-PGZ)-loaded TB nanoparticles in HUVEC, HCT-116, and HT-29 cells. In (AO/PI) staining, the high percentage of apoptotic cells in the (CAP-PGZ)-loaded TB nanoparticles in HUVEC, HCT-116, and HT-29 were calculated as 78 %, 71.66 %, and 69.31 %, respectively.

CONCLUSION

The (CAP-PGZ)-loaded TB nanoparticles in this research offer an effective strategy for targeted combinational colorectal cancer therapy.

The Outcome of Induction Chemotherapy, Followed by Neoadjuvant Chemoradiotherapy and Surgery, in Locally Advanced Rectal Cancer

Background & Objective

Currently, neoadjuvant chemoradiotherapy, followed by surgery, is the standard treatment for locally advanced rectal cancer. The use of induction chemotherapy for this tumor is controversial. In this study, the benefits and side effects of induction chemotherapy in locally advanced rectal cancer are evaluated.

Methods

Twenty-nine patients with locally advanced rectal cancer in 2018-2019 were enrolled in this study. Initially, they underwent induction chemotherapy (oxaliplatin 130 mg/m² every 3 weeks and capecitabine 1000 mg/m² twice a day for 14 days every 3 weeks for 2 courses). Then, neoadjuvant chemoradiotherapy (radiotherapy 50.4 Gy/28 for 5 days a week concomitant with weekly oxaliplatin 50 mg/m², as well as capecitabine 825 mg/m²/bid on the days of radiotherapy) was administered. After 4 weeks, computed tomography (CT) scan of thorax, pelvis, and abdomen with and without contrast was performed. Total mesorectal surgery was performed 6-8 weeks after the end of radiotherapy. Four courses of adjuvant chemotherapy were applied. Pathologic complete response (pCR), margin, sphincter preservation, and adverse effects were assessed.

Results

In this study, pCR was present in 6 (20.7%) patients. R0 resection was done in 96.05%. Sphincter was preserved in 44.4% of lower rectal tumors. Two patients (6.9%) did not complete adjuvant treatment. Grade 3 adverse effects were documented in 13.7% of cases during induction chemotherapy and 17.2% of cases during neoadjuvant chemoradiation. Mortality was not reported.

Conclusion

Induction chemotherapy, followed by neoadjuvant chemoradiotherapy and surgery, would be an effective and safe modality in locally advanced rectal cancer.

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.

Predicting poor response to neoadjuvant chemoradiotherapy for locally advanced rectal cancer: Model constructed using pre-treatment MRI features of structured report template

PURPOSE

To develop a predictive model with pre-treatment magnetic resonance imaging (MRI) findings of the structured report template and clinical parameters for poor responses prediction after neoadjuvant chemoradiotherapy (neoCRT) in locally advanced rectal cancers (LARC) patients.

METHOD

Patients with clinicopathologically confirmed LARC (training and validation datasets, n = 100 and 71, respectively) were enrolled. Patients' clinical data were retrospectively collected. MRI findings of the structured report template were analysed. The tumour regression grade (TRG) system as proposed by Mandard et al was used. Poor response was defined as TRG 3-5. Univariate logistic regression analysis and a lasso regression model were performed to select the significant predictive features from the training set. A nomogram was constructed based on a multivariable logistic regression analysis. Calibration, discrimination, and clinical usefulness of the nomogram were assessed. The calibrative and discriminative ability of our model were compared with those of models including the tumour-node-metastasis (TNM) stage and clinical factors.

RESULTS

The MRI-reported T4b stage, MRI-reported extramural venous invasion (EMVI) positivity, MRI-detected number of positive mesorectal lymph nodes (LNs) > 0, and preoperative oxaliplatin and capecitabine (CAPOX) chemotherapy regimen were incorporated into our nomogram. The nomogram showed good discrimination, with areas under the receiver operating characteristic (ROC) curves of 0·823 and 0·820 in the training and test sets, respectively, and good calibration in both datasets. The decision curve analysis confirmed that the nomogram was clinically useful. The calibrative and discriminative ability of our model were better than those models including the TNM stage and clinical factors.

CONCLUSION

A nomogram based on pre-treatment MRI features of the structured report template and clinical risk factors has potential for use as a non-invasive tool to preoperatively predict poor responses in LARC patients after neoCRT.