Current approaches in intensification of long-course chemoradiotherapy in locally advanced rectal cancer: a review

Diagnostic performance of Node-RADS score for mesorectal lymph node metastasis in rectal cancer

PURPOSE

To explore the diagnostic performance of the Node-RADS scoring system on preoperative assessment of mesorectal lymph node metastasis (LNM) status in rectal cancer, in comparison with the ESGAR category and size of lymph node (LN).

METHODS

Preoperative clinical and MRI data of 154 rectal adenocarcinoma patients treated with radical resection surgery were retrospectively analyzed. The differences in the clinical, pathological and imaging characteristics between the pN- and pN + groups were surveyed. The correlations of Node-RADS score and ESGAR category to pN stage, LNM number and lymph node ratio (LNR) were investigated. The performances on assessing pathological LNM were compared among individual approaches. A nomogram combined the imaging and clinical features was also established and evaluated.

RESULTS

Significant differences in CEA, tumor maximum diameter, tumor location, LN short-axis diameter, Node-RADS score and ESGAR category were found between the pN- and pN + groups. Node-RADS correlated significantly with pN stage, LNM number, and LNR (r = 0.665, 0.685, and 0.675, p < 0.001). Node-RADS had the highest AUC (0.862) for predicting pN + status, surpassing ESGAR (AUC = 0.797, p = 0.040) and LN size (AUC = 0.762, p = 0.015). The nomogram had the best diagnostic performance (AUC = 0.901), significantly outperforming Node-RADS alone (p = 0.037).

CONCLUSIONS

The Node-RADS scoring system is comparable to the ESGAR category and surpasses short-axis diameter in preoperatively predicting LNM in rectal cancer. Integrating imaging and clinical features will lead to an enhancement in diagnostic performance. Moreover, a clear relationship was demonstrated between the Node-RADS score and the quantity-dependent pathological characteristics of LNM.

Diagnostic performance of Node Reporting and Data System (Node-RADS) for assessing mesorectal lymph node in rectal cancer by CT

BACKGROUND

To compare the diagnostic performance of the Node-RADS scoring system and lymph node (LN) size in preoperative LN assessment for rectal cancer (RC), and to investigate whether the selection of size as the primary criterion whereas morphology as the secondary criterion for LNs can be considered the preferred method for clinical assessment.

METHODS

Preoperative CT data of 146 RC patients treated with radical resection surgery were retrospectively analyzed. The Node-RADS score and short-axis diameter of size-prioritized LNs and the morphology-prioritized LNs were obtained. The correlations of Node-RADS score to the pN stage, LNM number and lymph node ratio (LNR) were investigated. The performances on assessing pathological lymph node metastasis were compared between Node-RADS score and short-axis diameter. A nomogram combined the Node-RADS score and clinical features was also evaluated.

RESULTS

Node-RADS score showed significant correlation with pN stage, LNM number and LNR (Node-RADS of size-prioritized LN: r = 0.600, 0.592, and 0.606; Node-RADS of morphology-prioritized LN: r = 0.547, 0.538, and 0.527; Node-RADSmax: r = 0.612, 0.604, and 0.610; all p < 0.001). For size-prioritized LN, Node-RADS achieved an AUC of 0.826, significantly superior to short-axis diameter (0.826 vs. 0.743, p = 0.009). For morphology-prioritized LN, Node-RADS exhibited an AUC of 0.758, slightly better than short-axis diameter (0.758 vs. 0.718, p = 0.098). The Node-RADS score of size-prioritized LN was significantly better than that of morphology-prioritized LN (0.826 vs. 0.758, p = 0.038). The nomogram achieved the best diagnostic performance (AUC = 0.861) than all the other assessment methods (p < 0.05).

CONCLUSIONS

The Node-RADS scoring system outperforms the short-axis diameter in predicting lymph node metastasis in RC. Size-prioritized LN demonstrates superior predictive efficacy compared to morphology-prioritized LN. The nomogram combined the Node-RADS score of size-prioritized LN with clinical features exhibits the best diagnostic performance. Moreover, a clear relationship was demonstrated between the Node-RADS score and the quantity-dependent pathological characteristics of LNM.

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.

State of the neoadjuvant therapy for glioblastoma multiforme-Where do we stand?

Glioblastoma multiforme (GBM) is the most common malignant primary brain tumor in adults. Despite several investigations in this field, maximal safe resection followed by chemoradiotherapy and adjuvant temozolomide with or without tumor-treating fields remains the standard of care with poor survival outcomes. Many endeavors have failed to make a dramatic change in the outcomes of GBM patients. This study aimed to review the available strategies for newly diagnosed GBM in the neoadjuvant setting, which have been mainly neglected in contrast to other solid tumors.

Complication and response assessment of high-dose-rate endorectal brachytherapy boost in neo-adjuvant chemoradiotherapy of locally advanced rectal cancer with long-term outcomes

Purpose

To identify efficacy, complication, and pathologic response of high-dose-rate endorectal brachytherapy (HDR-BRT) boost in neo-adjuvant chemoradiotherapy (nCRT) of locally advanced rectal cancer.

Material and methods

Forty-four patients who met eligibility criteria were included in this non-randomized comparative study. Control group was recruited retrospectively. nCRT (50.40 Gy/28 fr. plus capecitabine 825 mg/m² twice daily) was administered to both groups before surgery. In the case group, HDR-BRT (8 Gy/2 fr.) was supplemented after chemoradiation. Surgery was done 6-8 weeks after completion of neo-adjuvant therapy. Pathologic complete response (pCR) was the study's primary endpoint.

Results

From 44 patients in the case and control groups, pCR was 11 (50%) and 8 (36.4%), respectively (p = 0.27). According to Ryan's grading system, tumor regression grade (TRG) TRG1, TRG2, and TRG3 were 16 (72.7%), 2 (9.1%), and 4 (18.2%) in the case, and 10 (45.5%), 7 (31.8%), and 5 (22.7%) in the control group (p = 0.118). T down-staging was found in 19 (86.4%) and 13 (59.1%) patients in the case and control groups, respectively. No grade > 2 toxicity was identified in both the groups. Organ preservation was achieved in 42.8% and 15.3% in the case and control arm (p = 0.192). In the case group, 8-year overall survival (OS) and disease-free survival (DFS) were 89% (95% CI: 73-100%) and 78% (95% CI: 58-98%), respectively. Our study did not reach median OS and median DFS.

Conclusions

Treatment schedule was well-tolerated, and neo-adjuvant HDR-BRT could achieve better T down-staging as a boost comparing with nCRT, without significant complication. However, the optimal dose and fractions in the context of HDR-BRT boost needs further studies.

Pathologic Implications of Radial Resection Margin and Perineural Invasion to Adjuvant Chemotherapy after Preoperative Chemoradiotherapy and Surgery for Rectal Cancer: A Multi-Institutional and Case-Matched Control Study

We assessed the exact role of adjuvant chemotherapy after neoadjuvant chemoradiotherapy (CRT) and surgery in rectal cancer patients with positive surgical margin or perineural invasion (PNI). This multi-institutional study included 1799 patients with rectal cancer at cT3-4N0-2M0 stages. Patients were divided into two groups. The high-risk group had a positive margin and/or perineural invasion. The low-risk group showed no positive margin or PNI. Propensity-score matching analysis was performed, and a total of 928 patients, with 464 in each arm, were evaluated. The high-risk group showed significant differences in overall survival (OS, 73.4% vs. 53.9%, p < 0.01) and recurrence-free survival (RFS, 52.7% vs. 40.9%, p = 0.01) at five years between the adjuvant chemotherapy arm and observation arm. The low-risk group showed no significant differences in 5-year OS (p = 0.61) and RFS (p = 0.75) between the two arms. Multivariate analyses showed that age, pathologic N stage, and adjuvant chemotherapy were significantly correlated with OS and RFS in the high-risk group (all p < 0.05). Adjuvant chemotherapy improved OS and RFS more significantly in rectal cancer patients with positive surgical margin or PNI than in those with negative surgical margin and PNI.

Simultaneous Integrated Boost Volumetric Modulated Arc Therapy for Rectal Cancer: Long-Term Results after Protocol-Based Treatment

Background

Volumetric modulated arc therapy (VMAT) with simultaneous integrated boost (SIB) is an advanced form of radiotherapy (RT) technology. The purpose of this study was to report long-term treatment outcomes in patients with locally advanced rectal cancer undergoing VMAT-SIB based concurrent chemoradiotherapy (CRT).

Methods

Between January 2016 and January 2018, a total of 22 patients with operable stage II-III rectal adenocarcinoma were recruited for the pre-designed VMAT-SIB RT protocol. All patients underwent standard diagnostic and staging work-up. The RT target volumes included the following areas: PTV1 = mesorectum that contained gross tumors and enlarged lymph node regions and PTV2 = mesorectum and regional lymphatics from L4-5/S1 to 3-4 cm below the tumor or levator ani muscle, excluding PTV1. The VMAT-SIB dose prescription was as follows: PTV1 = 52.5 Gy/daily 2.1 Gy/25 fractions, PTV2 = 45 Gy/daily 1.8 Gy/25 fractions.

Results

The mean age of the study population was 64 (range, 18-84) years, and 15 (68.2%) patients were male. Radical operation (total mesorectal excision) was performed by either low anterior resection, ultralow anterior resection, or abdominal perineal resection. All five (22.7%) of the patients with confirmed increasing serum carcinoembryonic antigen (CEA) level at diagnosis showed normalization of serum CEA level after the planned treatment. Among 20 patients who underwent preoperative CRT and surgery, tumor down staging in T- and N-stages was achieved in 10 patients (50%) and 13 patients (65%), respectively, with 20% of ypT0/Tis. With a median follow-up of 54.2 (range, 22.6-61.1) months, the 5-year disease-free survival, overall survival, and local control rates were 64.6%, 81.8%, and 84.4%, respectively. Five patients developed distant metastasis and one developed local recurrence as a first event. Two cases with anastomosis site leakage, three with adhesive ileus, and two with abscess formation were observed during postoperative periods.

Conclusions

The current VMAT-SIB-based CRT protocol provided acceptable treatment and toxicity outcomes.

Long-Term Feasibility of 13.56 MHz Modulated Electro-Hyperthermia-Based Preoperative Thermoradiochemotherapy in Locally Advanced Rectal Cancer

Simple Summary

We demonstrated that a 13.56 MHz modulated electro-hyperthermia (mEHT) boost is feasible in neoadjuvant treatment for rectal cancer. Herein, we attempted to present the long-term results for this phase 2 trial. Although there are many reports on the usefulness of thermoradiochemotherapy for loco-regional control, so far, only a few cases of survival benefit exist. Thus, this study assessed whether this limitation of hyperthermia could be overcome through the mEHT method featuring an applied energy variable. Following a median follow-up of 58 months for 60 patients, mEHT boost showed comparable results with conventional hyperthermia; potential therapeutic effects were also observed. Moreover, mEHT could be considered a useful tool in combination treatment with radiotherapy owing to its low thermotoxicity and improved treatment compliance.

Abstract

We evaluated the effect of 13.56 MHz modulated electro-hyperthermia (mEHT) boost in neoadjuvant treatment for cT3-4- or cN-positive rectal cancer. Sixty patients who completed the mEHT feasibility trial (ClinicalTrials.gov Identifier: NCT02546596) were analyzed. Whole pelvis radiotherapy of 40 Gy, mEHT boost twice a week during radiotherapy, and surgical resection 6–8 weeks following radiotherapy were performed. The median age was 59. The median follow-up period was 58 (6–85) months. Total/near total tumor regression was observed in 20 patients (33.3%), including nine cases of complete response. T- and N-downstaging was identified in 40 (66.6%) and 53 (88.3%) patients, respectively. The 5-year overall and disease-free survival were 94.0% and 77.1%, respectively. mEHT energy of ≥3800 kJ potentially increased the overall survival (p = 0.039). The ypN-stage and perineural invasion were possible significant factors in disease-free (p = 0.003 and p = 0.005, respectively) and distant metastasis-free (p = 0.011 and p = 0.034, respectively) survival. Tumor regression, resection margin status, and other molecular genetic factors showed no correlation with survival. Although a limited analysis of a small number of patients, mEHT was feasible considering long-term survival. A relatively low dose irradiation (40 Gy) plus mEHT setting could ensure comparable clinical outcomes with possible mEHT-related prognostic features.