Is there a need for neoadjuvant short-course radiotherapy in T3 rectal cancer with positive lymph node involvement? A single-center retrospective cohort study

Efficacies of radiotherapy in rectal cancer patients treated with total mesorectal excision or other types of surgery: an updated meta-analysis

Background

An updated meta-analysis was conducted to evaluate the efficacy of radiotherapy in rectal cancer patients treated with total mesorectal excision (TME) or other types of surgery (non-TME-only).

Methods

The PubMed, Cochrane Library, and CNKI databases were searched. Data on overall survival (OS) were extracted.

Results

Hazard ratios (HRs) for OS associated with preoperative radiotherapy, preoperative long-course concurrent chemoradiotherapy (LCCRT), preoperative radiotherapy alone, and postoperative radiotherapy in patients treated with TME were 1.02 [95% CI: 0.92-1.14, P = 0.65], 1.04 [95% CI: 0.93-1.16, P = 0.47], 0.87 [95% CI: 0.61-1.25, P = 0.46], and 1.18 [95% CI: 0.91-1.52, P = 0.20], respectively. HRs for OS associated with preoperative radiotherapy, preoperative LCCRT, preoperative radiotherapy alone, preoperative long-course RT (LCRT), and preoperative short-course radiotherapy (SCRT) in patients treated with non-TME-only surgery were 0.85 [95% CI: 0.79-0.90, P < 0.00001], 0.77 [95% CI: 0.63-0.94, P = 0.009], 0.86 [95% CI: 0.80-0.92, P < 0.0001], 0.83 [95% CI: 0.73-0.95, P = 0.005], and 0.84 [95% CI: 0.77-0.91, P= <0.0001], respectively. The HR for postoperative radiotherapy in patients treated with non-TME-only surgery was 1.08 [95% CI: 0.84-1.39, P = 0.57].

Conclusion

Preoperative radiotherapy, regardless of the regimen, improves the OS in patients treated with non-TME-only surgery, but not in those treated with TME. Postoperative radiotherapy does not improve OS.

Advances in knowledge

This meta-analysis will serve as a reference for decision-making in multidisciplinary approaches for rectal cancer patients.

Long-term outcomes and prognostic factors of short-course radiotherapy (SCRT) in rectal cancer: a monocentric retrospective study

PURPOSE

To evaluate efficacy and tolerance of short-course radiotherapy (SCRT) prior to possible chemotherapy (CHT) and surgery in 64 patients with locally advanced rectal cancer, in terms of acute and early late toxicity and survival outcomes with prognostic factors.

METHODS

Sixty-four patients affected by rectal tumor were treated from 2008 to 2023 radiation therapy, with a total dose of 25 Gy in 5 fractions. The Kaplan-Meier method was used to estimate the rates of overall survival (OS), cancer specific survival (CSS), local control (LC), disease free survival (DFS) and metastasis free survival (MFS). Univariate analysis for prognostic factors was performed with the log-rank test, and Cox proportional hazards regression was used to estimate hazard ratios. Toxicity assessment has been considered in acute and in early late for gastrointestinal (GI), genitourinary (GU) districts.

RESULTS

Median follow-up was 49.6 months. The median OS was 65 months with 1-year, 2-year and 5-year OS at 90.6%, 77.7% and 60% respectively. CSS at the 1-year, 2-year and 5-year was 98.3%, 96.2% and 86.2% respectively. LC at 1-year, 2-year and 5-year was 93.4%, 89.4% and 87.2% respectively. DFS at the 1-year, 2-year and 5-year was 93.4%, 89% and 87% respectively. The status of lymph nodes at diagnosis was a prognostic factor in term of LC and DFS. Acute GI toxicity was G1 in 10 (15.6%) patients. Five (7.8%) patients had a G1 acute GU toxicity. Fifteen (23.4%) patients developed chronic GI toxicities.

CONCLUSIONS

SCRT is an effective treatment in patients with rectal cancer and provides good outcomes with very low rates of toxicity profile.

Clinical development of MRI-based multi-sequence multi-regional radiomics model to predict lymph node metastasis in rectal cancer

OBJECTIVE

We aim to construct a magnetic resonance imaging (MRI)-based multi-sequence multi-regional radiomics model that will improve the preoperative prediction ability of lymph node metastasis (LNM) in T3 rectal cancer.

METHODS

Multi-sequence MRI data from 190 patients with T3 rectal cancer were retrospectively analyzed, with 94 patients in the LNM group and 96 patients in the non-LNM group. The clinical factors, subjective imaging features, and the radiomic features of tumor and peritumoral mesorectum region of patients were extracted from T2WI and ADC images. Spearman's rank correlation coefficient, Mann-Whitney's U test, and the least absolute shrinkage and selection operator were used for feature selection and dimensionality reduction. Logistic regression was used to construct six models. The predictive performance of each model was evaluated by the receiver operating characteristic curve (ROC). The differences of each model were characterized by area under the curve (AUC) via the DeLong test.

RESULTS

The AUCs of T2WI, ADC single-sequence radiomics model and multi-sequence radiomics model were 0.73, 0.75, and 0.78, respectively. The multi-sequence multi-regional radiomics model with improved performance was created by combining the radiomics characteristics of the peritumoral mesorectum region with the multi-sequence radiomics model (AUC, 0.87; p < 0.01). The AUC of the clinical model was 0.68, and the MRI-clinical composite evaluation model was obtained by incorporating the clinical data with the multi-sequence multi-regional radiomics features, with an AUC of 0.89.

CONCLUSION

The MRI-based multi-sequence multi-regional radiomics model significantly improved the prediction ability of LNM for T3 rectal cancer and could be applied to guide surgical decision-making in patients with T3 rectal cancer.

Individualized Treatment Approach for Rectal Adenocarcinoma in the Setting of Congenital Neutropenia

Congenial neutropenia is a rare genetic disorder that puts individuals at risk of life-threatening bacterial infections early in life, and the current standard of care includes the use of colony-stimulating factors or curative intent bone marrow transplant. Cancer treatment strategies that include surgery, chemotherapy, radiation, and immunotherapy present significant challenges to an individual with a baseline immunodeficiency as seen in this condition. Evidence-based national guidelines aid physicians and patients in moving through complex cancer care regimens. However, these are altered when the intensity of the patient's comorbidities puts them at increased risk of developing a potentially life-threatening infection. Here, we present a patient treated for rectal carcinoma in the setting of severe congenital neutropenia.

Efficacy of Neoadjuvant Therapy in Improving Long-Term Survival of Patients with Resectable Rectal Cancer: A Meta-Analysis

BACKGROUND

The impact of neoadjuvant therapy on long-term prognosis of patients with resectable rectal cancer is currently unknown.

OBJECTIVE

This study aimed to explore the long-term prognosis of patients with resectable rectal cancer following treatment with neoadjuvant therapy.

METHODS

Four major databases (PubMed, Web of Science, Embase, Cochrane library) were searched to identify relevant articles published between January 2000 and July 2020. The main outcome indicators were the 5-year overall survival (OS) and disease-free survival (DFS).

RESULTS

The meta-analysis revealed that 5-year OS (HR: 0.88, 95% Cl: 0.83-0.93) and DFS (HR: 0.95, 95% Cl: 0.91-0.98) were higher in patients with resectable rectal cancer after receiving neoadjuvant therapy than those treated with upfront surgery. Subgroup analysis demonstrated that the long-term survival of patients in Asia and Europe could benefit from neoadjuvant therapy. The neoadjuvant short-course radiotherapy (SCRT) and neoadjuvant chemo-radiotherapy (CRT) improved the 5-year OS and DFS of patients with stage Ⅱ-Ⅲ rectal cancer and mid/low rectal cancer. Further research found that patients with stage Ⅱ only had an increase in OS, while patients with stage Ⅲ have improved 5-year OS and DFS.

CONCLUSION

Neoadjuvant therapy improved the long-term survival of patients with mid/low rectal cancer in stage Ⅱ-Ⅲ (especially stage Ⅲ). Additionally, patients in Asia and Europe seemed to be more likely to benefit from neoadjuvant therapy. For the treatment, we recommend neoadjuvant SCRT and neoadjuvant CRT for resectable rectal cancer.

Histogram Analysis of Diffusion-Weighted Magnetic Resonance Imaging as a Biomarker to Predict Lymph Node Metastasis in T3 Stage Rectal Carcinoma

Purpose

This study investigated the predictive value of apparent diffusion coefficient (ADC) histogram parameters of the primary tumor for regional lymph node metastasis (LNM) in pathological T3 stage rectal cancer.

Patients and Methods

We retrospectively studied 175 patients with T3 stage rectal cancer who underwent preoperative MRI, including diffusion-weighted imaging, between January 2015 and October 2017. Based on pathological analysis of surgical specimens, 113 patients were classified into the LN− group and 62 in the LN+ group. We analyzed clinical data, radiological characteristics and histogram parameters derived from ADC maps. Then, receiver operating characteristic curve (ROC) analyses were generated to determine the best diagnostic performance.

Results

The mean (p=0.002, cutoff=1.08×10^–3 s/mm²), coefficient of variation (CV) (p=0.040, cutoff=0.249) of the ADC map, carbohydrate antigen 199, and N stage with magnetic resonance (mrN stage) were independent factors for LNM. Combining these factors yielded the best diagnostic performance, with the area under the ROC curve of 0.838, 72.9% sensitivity, 79.1% specificity, 65.2% positive predictive value, and 84.5% negative predictive value.

Conclusion

With the mean >1.08×10^–3 s/mm² and CV <0.249, the ADC improved the diagnostic performance of LNM in T3 stage rectal cancer, which could assist surgeons with neoadjuvant chemoradiotherapy.

Resistance to Cell Death in Mucinous Colorectal Cancer-A Review

Mucinous colorectal cancer (CRC) is estimated to occur in approximately 10-15% of CRC cases and is characterized by abundant extracellular mucin. Mucinous CRC is frequently associated with resistance to apoptosis. Inferior prognosis is observed in mucinous CRC, particularly in rectal cancer and metastatic cases. Mucins are heavily glycosylated secretory or transmembrane proteins that participate in protection of the colonic epithelium. MUC2 overexpression is a hallmark of mucinous CRCs. Mucinous CRC is associated with KRAS and BRAF mutation, microsatellite instability and the CpG island methylator phenotype. Mutations of the APC gene and p53 mutations which are characteristic non-mucinous colorectal adenocarcinoma are less common in mucinous CRC. Both physical and anti-apoptotic properties of mucin provide mechanisms for resistance to cell death. Mucin glycoproteins are associated with decreased expression of pro-apoptotic proteins, increased expression of anti-apoptotic proteins and increased cell survival signaling. The role for BCL-2 proteins, including BCL-X_L, in preventing apoptosis in mucinous CRC has been explored to a limited extent. Additional mechanisms opposing cell death include altered death receptor expression and altered mutation rates in genes responsible for chemotherapy resistance. The roles of alternate cell death programs including necroptosis and pyroptosis are not well understood in mucinous CRC. While the presence of MUC2 is associated with an immunosuppressive environment, the tumor immune environment of mucinous CRC and the role of immune-mediated tumor cell death likewise require further investigation. Improved understanding of cell death mechanisms in mucinous CRC may allow modification of currently used regimens and facilitate targeted treatment.

Development of the 'PREDICT' score through a systematic review and meta-analysis of the predictive parameters for locoregional recurrence after total mesorectal excision

BACKGROUND

Despite robust management techniques, locoregional recurrence rates of rectal cancer are still significant. Although offering intensive follow-up has been shown to be beneficial in the early detection, it can be resource consuming. Having a robust knowledge of risk factors of locoregional recurrence will help in identification of patients who actually need intensive follow-up programs. This review aimed to identify the factors that can predict locoregional recurrence after Total mesorectal excision (TME).

METHODS

We systematically reviewed PubMed, Scopus and Cochrane for relevant articles with no date restrictions while language was restricted to English. We only included articles that had either provided Hazards ratio (HR)/odds ratio (OR) or provided enough data that allowed calculation of HR/OR specifically for rectal cancer. Articles were deemed eligible if they included patients undergoing (TME).

RESULTS

Seventeen studies (18,605 patients) published between 2002 and 2019 were included. A total of 699 patients developed locoregional recurrence at a median time of 25.2 months after surgery. There were eight significant predictors evaluated by more than one study; T3-T4 stage, circumferential resection margin, lymphovascular invasion, mucinous histology, N1-N2 stage, positive distal resection margin, Tumor < 5 cm from anal verge, and lack of neoadjuvant radiotherapy. A scoring system was developed based on the weight and pooled OR/HR of each predictor.

CONCLUSION

Using predictive factors identified in our review in context of scoring system may help in the early detection of locoregional recurrence after TME. This may help in tailoring the application of intensive follow-up programs.