Consolidation chemotherapy with capecitabine after neoadjuvant chemoradiotherapy in high-risk patients with locally advanced rectal cancer: Propensity score study.

BACKGROUND: The effects of consolidation chemotherapy (CC) in neoadjuvant therapy in locally advanced rectal cancer (LARC) have been explored. However, the optimal neoadjuvant chemoradiotherapy (NCRT) and surgery interval, regimen, and cycles of chemotherapy remains unclear. AIM: To evaluate the effects of one to two cycles of CC with capecitabine on high-risk patients with LARC without extending NCRT and surgery interval. METHODS: We retrospectively evaluated high-risk patients with LARC, who were defined as having at least one of the following factors by magnetic resonance imaging: depth of invasion beyond the muscularis propria of more than 5 mm (cT3c-cT3d), T4, meso-rectal fascia or extramural vascular invasion positive, and treatment date between January 2015 and July 2019 in our center. Patients were divided into the CC and non-CC group according to whether they received CC (capecitabine 1000 mg/m2 twice daily from days 1 to 14 every 21 d) after NCRT. Propensity score matching (PSM) and inverse probability of treatment weight (IPTW) were used to balance the differences between the two groups. The main outcome was the complete response (CR) rate. RESULTS: A total of 265 patients were enrolled: 136 patients in the CC group and 129 patients in the non-CC group. The median interval was 70 d (range, 37-168). The CR rate was 24.3% and 16.3% (P = 0.107) in the CC and non-CC groups' original samples, respectively. After PSM and IPTW, the CR rate in the CC group was higher than that in non-CC group (27.6% vs 16.2%, P = 0.045; 25.9% vs 16.3%, P = 0.045). The median follow-up was 39.8 mo (range, 2.9-74.8), and there were no differences in 3-year non-regrowth disease-free survival nor overall survival in the original samples (73.2% vs 71.9%, P = 0.913; 92.3% vs 86.7%, P = 0.294), PSM (73.2% vs 73.5%, P = 0.865; 92.5% vs 89.3%, P = 0.612), and IPTW (73.8% vs 72.1%, P = 0.913; 92.4% vs 87.4%, P = 0.294). There was also no difference in grade 2 or higher acute toxicity during neoadjuvant therapy in the two groups (49.3% vs 53.5%, P = 0.492). CONCLUSION: One to two cycles of CC with capecitabine after NCRT was safe and increased the CR rate in high-risk LARC but failed to improve the long-term outcomes.

Improving the accuracy and consistency of clinical target volume delineation for rectal cancer by an education program.

BACKGROUND: Accurate target volume delineation is the premise for the implementation of precise radiotherapy. Inadequate target volume delineation may diminish tumor control or increase toxicity. Although several clinical target volume (CTV) delineation guidelines for rectal cancer have been published in recent years, significant interobserver variation (IOV) in CTV delineation still exists among radiation oncologists. However, proper education may serve as a bridge that connects complex guidelines with clinical practice. AIM: To examine whether an education program could improve the accuracy and consistency of preoperative radiotherapy CTV delineation for rectal cancer. METHODS: The study consisted of a baseline target volume delineation, a 150-min education intervention, and a follow-up evaluation. A 42-year-old man diagnosed with stage IIIC (T3N2bM0) rectal adenocarcinoma was selected for target volume delineation. CTVs obtained before and after the program were compared. Dice similarity coefficient (DSC), inclusiveness index (IncI), conformal index (CI), and relative volume difference [ΔV (%)] were analyzed to quantitatively evaluate the disparities between the participants' delineation and the standard CTV. Maximum volume ratio (MVR) and coefficient of variation (CV) were calculated to assess the IOV. Qualitative analysis included four common controversies in CTV delineation concerning the upper boundary of the target volume, external iliac area, groin area, and ischiorectal fossa. RESULTS: Of the 18 radiation oncologists from 10 provinces in China, 13 completed two sets of CTVs. In quantitative analysis, the average CTV volume decreased from 809.82 cm3 to 705.21 cm3 (P = 0.001) after the education program. Regarding the indices for geometric comparison, the mean DSC, IncI, and CI increased significantly, while ΔV (%) decreased remarkably, indicating improved agreement between participants' delineation and the standard CTV. Moreover, an 11.80% reduction in MVR and 18.19% reduction in CV were noted, demonstrating a smaller IOV in delineation after the education program. Regarding qualitative analysis, the greatest variations in baseline were observed at the external iliac area and ischiorectal fossa; 61.54% (8/13) and 53.85% (7/13) of the participants unnecessarily delineated the external iliac area and the ischiorectal fossa, respectively. However, the education program reduced these variations. CONCLUSION: Wide variations in CTV delineation for rectal cancer are present among radiation oncologists in mainland China. A well-structured education program could improve delineation accuracy and reduce IOVs.

Patterns of failure and implications for clinical target volume definition of locally advanced T4b rectal cancer identified with magnetic resonance imaging and treated using neoadjuvant chemoradiotherapy and surgery.

BACKGROUND AND PURPOSE: Elective irradiation of the external iliac lymph nodes (EIN) has always been advocated for T4b rectal cancer with anterior organ invasion without convincing evidence. This study aimed to explore the patterns of treatment failure for locally advanced T4b rectal cancer treated using neoadjuvant chemoradiotherapy (NCRT) and surgery. This information may help to clarify whether the current definition of the clinical target volume (CTV) is still appropriate. MATERIALS AND METHODS: We retrospectively analyzed data from 126 patients with locally advanced T4b rectal cancer who received NCRT, without elective EIN irradiation, followed by surgery between January 2010 and October 2018. Pretreatment magnetic resonance imaging was used to identify the T4b disease in all cases. The locoregional recurrence (LRR) rate and EIN failure rate were evaluated, and the LRR locations were identified using a three-dimensional model. RESULTS: After a median follow-up of 53.9 months, LRR occurred in 11.1% of patients (14/126). All LRRs were located in the previously irradiated fields and below the S2-S3 junction. The EIN failure rate was 0.8% (1/126) among all patients and 1.8% (1/56) in the group with anterior genitourinary organ invasion. The estimated 4-year distant relapse-free survival, disease-free survival and overall survival were 79.3%, 73.2% and 86.9%, respectively. CONCLUSIONS: It may be feasible to exclude the external iliac region from the CTV during NCRT for locally advanced T4b rectal cancer. However, further studies are needed to clarify whether the cranial border of the CTV can be lowered.

Preliminary results of simultaneous integrated boost intensity-modulated radiation therapy based neoadjuvant chemoradiotherapy on locally advanced rectal cancer with clinically suspected positive lateral pelvic lymph nodes.

BACKGROUND: Lateral pelvic lymph node (LPLN) is approximately 11-14% and always associated with poorer prognosis. This study investigated the efficacy and safety of simultaneous integrated boost intensity-modulated radiation therapy (SIB-IMRT) based on neoadjuvant chemoradiotherapy (NCRT) on locally advanced rectal cancer (LARC) patients with clinically suspected positive LPLNs. METHODS: We retrospectively screened distal LARC patients with NCRT in our center from May 2016 and June 2019. The diagnostic criteria of positive LPLN were nodes of over 7 mm in short axis and irregular border or mixed-signal intensity. All patients with clinically suspected positive LPLN received 56-60 Gy SIB-IMRT in the LPLN area. Concurrent chemotherapy regimens were capecitabine as monotherapy treatment or in combination with oxaliplatin. The toxicities, local-regional recurrence (LRR), and disease-free survival (DFS) were investigated. RESULTS: Fifty-two eligible patients with clinically suspected positive LPLN were screened and analyzed. The median distance from the distal tumor to the anal verge was 4 cm (range, 0-8 cm), while magnetic resonance imaging (MRI) analysis revealed the median short diameter of the pelvic LPLN to be 8 mm (range, 7-20 mm). There were 28 (53.8%) mesorectal fascia (MRF) positive and 22 (42.3%) extramural venous invasion (EMVI) positive patients. A radiotherapy dose of 41.8 Gy was administered to the pelvic area, while the LPLN received a median SIB dose of 60.0 Gy (range, 56-60 Gy) across 22 fractions. Synchronous capecitabine with or without oxaliplatin was administered during radiotherapy. In summary, 15 (28.8%) patients displayed grade 2-3 radiation-related toxicity, 8 (15.4%) patients underwent additional LPLN dissection, and positive nodes (26 nodes in total) were not observed. One patient suffered a LLR in the presacral region. The median follow-up duration was 21.2 months (range, 4.7-45.0 months), while the duration of 1- and 2-year DFS were 89.9% and 74.6%, respectively. Patients did not display LPLN recurrence. CONCLUSIONS: The safety and efficacy of SIB-IMRT on clinically suspected positive LPLN of LARC patients were deemed acceptable. Patients did not exhibit in-field LPLN recurrence after NCRT combined with single total mesorectal excision (TME).

MRI-based radiomics model for preoperative prediction of 5-year survival in patients with hepatocellular carcinoma.

BACKGROUND: Recurrence is the major cause of mortality in patients with resected HCC. However, without a standard approach to evaluate prognosis, it is difficult to select candidates for additional therapy. METHODS: A total of 201 patients with HCC who were followed up for at least 5 years after curative hepatectomy were enrolled in this retrospective, multicentre study. A total of 3144 radiomics features were extracted from preoperative MRI. The random forest method was used for radiomics signature building, and five-fold cross-validation was applied. A radiomics model incorporating the radiomics signature and clinical risk factors was developed. RESULTS: Patients were divided into survivor (n = 97) and non-survivor (n = 104) groups based on the 5-year survival after surgery. The 30 most survival-related radiomics features were selected for the radiomics signature. Preoperative AFP and AST were integrated into the model as independent clinical risk factors. The model demonstrated good calibration and satisfactory discrimination, with a mean AUC of 0.9804 and 0.7578 in the training and validation sets, respectively. CONCLUSIONS: This radiomics model is a valid method to predict 5-year survival in patients with HCC and may be used to identify patients for clinical trials of perioperative therapies and for additional surveillance.

Associations of tumor regression grade with outcomes in patients with locally advanced rectal cancer treated with preoperative two-week course of radiotherapy.

PURPOSE: Studies concerning tumor regression grade (TRG) after two-week course of radiotherapy (RT) are limited. We tried to assess associations of TRG and outcomes in patients with locally advanced rectal cancer (LARC) treated with preoperative two-week course of RT. METHODS: 356 consecutive LARC patients were retrospectively assessed. Patients with complete/intermediate (TRG1-3) and poor (TRG4-5) regressions were compared for overall survival (OS), disease-free survival (DFS) and metastasis-free survival (MFS). RESULTS: By univariate analysis, pretreatment and postoperative factors including TNM stages, ypT, ypN, surgical procedure, pathological grade, and TRG impacted survival outcomes. Complete/intermediate regressions (TRG1-3) had significantly improved survival outcomes compared with poor ones (TRG4-5) (5y-OS, 85.8% vs. 65.8%, P=0.001; 5y-DFS, 76.0% vs. 53.7%, P<0.001; 5y-MFS, 84.2% vs. 66.7%, P<0.001). Multivariate analysis showed that ypN (P<0.001) and pathological grade (P=0.018) were the most important independent prognostic factors for DFS. ypT (P=0.014) and ypN (P=0.001) were the independent prognostic factors for MFS. Meanwhile, ypT (P=0.009), ypN (P=0.001), surgical procedure (p=0.001), and TRG (p=0.019) were the independent prognostic factors for OS. CONCLUSIONS: Complete/intermediate TRG regressions had a more favorable prognosis than the poor group. When treated with preoperative two-week course of RT; ypT, ypN, surgical procedure, and TRG seem to affect OS.

Two-week Course of Preoperative Radiotherapy for Locally Advanced Rectal Adenocarcinoma: 8 Years' Experience in a Single Institute.

OBJECTIVES: To evaluate local control and survival in locally advanced rectal adenocarcinoma patients who underwent a preoperative 2-week course of radiotherapy (RT) and to identify prognostic factors influencing the survival rate. METHODS: We analyzed 377 consecutively treated patients with locally advanced (T3/T4 or node positive) rectal adenocarcinoma. All patients underwent a preoperative 2-week course of RT (30 Gy in 10 fractions) followed by curative surgery. Regression model was used to examine prognostic factors for the disease-free survival (DFS) and overall survival (OS) rates. The Statistical Analysis System software package, version 9.3, was used for analysis. RESULTS: The median follow-up for all living patients was 63.8 months (range, 5.1 to 131.7). The 5-year DFS and OS rates were 64.5% (95% CI, 59.0-69.4) and 75.6% (95% CI, 70.5-80.0), respectively. The 5-year cumulative incidences of local recurrence and distant metastases were 5.4% (95% CI, 2.9-7.9) and 29.0% (95% CI, 23.9-30.1), respectively. The pathologic complete response rate was achieved in 17 patients (4.5%). The Multivariate Cox Regression model showed that factors affecting DFS were the surgical technique, pre-RT pathologic grade, ypT, ypN, and comorbidity; and factors improving OS were low anterior resection, low pre-RT grade, low ypT, and low ypN. CONCLUSIONS: Patients treated with preoperative RT with 30 Gy in 10 fractions had similar local control, 5-year DFS and OS to reported long course RT regimen. The surgical technique, pre-RT pathologic grade, ypT, and ypN seemed to affect the OS. Further study on combining a 2-week course of preoperative RT with concurrent chemotherapy would be warranted.

Intensity-modulated radiation therapy for pelvic oligo-recurrence from rectal cancer: long-term results from a single institution.

BACKGROUND: Pelvic oligo-recurrence is common in rectal cancer patients, and some could not achieve radical resection. OBJECTIVE: The study was to analyze long-term outcomes and prognostic factors associated with survival in patients treated with intensity-modulated radiation therapy (IMRT). METHODS: Study participants were identified from rectal patients with pelvic oligo-recurrence without distant metastases, who were not suitable for surgery (n=135). Patients were recommended to receive concurrent chemotherapy in the course of IMRT (median dose 64.5 Gy, range: 45-70 Gy). Additionally, 24.4% (33/135) of patients received radical surgery after preoperative radiotherapy. Median time to pelvic failure was 25.4 months (range: 1-144 months). With a median follow-up period of 45.5 months (range: 3-104 months), 5-year overall survival (OS) and disease-free survival (DFS) were 55.6% and 45.5%, respectively. RESULTS: In univariate survival analysis, OS stratified by subsites indicated that 5-year OS for anastomotic recurrence (80.5%) was better than for anterior recurrence (57.7%) and other pelvic oligo-recurrences (44.5%) (P=0.005). Five-year DFS in the three groups was 60.3%, 49% and 36.6%, respectively (P=0.037). In multivariate survival analysis, pelvic oligo-recurrence and symptomatic recurrence patterns were independently associated with OS in recurrent rectal cancer after pelvic radiotherapy (RT). CONCLUSIONS: These results indicate that RT for rectal cancer patients with pelvic oligo-recurrence had favorable prognosis, especially for patients with anastomotic recurrence.