Neoadjuvant Chemotherapy in Locally Advanced Rectal Cancer

Comprehensive Review of Endometrial Cancer: New Molecular and FIGO Classification and Recent Treatment Changes

Endometrial cancer (EC) is the most common gynecologic malignancy in developed countries, with rising incidence due to aging populations and obesity-related factors. This review explores the evolving molecular and FIGO classifications of EC, highlighting their significance in diagnosis, prognosis, and personalized treatment strategies. Molecular subtyping based on The Cancer Genome Atlas (TCGA) classification offers a more precise understanding of EC, dividing it into POLE ultramutated, microsatellite instability-high (MSI-H), copy-number low (CNL), and copy-number high (CNH) subtypes. Each subgroup has distinct genetic, histological, and prognostic characteristics. Recent updates to the FIGO staging system incorporate molecular features, allowing for more tailored treatment approaches. Advances in immunotherapy, targeted therapies, and novel therapeutic combinations have reshaped clinical management. This review emphasizes the integration of molecular diagnostics into routine practice, outlining challenges and future perspectives in managing EC for improved patient outcomes.

Therapeutic Management of Locally Advanced Rectal Cancer: Existing and Prospective Approaches

Rectal cancer (RC) presents significant challenges in diagnosis and treatment, with increasing incidence among younger populations. Treatment approaches, particularly for locally advanced rectal cancer (LARC), have evolved, notably with the introduction of total neoadjuvant therapy (TNT). TNT combines neoadjuvant chemotherapy and chemoradiotherapy before surgery, improving overall survival and reducing both metastasis and local recurrence rates compared to traditional methods, while enabling more patients to complete the full oncological treatment. Clinical trials, such as RAPIDO, OPRA, and PRODIGE 23, have demonstrated the effectiveness of TNT in tumor downstaging and complete pathological responses, offering better outcomes for patients; however, debates persist regarding the role of neoadjuvant radiotherapy, with novel strategies exploring its omission in specific cases to reduce toxicity and enhance quality of life. In addition, organ preservation strategies, such as the watch-and-wait (WW) approach, have emerged as viable options for patients with a complete response to neoadjuvant therapy. Future directions point towards personalized treatment plans incorporating radiogenomics and the integration of artificial intelligence into diagnostics to optimize patient outcomes. This review aims to synthesize current treatment strategies and ongoing advancements in rectal cancer management, providing insights into potential future innovations.

YAP Promotes Chemoresistance to 5-FU in Colorectal Cancer Through mTOR/GLUT3 Axis

Background: Although chemoresistance constitutes a significant barrier to the effectiveness of chemotherapy in colorectal cancer (CRC), its precise mechanisms remain unclear. YAP functions as an oncogene in various malignancies. However, the relationship between YAP and chemoresistance in CRC needs clarification. Methods: The expression level of YAP in CRC tissues was assessed through immunohistochemistry (IHC), and the impact of YAP on CRC cell chemoresistance was evaluated using the Cell Counting Kit-8, EdU, and flow cytometry assays. Meanwhile, tumor proliferation was assessed in vivo by analyzing the expression of PCNA and Ki-67 in subcutaneous tumors via IHC. In addition, the TUNEL assay was employed to evaluate tumor apoptosis levels and western blot was utilized to detect the mTOR/GLUT3 pathway-related protein expression to provide insights into the underlying mechanism. Results: YAP was highly expressed in CRC tissues and correlated with patient prognosis and clinicopathological features. Bioinformatic analysis based on the TCGA database revealed that YAP was associated with DNA replication, glycolysis, and the mTOR pathway. Meanwhile, YAP could enhance chemoresistance and glycolysis in CRC cells both in vitro and in vivo. Additional mechanistic experiments unveiled that YAP promoted CRC cell chemoresistance via the mTOR/GLUT3 axis. Conclusion: This study validated the role of YAP as an oncogene in CRC, as it promoted chemoresistance through the mTOR/GLUT3 axis. These results suggested YAP as a potential target for promoting the efficacy of chemotherapy in patients with CRC.

Colon Cancer With Bladder Invasion: A Single Center Experience

BACKGROUND/AIM

The aim of our study was to investigate the outcome of colon cancer with bladder invasion after surgical intervention.

PATIENTS AND METHODS

Between 2011 and 2022, a total of 41 patients diagnosed with colon cancer and bladder invasion underwent surgical procedures at Taichung Veterans General Hospital. The impact of various risk factors on overall survival (OS) was assessed using Kaplan-Meier analyses and Cox proportional hazards models.

RESULTS

Among the enrolled patients, 21 underwent radical cystectomy, while 20 underwent partial cystectomy. Twelve had tumors located in the rectum, 19 in the sigmoid colon, and 10 in both the rectum and sigmoid colon. The median OS was 71.8 months in stage 2, 50.8 months in stage 3, and 11.2 months in stage 4 (p=0.061). Median OS was 71.8 months in patients with negative surgical margins and 10.5 months in those with positive surgical margins (p=0.003). In multivariate regression analysis, positive surgical margins [hazard ratio (HR)=3.64, 95% confidence interval (CI)=1.28-10.34, p=0.015] and emergency operations (HR=4.57, 95%CI=1.34-15.55, p=0.015) significantly impacted OS.

CONCLUSION

Complete resection of colon cancer with bladder invasion can yield excellent oncologic outcomes. The decision between partial and radical cystectomy should balance surgical margin clearance and the preservation of quality of life. Both surgical margin involvement and emergency operations are independent risk factors for OS.

Sarcopenia among treated cancer patients before and after neoadjuvant chemotherapy: a systematic review and meta-analysis of high-quality studies

BACKGROUND

Neoadjuvant chemotherapy, used to shrink tumors before surgery, is increasingly applied in clinical practice. However, retrospective studies indicate that it may increase sarcopenia rates and consequently result in an elevated occurrence rate of postoperative severe complications such as severe surgical incision infection, severe respiratory failure, and severe postoperative hemorrhage, especially in the elderly population. Currently, no systematic analysis examines the association between neoadjuvant chemotherapy and sarcopenia. This study aims to fill this gap with a comprehensive meta-analysis focused on this critical aspect of the field.

METHODS

A systematic literature search was conducted in the PubMed and Web of Science databases from their inception to January 2024. The included studies encompassed patients who received neoadjuvant chemotherapy and underwent computed tomography (CT) scans both before and after treatment to calculate skeletal muscle index (SMI) or categorize them for the presence of sarcopenia. The determination of sarcopenia status was based on well-established and validated threshold criteria. Data extraction was performed independently by two reviewers. A meta-analysis was employed to estimate the pooled odds ratio (OR) and its corresponding 95% confidence interval (95% CI) to assess the risk of neoadjuvant chemotherapy-induced muscle reduction.

RESULTS

In the 14 studies with complete categorical variable data, comprising 1853 patients, 773 patients were identified as having sarcopenia before neoadjuvant treatment and 941 patients had sarcopenia after neoadjuvant therapy. The OR and its 95% CI was calculated as 1.51 [1.31, 1.73]. Among these, 719 patients had digestive system cancer, with 357 patients having sarcopenia before neoadjuvant treatment and 447 patients after, resulting in an OR of 1.74 [1.40, 2.17]. In the remaining 1134 patients with non-digestive system cancers, 416 were identified as having sarcopenia before neoadjuvant treatment, and 494 patients had sarcopenia after, with an OR of 1.37 [1.15, 1.63]. Additionally, in seven studies with complete continuous variable data, including 1228 patients, the mean difference in the change of SMI before and after neoadjuvant treatment was  - 1.13 [- 1.65,  - 0.62]. After excluding low-quality small-sample studies with fewer than 50 patients, the same trend was observed in the analysis.

CONCLUSION

The risk of muscle reduction significantly increases in cancer patients after neoadjuvant chemotherapy and digestive system cancers tend to have a higher risk of developing sarcopenia post-treatment compared to non-digestive system cancers.

Longitudinal Risk Analysis of Second Primary Cancer after Curative Treatment in Patients with Rectal Cancer

Predicting and improving the response of rectal cancer to second primary cancers (SPCs) remains an active and challenging field of clinical research. Identifying predictive risk factors for SPCs will help guide more personalized treatment strategies. In this study, we propose that experience data be used as evidence to support patient-oriented decision-making. The proposed model consists of two main components: a pipeline for extraction and classification and a clinical risk assessment. The study includes 4402 patient datasets, including 395 SPC patients, collected from three cancer registry databases at three medical centers; based on literature reviews and discussion with clinical experts, 10 predictive variables were considered risk factors for SPCs. The proposed extraction and classification pipelines that classified patients according to importance were age at diagnosis, chemotherapy, smoking behavior, combined stage group, and sex, as has been proven in previous studies. The C5 method had the highest predicted AUC (84.88%). In addition, the proposed model was associated with a classification pipeline that showed an acceptable testing accuracy of 80.85%, a recall of 79.97%, a specificity of 88.12%, a precision of 85.79%, and an F1 score of 79.88%. Our results indicate that chemotherapy is the most important prognostic risk factor for SPCs in rectal cancer survivors. Furthermore, our decision tree for clinical risk assessment illuminates the possibility of assessing the effectiveness of a combination of these risk factors. This proposed model may provide an essential evaluation and longitudinal change for personalized treatment of rectal cancer survivors in the future.

Magnetic resonance imaging-based radiomics analysis for prediction of treatment response to neoadjuvant chemoradiotherapy and clinical outcome in patients with locally advanced rectal cancer: A large multicentric and validated study

Our study investigated whether magnetic resonance imaging (MRI)-based radiomics features could predict good response (GR) to neoadjuvant chemoradiotherapy (nCRT) and clinical outcome in patients with locally advanced rectal cancer (LARC). Radiomics features were extracted from the T2 weighted (T2W) and Apparent diffusion coefficient (ADC) images of 1070 LARC patients retrospectively and prospectively recruited from three hospitals. To create radiomic models for GR prediction, three classifications were utilized. The radiomic model with the best performance was integrated with important clinical MRI features to create the combined model. Finally, two clinical MRI features and ten radiomic features were chosen for GR prediction. The combined model, constructed with the tumor size, MR-detected extramural venous invasion, and radiomic signature generated by Support Vector Machine (SVM), showed promising discrimination of GR, with area under the curves of 0.799 (95% CI, 0.760-0.838), 0.797 (95% CI, 0.733-0.860), 0.754 (95% CI, 0.678-0.829), and 0.727 (95% CI, 0.641-0.813) in the training and three validation datasets, respectively. Decision curve analysis verified the clinical usefulness. Furthermore, according to Kaplan-Meier curves, patients with a high likelihood of GR as determined by the combined model had better disease-free survival than those with a low probability. This radiomics model was developed based on large-sample size, multicenter datasets, and prospective validation with high radiomics quality score, and also had clinical utility.

Current Applications and Future Directions of Circulating Tumor Cells in Colorectal Cancer Recurrence

The ability to predict or detect colorectal cancer (CRC) recurrence early after surgery enables physicians to apply appropriate treatment plans and different follow-up strategies to improve patient survival. Overall, 30-50% of CRC patients experience cancer recurrence after radical surgery, but current surveillance tools have limitations in the precise and early detection of cancer recurrence. Circulating tumor cells (CTCs) are cancer cells that detach from the primary tumor and enter the bloodstream. These can provide real-time information on disease status. CTCs might become novel markers for predicting CRC recurrence and, more importantly, for making decisions about additional adjuvant chemotherapy. In this review, the clinical application of CTCs as a therapeutic marker for stage II CRC is described. It then discusses the utility of CTCs for monitoring cancer recurrence in advanced rectal cancer patients who undergo neoadjuvant chemoradiotherapy. Finally, it discusses the roles of CTC subtypes and CTCs combined with clinicopathological factors in establishing a multimarker model for predicting CRC recurrence.

A nomogram based on MRI radiomics features of mesorectal fat for diagnosing T2- and T3-stage rectal cancer

PURPOSE

To develop and validate a nomogram for the preoperative diagnosis of T2 and T3 stage rectal cancer using MRI radiomics features of mesorectal fat.

METHODS

The data of 288 patients with T2 and T3 stage rectal cancer were retrospectively collected. Radiomics features were extracted from the lesion region of interest (ROI) in the MRI high-resolution T2WI, apparent diffusion coefficient (ADC), and diffusion-weighted imaging (DWI) sequences. After using ICC inter-group consistency analysis and Pearson correlation analysis to reduce dimensions, LASSO regression analysis was performed to select features and calculate Rad-score for each sequence. Then, Combined_Radscore and nomogram were constructed based on the LASSO-selected features and clinical data for each sequence. Receiver operating characteristic curve (ROC) area under the curve (AUC) was used to evaluate the performance of the Rad-score model and nomogram. Decision curve analysis (DCA) was performed to evaluate the clinical usability of the radiomics nomogram, which were combined with calibration curves to evaluate the prediction accuracy.

RESULTS

The nomogram based on MRI-report T status and Combined_Radscore achieved AUCs of 0.921 and 0.889 in the training and validation cohorts, respectively.

CONCLUSION

The nomogram can be stated that the radiomics nomogram based on multi-sequence MRI imaging of the mesorectal fat has excellent diagnosing performance for preoperative differentiation of T2 and T3 stage rectal cancer.

Effect of Tumor Regression Grade on Survival and Disease-Free Interval in Patients Operated on for Locally Advanced Rectal Cancer

INTRODUCTION

Colorectal cancer is the fourth leading cause of cancer-related death in both men and women in our population. In this regard, rectal cancer accounts for more than half of colorectal cancer deaths, and its incidence is expected to increase in the coming years. There have been significant changes in neoadjuvant therapy regimens, with promising results, as demonstrated by the recent RAPIDO and PRODIGE23 studies. Around 40% of patients diagnosed with locally advanced rectal cancer show some degree of response to neoadjuvant treatment, with complete tumor regression observed in up to one in five patients.

MATERIALS AND METHODS

Retrospective observational study. A total of 181 patients with locally advanced rectal cancer treated with neoadjuvant chemoradiotherapy followed by surgery were analyzed. Clinical and pathological data were collected from the patients, including assessment of tumor regression through histopathological studies after surgery. The Mandard tumor regression grading system was used to categorize tumor response into different grades.

RESULTS

The results showed a significant association between the degree of tumor regression and several important clinical outcomes. Specifically, patients with higher tumor regression had significantly better disease-free survival than those with less regression (p = 0.004). In addition, tumor regression was also correlated with the incidence of local recurrence (p = 0.018) and distant metastasis (p = 0.032). These associations suggest that tumor responsiveness to neoadjuvant therapy may influence the long-term progression of the disease. Regarding tumor deposits and the presence of lymphadenopathy, these factors were also found to be significantly associated with clinical outcomes. Patients with tumor deposits had a higher incidence of local recurrence (p = 0.025) and distant metastases (p = 0.041), while the presence of lymphadenopathy increased the risk of local recurrence (p = 0.013). These findings highlight the importance of evaluating not only tumor regression but also other pathological markers to predict prognosis and guide clinical management.

CONCLUSIONS

The degree of tumor regression was not an independent predictor of survival compared to other variables such as nodal stage and presence of tumor deposits. This indicates that while tumor regression is an important factor, other elements also play a crucial role in determining the prognosis of patients with locally advanced rectal cancer. This study provides additional evidence for the importance of tumor regression, tumor deposits, and lymphadenopathy as predictors of clinical outcomes in patients with rectal cancer treated with neoadjuvant chemoradiotherapy.

Longitudinal Analysis of Local Recurrence and Survival After Transanal Abdominal Transanal Radical Proctosigmoidectomy for Low Rectal Cancer Treated With Neoadjuvant Chemoradiation Therapy

BACKGROUND

The transanal abdominal transanal radical proctosigmoidectomy was developed in 1984 as a sphincter preservation surgery in patients with low rectal cancers after preoperative radiation therapy. While serving as a catalyst for disruptive sphincter preservation surgery, it continues to be used and evolve. With the controversy over safety and local recurrence in other sphincter-preserving surgery, review of transanal abdominal transanal radical proctosigmoidectomy long-term oncologic outcomes is warranted.

OBJECTIVE

To assess local recurrence and survival after transanal abdominal transanal radical proctosigmoidectomy after neoadjuvant chemoradiation therapy.

DESIGN

Retrospective cohort study of a prospectively maintained database.

SETTINGS

Tertiary rectal cancer referral center.

PATIENTS

Patients with low adenocarcinoma (≤5 cm anorectal ring) receiving neoadjuvant chemoradiation therapy and then transanal abdominal transanal radical proctosigmoidectomy for curative resection between 1998 and 2021.

MAIN OUTCOME MEASURES

Local recurrence rates and overall survival rates.

RESULTS

Of 255 included patients, 67.8% were men (n = 173); the mean age was 58.7 years (SD 11.5) and the mean BMI was 27.1 (SD 5.4), with 50.2% (n = 128) having ASA class II and 49.8% (n = 127) having ASA class III/IV. The mean tumor size was 4.8 cm (SD 1.9), the majority of patients had clinical T3 disease (81.8%; n = 184), and 52.1% had nodal disease (n = 100). The median radiation dose was 5400 cGy, with 73.7% (n = 149) achieving good response and 90.2% (n = 230) receiving minimally invasive surgery. The complete total mesorectal excision rate was 94.3%, and 100% of patients (n = 255) had negative distal margins. The mean number of examined lymph nodes were 13.9 (SD 10.7). After a median follow-up of 55.4 months, 5.1% of patients (n = 13) developed local recurrence at a median time of 29.6 months. The 5-year overall survival was 84.1% (95% CI, 78.8-89.4).

LIMITATIONS

Retrospective review with risk of bias and lack of generalizability.

CONCLUSIONS

In this longitudinal study, the transanal abdominal transanal radical proctosigmoidectomy demonstrated excellent long-term locoregional control and survival in very low rectal cancers. The superior transanal abdominal transanal radical proctosigmoidectomy outcomes are durable over time, warranting expansion of the sphincter-preserving surgery technique. See Video Abstract .

ANLISIS LONGITUDINAL DE LA RECURRENCIA LOCAL Y LA SUPERVIVENCIA DESPUS DE LA PROCTOSIGMOIDECTOMA RADICAL TRANSANAL ABDOMINAL TATA PARA EL CNCER DE RECTO BAJO TRATADO CON QUIMIORRADIACIN NEOADYUVANTE

ANTECEDENTES:La proctosigmoidectomía radical transanal abdominal se desarrolló en 1984 como una cirugía de preservación del esfínter en cánceres de recto bajo después de la radiación preoperatoria. Si bien sirve como catalizador para la cirugía disruptiva de preservación del esfínter, continúa utilizándose y evolucionando. Con la controversia sobre la seguridad y la recurrencia local en otras cirugías que preservan el esfínter, se justifica la revisión de los resultados oncológicos a largo plazo de la proctosigmoidectomía radical transanal abdominal.OBJETIVO:Evaluar localmente después de Proctosigmoidectomía Radical Transanal Abdominal Transanal después de quimiorradiación neoadyuvante.DISEÑO:Estudio de cohorte retrospectivo de una base de datos mantenida de forma prospectiva.AJUSTES:Centro terciario de referencia para el cáncer de recto.PACIENTES:Adenocarcinoma bajo (=/ Collapse

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MESH Headings

• Humans
• Male
• Middle Aged
• Female
• Retrospective Studies
• Longitudinal Studies
• Neoadjuvant Therapy
• Rectal Neoplasms/surgery
• Adenocarcinoma/therapy
• Adenocarcinoma/pathology
• Neoplasm Staging

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Affiliation(s)

John H Marks Lankenau Medical Center, Lankenau Institute for Medical Research, Wynnewood, Pennsylvania
Thais Reif de Paula
Hela Saidi
Taylor P Ikner
Henry Schoonyoung
Gerald Marks
Deborah S Keller

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A Rare Case of Submandibular Gland Squamous Cell Carcinoma: Diagnostic Challenges and Surgical Management

Squamous cell carcinoma (SCC) in salivary glands is rare, often posing diagnostic challenges. This case report presents a 75-year-old male with progressively increasing swelling and pain in the right submandibular gland, eventually diagnosed as moderately differentiated SCC. The diagnostic journey involved fine needle aspiration cytology, imaging studies, and histopathological examination. The patient underwent surgical intervention, including submandibular gland excision and selective neck dissection, which successfully achieved local control. Subsequent postoperative follow-up indicated a favorable outcome, with no significant complaints. This report contributes insights into the multidisciplinary diagnostic approach and underscores the importance of imaging modalities in managing salivary gland SCC. This rare case emphasizes the need for ongoing research to refine management strategies for salivary gland SCC. By presenting a comprehensive diagnostic and therapeutic approach, this report contributes to the limited literature on this malignancy, emphasizing its rarity and the necessity for continued exploration of long-term outcomes. In conclusion, our case provides valuable insights into the medical knowledge surrounding SCC in salivary glands, warranting attention and further investigation.

Efferent limb stimulation prior to loop ileostomy closure: a systematic review and meta-analysis

BACKGROUND

Postoperative ileus (POI) remains a common phenomenon following loop ileostomy closure. Our aim was to determine whether preoperative physiological stimulation (PPS) of the efferent limb reduced POI incidence.

METHODS

A PRISMA-compliant meta-analysis searching PubMed, EMBASE and CENTRAL databases was performed. The last search was carried out on 30 January 2023. All randomized studies comparing PPS versus no stimulation were included. The primary endpoint was POI incidence. Secondary endpoints included the time to first passage of flatus/stool, time to resume oral diet, need for nasogastric tube (NGT) placement postoperatively, length of stay (LOS) and other complications. Random effects models were used to calculate pooled effect size estimates. Trial sequential analyses (TSA) were also performed.

RESULTS

Three randomized studies capturing 235 patients (116 PPS, 119 no stimulation) were included. On random effects analysis, PPS was associated with a quicker time to resume oral diet (MD - 1.47 days, 95% CI - 2.75 to - 0.19, p = 0.02), shorter LOS (MD - 1.47 days, 95% CI - 2.47 to - 0.46, p = 0.004) (MD - 1.41 days, 95% CI - 2.32 to - 0.50, p = 0.002, I2 = 56%) and fewer other complications (OR 0.42, 95% CI 0.18 to 1.01, p = 0.05). However, there was no difference in POI incidence (OR 0.35, 95% CI 0.10 to 1.21, p = 0.10), the requirement for NGT placement (OR 0.50, 95% CI 0.21 to 1.20, p = 0.12) or time to first passage of flatus/stool (MD - 0.60 days, 95% CI - 1.95 to 0.76, p = 0.39). TSA revealed imprecise estimates for all outcomes (except LOS) and further studies are warranted to meet the required information threshold.

CONCLUSIONS

PPS prior to stoma closure may reduce LOS and postoperative complications albeit without a demonstrable beneficial effect on POI. Further high-powered studies are required to confirm or refute these findings.

Fully automated volumetric modulated arc therapy planning for locally advanced rectal cancer: feasibility and efficiency

BACKGROUND

Volumetric modulated arc therapy (VMAT) for locally advanced rectal cancer (LARC) has emerged as a promising technique, but the planning process can be time-consuming and dependent on planner expertise. We aimed to develop a fully automated VMAT planning program for LARC and evaluate its feasibility and efficiency.

METHODS

A total of 26 LARC patients who received VMAT treatment and the computed tomography (CT) scans were included in this study. Clinical target volumes and organs at risk were contoured by radiation oncologists. The automatic planning program, developed within the Raystation treatment planning system, used scripting capabilities and a Python environment to automate the entire planning process. The automated VMAT plan (auto-VMAT) was created by our automated planning program with the 26 CT scans used in the manual VMAT plan (manual-VMAT) and their regions of interests. Dosimetric parameters and time efficiency were compared between the auto-VMAT and the manual-VMAT created by experienced planners. All results were analyzed using the Wilcoxon signed-rank sum test.

RESULTS

The auto-VMAT achieved comparable coverage of the target volume while demonstrating improved dose conformity and uniformity compared with the manual-VMAT. V30 and V40 in the small bowel were significantly lower in the auto-VMAT compared with those in the manual-VMAT (p < 0.001 and < 0.001, respectively); the mean dose of the bladder was also significantly reduced in the auto-VMAT (p < 0.001). Furthermore, auto-VMAT plans were consistently generated with less variability in quality. In terms of efficiency, the auto-VMAT markedly reduced the time required for planning and expedited plan approval, with 93% of cases approved within one day.

CONCLUSION

We developed a fully automatic feasible VMAT plan creation program for LARC. The auto-VMAT maintained target coverage while providing organs at risk dose reduction. The developed program dramatically reduced the time to approval.

XPF-ERCC1 Blocker Improves the Therapeutic Efficacy of 5-FU- and Oxaliplatin-Based Chemoradiotherapy in Colorectal Cancer

5-FU-based chemoradiotherapy (CRT) and oxaliplatin-based CRT are commonly used therapies for advanced colorectal cancer (CRC). However, patients with a high expression of ERCC1 have a worse prognosis than those with a low expression. In this study, we investigated the effect of XPF-ERCC1 blockers on chemotherapy and 5-FU-based CRT and oxaliplatin (OXA)-based CRT in colorectal cancer cell lines. We investigated the half-maximal inhibitory concentration (IC50) of 5-FU, OXA, XPF-ERCC1 blocker, and XPF-ERCC1 blocker, and 5-FU or OXA combined and analyzed the effect of XPF-ERCC1 blocker on 5-FU-based CRT and oxaliplatin-based CRT. Furthermore, the expression of XPF and γ-H2AX in colorectal cells was analyzed. In animal models, we combined the XPF-ERCC1 blocker with 5-FU and OXA to investigate the effects of RC and finally combined the XPF-ERCC1 blocker with 5-FU- and oxaliplatin-based CRT. In the IC50 analysis of each compound, the cytotoxicity of the XPF-ERCC1 blocker was lower than that of 5-FU and OXA. In addition, the XPF-ERCC1 blocker combined with 5-FU or OXA enhanced the cytotoxicity of the chemotherapy drugs in colorectal cells. Furthermore, the XPF-ERCC1 blocker also increased the cytotoxicity of 5-FU-based CRT and OXA -based CRT by inhibiting the XPF product DNA locus. In vivo, the XPF-ERCC1 blocker was confirmed to enhance the therapeutic efficacy of 5-FU, OXA, 5-FU-based CRT, and OXA CRT. These findings show that XPF-ERCC1 blockers not only increase the toxicity of chemotherapy drugs but also increase the efficacy of combined chemoradiotherapy. In the future, the XPF-ERCC1 blocker may be used to improve the efficacy of 5-FU- and oxaliplatin-based CRT.

Short-Course Radiotherapy Followed by Consolidation Chemotherapy Is Safe and Effective in Locally Advanced Rectal Cancer: Comparative Short-term Results of Multicenter Propensity Score Case-Matched Study

BACKGROUND

Consolidation chemotherapy strategies have demonstrated improved pathological complete response and tumor downstaging rates for patients diagnosed with rectal cancer.

OBJECTIVE

This study aimed to compare perioperative outcomes and pathological complete response rates among different neoadjuvant treatment strategies in patients undergoing total mesorectal excision for locally advanced rectal cancer.

DESIGN

Propensity score case-matched study.

SETTING

High-volume tertiary care centers.

PATIENTS

Consecutive patients undergoing curative total mesorectal excision between January 2014 and June 2021 were queried.

INTERVENTIONS

Patients were divided into 3 groups: long-course chemoradiation therapy with (N = 128) or without (N = 164) consolidation chemotherapy or short-course radiotherapy (N = 53) followed by consolidation chemotherapy.

MAIN OUTCOME MEASURES

Demographics, preoperative tumor characteristics, histopathologic outcomes, and postoperative complication rates were reviewed and compared. Propensity score match analysis was conducted.

RESULTS

A total of 345 patients (mean age: 58 ± 12 years; female: 36%) met the study inclusion criteria. Time interval from neoadjuvant treatment until surgery was longer for patients receiving consolidation chemotherapy ( p < 0.001). Pathological complete response rates were comparable among patients receiving long-course chemoradiation therapy (20.3%) and short-course radiotherapy with consolidation chemotherapy (20.8%) compared to long-course chemoradiation therapy alone (14.6%) ( p = 0.36). After the propensity score case-matched analysis, 48 patients in the long-course chemoradiation therapy with consolidation chemotherapy group were matched to 48 patients in the short-course radiotherapy with consolidation chemotherapy group. Groups were comparable with respect to age, sex, clinical stage, tumor location, type of surgical approach, and technique. Pathological complete response rate was comparable between the groups (20.8% and 18.8%, p = 0.99).

LIMITATIONS

Study was limited by its retrospective nature.

CONCLUSIONS

Among recent neoadjuvant treatment modalities, pathological complete response rates, and short-term clinical outcomes were comparable. Short-course radiotherapy with consolidation chemotherapy is safe and effective as long-course chemoradiation therapy as in a short-term period. See Video Abstract at http://links.lww.com/DCR/C174 .

LA RADIOTERAPIA DE CORTA DURACIN SEGUIDA DE QUIMIOTERAPIA DE CONSOLIDACIN ES SEGURA Y EFICAZ EN EL CNCER DE RECTO LOCALMENTE AVANZADO RESULTADOS COMPARATIVOS A CORTO PLAZO DEL ESTUDIO MULTICNTRICO DE CASOS EMPAREJADOS POR PUNTAJE DE PROPENSION

ANTECEDENTES: Las estrategias de quimioterapia de consolidación han demostrado una mejor respuesta patológica completa y tasas de reducción del estadio del tumor para pacientes diagnosticados con cáncer de recto.OBJETIVO: Comparar los resultados perioperatorios y las tasas de respuesta patológica completa entre diferentes estrategias de tratamiento neoadyuvante en pacientes sometidos a escisión mesorrectal total por cáncer de recto localmente avanzado.DISEÑO: Estudio de casos emparejados por puntaje de propensión.ENTORNO CLINICO: Centros de atención terciaria de alto volumen.PACIENTES: Pacientes consecutivos sometidos a escisión mesorrectal total curativa por cáncer de recto localmente avanzado entre enero de 2014 y junio de 2021.INTERVENCIONES: Los pacientes se dividieron en tres grupos según la modalidad de tratamiento neoadyuvante: quimiorradioterapia de ciclo largo con (N = 128) o sin (N = 164) quimioterapia de consolidación o radioterapia de ciclo corto (N = 53) seguida de quimioterapia de consolidación.PRINCIPALES MEDIDAS DE RESULTADO: El punto final primario fue la respuesta patológica completa. Se revisaron y compararon los datos demográficos, las características preoperatorias del tumor, los resultados histopatológicos y las tasas de complicaciones posoperatorias entre los grupos de estudio. Se realizó un análisis de casos emparejados por puntaje de propensión.RESULTADOS: Un total de 345 pacientes (edad media de 58 ± 12 años y mujeres: 36%) cumplieron los criterios de inclusión del estudio. El intervalo de tiempo desde el tratamiento neoadyuvante hasta la cirugía fue mayor para los pacientes que recibieron quimioterapia de consolidación ( p < 0,001). Las tasas de respuesta patológica completa fueron comparables entre los pacientes que recibieron quimiorradioterapia de larga duración con quimioterapia de consolidación (20,3 %) y radioterapia de corta duración con quimioterapia de consolidación (20,8%) en comparación con la quimiorradiación de larga duración sola (14,6%) ( p = 0,36). Después del análisis de casos emparejados por puntaje de propensión, 48 pacientes en el grupo de quimiorradioterapia de ciclo largo con quimioterapia de consolidación se emparejaron con 48 pacientes en el grupo de radioterapia de ciclo corto con quimioterapia de consolidación. Los grupos fueron comparables con respecto a la edad, sexo, estadio clínico, ubicación del tumor, tipo de abordaje quirúrgico y la técnica. La tasa de respuesta patológica completa fue comparable entre los grupos (20,8% y 18,8%, p = 0,99). La morbilidad postoperatoria a los 30 días y las tasas de fuga anastomótica fueron similares.LIMITACIONES: El estudio estuvo limitado por su naturaleza retrospectiva.CONCLUSIONES: Entre las modalidades de tratamiento neoadyuvante recientes, las tasas de respuesta patológica completa y los resultados clínicos a corto plazo fueron comparables. La radioterapia de corta duración con quimioterapia de consolidación es segura y eficaz como terapia de quimiorradioterapia de larga duración en un período corto. Consulte Video Resumen en http://links.lww.com/DCR/C174 . (Traducción-Dr. Fidel Ruiz Healy ).

Microwave ablation induces abscopal effect via enhanced systemic antitumor immunity in colorectal cancer

BACKGROUND

Thermal ablation is the primary procedure for the local treatment of lung metastases. It is known that radiotherapy and cryoablation can stimulate an abscopal effect, while the occurrence of abscopal effect induced by microwave ablation is less; the cellular and molecular mechanisms involved in the abscopal effect after microwave ablation should be further elucidated.

METHODS

CT26 tumor-bearing Balb/c mice were treated with microwave ablation with several combinations of ablation power and time duration. The growth of primary or abscopal tumors and the survival of mice were both monitored; moreover, immune profiles in abscopal tumors, spleens, and lymph nodes were examined by flow cytometry.

RESULTS

Microwave ablation suppressed tumor growth in both primary and abscopal tumors. Both local and systemic T-cell responses were induced by microwave ablation. Furthermore, the mice exhibiting significant abscopal effect after microwave ablation markedly elevated Th1 cell proportion both in the abscopal tumors and spleens.

CONCLUSIONS

Microwave ablation at 3 w-3 min not only suppressed tumor growth in the primary tumors but also stimulated an abscopal effect in the CT26-bearing mice via the improvement of systemic and intratumoral antitumor immunity.

Current status of locally advanced rectal cancer therapy and future prospects

Rectal cancer treatment has been evolving ever since the beginning of the 20th century. Surgery was originally the only available method regardless of the extent of tumor invasion or nodal involvement status. Total mesorectal excision was established as the standard procedure in the early 1990s. Advances in the utilization of radiation for rectal cancer led to the addition of radiotherapy (RT) combined with chemotherapy to the postoperative treatment algorithm. The promising results of the Swedish short-course preoperative RT set the basis for a number of large randomized trials investigating the efficacy of neoadjuvant RT or chemoradiotherapy (CRT) for advanced rectal cancer. Both short-course RT and long-course preoperative CRT compared favorably to adjuvant treatment and became the standard of choice for patients with extramural invasion or lymph node involvement. Recently, the focus of clinical research has been shifted towards total neoadjuvant therapy (TNT), delivering the whole course of RT and chemotherapy before surgery, and showing good tolerance and encouraging efficacy. Although targeted therapies haven't displayed a benefit in the neoadjuvant setting, preliminary evidence suggests impressive efficacy of immunotherapy in rectal carcinomas with mismatch-repair deficiency. In this review, we provide an in-depth critical overview of all significant randomized trials that have shaped the current treatment guidelines for locally advanced rectal cancer and discuss future trends for the treatment of this common malignancy.

Impact of Microscopically Positive (≤1 mm) Distal Margins on Disease Recurrence in Rectal Cancer Treated by Neoadjuvant Chemoradiotherapy

BACKGROUND

The adequate distal resection margin is still controversial in rectal cancer treated by neoadjuvant chemoradiotherapy (nCRT). The aim of this study was to assess the impact of a distal margin of ≤1 mm on locoregional recurrence-free survival (LRRFS).

METHODS

Among 255 patients treated with nCRT and surgery at the National Cancer Institute of Milan, 83 (32.5%) had a distal margin of ≤1 mm and 172 (67.5%) had a distal margin of >1 mm. Survival analyses were performed to assess the impact of distal margin on 5-year LRRFS, as well as Cox survival analysis. The role of distal margin on survival was analyzed according to different tumor regression grades (TRGs).

RESULTS

The overall 5-year LRRFS rate was 77.6% with a distal margin of ≤1 mm vs. 88.3% with a distal margin of >1 mm (Log-rank p = 0.09). Only stage ypT4 was an independent predictor of worse LRRFS (HR 15.14, p = 0.026). The 5-year LRRFS was significantly lower in TRG3-5 patients with a distal margin of ≤1 mm compared to those with a distal margin of >1 mm (68.5% vs. 84.2%, p = 0.027), while no difference was observed in case of TRG1-2 (p = 0.77).

CONCLUSIONS

Low-responder rectal cancers after nCRT still require a distal margin of >1 mm to reduce the high likelihood of local relapse.

Extramural vascular invasion nomogram before radical resection of rectal cancer based on magnetic resonance imaging

Purpose

This study verified the value of magnetic resonance imaging (MRI) to construct a nomogram to preoperatively predict extramural vascular invasion (EMVI) in rectal cancer using MRI characteristics.

Materials and methods

There were 55 rectal cancer patients with EMVI and 49 without EMVI in the internal training group. The external validation group consisted of 54 rectal cancer patients with EMVI and 55 without EMVI. High-resolution rectal T2WI, pelvic diffusion-weighted imaging (DWI) sequences, and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) were used. We collected the following data: distance between the lower tumor margin and the anal margin, distance between the lower tumor margin and the anorectal ring, tumor proportion of intestinal wall, mrT stage, maximum tumor diameter, circumferential resection margin, superior rectal vein width, apparent diffusion coefficient (ADC), T2WI EMVI score, DWI and DCE-MRI EMVI scores, demographic information, and preoperative serum tumor marker data. Logistic regression analyses were used to identify independent risk factors of EMVI. A nomogram prediction model was constructed. Receiver operating characteristic curve analysis verified the predictive ability of the nomogram. P &lt; 0.05 was considered significant.

Result

Tumor proportion of intestinal wall, superior rectal vein width, T2WI EMVI score, and carbohydrate antigen 19-9 were significant independent predictors of EMVI in rectal cancer and were used to create the model. The areas under the receiver operating characteristic curve, sensitivities, and specificities of the nomogram were 0.746, 65.45%, and 83.67% for the internal training group, respectively, and 0.780, 77.1%, and 71.3% for the external validation group, respectively.

Data conclusion

A nomogram including MRI characteristics can predict EMVI in rectal cancer preoperatively and provides a valuable reference to formulate individualized treatment plans and predict prognosis.

Patient-derived tumor organoids predict responses to irinotecan-based neoadjuvant chemoradiotherapy in patients with locally advanced rectal cancer

Adding irinotecan to neoadjuvant chemoradiotherapy (nCRT) in locally advanced rectal cancer (LARC) increases the pathologic complete response (pCR) rate but brings more toxicities. Robust biomarkers to predict response to irinotecan-based nCRT are extremely necessary for selecting the right patients. Our previous study suggests that patient-derived tumor organoids (PDTOs) sensitivity to chemoradiotherapy matches patient responses. In this study, we investigated whether PDTOs sensitivity to irinotecan can predict complete response (CR) and survival. Eligible patients receiving irinotecan-based nCRT between April 5, 2017 and December 11, 2020 were enrolled in the training cohort (n = 91) for response prediction and survival analysis. Patients receiving nCRT between February 21, 2021 and September 17, 2021 were included in the validation cohort (n = 27). Predictive performances of irinotecan organoid size ratio (OSR) for CR or pCR were evaluated. The irinotecan-sensitive groups had higher response rates compared with the insensitive groups (training cohort: 71.8% vs 24.4%, P < .0001; validation cohort, 81.8% vs 18.8%, P = .002). Moreover, the irinotecan-sensitive group had higher rates of 3-year disease-free survival (DFS: 71.6% vs 55.5%, P = .034) and distant metastasis-free survival (DMFS, 77.9% vs 57.2%, P = .015) than the irinotecan-insensitive group. 5-FU and irradiation sensitivities failed to predict 3-year DFS (5-FU: 65.4% vs 61.9%, P = .643; irradiation: 84.8% vs 57.8%; P = .072). Performances of irinotecan OSR to predict CR or pCR were good in the training cohort (CR: AUC = 0.828; 95% CI = 0.723-0.932; pCR: AUC = 0.864; 95% CI = 0.759-0.961). The validation showed robust predictive ability (CR: AUC = 0.796, 95% CI = 0.5974-0.9952; pCR: AUC = 0.917, 95% CI = 0.7921-1.0000). Irinotecan sensitivity in PDTOs was a predictive and prognostic factor in LARC.

Integrated Intensified Chemoradiation in the Setting of Total Neoadjuvant Therapy (TNT) in Patients with Locally Advanced Rectal Cancer: A Retrospective Single-Arm Study on Feasibility and Efficacy

While surgery is considered the main treatment for early-stage rectal cancer, locally advanced rectal cancer needs to be handled with a multidisciplinary approach. Based on literature data suggesting promising advantages of total neoadjuvant therapy (TNT), we performed a retrospective, single-arm, single-center study on 45 patients affected by histologically and radiologically proven locally advanced rectal cancer, with the aim of analyzing the feasibility and short-term efficacy of an integrated intensified treatment in the setting of TNT. Each analyzed patient performed three cycles of FOLFOX4 or De Gramont induction chemotherapy (iCT), followed by concurrent chemoradiotherapy (CRT) with long course radiotherapy (LCRT) plus concomitant boost and continuous 5-FU infusion, followed by three cycles of FOLFOX4 or De Gramont consolidation chemotherapy (conCT) and then surgery with total mesorectal excision. At a median follow-up of 30 months, this strategy has shown to be feasible and effective in terms of pathological complete response (pCR) and short-term disease-free survival (DFS).

Associations between disrupted functional brain network topology and cognitive impairment in patients with rectal cancer during chemotherapy

Introduction

Cognitive impairment has been identified in patients with non-central nervous system cancer received chemotherapy. Chemotherapy-induced changes in the brain are considered as the possible causes of the cognitive deficits of patients. This study aimed to explore chemotherapy-related functional brain changes and cognitive impairment in rectal cancer (RC) patients who had just finished chemotherapy treatment.

Methods

In this study, RC patients after chemotherapy (on the day patients received the last dose of chemotherapy) (n=30) and matched healthy controls (HCs) (n=30) underwent cognitive assessments, structural magnetic resonance imaging (MRI) and resting-state functional MRI. The functional brain networks were constructed by thresholding the partial correlation matrices of 90 brain regions in the Anatomical Automatic Labeling template and the topologic properties were evaluated by graph theory analysis. Moreover, correlations between altered topological measures and scores of cognitive scales were explored in the patient group.

Results

Compared with HCs, RC patients had lower scores of cognitive scales. The functional brain network had preserved small-world topological features but with a tendency towards higher path length in the whole network. In addition, patients had decreased nodal global efficiency (E_glo(i)) in the left superior frontal gyrus (dorsolateral), superior frontal gyrus (orbital part), inferior frontal gyrus (opercular part), inferior frontal gyrus (triangular part) and right inferior frontal gyrus (triangular part). Moreover, values of E_glo(i) in the superior and inferior frontal gyrus were positively associated with cognitive function in the patient group.

Conclusion

These results suggested that cognitive impairment was associated with disruptions of the topological organization in functional brain networks of RC patients who had just finished chemotherapy, which provided new insights into the pathophysiology underlying acute effects of chemotherapy on cognitive function.

Will Organoids Fill the Gap towards Functional Precision Medicine?

Precision medicine approaches for solid tumors are mainly based on genomics. Its employment in clinical trials has led to somewhat underwhelming results, except for single responses. Moreover, several factors can influence the response, such as gene and protein expression, the coexistence of different genomic alterations or post-transcriptional/translational modifications, the impact of tumor microenvironment, etc., therefore making it insufficient to employ a genomics-only approach to predict response. Recently, the implementation of patient-derived organoids has shed light on the possibility to use them to predict patient response to drug treatment. This could offer for the first time the possibility to move precision medicine to a functional environment.

MicroRNA-19b Plays a Key Role in 5-Fluorouracil Resistance and Predicts Tumor Progression in Locally Advanced Rectal Cancer Patients

The standard clinical management of locally advanced rectal cancer (LARC) patients includes neoadjuvant 5-fluorouracil (5-FU)-based chemoradiotherapy (CRT) followed by mesorectal excision. MicroRNA (miR)-19b expression levels in LARC biopsies obtained from initial colonoscopy have recently been identified as independent predictors of both patient outcome and pathological response to preoperative CRT in this disease. Moreover, it has been discovered that this miR increases its expression in 5-FU resistant colon cancer cells after 5-FU exposure. Despite the fact that these observations suggest a functional role of miR-19b modulating 5-FU response of LARC cells, this issue still remains to be clarified. Here, we show that downregulation of miR-19b enhances the antitumor effects of 5-FU treatment. Moreover, ectopic miR-19b modulation was able to restore sensitivity to 5-FU treatment using an acquired resistant model to this compound. Notably, we also evaluated the potential clinical impact of miR-19b as a predictive marker of disease progression after tumor surgery resection in LARC patients, observing that miR-19b overexpression significantly anticipates patient recurrence in our cohort (p = 0.002). Altogether, our findings demonstrate the functional role of miR-19b in the progressively decreasing sensitivity to 5-FU treatment and its potential usefulness as a therapeutic target to overcome 5-FU resistance, as well as its clinical impact as predictor of tumor progression and relapse.

Liquid biopsies to monitor and direct cancer treatment in colorectal cancer

Colorectal cancer (CRC) is one of the most prevalent and deadly cancers worldwide. Despite recent improvements in treatment and prevention, most of the current therapeutic options are weighted by side effects impacting patients' quality of life. Better patient selection towards systemic treatments represents an unmet clinical need. The recent multidisciplinary and molecular advancements in the treatment of CRC patients demand the identification of efficient biomarkers allowing to personalise patient care. Currently, core tumour biopsy specimens represent the gold-standard biological tissue to identify such biomarkers. However, technical feasibility, tumour heterogeneity and cancer evolution are major limitations of this single-snapshot approach. Genotyping circulating tumour DNA (ctDNA) has been addressed as potentially overcoming such limitations. Indeed, ctDNA has been retrospectively demonstrated capable of identifying minimal residual disease post-surgery and post-adjuvant treatment, as well as spotting druggable molecular alterations for tailoring treatments in metastatic disease. In this review, we summarise the available evidence on ctDNA applicability in CRC. Then, we review ongoing clinical trials assessing how liquid biopsy can be used interventionally to guide therapeutic choice in localised, locally advanced and metastatic CRC. Finally, we discuss how its widespread could transform CRC patients' management, dissecting its limitations while suggesting improvement strategies.

SEOM-GEMCAD-TTD clinical guidelines for localized rectal cancer (2021)

The management of localized rectal cancer requires a multidisciplinary approach to optimize outcomes, reduce morbidity and prevent under or overtreatments. While early stages may obtain benefit of local resections without any additional therapies, locally advanced rectal cancer becomes a challenge defining the better sequential strategy of surgery, radiotherapy and chemotherapy. The latest results of international phase III studies have positioned the total neoadjuvant therapy as a potential new standard of care in high risk rectal cancers, however, the best schedule is still not well defined.

MicroRNA-199b Deregulation Shows Oncogenic Properties and Promising Clinical Value as Circulating Marker in Locally Advanced Rectal Cancer Patients

The identification of robust prognostic markers still represents a need in locally advanced rectal cancer (LARC). MicroRNAs (miRs) have progressively emerged as promising circulating markers, overcoming some limitations that traditional biopsy comprises. Tissue miR-199b deregulation has been reported to predict outcome and response to neoadjuvant chemoradiotherapy (nCRT) in LARC, and was also found to be associated with disease progression in colorectal cancer. However, its biological and clinical relevance remains to be fully clarified. Thus, we observed here that miR-199b regulates cell migration, aggressiveness, and cell growth, and inhibits colonosphere formation and induces caspase-dependent apoptosis. Moreover, miR-199b expression was quantified by real-time PCR in plasma samples from LARC patients and its downregulation was observed in 22.7% of cases. This alteration was found to be associated with higher tumor size (p = 0.002) and pathological stage (p = 0.020) after nCRT. Notably, we observed substantially lower global miR-199b expression associated with patient downstaging (p = 0.009), as well as in non-responders compared to those cases who responded to nCRT in both pre- (p = 0.003) and post-treatment samples (p = 0.038). In concordance, we found that miR-199b served as a predictor marker of response to neoadjuvant therapy in our cohort (p = 0.011). Altogether, our findings here demonstrate the functional relevance of miR-199b in this disease and its potential value as a novel circulating marker in LARC.

SMAD3 Host and Tumor Profiling to Identify Locally Advanced Rectal Cancer Patients at High Risk of Poor Response to Neoadjuvant Chemoradiotherapy

Identifying patients at risk of poor response to neoadjuvant chemoradiotherapy (nCRT) is an emerging clinical need in locally advanced rectal cancer (LARC). SMAD3 is a key player in the chemoradio-resistance phenotype and its expression is both constitutive and locally induced. The aim was to investigate both host (genetic polymorphisms) and tumor SMAD3 profiling to predict response to nCRT. In a group of 76 LARC patients, SMAD3 and phosphorylated-SMAD3 expression was assessed by immunohistochemistry in preoperative tumor tissue. In an expanded study group (n = 378), a set of SMAD3 polymorphisms (rs35874463, rs1065080, rs1061427, rs17228212, rs744910, and rs745103) was analyzed. Association with tumor regression grade (TRG) and patient prognosis (progression-free survival [PFS] and overall survival [OS]) was assessed. Patients with high tumor expression of SMAD3 had a significantly increased risk of poor response (TRG≥2) [cellularity >55% (OR:10.36, p = 0.0004), or moderate/high intensity (OR:5.20, p = 0.0038), or an H-score≥1 (OR:9.84, p = 0.0004)]. Patients carrying the variant SMAD3 rs745103-G allele had a poorer response (OR:0.48, p = 0.0093), a longer OS (HR:0.65, p = 0.0307), and a trend for longer PFS (HR:0.75, p = 0.0944). Patients who carried both high SMAD3 tumor expression and the wild-type rs745103-A allele had an extremely high risk of not achieving a complete response (OR:13.45, p = 0.0005). Host and tumor SMAD3 status might be considered to improve risk stratification of LARC patients to facilitate selection for alternative personalized neoadjuvant strategies including intensified regimens.

Watch and Wait Approach for Rectal Cancer Following Neoadjuvant Treatment: The Experience of a High Volume Cancer Center

Multimodal treatments for rectal cancer, along with significant research on predictors to response to therapy, have led to more conservative surgical strategies. We describe our experience of the rectal sparing approach in rectal cancer patients with clinical complete response (cCR) after neoadjuvant treatment. We also specifically highlight our clinical and imaging criteria to select patients for the watch and wait strategy (w&w). Data came from 39 out of 670 patients treated for locally advanced rectal cancer between January 2016 until February 2020. The selection criteria were a clinical complete response after neoadjuvant chemotherapy managed with a watch and wait (w&w) strategy. A strict follow-up period was adopted in these selected patients and follow-ups were performed every three months during the first two years and every six months after that. The median follow-up time was 28 months. Six patients had a local recurrence (15.3%); all were salvageable by total mesorectal excision (TME). Five patients had a distant metastasis (12.8%). There was no local unsalvageable disease after w&w strategy. The rectal sparing approach in patients with clinical complete response after neoadjuvant treatment is the best possible treatment and is appropriate to analyze from this perspective. The watch and wait approach after neoadjuvant treatment for rectal cancer can be successfully explored after inflexible and strict patient selection.

A Patient-Derived Organoid-Based Radiosensitivity Model for the Prediction of Radiation Responses in Patients with Rectal Cancer

Simple Summary

Predicting the tumor regression grade of locally advanced rectal cancer after neoadjuvant chemoradiation is important for customized treatment strategies; however, there are no reliable prediction tools. A novel preclinical model based on patient-derived tumor organoids has shown promising features of the recapitulation of real tumors and their treatment response. We conducted a small co-clinical trial to determine the correlation between the irradiation response of individual patient-derived rectal cancer organoids and the results of actual radiotherapy. Among the quantitative experimental data, the survival fraction was best matched and correlated with the patients’ real treatment outcome. In the machine learning-based prediction model for radiotherapy results using the survival fraction data, the prediction accuracy was excellent at more than 89%. Enhanced machine learning with the accumulation of further new experimental data would help in creating a more reliable prediction model, and this new preclinical model can lead to more advanced precision medicine.

Abstract

Patient-derived tumor organoids closely resemble original patient tumors. We conducted this co-clinical trial with treatment-naive rectal cancer patients and matched patient-derived tumor organoids to determine whether a correlation exists between experimental results obtained after irradiation in patients and organoids. Between November 2017 and March 2020, we prospectively enrolled 33 patients who were diagnosed with mid-to-lower rectal adenocarcinoma based on endoscopic biopsy findings. We constructed a prediction model through a machine learning algorithm using clinical and experimental radioresponse data. Our data confirmed that patient-derived tumor organoids closely recapitulated original tumors, both pathophysiologically and genetically. Radiation responses in patients were positively correlated with those in patient-derived tumor organoids. Our machine learning-based prediction model showed excellent performance. In the prediction model for good responders trained using the random forest algorithm, the area under the curve, accuracy, and kappa value were 0.918, 81.5%, and 0.51, respectively. In the prediction model for poor responders, the area under the curve, accuracy, and kappa value were 0.971, 92.1%, and 0.75, respectively. Our patient-derived tumor organoid-based radiosensitivity model could lead to more advanced precision medicine for treating patients with rectal cancer.

Predictive factors for early distant metastasis after neoadjuvant chemoradiotherapy in locally advanced rectal cancer

BACKGROUND

Distant relapse is the leading cause of cancer-related death in locally advanced rectal cancer. Neoadjuvant chemoradiation (NACRT) followed by surgery inevitably delays delivery of systemic treatment. Some patients show early distant metastasis before systemic treatment.

AIM

To identify the most effective treatments. We investigated prognostic factors for distant metastasis, especially early distant metastasis, using the standard treatment paradigm to identify the most effective treatments according to recurrence risk.

METHODS

From January 2015 through December 2019, rectal cancer patients who underwent NACRT for having clinical T 3-4 or clinical N 1-2 disease according to the 8^th American Joint Committee on Cancer staging system were included. Radiotherapy was delivered to the whole pelvis with concomitant chemotherapy. Patients received surgery 6-8 wk after completion of NACRT. Adjuvant chemotherapy was administered at the physician’s discretion.

RESULTS

A total of 127 patients received NACRT. Ninety-three patients (73.2%) underwent surgery. The R0 resection rate was 89.2% in all patients. Pathologic tumor and node downstaging rates were 41.9% and 76.3%. Half the patients (n = 69) received adjuvant chemotherapy after surgery. The 3-year distant metastasis-free survival (DMFS) and overall survival (OS) rates were 81.7% and 83.5%. On univariate analyses, poorly differentiated tumors, > 5 cm, involvement of mesorectal fascia (MRF), or presence of extramural involvement (EMVI) were associated with worse DMFS and OS. Five patients showed distant metastasis at their first evaluation after NACRT. Patients with early distant metastasis were more likely to have poorly differentiated tumor (P = 0.025), tumors with involved MRF (P = 0.002), and EMVI (P = 0.012) than those who did not.

CONCLUSION

EMVI, the involvement of MRF, and poor histologic grade were associated with early distant metastasis. In order to control distant metastasis and improve treatment outcome, selective use of neoadjuvant treatment according to individualized risk factors is necessary. Future studies are required to determine effective treatment strategies for patients at high risk for distant metastasis.