Association between neoadjuvant chemoradiation and survival for patients with locally advanced rectal cancer

Impact of lymph node retrieval on prognosis in elderly and non-elderly patients with T3-4/N+ rectal cancer following neoadjuvant therapy: a retrospective cohort study

PURPOSE

The optimal number of lymph nodes to be resected in patients with rectal cancer who undergo radical surgery after neoadjuvant therapy remains controversial. This study evaluated the prognostic variances between elderly and non-elderly patients and determined the ideal number of lymph nodes to be removed in these patients.

METHODS

The Surveillance, Epidemiology, and End Results (SEER) datasets were used to gather information on 7894 patients diagnosed with stage T3-4/N+ rectal cancer who underwent neoadjuvant therapy from 2010 to 2019. Of these patients, 2787 were elderly and 5107 were non-elderly. A total of 152 patients from the Longyan First Affiliated Hospital of Fujian Medical University were used for external validation. Overall survival (OS) and cancer-specific survival (CSS) were evaluated to determine the optimal quantity of lymph nodes for surgical resection.

RESULTS

The study found significant differences in OS and CSS between elderly and non-elderly patients, both before and after adjustment for confounders (P < 0.001). The removal of 14 lymph nodes may be considered a benchmark for patients with stage T3-4/N+ rectal cancer who undergo radical surgery following neoadjuvant therapy, as this number provides a more accurate foundation for the personalized treatment of rectal cancer. External data validated the differences in OS and CSS and supported the 14 lymph nodes as a new benchmark in these patients.

CONCLUSION

For patients with T3-4/N+ stage rectal cancer who undergo radical surgery following neoadjuvant therapy, the removal of 14 lymph nodes serves as a cutoff point that distinctly separates patients with a favorable prognosis from those with an unfavorable one.

Rectal cancer survival and prognostic factors in Iranian population: A retrospective cohort study

BACKGROUND

Rectal cancer (RC) poses a significant global health challenge, causing substantial morbidity and mortality. This study aims to investigate the survival rates of RC patients and identify the factors that influence their survival. The study considers demographic characteristics, tumor features, and treatment received as the factors under consideration.

METHODS

A retrospective analysis was conducted on the medical records of 593 RC patients. Data were collected through a comprehensive review of medical records and conducting telephone interviews. Survival rates were estimated using the life table method, and subgroup comparisons were performed using the log-rank test. Cox regression analysis was utilized to assess the independent associations between RC survival time and various covariates.

RESULTS

The study cohort comprised 593 RC patients, with a predominantly male representation. The mean age at diagnosis was 58.18 years, and the majority of patients (78.6 %) underwent surgical interventions. The median age at symptom onset and diagnosis were 58 and 59 years, respectively. Survival rates at 1st, 3rd, 5th, and 10th years were estimated to be 85 %, 59 %, 47 %, and 36 %, respectively. Statistical analysis revealed several significant prognostic factors, including age, education, symptoms, and cancer stage. In the multivariate Cox proportional-hazards analysis, advanced regional stage (HR = 1.54, 95 % CI, 1.13-2.08), presence of metastasis (HR = 3.73, 95 % CI, 2.49-5.58), and age over 70 (HR = 1.65) were associated with a higher risk of mortality.

CONCLUSION

Given the alarming prognosis of RC observed in the study area and the significant delay between symptom onset and diagnosis, it is crucial to address this issue and potentially improve the survival rates of RC patients.

Magnetic resonance imaging radiomics modeling predicts tumor deposits and prognosis in stage T3 lymph node positive rectal cancer

PURPOSE

To develop a magnetic resonance imaging radiomics model to predict tumor deposits (TDs) and prognosis in stage T3 lymph node positive (T3N+) rectal cancer (RC).

METHODS

This retrospective study included 163 patients with pathologically confirmed T3N + RC from December 2013 to December 2015. The patients were divided into two groups for training and testing. Extracting radiomic features from MR images and selecting features using principal component analysis (PCA), then radiomic scores (rad-scores) were obtained by logistic regression analysis. Finally, a combined TDs prediction model containing rad-scores and clinical features was developed. A receiver operating characteristic (ROC) curve was used to assess the prediction performance. The overall survival (OS) rate in patients with high-risk and low-risk TDs predicted by rad-scores was validated by Kaplan-Meier survival curves.

RESULTS

Of the 163 patients included, histological TDs was diagnosed in 45 patients. The area under the curve (AUC) of the final model was 0.833 (training) and 0.844 (testing). The patients with rad-scores predicted high-risk were associated with OS. In addition, postoperative adjuvant therapy improved the OS of the high-risk TDs group (P < 0.05).

CONCLUSION

MRI-based radiomics modeling helps in the preoperative prediction of patients with TDs+ in T3N + RC and provides risk stratification for neoadjuvant therapy. In addition, the rad-scores of TDs could suggest different survival benefits of postoperative adjuvant therapy for T3N + RC patients and guide clinical treatment.

Role of MRI‑based radiomics in locally advanced rectal cancer (Review)

Colorectal cancer is the third most common type of cancer, with high morbidity and mortality rates. In particular, locally advanced rectal cancer (LARC) is difficult to treat and has a high recurrence rate. Neoadjuvant chemoradiotherapy (NCRT) is one of the standard treatment programs of LARC. If the response to treatment and prognosis in patients with LARC can be predicted, it will guide clinical decision‑making. Radiomics is characterized by the extraction of high‑dimensional quantitative features from medical imaging data, followed by data analysis and model construction, which can be used for tumor diagnosis, staging, prediction of treatment response and prognosis. In recent years, a number of studies have assessed the role of radiomics in NCRT for LARC. MRI‑based radiomics provides valuable data and is expected to become an imaging biomarker for predicting treatment response and prognosis. The potential of radiomics to guide personalized medicine is widely recognized; however, current limitations and challenges prevent its application to clinical decision‑making. The present review summarizes the applications, limitations and prospects of MRI‑based radiomics in LARC.

Is Metformin Associated With Improved Response to Neoadjuvant Chemoradiotherapy in Locally Advanced Rectal Cancer?

Efforts to determine whether metformin can increase the effectiveness of neoadjuvant chemoradiotherapy in rectal cancer have increased in recent years. However, retrospective studies have yielded inconclusive results.

OBJECTIVES

The aim of this study was to compare oncological outcomes and survival after neoadjuvant chemoradiotherapy in patients with rectal cancer taking metformin versus in those not taking metformin.

METHODS

This study analyzed 423 consecutive patients with locally advanced rectal cancer who underwent neoadjuvant chemoradiotherapy and curative surgery between January 2010 and May 2020; of these, 59 were taking metformin and 364 were not taking metformin.

RESULTS

Patients taking metformin had a lower proportion of tumor regression (6.8% versus 22.0%, P = 0.012) as well as a lower proportion of patients achieving a pathological complete response (6.8% versus 20.6%, P = 0.011). In the multivariate analysis, independent predictors of pathologic complete response were not taking metformin (OR: 5.26, 95% CI: 1.12-24.85, P= 0.035) and cT2 stage (OR: 3.49, 95% CI: 1.10-11.07, P= 0.034); the interval was also an independent predictor of tumor regression (OR: 1.78, 95% CI: 1.06-2.96, P= 0.028). No differences were observed in survival between groups.

CONCLUSION

Metformin was not associated with better tumor responses or survival after neoadjuvant treatment.

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.

A New MRI-Defined Biomarker for Rectal Mucinous Adenocarcinoma: Mucin Pool Patterns in Determining the Efficacy of Neoadjuvant Therapy

Background and Aim: This work aims to study the relationship between MRI-defined mucin pool (MP) patterns prior to treatment and the efficacy of neoadjuvant therapy (NAT) in locally advanced rectal mucinous adenocarcinoma (RMAC).

Methods: This retrospective study included 278 RMAC patients evaluated between January 2012 and January 2019. After having been trained by using 118 cases with postoperative pathological images, radiologists distinguished MRI-defined MP status as mixed type (MTMP) and separate type (STMP) in a NAT cohort (160 patients) in addition to tumor characteristics, invasion of mesorectal facia, and nodal status. Reader reproducibility was determined using the κ coefficient. The main outcome was the accuracy of MP dichotomy in predicting whether patients had tumor responsiveness or not.

Results: Among 278 cases, MTMP and STMP accounted for 49.6 and 50.4% of MPs, respectively. A total of 72 patients received neoadjuvant chemoradiotherapy and 88 received chemotherapy. The tumor responsiveness rate in the chemoradiotherapy group was higher than that in the chemotherapy group (58.3 vs. 21.6%, P < 0.001). In the chemotherapy group, the tumor responsiveness rate in patients with MTMPs was lower than that in patients with STMPs (4.9 vs. 25.5%, P = 0.002). The baseline MRI-defined MTMP was associated with lower responsiveness rates after NAT in the chemotherapy group (odds ratio, 11.050, with 95% CI, 2.368–51.571, P = 0.002).

Conclusions: MP dichotomy can be reliably evaluated by using MRI. In the chemotherapy group, MTMP may be a dependent predictor to indicate a lower likelihood of tumor responsiveness after NAT.

Superoxide Dismutase Mimic, MnTE-2-PyP Enhances Rectal Anastomotic Strength in Rats after Preoperative Chemoradiotherapy

Background

Rectal cancer is one of the malignant diseases with high morbidity and mortality in the world. Currently, surgical resection is the main treatment method, and preoperative chemoradiotherapy (CRT) is widely used in clinical application to increase resectability and decrease the local recurrence rate. However, CRT increases the risk of colon anastomotic leak, and currently, there are no FDA approved treatments against this side effect. It is essential to develop new drugs to reduce postoperative anastomotic leak after preoperative CRT.

Methods

90 rats underwent standard resection and intestine anastomosis treatment and were divided into six groups for different treatments. During the relaparotomy, bursting pressure of anastomosis was measured and intestinal segments were taken for histopathologic examination and biochemical analyses. RT-PCR and ELISA were applied to measure matrix metalloproteinase (MMP) mRNA and protein levels. Blood vessels were observed by immunohistochemistry, and collagen deposition was observed by Picrosirius Red staining.

Results

Preoperative CRT reduced the postoperative anastomotic strength. MnTE-2-PyP increased the bursting pressure and hydroxyproline levels of intestine anastomosis after CRT treatment. Mechanically, MnTE-2-PyP decreased the MMP levels and increased microvessel density (MVD) and collagen deposition. The MMP inhibitor doxycycline had a positive effect on anastomosis healing, but was inferior to MnTE-2-PyP.

Conclusions

MnTE-2-PyP enhanced intestine anastomotic strength in rats with preoperative CRT. Specifically, MnTE-2-PyP decreased MMP levels and increased MVD in anastomosis. Therefore, MnTE-2-PyP may be helpful in the prevention of anastomotic leak after preoperative CRT.

Facility Variation in Local Staging of Rectal Adenocarcinoma and its Contribution to Underutilization of Neoadjuvant Therapy

BACKGROUND

Guidelines recommend neoadjuvant therapy (NT) for clinical stage II-III (locally advanced) rectal adenocarcinoma, but utilization remains suboptimal. The causes of NT omission remain poorly understood.

METHODS

The main outcomes in this study of patients with resected clinically non-metastatic rectal adenocarcinoma in the 2010-2015 National Cancer Database were local staging utilization in patients with non-metastatic tumors (i.e., undocumented clinical stage/pathologic stage I-III) and NT utilization for locally advanced tumors. Multivariable regression was used to examine predictors of these outcomes. Facility-specific risk- and reliability-adjusted local staging and NT rates were calculated. Positive margins and overall survival (OS) were examined as secondary outcomes.

RESULTS

Local staging was omitted in 7737/43,819 (17.7%) patients with clinically non-metastatic tumors and NT was omitted in 5199/31,632 (16.4%) patients with locally advanced tumors. NT was utilized in 24,826 (91.1%) locally advanced patients who had local staging vs. 1607 (36.6%) patients who did not; 2785 (53.6%) locally advanced patients with NT omitted also had local staging omitted. Treatment at facilities with lowest quintile local staging rates was associated with NT omission (relative risk 2.41, 95% confidence interval 2.11, 2.75). Adjusted facility local staging rates varied sixfold (16.1-98.0%), facility NT rates varied twofold (43.9-95.9%), and they were correlated (r = 0.58; P < 0.001). Local staging omission and NT omission were independently associated with positive margins and decreased OS.

CONCLUSIONS

Local staging omission is a common care process in over half of cases of omitted NT. These data emphasize the need for quality improvement efforts directed at providing facilities feedback about their local staging rates.