Total neoadjuvant therapy versus chemoradiotherapy for locally advanced rectal cancer: Bayesian network meta-analysis

Oncological Outcomes and Response Rate After Total Neoadjuvant Therapy for Locally Advanced Rectal Cancer: A Network Meta-Analysis Comparing Induction vs. Consolidation Chemotherapy vs. Standard Chemoradiation

TNT is now considered the preferred option for stage II-III locally advanced rectal cancer (LARC). However, the prognostic benefit and optimal sequence of TNT remains unclear. This network meta-analysis (NMA) compared short- and long-term outcomes amongst patients with LARC receiving total neoadjuvant therapy (TNT) as induction (iTNT) or consolidation chemotherapy (cTNT) with those receiving neoadjuvant chemoradiation (nCRT) alone. A systematic literature search was performed between 2012 and 2023. A Bayesian NMA was conducted using a Markov Chain Monte Carlo method with a random-effects model and vague prior distribution to calculate odds ratios (OR) with 95% credible intervals (CrI). The surface under the cumulative ranking (SUCRA) curves were used to rank treatment(s) for each outcome. In total, 11 cohorts involving 8360 patients with LARC were included. There was no significant difference in disease-free survival (DFS) and overall survival (OS) amongst the 3 treatments. Compared with nCRT, both cTNT (OR 2.36; 95% CrI, 1.57-3.66) and iTNT (OR 1.99; 95% CrI, 1.44-2.95) significantly improved complete response (CR) rate. Notably, cTNT ranked as the best treatment for CR (SUCRA 0.90) and iTNT as the best treatment for 3-year DFS and OS (SUCRA 0.72 and 0.87, respectively). Both iTNT and cTNT strategies significantly improved CR rates compared with nCRT. cTNT was ranked highest for CR rates, while iTNT was ranked highest for 3-year survival outcomes. However, no other significant differences in DFS, OS, sphincter-saving surgery, R0 resection and postoperative complications were found amongst the treatment groups.

Negative prognostic impact of Co-mutations in TGFβ and TP53 pathways in surgically resected rectal tumors following neoadjuvant chemoradiotherapy

BACKGROUND

Preoperative neoadjuvant chemoradiotherapy (nCRT) followed by total mesorectal excision (TME) is a common approach for treating patients with locally advanced rectal cancer. Nevertheless, the mutational profile and its prognostic impact in surgically resected tumor specimens after nCRT remains to be clarified.

METHODS

The comprehensive analysis of mutational landscape was retrospectively conducted by target regions sequencing approach that covered 150 tumor-related genes. Univariate and multivariate logistic regression and Cox regression was used to examine the association of mutation status in genes and pathways with pathological response and prognosis. Data from Memorial Sloan Kettering Cancer Center (MSK) cohort was used for comparison with our results.

RESULTS

The top five commonly mutated genes in resected rectal tumor tissue samples following nCRT were TP53 (42%), APC (31%), KRAS (27%), PIK3CA (14%) and FBXW7 (11%). Mutations in the WNT pathway, which was mainly represented by APC mutation, were found to be significantly associated with tumor regression grade (TRG) 3. In our cohort, co-mutations in the receptor tyrosine kinase (RTK)/RAS and WNT pathways were found to be independently associated with reduced risk of recurrent and significantly associated with longer disease-free survival (DFS). In both our cohort and the MSK cohort, co-mutations in the TGF-β and TP53 pathways were significantly associated with worse DFS.

CONCLUSIONS

Resected rectal tumor samples from patients without complete pathological response can be appropriately used to detect mutations. Co-mutations in the TGF-β and TP53 pathways may provide more prognostic information beyond commonly used clinical factors.

Total neoadjuvant therapy for locally advanced rectal cancer: a three-group propensity score matched study

PURPOSE

Total neoadjuvant therapy (TNT) has emerged as a therapeutic approach for locally advanced rectal cancer (LARC). However, the optimal chemotherapy cycles within TNT remain uncertain. This study aimed to evaluate and compare the prognostic efficacy of varying cycles of chemotherapy during TNT for LARC.

METHODS

Patients diagnosed with LARC (T3-4N0M0/T1-4N1-2M0), who underwent TNT or chemoradiotherapy followed by total mesorectal excision (TME) between 2015 and 2020, were retrospective included. Patients were categorized into three groups based on their neoadjuvant strategy: CRT (long-course chemoradiotherapy), STNT (long-course CRT with one to three cycles of chemotherapy), and LTNT (long-course CRT with four or more cycles of chemotherapy). Propensity score matching (PSM) based on gender, age, body mass index, tumor distance from the anal verge, clinical T stage, clinical N stage, and mesorectal fascia status was employed to reduce confounding bias. Primary endpoints were disease-free survival (DFS) and metastasis-free survival (MFS).

RESULTS

The study comprised 372 patients, with 73 patients in each group after PSM. Compared with CRT, both STNT and LTNT demonstrated improved DFS (5-year rate: 59.7% vs. 77.8% vs. 76.5%, p = 0.027) and MFS (5-year rate: 65.1% vs. 81.3% vs. 81.4%, p = 0.030). There was no difference in DFS or MFS between STNT and LTNT. These favorable outcomes were consistent among subgroups defined by tumor distance from the anal verge ≥ 5 cm, clinical T3 stage, clinical N positive status, or involved mesorectal fascia.

CONCLUSION

Compared to CRT, both STNT and LTNT demonstrated improved DFS and MFS outcomes. Notably, survival outcomes were similar between STNT and LTNT, suggesting that chemotherapy cycles in TNT may not significantly impact survival.

Tata Memorial Centre Evidence Based Management of Colorectal cancer

ABSTRACT

This review article examines the evidence-based management of colorectal cancers, focusing on topics characterized by ongoing debates and evolving evidence. To contribute to the scientific discourse, we intentionally exclude subjects with established guidelines, concentrating instead on areas where the current understanding is dynamic. Our analysis encompasses a thorough exploration of critical themes, including the evidence surrounding complete mesocolic excision and D3 lymphadenectomy in colon cancers. Additionally, we delve into the evolving landscape of perioperative chemotherapy in both colon and rectal cancers, considering its nuanced role in the context of contemporary treatment strategies. Advancements in surgical techniques are a pivotal aspect of our discussion, with an emphasis on the utilization of minimally invasive approaches such as laparoscopy and robotic surgery in both colon and rectal cancers, including advanced rectal cases. Moving beyond conventional radical procedures, we scrutinize the feasibility and implications of endoscopic resections for small tumors, explore the paradigm of organ preservation in locally advanced rectal cancers, and assess the utility of total neoadjuvant therapy in the current treatment landscape. Our final segment reviews pivotal trials that have significantly influenced the management of colorectal liver and peritoneal metastasis.

Development and validation of a competitive risk model in patients with rectal cancer: based on SEER database

BACKGROUND

Rectal cancer is one of the most common malignancies. To predict the specific mortality risk of rectal cancer patients, we constructed a predictive nomogram based on a competing risk model.

METHODS

The information on rectal cancer patients was extracted from the SEER database. Traditional survival analysis and specific death analysis were performed separately on the data.

RESULTS

The present study included 23,680 patients, with 16,580 in the training set and 7100 in the validation set. The specific mortality rate calculated by the competing risk model was lower than that of the traditional survival analysis. Age, Marriage, Race, Sex, ICD-O-3Hist/Behav, Grade, AJCC stage, T stage, N stage, Surgery, Examined LN, RX SUMM-SURG OTH, Chemotherapy, CEA, Deposits, Regional nodes positive, Brain, Bone, Liver, Lung, Tumor size, and Malignant were independent influencing factors of specific death. The overall C statistic of the model in the training set was 0.821 (Se = 0.001), and the areas under the ROC curve for cancer-specific survival (CSS) at 1, 3, and 5 years were 0.842, 0.830, and 0.812, respectively. The overall C statistic of the model in the validation set was 0.829 (Se = 0.002), and the areas under the ROC curve for CSS at 1, 3, and 5 years were 0.851, 0.836, and 0.813, respectively.

CONCLUSIONS

The predictive nomogram based on a competing risk model for time-specific mortality in patients with rectal cancer has very desirable accuracy. Thus, the application of the predictive nomogram in clinical practice can help physicians make clinical decisions and follow-up strategies.