Poorer Oncologic Outcome of Good Responders to PCRT With Remnant Lymph Nodes Defies the Oncologic Paradox in Patients With Rectal Cancer

Prognosis and quality of life in patients with locally advanced rectal cancer after abdominoperineal resection in the CAO/ARO/AIO-04 randomized phase 3 trial

Low anterior resection (LAR) and abdominoperineal resection (APR) are the two main surgical procedures after preoperative chemoradiotherapy (CRT) for locally advanced rectal cancer. APR is associated with poorer prognosis; however existing data do not consider intensified CRT (5-Fluorouracil (5-FU)/Oxaliplatin + radiation) protocols. Clinicopathological data of patients treated with APR and LAR from the CAO/ARO/AIO-04 trial were analysed in terms of prognostic parameters and quality of life (QoL). Based on higher response rate after intensified CRT, subgroup analyses were performed. Data from n = 1173 patients were assessed. APR after preoperative CRT was associated with a significantly worse overall survival (p = 0.0056), disease-free survival (p < 0.0001) and local recurrence rate (p = 0.0047). Clinicopathological data including clinical T stage (p < 0.000001), grading (p = 0.0038), postoperative lymph node (LN) positivity (p = 0.013), and number of positive LN (p = 0.0049) significantly differed between procedures and showed higher values in APR patients. The quality of total mesorectal excision (TME) was significantly better (p < 0.0001) and complete resection rates were higher (p = 0.0022) in LAR compared to APR patients. Subgroup analyses showed worse LR rates in APR patients after standard CRT (5-FU mono and radiation) but not after intensified CRT. After 3 years, role functioning (p = 0.019) and physical functioning (p = 0.001) had a slightly poorer outcome in APR patients. The poorer prognosis of patients undergoing APR for locally advanced rectal cancer may be explained by clinicopathological characteristics. Intensified CRT may compensate for the higher risk of LR after APR in patients with worse TME quality. QoL in APR patients was comparable to LAR patients.

Primary staging of rectal cancer on MRI: an updated pictorial review with focus on common pitfalls and current controversies

Magnetic resonance imaging (MRI) plays a pivotal role in primary staging of rectal cancer, enabling the determination of appropriate management strategies and prediction of patient outcomes. However, inconsistencies and pitfalls exist in various aspects, including rectal anatomy, MRI protocols and strategies for artifact resolution, as well as in T- and N-staging, all of which limit the diagnostic value of MRI. This narrative and pictorial review offers a comprehensive overview of factors influencing primary staging of rectal cancer and the role of MRI in assessing them. It highlights the significance of the circumferential resection margin and its relationship with the mesorectal fascia, as well as the prognostic role of extramural venous invasion and tumor deposits. Special attention is given to tumors of the lower rectum due to their complex anatomy and the challenges they pose in MRI staging. The review also addresses current controversies in rectal cancer staging and the need for personalized risk stratification. In summary, this review provides valuable insights into the role of MRI in the primary staging of rectal cancer, emphasizing key aspects for accurate assessment to enhance patient outcomes.

Efficacy of hypofractionated preoperative chemoradiotherapy in rectal cancer

The efficacy and toxicity of hypofractionated preoperative chemoradiotherapy (HPCRT) combined with oral capecitabine was evaluated in patients with rectal cancer. HPCRT was delivered by intensity-modulated radiotherapy of either 33 Gy to the whole pelvis or 35 Gy in 10 fractions to the primary tumor and 33 Gy to the surrounding pelvis. Surgery was performed 4-8 weeks after HPCRT completion. Oral capecitabine was administered concurrently. A total of 76 patients were eligible for this study, and patient numbers in clinical stages I, II, III and IVA were 5, 29, 36 and 6, respectively. Tumor response, toxicity and survival were analyzed. A total of 9/76 patients (11.8%) achieved a pathological complete response. Sphincter preservation was achieved in 23/32 (71.9%) and 44/44 (100%) of patients with a distal extent from the anal verge of ≤5 and >5 cm, respectively. A total of 28/76 patients (36.8%) achieved tumor-downstaging and 25/76 (32.9%) achieved nodal (N)-downstaging. The 5-year disease-free survival (DFS) and overall survival rates were 76.5% and 90.6%, respectively. In the multivariate analysis for DFS, pathological N stage and lymphovascular space invasion were notable prognostic factors. A total of 6 patients in stage IVA underwent salvage treatments for lung or liver metastasis after HPCRT completion, and all 6 were alive at the last follow-up. Only 4 patients experienced grade 3 postoperative complications. No grade 4 toxicities were observed. HPCRT of 33 or 35 Gy in 10 fractions showed similar results to those of long-course fractionation. This fractionation scheme could be beneficial for patients with early stage disease, locally advanced rectal cancer, simultaneous distant metastasis requiring early intervention or for patients who wish to avoid multiple hospital visits.

Retrospective survival analysis of stage II-III rectal cancer: tumour regression grade, grading and lymphovascular invasion are the only predictors

BACKGROUND

Tumour regression grade is gaining interest as a prognostic factor of patients undergoing neoadjuvant chemoradiotherapy and surgery for locally advanced rectal cancer.

METHODS

A series of 68 consecutive patients with locally advanced rectal cancer treated by neoadjuvant chemoradiotherapy and surgery between 2010 and 2016 was retrospectively studied. The impact on disease-free survival (DFS) and overall survival (OS) of several criteria was analysed. Univariate analysis was performed through Kaplan-Meier statistics. Multivariate analysis was performed through Cox regression model. Using criteria found to be related to long-term outcomes, a predictive model of patient's OS was calculated.

RESULTS

Poor tumour regression grade - TRG3 (P = 0.010), poor grading - G3 (P = 0.001) and lymphovascular invasion (LVI; P = 0.030) were associated with short OS at univariate analysis. OS was associated with TRG3 and G3 at multivariate analysis (P = 0.016 and P = 0.027, respectively). DFS was associated with LVI (P = 0.001), G3 tumours (P = 0.046) and TRG3 (P = 0.045) at univariate analysis. At multivariate analysis, only LVI was associated with DFS (P = 0.041). A score, pondering the impact of three parameters (2 points for TRG3, 2 for G3 and 1 for LVI), was created and resulted to predict patient OS (P = 0.008), ranging from 94.5 months (score = 0-1) to 32 months (score = 3-5).

CONCLUSION

TRG3 and G3 were associated with poor OS, and LVI was the most significant predictor of DFS. An easy-to-use score may allow for a more accurate prediction of OS.

A Nine-Gene Signature for Predicting the Response to Preoperative Chemoradiotherapy in Patients with Locally Advanced Rectal Cancer

Preoperative chemoradiotherapy (PCRT) and subsequent surgery is the standard multimodal treatment for locally advanced rectal cancer (LARC), albeit PCRT response varies among the individuals. This creates a dire necessity to identify a predictive model to forecast treatment response outcomes and identify patients who would benefit from PCRT. In this study, we performed a gene expression study using formalin-fixed paraffin-embedded (FFPE) tumor biopsy samples from 156 LARC patients (training cohort n = 60; validation cohort n = 96); we identified the nine-gene signature (FGFR3, GNA11, H3F3A, IL12A, IL1R1, IL2RB, NKD1, SGK2, and SPRY2) that distinctively differentiated responders from non-responders in the training cohort (accuracy = 86.9%, specificity = 84.8%, sensitivity = 81.5%) as well as in an independent validation cohort (accuracy = 81.0%, specificity = 79.4%, sensitivity = 82.3%). The signature was independent of all pathological and clinical features and was robust in predicting PCRT response. It is readily applicable to the clinical setting using FFPE samples and Food and Drug Administration (FDA) approved hardware and reagents. Predicting the response to PCRT may aid in tailored therapies for respective responders to PCRT and improve the oncologic outcomes for LARC patients.