Effect of understaging on local recurrence of rectal cancer

Abstract

Background and Objectives: Magnetic resonance imaging of the pelvis has a limited accuracy to detect positive lymph nodes but does dictate neoadjuvant treatment in rectal cancer. This study aimed to investigate preoperative lymph node understaging and its effects on postoperative local recurrence rate. Methods: Patients were selected from a retrospective cross-sectional snapshot study. Patients with emergency surgery, cM1 disease, or unknown cN-or (y)pN category were excluded. Clinical and pathologic N-categories were compared and the impact on local recurrence was determined by multivariable analysis. Results: Out of 1548 included patients, 233 had preoperatively underestimated lymph node staging based on (y)pN category. Out of the 695 patients staged cN0, 168 (24%) had positive lymph nodes at pathology, and out of the 594 patients staged cN1, 65 (11%) were (y)pN2. Overall 3-year local recurrence rate was 5%. Clinical N-category was not associated with local recurrence when corrected for pT-category, neoadjuvant therapy, and resection margin, neither in patients with (y)pN1 (hazard ratio [HR]: 1.67 (95% confidence interval [CI]: 0.68-4.12) P = .263) nor (y)pN2-category (HR: 1.91 95% CI: [0.75-4.84], P = .175). Conclusion: Preoperative understaging of nodal status in rectal cancer is not uncommon. No significant effect on local recurrence or overall survival rates were found in the present study.

Abandonment of Routine Radiotherapy for Nonlocally Advanced Rectal Cancer and Oncological Outcomes

“…Most patients with an intermediate-risk tumor (cT1-3N1 MRF − ) still received n(C)RT in 2016; therefore, the association of omission of n(C)RT in this patient group could less reliably be analyzed. There is still controversy whether patients with a cT1-3N1 MRF − rectal tumor should receive n(C)RT if there is no intention for organ preservation in the higher tumors, especially since the clinical suspicion of nodal involvement based on imaging remains inaccurate and has limited prognostic relevance . The MERCURY study showed that the assessment of the CRM via magnetic resonance imaging by trained radiologists is superior to the TNM-based criteria in predicting LR, DFS, and OS .…”

The prognostic value of extramural venous invasion in preoperative MRI of rectal cancer patients

“…Involved surgical margin and mucinous histology are additional risk factors for a local recurrence [12]. After adoption of the TME technique, the effect of mesenteric nodal involvement on local recurrence risk is less clear [13][14][15].…”