Preoperative Chemoradiotherapy Does Not Necessarily Reduce Lymph Node Retrieval in Rectal Cancer Specimens—Results from a Prospective Evaluation with Extensive Pathological Work-up

Abstract

Purpose Preoperative chemoradiotherapy (CRT) is supposed not only to reduce lymph node metastases but also lymph node recovery in rectal cancer specimens. The objective of this prospective study was to determine the effects of chemoradiation on mesorectal lymph node retrieval under terms of a meticulous histopathological evaluation. Methods Specimens from 64 consecutive patients with stage II/III rectal cancer receiving preoperative 5-FU-based CRT were investigated. All patients were treated within the German Rectal Cancer Trial CAO/ARO/AIO-04. After surgery (including quality assessed total mesorectal excision), extensive pathological diagnostics was performed with embedding and microscopic evaluation of the whole mesorectal soft tissue compartment. Results A total number of 2,021 lymph nodes were recovered (31.6 per specimen) within pathological work-up. There was no significant correlation between the number of retrieved nodes and patient-as well as tumor-dependent parameters. Lymph node size constantly amounted for less than 0.5 cm. Twenty patients (31.3%) had persistent nodal metastases. A considerable incidence of residual micrometastatic involvement in lymph nodes <0.3 cm (in 9.4% of all patients) was detected by extensive pathologic work-up. Conclusion Reliable nodal staging with high numbers of detected nodes was feasible after neoadjuvant CRT. Micrometastases frequently occur in small lymph nodes detected by microscopic evaluation.

Gastrointestinale Tumore – interdisziplinäre Diskussion neuer Daten

“…Bei Lymphknoten-negativen Patienten (ypN0) wurden über die standardisierte Aufarbeitung des mesorektalen Kompartiments nur in 0,3% der Fälle okkulte Mikrometastasen entdeckt, sodass hier keine Rationale für ein zusätzliches Screening besteht [113].…”

Evaluation of quality parameters of rectal cancer surgery at the Coloproctology Unit of Hospital de Braga

“…The evaluation of the ganglia involvement is essential for the staging of the RC, and significant correlations have been established between the number of analyzed ganglia and the survival of patients 46 . In order to study the number of analyzed ganglia, the cohort value was established based on criteria of different surgeon associations, which recommend the analysis of at least 12 negative ganglia 41,46,47 .…”

“…In order to study the number of analyzed ganglia, the cohort value was established based on criteria of different surgeon associations, which recommend the analysis of at least 12 negative ganglia 41,46,47 . This way, it is possible to confirm with 90% accuracy that the patient is free of lymphatic invasion 38,48 .…”

“…Concerning the factors that depend on the patient, the anatomical factors stand out, with individual variations related to the number of lymphatic ganglia, the age of the patient, with the tendency to perform surgeries that are less aggressive in oncological terms, with the old age of the patients48 and the administration of the primary treatment, which causes the ganglia to decrease in size, thus making resection harder 46 . Concerning this last aspect in the analyzed study, 70% of the cases that were submitted to primary therapy presented a number of analyzed ganglia inferior to 12; however, they represent only 34.1% of the cases with less than 12 analyzed ganglia, thus, the low percentage cannot be only related to that fact.…”

Gender-Specific Acute Organ Toxicity during Intensified Preoperative Radiochemotherapy for Rectal Cancer

“…Five to 6 weeks after the preoperative RCT was completed, a quality-controlled rectal resection, including a total mesorectal excision, was performed using a standard technique [24]. Assessment of the intended surgical procedure and of the possibility of sphincter preservation was performed by the surgeon before the oncological resection.…”