[Lymph node metastases in ypT1/2 rectal cancer after neoadjuvant chemoradiotherapy : The Achilles heel of organ-preserving operative procedures?].
BACKGROUND
For patients with rectal cancer and complete remission (ypT0) or with good response and residual tumor restricted only to the bowel wall (ypT1-2) after neoadjuvant chemoradiotherapy (CRT), local excision has been suggested as an alternative to avoid the significant morbidity and functional deficits associated with total mesorectal excision (TME). The aim of this investigation was to investigate the incidence, distribution and tumor-related localization of mesorectal lymph node (LN) metastases in TME specimens with complete remission (ypT0), intramural (ypT1-2) and extramural (ypT3-4) residual tumor tissue.


METHODS
Specimens of TME from 81 patients with locally advanced rectal cancer (UICC II-III) undergoing neoadjuvant CRT within the phase III German rectal cancer trial CAO/ARO/AIO-04 were prospectively evaluated. The entire mesorectal compartment was microscopically screened after complete paraffin embedding. The number and localization of all detectable LN metastases were documented in relation to the primary tumor.


RESULTS
Whereas 50 patients (62 %) had ypT3-4 rectal cancer after neoadjuvant CRT, 20 patients (25 %) presented with residual tumor within the bowel wall (ypT1-2), 11 patients (14 %) had pathological complete remission (ypT0), an average of 28 ± 13.7 LN were detected per specimen and 25 patients (31 %) had residual LN metastases after CRT. Although the incidence of LN metastases was higher in the ypT3-4 group (40 %), 25 % of patients in the ypT1-2 group with intramural residual tumor had a mean number of 2.2 residual LN metastases of which 55 % were located far from the primary lesion in the proximal mesorectum. None of the patients with ypT0 status (complete response) had residual LN metastases.


CONCLUSIONS
Even in patients with good response and post-CRT tumor tissue restricted only to the bowel wall (ypT1-2), there is still a considerable risk for residual LN metastases. Local excision of residual rectal cancer was accompanied by a higher rate of local failure and radical surgery with TME should remain the standard treatment in these patients. To date, valid selection criteria for patients eligible for organ-sparing surgery are still lacking.
Klinik für Allgemein-, Viszeral- und Kinderchirurgie, Universitätsmedizin Göttingen, Robert-Koch-Str. 40, 37099, Göttingen, Deutschland. tsprenger@chirurgie-goettingen.de.
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Sprenger
Medizinisches Versorgungszentrum Göttingen (MVZ), 37081, Göttingen, Deutschland.
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Rothe
Institut für Medizinische Statistik, Universitätsmedizin Göttingen, 37099, Göttingen, Deutschland.
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Beissbarth
Klinik für Allgemein-, Viszeral- und Kinderchirurgie, Universitätsmedizin Göttingen, Robert-Koch-Str. 40, 37099, Göttingen, Deutschland.
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Conradi
Klinik für Allgemein-, Viszeral- und Kinderchirurgie, Universitätsmedizin Göttingen, Robert-Koch-Str. 40, 37099, Göttingen, Deutschland.
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Kauffels
Klinik für Allgemein-, Viszeral- und Kinderchirurgie, Universitätsmedizin Göttingen, Robert-Koch-Str. 40, 37099, Göttingen, Deutschland.
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Homayounfar
Institut für Pathologie, Universitätsmedizin Göttingen, 37099, Göttingen, Deutschland.
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Behnes
Klinik für Strahlentherapie und Onkologie, Universitätsklinikum Frankfurt, 60590, Frankfurt/Main, Deutschland.
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Rödel
Klinik für Allgemein-, Viszeral- und Kinderchirurgie, Universitätsmedizin Göttingen, Robert-Koch-Str. 40, 37099, Göttingen, Deutschland.
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Liersch
Klinik für Allgemein-, Viszeral- und Kinderchirurgie, Universitätsmedizin Göttingen, Robert-Koch-Str. 40, 37099, Göttingen, Deutschland.
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Ghadimi
D000230:Adenocarcinoma / Q000401:mortality / Q000473:pathology* / Q000628:therapy*; D000368:Aged; D059186:Chemoradiotherapy, Adjuvant; D003131:Combined Modality Therapy; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D018365:Neoplasm, Residual / Q000473:pathology* / Q000628:therapy*; D011379:Prognosis; D011446:Prospective Studies; D012004:Rectal Neoplasms / Q000401:mortality / Q000473:pathology* / Q000628:therapy*; D012007:Rectum / Q000473:pathology / Q000601:surgery
Local excision; Lymph node metastases; Neoadjuvant chemoradiotherapy; Rectal cancer