Significance of the immunohistochemical detection of lymph node micrometastases in stage II colorectal carcinoma.
BACKGROUND
Survival results of stage II colorectal cancer patients have led to major efforts to identify the subset of patients at risk for disease relapse and adjuvant therapies benefit. Immunohistochemistry is being explored to detect undetectable microscopic lymph node micrometastases.


METHODS
A retrospective analysis of a 105 consecutive stage II colorectal cancer patients was performed. Two four-micres sections were obtained from each lymph node. These slides were stained with AE1-AE3 monoclonal antibodies against cytoskeleton using DAKO EnVision visualization system. Micrometastases were identified either as isolated cells or as well-defined glandular cell clusters with cytoplasm but not the nucleus stained with cytoskeleton antibodies.


RESULTS
665 lymph nodes isolated from 105 patients were analyzed. Lymph nodes micrometastases were assessed in 26 out of the 105 patients. 42 (6.3%) out of 665 lymph nodes were infiltrated. Most of these metastases consisted of isolated cell cluster localized in marginal and interfollicular sinus of lymph nodes. The relapse rate was 23.1% among the patients with immunohistochemical detected lymph node micrometastes and 20.3% for the patients without lymph node involvement. This result lacked statistical significance (p = 0.759).


CONCLUSIONS
AE1/AE3 lymph node immunohistochemical staining in stage II colorectal cancer is an interesting biological phenomenon but it fails to identify patients at higher risk of relapse who deserve a more aggressive adjuvant attitude.
García-Sáenz
José A
JA
Oncology Department, Hospital Clínico San Carlos, Madrid, Spain. jagsaenz@yahoo.com
Sáenz
María C
MC
González
Lucía
L
Pérez-Segura
Pedro
P
Puente
Javier
J
López-Tarruella
Sara
S
Sastre
Javier
J
Casado
Antonio
A
López-Asenjo
José G
JG
Díaz-Rubio
Eduardo
E
D000230:Adenocarcinoma / Q000378:metabolism / Q000473:pathology*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000378:metabolism / Q000473:pathology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007633:Keratins / Q000378:metabolism*; D008198:Lymph Nodes / Q000378:metabolism / Q000473:pathology; D008207:Lymphatic Metastasis / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D012189:Retrospective Studies; D016019:Survival Analysis
D007633:Keratins