Introduction Accurate assessment of lymph node status is essential in determining optimal patient management in colorectal cancer (CRC). Local excision is feasible for early rectal and polyp cancers but without lymph node harvesting, postoperative histological stage may be inaccurate and patients may not receive the survival benefit conferred from appropriate adjuvant therapy.1,2
Biomarkers in the primary tumour may predict patients at risk of nodal metastases who would benefit from standard surgical resection. We aimed to assess the relationship between β-Catenin expression within the primary tumour and lymph node status.
Method Patients with colorectal adenocarcinoma and complete lymph node staging were included. A tissue microarray (TMA) of multiple cores from formalin fixed paraffin embedded blocks was created. TMA sections were stained in duplicate for β-Catenin, and scored (0–3) for nuclear staining intensity relative to cytoplasm, an adaptation of the breast cancer H-Score method.3These scores were correlated with lymph node status as reported in the resection specimen. Statistical analysis was performed using SPSS Statistics.
Results Complete data were available on 19 patients comprising; two polyp cancers, six Dukes’ A, four Dukes’ B and seven Dukes’ C tumours. There were eight right-sided, seven left-sided and four rectal tumours. Higher levels of nuclear β-Catenin staining were noted in the 11 patients with node negative disease (mean H-score = 1.8; SD = 0.4) than in node positive disease (mean H-score = 1.3; SD = 0.2; p = 0.03, Mann-Whitney). Interestingly lower nuclear expression of β-Catenin was seen in the patient with a polyp cancer and node positive disease than in the polyp cancer without nodal disease (H-score 1.4 vs. 2.4).
Conclusion Reduced nuclear expression of β-Catenin in the primary tumour is associated with node positive disease. Further evaluation of these findings in a larger data set is required to assess if this phenotype should be considered for formal surgical resection to ensure accurate staging and prevent under-treatment.
Disclosure of interest J. Evans Grant/ Research Support from: Cancer Research UK, N. Al-Khafaj: None Declared, P. Sutton: None Declared, D. Bowden: None Declared, P. Rooney: None Declared, D. Vimalchandran: None Declared, J. Jenkins: None Declared.
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