Beta 1 integrin expression in malignant melanoma predicts occult lymph node metastases.
BACKGROUND
Elective lymph node dissection for malignant melanoma is still controversial. Experimental studies suggest that differential expression, activation, or both of beta1 integrins facilitate melanoma metastases. However, the clinical significance of beta1 integrin expression in human melanoma is unclear.


METHODS
We examined primary cutaneous melanomas from 76 patients undergoing elective lymph mode dissection. We quantified the percentage of tumor area stained by beta1 integrin antibody with an image analyzer.


RESULTS
beta1 integrin was expressed in all 23 primary tumors from patients with pathologically positive lymph nodes (LNs) but in only 14 (26%) of 53 cases with pathologically negative nodes (p < 0.001). No patients with beta1 integrin-negative tumors had LN involvement, whereas 23 (62%) of 37 patients with beta1 integrin-positive tumors had LN metastases (p < 0.001). Furthermore, 21 (91%) of 23 cases with LN metastases but only 4 (8%) of 53 cases without had beta1 integrin staining of 10% or more of tumor area (p < 0.001).


CONCLUSIONS
Our study is the first to show a correlation between expression of a molecular marker in the primary cutaneous melanoma and likelihood of regional LN metastases. beta1 immunostaining of 10% or more of tumor area reliably predicts patients most likely to harbor occult LN metastases and likely to benefit from ELND.
Hieken
T J
TJ
Department of Surgical Oncology, University of Illinois at Chicago 60612-7322, USA.
Ronan
S G
SG
Farolan
M
M
Shilkaitis
A L
AL
Kim
D K
DK
Das Gupta
T K
TK
D000328:Adult; D014408:Biomarkers, Tumor / Q000032:analysis* / Q000096:biosynthesis / Q000235:genetics; D018450:Disease Progression; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007091:Image Processing, Computer-Assisted; D019012:Integrin beta1 / Q000032:analysis* / Q000096:biosynthesis / Q000235:genetics; D015993:Life Tables; D008197:Lymph Node Excision; D008207:Lymphatic Metastasis / Q000175:diagnosis; D008297:Male; D008545:Melanoma / Q000737:chemistry / Q000401:mortality / Q000473:pathology*; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009363:Neoplasm Proteins / Q000032:analysis* / Q000096:biosynthesis / Q000235:genetics; D009367:Neoplasm Staging; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D012878:Skin Neoplasms / Q000737:chemistry / Q000473:pathology*; D016019:Survival Analysis
D014408:Biomarkers, Tumor; D019012:Integrin beta1; D009363:Neoplasm Proteins