Expression of sialyl-Tn predicts the effect of adjuvant chemotherapy in node-positive breast cancer.
Sialyl-Tn (STn) is a carcinoma-associated carbohydrate determinant expressed on cancer-associated mucins and has the structure NANA alpha(2-6)alpha GalNAc. Expression of STn in colon and ovarian cancer is associated with a poor prognosis independent of tumour grade, stage or histological type. We have examined 237 cases of primary breast cancer for expression of this antigen using the antibody HB-STn (Dako). The frequency of STn expression was 31% in the whole group, 36% in the node-negative and 28% in the node-positive group. Survival was lower, but not significantly so, in the STn-positive group (P = 0.07), but this effect was highly significant for patients with node-positive disease (P < 0.002), the curves for node-negative disease being coincident (P = 0.31). In node-positive disease the effect was limited to those receiving adjuvant chemotherapy (P = 0.001). In a multivariate (Cox) analysis on the whole group STn staining, combined with adjuvant chemotherapy, showed a highly significant correlation with survival. In STn-negative cases, adjuvant chemotherapy improved survival (relative risk 2.3, 95% confidence intervals 1.4-3.9), whereas adjuvant chemotherapy did not influence survival in patients which expressed STn (relative risk 1.1, 95% confidence intervals 0.6-2.2). Thus, by either direct or indirect mechanisms, STn positivity appears to be a marker of resistance to adjuvant chemotherapy.
Miles
D W
DW
ICRF Clinical Oncology Unit, Guy's Hospital, London, UK.
Happerfield
L C
LC
Smith
P
P
Gillibrand
R
R
Bobrow
L G
LG
Gregory
W M
WM
Rubens
R D
RD
D015295:Antigens, Tumor-Associated, Carbohydrate / Q000378:metabolism*; D014408:Biomarkers, Tumor; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000188:drug therapy / Q000473:pathology; D018270:Carcinoma, Ductal, Breast / Q000175:diagnosis* / Q000188:drug therapy; D006801:Humans; D008207:Lymphatic Metastasis; D011379:Prognosis; D016019:Survival Analysis
D015295:Antigens, Tumor-Associated, Carbohydrate; D014408:Biomarkers, Tumor; C055491:sialosyl-Tn antigen