Internal mammary nodal chain drainage is a prognostic indicator in axillary node-positive breast cancer.
BACKGROUND
Internal mammary (IM) nodes are a potential site of breast lymphatic drainage. We examined the relationship between lymphoscintigraphic evidence of IM drainage and survival in early-stage breast cancer patients (pts).


METHODS
From a prospective database of 855 consecutive sentinel node mapping procedures using peritumoral radiocolloid injection from 1996-2004, we analyzed the 604 cases with stage I-III breast cancer. Overall survival and recurrence-free survival (OS, RFS) rates were compared in pts with (IM+) and without (IM-) IM drainage on lymphoscintigraphy using Kaplan-Meier plots and Cox proportional hazards models.


RESULTS
100 of 604 pts (17%) showed IM drainage. Five-year OS and RFS were 92% vs 88% and 88% vs 85% in IM- vs IM+ pts. In the 186 pts with axillary metastases (node+), 5-year OS and RFS were 91% vs 71% and 84% vs 69% in IM- vs IM+ pts. Univariate analysis of node+ pts estimated increased mortality risk for IM+ (hazard ratio, HR 2.9, P = .04), >or=4 positive nodes (HR 3.2, P = .02), tumors that were ER-negative (HR 3.4, P = .02), or had high Ki-67 (HR 6.8, P = .01). Multivariate analysis estimated similar increased risks [>or=4 nodes (HR 4.0, P = .02), IM+ (HR 3.3, P = .06), and ER negativity (HR 2.6, P = .09)].


CONCLUSIONS
IM nodal drainage predicted a nearly 3-fold increased mortality risk in node+ pts. Peritumoral radiocolloid injection provides a clinically relevant assessment of IM drainage and should be prospectively tested for its value in tailoring treatment strategies for axillary node-positive pts.
Yao
Michelle S
MS
Department of Radiation Oncology, University of Washington Medical School, Seattle, WA, USA.
Kurland
Brenda F
BF
Smith
Anne H
AH
Schubert
Erin K
EK
Dunnwald
Lisa K
LK
Byrd
David R
DR
Mankoff
David A
DA
D000328:Adult; D000368:Aged; D001365:Axilla; D001940:Breast / Q000000981:diagnostic imaging* / Q000473:pathology; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000401:mortality / Q000473:pathology / Q000601:surgery; D044584:Carcinoma, Ductal / Q000000981:diagnostic imaging* / Q000401:mortality / Q000473:pathology / Q000601:surgery; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000000981:diagnostic imaging* / Q000473:pathology; D008207:Lymphatic Metastasis / Q000000981:diagnostic imaging* / Q000473:pathology; D008875:Middle Aged; D015999:Multivariate Analysis; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging / Q000401:mortality / Q000473:pathology / Q000601:surgery; D009367:Neoplasm Staging; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D011446:Prospective Studies; D011877:Radionuclide Imaging; D018570:Risk Assessment; D021701:Sentinel Lymph Node Biopsy; D013671:Technetium Tc 99m Sulfur Colloid
D013671:Technetium Tc 99m Sulfur Colloid