breast_anat_mayo.jpg (9676 bytes)

Predicting the odds that the breast cancer has already spread to the Lymph Nodes

breast_nodes_sgk.jpg (22724 bytes)

there are lymphatics throughout the breast and cancer can spread to the nodes in the arm pit (axilla) or less commonly to the node around the collar bone (supraclavicular/infraclavicul) or even in the middle under the breast bone (under the strenum, called internal mammary nodes.)

The risk that the cancer has spread to the lymph nodes (called positive nodes or nodal metastases) is higher if the tumor is big enough to feel (palpable) or size in general, or if the pathology report show the cells are invading vessels (lymphvascular invasion) or the tumor is high grade (meaning more rapid growing)
 
Risk Group Nodes Neg. Nodes Pos. More than 3 Nodes +
Very Low 95.2% 4.8% 1.4%
Low 87.6% 12.4% 1.8%
Intermediate 71.8% 28.2% 5.3%
High 25.8% 74.2% 29%
The highest risk group consisted of patients with clinically palpable axillary lymph nodes, patients with lymphatic or vascular invasion in palpable tumors 2 cm or larger, or patients with mammographically identified tumors 3 cm and larger with lymphatic or vascular invasion. The very low risk individuals had nonpalpable primary tumors 0.5 cm diameter or less without lymphatic or vascular invasion. the low risk group had no lymphatic or vascular invasion and a tumor size of 0.6-1.0 cm if it was palpable or 0.6-2.0 cm if it was detected mammographically and the primary was not palpable. Intermediate was everyone else.       Cancer 83:948-55, 1998
 

Data on Risk of  % Positive Nodes from Cancer 83:948-55, 1998

Tumor Size Nodes + Lymph/Vascular Invasion Node +
0 - 0.5 10% Absent 22%
.6 - 1.0 17% Present 58%
1.1 - 1.5 25% Palpable  
1.6 - 2.0 34% nothing 16%
2.1 - 2.5 49% breast mass 35%
2.6 - 3.0 52% axilla mass 89%
3.1 - 5.0 59% Histologic Grade  
5.1 - 10 80% Well Diff 20%
    Mod Diff 32%
    Poor Diff 45%

Data from Cancer 1997;79:1918
LymphVascular Invasion % Nodes Positive Nuclear Grade % Nodes Positive
absent 19% 1 9%
present 46% 2 21%
    3 33%
Tumor Palpable   Tumor Size  
no 10% T1a 4%
yes 28% T1b 17%
    T1c 28%

Data from Cancer 1995;76:1493
Tumor Size % Positive Nodes
0 - 5mm 0 - 11%
6 - 10mm 7 - 20%
0 - 10mm 5 - 22%

Node Mets in Non-palpable Breast Cancer. Bull Cancer 1996;83:581
Category Positive Nodes
Ductal Ca In Situ (DCIS) 0% (0/36)
DCIS with microinvasion 0% (0/23)
Invasive 0 - 5mm 0% (0/38)
6 - 10 mm 8.3% (7/84)
>10 mm 10.7% (9/84)

 

Risk of Node Mets in 12,950 Cancers 1cm or less (Cancer 1999;85:1530)
tumor size % node mets tumor size % node mets
3mm 7.4% 7mm 10.6%
4mm 8.2% 8mm 12.8%
5mm 9.9% 9mm 13.3%
6mm 10.6% 10mm 17.4%