Staging is a system of categorizing a patient’s prognosis based upon tumor size (t), lymph node involvement (n) and cancer spread to organs outside the breast (m). It is still helpful but has become less important as we find more accurate data from the individual tumor genetics.
Stage 0:
Ductal carcinoma in situ (noninvasive carcinoma). No tumor in axillary lymph node. No distant disease (metastases) (tis,n0,m0)
Stage 1:
Invasive carcinoma less than or equal to 2 centimeters, negative axillary lymph node. No distant disease. (t1,n0,m0)
Stage 2:
- Invasive carcinoma between 2 and 5 centimeters, negative axillary lymph nodes, no distant metastases. (t2,n1.m0); or invasive carcinoma less than 2cm (including no identifiable tumor at all) with positive moveable ipsilateral (same side as cancer) axillary lymph nodes. No distant disease. (t2,n0,m0.)
- Invasive carcinoma between 2 and 5 cm, metastases to moveable ipsilateral axillary lymph nodes. No distant disease. (t2,n1,m0); or tumor over 5 cm. No positive axillary lymph nodes. No distant metastases. (t3,n0,m0.)
Stage 3:
- No evidence of primary tumor, metastases to fixed ipsilateral axillary lymph nodes. (t0,n2,m0) or tumor less than or equal to 2 cm, metastases to fixed ipsilateral axillary lymph nodes, no distant metastases. (t1,n2,m0.) Or tumor between 2 and 5 cm, metastases to fixed ipsilateral axillary lymph nodes, no distant metastases. (t2,n2,m0). Or tumor over 5cm, metastases to moveable or fixed ipsilateral axillary lymph nodes, no distant metastases. (t3,n1,n2,m0).
- Tumor extends to chest wall, any axillary nodal involvement, no distant metastases. (any t,n1,n2,m0). Or any size primary tumor, metastases to ipsilateral internal mammary nodes, and no distant metastases. (any t,n3,m0)
Stage 4:
Any size tumor, any nodal involvement, distant metastases. (any t, any n, m1)
Prognosis and life expectancy decrease with stage. The smaller the tumor and less it has spread, the better. So early detection and treatment is critical. Survival in stage one approaches 97%. Stage 4 is felt to be treatable (often for many years) but not curable. However, it is becoming clear that a patient’s individual tumor characteristics are perhaps even more predictive of their outcome than size and lymph node involvement alone.
