Lymph node first involved in Ca breast is/are

.Levels of the axillary nodes *Level I : Below and lateral to the pectoralis minor muscle--anterior, lateral, posterior *Level II : Behind the pectoralis minor muscle--central *Level III : Above and medial to pectoralis minor muscle-- apical Note in carcinoma breast * Spread restricted to level I nodes carries better prognosis * Spread to level II has poor prognosis * Spread to level III indicates worst prognosis. ref:SRB&;s manual of surgery,ed 3,pg no 455