Contralateral internal mammary node invasion in breast cancer: lymphoscintigraphic data

Contralateral internal mammary (IM) node invasion has been analyzed in 1025 patients where the two IM chains have been investigated by lymphoscintigra phy. Contralateral IM lymphoscintigrams (LySc) were classified as abnormal (nodes involved by metastatic cancer) in 153 cases (or 15.6% of the populat ion) and this included one-third of the cases with homolateral IMLySc abnor malities (114/318). Overall, patients with bilateral abnormalities on IMLyS c (Grp A) had a similar survival to those with homolateral abnormal IMLySc (Grp B). However, when other prognostic variables were taken into account a nd two matched groups were obtained, patients with bilateral internal mamma ry node involvement had a highest incidence of clinically evident systemic metastatic disease than patients with homolateral IM involvement. Contralat eral IM nodes are invaded in one-third of the cases with homolateral IM nod e invasion. These patients may have a prognosis worse than those with only homolateral IM disease. (C) 1999 Harcourt Publishers Ltd.