Uncertainties remain in the status of internal mammary lymph nodes in breast cancers located in lower inner zone

To the Editor,

We appreciate Dr. Altundag in response to our recent study [1]. In the analysis of molecular subtype of breast cancers in our study, the determination of molecular subtype was based on statuses of hormone receptors, HER-2 and ki-67. Hormone receptor and HER-2-positive patients were assigned as luminal B molecular subtype on a routine basis [2].

As for the rate of internal mammary lymph node (IMLN) involvement in lower inner zone tumors, pertinent data is unavailable because of the retrospective design of our study. We would like to restate the clinically occultness and difficulties in the assessment of IMLN. Currently, PET/CT or lymphoscintigraphic SPECT/CT may help to identify the IMLN drainage, while conventional diagnostic techniques such as CT are much less reliable. Pathological establishing of IMLN status is determinate, but IMLN dissection is not routinely recommended due to inaccessibility and the ongoing controversies in the strategy and survival benefit of IMLN management [3]. Since the status of IMLN was not regularly examined before treatment, such data were nowhere to be extracted in a retrospective analysis.

Theoretically, we are expecting a higher rate of IMLN involvement in breast cancers located in the lower inner zone compared with other tumor sites. But obviously, further clinical studies are needed to ascertain our hypothesis.