A tale of two nodules
I was at the Royal society of Medicine in London a few weeks ago where a classic paradigm of lung cancer was discussed: when a patient with lung cancer presents with 2 nodules, how do you determine if they are synchronous or metastatic?
The premise for this question rests on the implications for further management. If the two nodules are synchronous, say 2 lesions that are T1 N0 M0 and T1 N0 M0 then it is assumed that complete resection of both will lead to a survival of a T1 N0 M0 tumour. On the other hand, if one is metastatic, then surgical resection would achieve survival of a T1 N0 M1 lesion.
Martini considered a second nodule to be synchronous if it was in situ, a different cell type and did not share the same lymph supply of the (presumably) distal nodule.(1) If these criteria were fufilled, the tumours could be considered as synchronous. There was a comment during the discussions that Martini made up these criteria, but if you think about it, they do make some sense.
The 6th revision of the UICC classification for lung cancer does not differentiate between synchronous and metastatic but considers a seperate nodule in the same lobe as T4 and in a different lobe as M1.(2) On conventional selection criteria patients with stage IIIB and IV are not considered for surgery.
I think all these arguments are flawed...