Lymph node micrometastasis in N stage: a call for more evidence

We would like to thank Dr. Chen and his colleagues for their interest in and positive comments about our work (1). In lung cancer, even patients with pathological stage I non-small cell lung cancer (NSCLC), who have undergone a radical operation, including total tumor resection and systematic lymphadenectomy, may have recurrence rates between 25% and 40% and 5-year survival rates between 57% and 85% (2). These findings suggest that lymph node micrometastasis (LNMM) (3), consisting of metastases <2 mm that are difficult to detect using routine pathological examination methods, may positively correlate with post-operative recurrence and patient survival.