Refined staging by sentinel lymph node biopsy to individualize therapy in anal cancer.

We evaluated the feasibility of the sentinel lymph node technique to refine staging and potentially individualize therapy for anal cancer. Seventeen patients with cancer of the anal canal underwent peritumoral injection of 99mTc-colloid, followed 17 hours later by lymphoscintigraphy. A selective lymph node biopsy (SLNB) was attempted in 12 of 13 cases with scintigraphically detected SLNs. Lymph node metastases were present in 5 of 12 cases (42%); in 2 of these 5 cases, micrometastases were detected only by immunohistochemical staining. Hence, SLNB refines the diagnostic workup for anal cancer and provides an accurate basis for individualized therapy.