- Surgery: With the exception of patients with INSS 4S disease, patients undergo surgery to remove as much of the primary tumor and involved lymph nodes as can safely be accomplished. Reassessment for definitive surgery (for patients who undergo biopsy only or partial resection at diagnosis) is made at the completion of scheduled chemotherapy (after course 2 for group 2, after course 4 for group 3, and after course 8 for group 4).