Chemotherapy may be administered if there is evidence or suspicion of metastatic disease. Evidence supporting the effectiveness of chemotherapy is, in many cases, unclear due to a wide variety of prognostic factors and small sample size. However, there is some evidence to suggest that drugs such as paclitaxel,[6] doxorubicin,[7] ifosfamide, and gemcitabine[8] exhibit antitumor activity.