Gemcitabine and Pemetrexed in Primary Unknown Adenocarcinoma

There is no standard treatment for the patient population being asked to participate in this study. Although one current regimen, used by some investigators, has a high rate of response compared to other therapies, it is associated with moderate to severe toxicity. As gemcitabine and pemetrexed have a broad range of activity against cancer it is reasonable to determine how active and safe they are against patients with this type of cancer.The objective of this study is to determine the anti-tumor activity of pemetrexed and gemcitabine in patients with this condition.