Statement: patients diagnosed with a malignant brain tumour or colon cancer can participate in the primary clinical trial.
Primary_evidence: Inclusion Criteria:   Must have received prior chemotherapy with Taxol (paclitaxel) or Taxotere (docetaxel).   Less than 3 different chemotherapy treatments for metastatic disease.   Prior treatment with hormonal and/or radiation therapy.   Must have disease that can be measured.   Must be able to take care of self needs for example personal hygiene Exclusion Criteria:   Must not be pregnant or breast-feeding.   Cancer that has spread to the brain.   Treatment with Gemcitabine or Pemetrexed   Unable to take folic acid or Vitamin B12   Treatment for another cancer within the last 5 years