Pemetrexed Plus Tarceva as Salvage Treatment in EGFR Overexpressed Metastatic Colorectal Cancer Patients Who Were Failed After Standard Chemotherapy

Inclusion Criteria:

* Advanced colorectal cancer failed from all standard chemotherapy

  * History of refractoriness from chemotherapy including 5-FU, Oxaliplatin, Irinotecan
  * Oral 5-FU agents are included standard chemotherapy
  * Targeted agents such as cetuximab or bevacizumab are not included in inclusion criteria
* Patient must have willingness and ability to comply with the study protocol including visiting hospital for test and treatment during trial
* ECOG performance status 0\~2
* Measurable lesion (RECIST 1.1) must exist
* Expected survival should be more than 3 months from first dose of pemetrexed
* Adequate organ function as defined as below estimated 28 days before first doe of pemetrexed:

Exclusion Criteria:

* Poor performance status (ECOG PS ≥ 3)
* Patient can not take folic acid or Vitamin B12.
* History of previous treatment with pemetrexed
* History of malignant disease, except: non-melanoma skin cancer that properly treated, cured uterine cervical cancer or other solid tumor without evidence of recurrence within 5 years
* Patient can not swallow oral pills.
* Treatment with medication of clinical trial within 14 days (or longer duration according to specific agents)
* Systemic chemotherapy or radiation (except palliative purpose) within 3 weeks (or longer duration according to specific agents)
* Toxicity from previous treatment as CTCAE grade \> 1, except alopecia
* bowel obstruction or CTCAE grade 3/4 upper GI bleeding before 4 weeks
* QTc prolongation (QTc \> 480msec) at resting is documented more than twice within 24 hours or family history of QT prolongation syndrome