Gemcitabine Hydrochloride and Docetaxel in Treating Patients with Relapsed or Refractory Colorectal Cancer That Is Metastatic or Cannot Be Removed by Surgery

Inclusion Criteria

• Patients must have histologically or cytologically confirmed metastatic or unresectable adenocarcinoma of the colon or rectum
• Patients must have measurable disease, defined as at least one lesion that can be accurately measured in at least one dimension (longest diameter to be recorded for non-nodal lesions and short axis for nodal lesions) as >= 20 mm with conventional techniques or as >= 10 mm with spiral computed tomography (CT) scan, magnetic resonance imaging (MRI), or calipers by clinical exam
• Patients must be either intolerant or refractory to one or more standard line(s) of chemotherapy treatment prior to enrollment; toxicity from prior regimens must be resolved to less than or equal to grade 1 prior to enrollment; patients with grade 2 neurotoxicity may be enrolled on a case by case basis at the discretion of the principal investigator; patients should be off all treatment for at least 4 weeks prior to trial enrollment
• Eastern Cooperative Oncology Group (ECOG) performance status 0 or 1 (Karnofsky >= 70%)
• Life expectancy of greater than 12 weeks
• Leukocytes >= 3,000/mcL
• Absolute neutrophil count >= 1,500/mcL
• Platelets >= 100,000/mcL
• Total bilirubin =< 1.5 x upper limit of normal (ULN)
• Aspartate aminotransferase (AST) (serum glutamic oxaloacetic transaminase [SGOT])/alanine aminotransferase (ALT) (serum glutamate pyruvate transaminase [SGPT]) =< 2.5 X institutional upper limit of normal or 5 X ULN in the presence of liver metastases
• Creatinine within normal institutional limits or creatinine clearance >= 60 mL/min/1.73 m^2 for patients with creatinine levels above institutional normal
• Microsatellite instability (MSI) phenotype of archival tissue biopsy determined by treating institution by polymerase chain reaction (PCR) and immunohistochemistry (IHC) assay
• Methylation CHFR gene promoter in archival tissue biopsy * A patient will be considered to have CHFR methylation if he/she has a methylation specific band on methylation-specific PCR (MSP) for the CHFR gene or lack of expression by IHCs; MSP primers are publicly reported and developed at Oncomethylome in a Clinical Laboratory Improvement Amendments (CLIA) laboratory; patients who test positive for MSI at any of the 5 loci will be considered MSI+ as per standard convention or who have absent expression of mutL homolog 1 (MLH1), mutS homolog 2 (MSH2), mutS homolog 6 (MSH6), or PMS2 postmeiotic segregation increased 2 (PMS2) by IHC * Results from another institution’s CLIA-certified MSI/IHC will be considered for eligibility * Patients with microsatellite instability and a family history supportive for a possible diagnosis of hereditary nonpolyposis colorectal cancer will be referred to a genetics counselor for further evaluation and recommendations
• Women of child-bearing potential and men must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry and for the duration of study participation; should a woman become pregnant or suspect she is pregnant while she or her partner is participating in this study, she should inform her treating physician immediately; men treated or enrolled on this protocol must also agree to use adequate contraception prior to the study, for the duration of study participation, and 3 months after completion of treatment
• Ability to understand and the willingness to sign a written informed consent document

Exclusion Criteria

• Patients who have had chemotherapy or radiotherapy within 4 weeks prior to entering the study or those who have not recovered from adverse events due to agents administered more than 4 weeks earlier
• Patients who are receiving any other investigational agents
• Patients with known brain metastases should be excluded from this clinical trial
• History of allergic reactions attributed to compounds of similar chemical or biologic composition to gemcitabine or docetaxel
• Patients receiving any medications or substances that are inhibitors or inducers of cytochrome P450, family 3, subfamily A, polypeptide 4 (CYP3A4) are ineligible; investigator can change to a similar agent that is a non-CYP3A4 inhibitor/inducer with a washout period of 1 week
• Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations that would limit compliance with study requirements
• Pregnant women are excluded from this study; breastfeeding should be discontinued if the mother is treated
• Human immunodeficiency virus (HIV)-positive patients on combination antiretroviral therapy are ineligible