DISEASE CHARACTERISTICS:

• Histologically confirmed colorectal cancer

  • Metastatic or unresectable disease OR
• Diagnosis of solid tumor
• No known brain metastases

PATIENT CHARACTERISTICS:

Age

• 18 and over

Performance status

• ECOG 0-1 OR
• Karnofsky 70-100%

Life expectancy

• More than 12 weeks

Hematopoietic

• WBC ≥ 3,000/mm^3
• Absolute neutrophil count ≥ 1,500/mm^3
• Platelet count ≥ 100,000/mm^3

Hepatic

• Bilirubin normal
• AST and ALT ≤ 3 times upper limit of normal

Renal

• Creatinine normal OR
• Creatinine clearance ≥ 60 mL/min

Cardiovascular

• No symptomatic congestive heart failure
• No unstable angina pectoris
• No cardiac arrhythmia

Other

• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception during and for 3 months after study participation
• No ongoing or active infection
• No neuropathy > grade 1
• No history of allergic reaction attributed to compounds of similar chemical or biological composition to study drugs
• No psychiatric illness or social situation that would preclude study compliance
• No other uncontrolled illness

PRIOR CONCURRENT THERAPY:

Biologic therapy

• Prior bevacizumab and/or cetuximab allowed
• No concurrent routine or prophylactic filgrastim (G-CSF) or sargramostim (GM-CSF)

Chemotherapy

• See Disease Characteristics
• More than 4 weeks since prior chemotherapy (6 weeks for nitrosoureas or mitomycin)

Endocrine therapy

• Not specified

Radiotherapy

• More than 4 weeks since prior radiotherapy

Surgery

• Not specified

Other

• Recovered from prior therapy
• At least 2 weeks since prior valproic acid
• No concurrent combination anti-retroviral therapy for HIV-positive patients
• No other concurrent investigational agents
• No other concurrent anticancer therapy