DISEASE CHARACTERISTICS:

• Histologically confirmed squamous cell carcinoma of the head and neck

  • Metastatic or loco-regionally recurrent disease
• No undifferentiated or non-keratinizing carcinomas including lymphoepitheliomas
• No tumors of the nasal or paranasal cavities or of the nasopharynx
• Measurable disease
• No clinical symptomatic evidence of brain or leptomeningeal metastases
• Ineligible for loco-regional treatment after chemotherapy

PATIENT CHARACTERISTICS:

Age:

• 18 and over

Performance status:

• ECOG 0-2

Life expectancy:

• Not specified

Hematopoietic:

• Neutrophil count at least 1,500/mm^3
• Platelet count at least 100,000/mm^3

Hepatic:

• Bilirubin less than 1.5 times upper limit of normal (ULN)
• Transaminases no greater than 2.5 times ULN (5 times ULN if liver metastases present)

Renal:

• Creatinine no greater than 1.5 times ULN
• No uncontrolled hypercalcemia

Other:

• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception during and for 30 days after study
• No known hypersensitivity to systemic liposomal formulations or compounds chemically related to study drug
• No uncontrolled systemic disease or infection
• No psychological, familial, sociological, or geographical condition that would preclude study
• No other prior or concurrent malignancy except adequately treated cone-biopsied carcinoma in situ of the cervix or basal cell or squamous cell skin cancer

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• No concurrent anticancer biological therapy or immune response modifiers
• No concurrent prophylactic hematopoietic growth factors

Chemotherapy:

• See Disease Characteristics
• No prior chemotherapy for recurrent disease
• No prior therapy with camptothecin analogues
• At least 8 weeks since prior neoadjuvant or adjuvant chemotherapy
• No other concurrent anticancer cytotoxic therapy

Endocrine therapy:

• Not specified

Radiotherapy:

• At least 8 weeks since prior radiotherapy and recovered

Surgery:

• Not specified

Other:

• At least 30 days since prior experimental drug