DISEASE CHARACTERISTICS:

• Diagnosis of non-small cell lung cancer

  • Stage I, II, IIIA, or IIIB disease

• Diagnosis of radiation therapy-induced pulmonary fibrosis within 2 years of last radiation treatment

  • Grade I-III disease as defined by NCI CTCAE v3.0
  • Diagnosis and grading based on radiographic changes of ≥ grade 1, defined as minimal radiographic findings (or patchy or bibasilar changes) with estimated radiographic proportions of total lung volume < 25% (if fibrotic)

PATIENT CHARACTERISTICS:

• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception
• Not currently smoking or smoked within the past 6 months
• No baseline systolic blood pressure < 100 mm Hg
• No bilateral renal artery stenosis, hereditary or idiopathic angioedema, or uncontrolled hypotension
• No history of kidney failure or liver disease
• Able to attend clinic visits
• No allergy or allergic reaction to losartan potassium or any other angiotensin II receptor blocker

PRIOR CONCURRENT THERAPY:

• See Disease Characteristics
• More than 6 months since prior and no concurrent use of another angiotensin II receptor blocker (i.e., losartan potassium, valsartan, irbesartan, candesartan, cilexetil, eprosartan mesylate, or telmisartan)
• No history of lung transplant
• No prior pneumonectomy
• No concurrent lithium