RATIONALE: Gathering information about vitamin D supplementation and sun exposure in patients with melanoma may help doctors learn more about the disease and find what may affect cancer relapse.

PURPOSE: This clinical trial is studying vitamin D supplementation and sun exposure in patients who have undergone surgery for stage IB, stage II, or stage IIIA melanoma.

OBJECTIVES:

• To examine the findings of the pilot study, that vitamin D supplementation in combination with vitamin D receptor (VDR) polymorphisms protects from late relapse (after 3 years) in patients who have had melanoma.
• To investigate the effects of vitamin D supplement dosage in reducing the risk of late relapse.
• To examine if vitamin D supplementation in combination with particular VDR polymorphisms protects from early relapse (before 3 years).
• To examine if serum levels of vitamin D correlate with risk of relapse in groups of patients with different VDR polymorphisms.
• To examine the effect of vitamin supplementation and VDR status on time to relapse and survival in these patients.
• To examine other factors that may affect risk of relapse by assembling a tissue (genomic DNA and serum) resource.
• To investigate the effect of exposure to incidental drugs, such as statins, on risk of relapse in these patients.

OUTLINE: Patients are stratified according to disease relapse in the past 5 years (yes vs no).

Patients are asked to complete a food frequency questionnaire focusing on vitamin D and the following area: supplementation of diet with vitamins/fish oil and duration of use; sun exposure and sunscreen-use per decade prior to and after diagnosis. Patients are also asked to provide a blood sample for serum and DNA analysis. Consenting patients are also tagged with the Office of National Statistics to allow passive follow up.

Stored tissue from the patient's primary melanoma may be used to corroborate research findings using immunohistochemistry or studies of gene expression, polymorphism, or mutation.

DISEASE CHARACTERISTICS:

• Diagnosed with melanoma

• Must meet either of the following conditions:

  • Resected stage IB, II, or IIIA disease that has relapsed as either stage III or IV disease (cases)

    • First loco regional and/or visceral relapse (with/without sentinel node biopsy)

      • No more than 3 months since first relapse

  • Resected stage IB, II, or IIIA disease that has not relapsed for ≥ 5 years (controls)

PATIENT CHARACTERISTICS:

• Not specified

PRIOR CONCURRENT THERAPY:

• See Disease Characteristics