RATIONALE: Studying samples of blood from patients with cancer in the laboratory may help doctors learn more about changes that occur in peptides and proteins and identify biomarkers related to cancer.

PURPOSE: This research study is looking at blood samples from patients with malignant melanoma, metastatic breast cancer, advanced lung cancer, pancreatic cancer, or colorectal cancer.

OBJECTIVES:

Primary

• To assess which potential peptide and protein markers produced by human melanoma, lung, breast, pancreatic, and colorectal cell lines may be detectable in serum of patients from these five disease groups.

Secondary

• To conduct further extensive investigation with respect to identification of the protein/peptide involved, determination of specificity for each cancer, and development of more sensitive assays to look for such markers in a wider population of patients, including those undergoing therapy.

OUTLINE: This is a multicenter study.

Blood samples are collected before surgical intervention or treatment to assess peptide and protein markers.

DISEASE CHARACTERISTICS:

• Diagnosis of 1 of the following advanced metastatic malignancies:

  • Malignant melanoma
  • Lung cancer
  • Breast cancer
  • Pancreatic carcinoma
  • Colorectal cancer

• Advanced and/or metastatic disease

• Hormone receptor status not specified

PATIENT CHARACTERISTICS:

• Menopausal status not specified

PRIOR CONCURRENT THERAPY:

• Not specified

5 different tumour types