title: Impaired platelet aggregation in melanoma patients treated with interferon-alpha-2b adjuvant therapy.
abstract: BACKGROUND
  High-dose interferon (INF)- alpha-2b is the only Food and Drug Administration-approved adjuvant treatment for patients with melanoma who are at high risk of recurrence. Although circumstantial evidence points to a potentially harmful effect of INF-alpha-2b on platelet function, to the authors' knowledge this has never been studied in humans.
  
  
  METHODS
  The study group was comprised of patients who had undergone surgery for melanoma and were free of disease but at a high risk of recurrence. All patients were candidates for adjuvant INF treatment (high-dose) and were undergoing routine evaluation to which platelet aggregation was added. Aggregation was triggered in standard fashion with adenosine diphosphate, epinephrine, collagen, thrombin, arachidonic acid, and ristocetin. Blood samples were drawn immediately before treatment, during the intravenous loading phase, during the subcutaneous maintenance phase, and 3-6 weeks after cessation of treatment. Patients receiving low-dose, long-standing INF-alpha-2b treatment also were tested. All results at each phase were compared with those of normal controls.
  
  
  RESULTS
  In those patients receiving high-dose INF-alpha-2b, ristocetin-induced aggregation did not appear to be affected. However, the response to > or = 1 of the other agonists was impaired in 5 of 6 samples during loading, 14 of 15 samples during the maintenance phase, and 8 of 13 samples after treatment, compared with only 1 of 8 samples before treatment (P = 0.025, P = 0.002, and P = 0.067, respectively). During treatment with low-dose INF, platelet function was affected to a lesser extent.
  
  
  CONCLUSIONS
  INF treatment in melanoma patients appears to be associated with severe impairment of platelet aggregation, which appears to be dose-dependent and cumulative-dose-dependent. This is not detectable by the standard coagulation profile. This effect has significant implications in the event of accidental injury or elective surgery. The antiaggregation activity may be the mechanism by which INF delays, reduces, or prevents the formation of melanoma metastases.
authors.affiliation: Department of Surgery B, Rabin Medical Center, Beilinson Campus, Petah Tiqva, and Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel. hgutman@clalit.org.il
authors.forename: Haim
authors.initials: H
authors.lastname: Gutman
authors.forename: Jacob
authors.initials: J
authors.lastname: Schachter
authors.forename: Ella
authors.initials: E
authors.lastname: Stopel
authors.forename: Roee
authors.initials: R
authors.lastname: Gutman
authors.forename: Judith
authors.initials: J
authors.lastname: Lahav
mesh_terms: D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000009:adverse effects* / Q000627:therapeutic use; D001778:Blood Coagulation Disorders / Q000139:chemically induced*; D017024:Chemotherapy, Adjuvant; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D000077190:Interferon alpha-2; D016898:Interferon-alpha / Q000009:adverse effects* / Q000627:therapeutic use; D008297:Male; D008545:Melanoma / Q000188:drug therapy* / Q000601:surgery; D008875:Middle Aged; D010974:Platelet Aggregation / Q000187:drug effects*; D011994:Recombinant Proteins; D012878:Skin Neoplasms / Q000188:drug therapy* / Q000601:surgery
chemical_list: D000970:Antineoplastic Agents; D000077190:Interferon alpha-2; D016898:Interferon-alpha; D011994:Recombinant Proteins