title: [Relationship between the Incidence of Hypomagnesemia and Acneiform Rash and the Therapeutic Effect of Anti-EGFR Monoclonal Antibody in Patients with Metastatic Colorectal Cancer].
abstract: OBJECTIVE
  Although anti-EGFR monoclonal antibodies, including cetuximab and panitumumab, are highly effective in KRAS wild-type advanced colorectal cancer, these drugs frequently cause several adverse events. These events include hypomagnesemia and acneiform rash, which may lead to the dose reduction or discontinuation of therapy. In the present study, we retrospectively investigated the incidence of hypomagnesemia and acneiform rash in patients with metastatic colorectal cancer (mCRC). We examined the relationship between the incidence of such adverse events and the therapeutic effect.
  
  
  METHODS
  Thirty-four mCRC patients receiving anti -EGFR monoclonal antibody as a first-line therapy during April 2012 to March 2015 were the subjects of the present study. The symptoms of hypomagnesemia and acneiform rash were graded in accordance with the Common Terminology Criteria for Adverse Events, v4.0.
  
  
  RESULTS
  The incidence rates of hypomagnesemia (all grades) and the acneiform rash (≥grade 2) were 29%and 50%, respectively. Eight patients (24%) exhibited both of these adverse events. The tumor response rate was notable, as it was significantly higher in patients who experienced both of these adverse events compared to those who did not(88% vs 38% for complete response plus partial response, p=0.039). However, the tumor response rate tended to be higher, although not significantly, in patients with either of these adverse events compared to those without it.
  
  
  CONCLUSIONS
  Concurrent onset of hypomagnesemia and acneiform rash may become a reliable factor capable of predicting the therapeutic effect of anti-EGFR monoclonal antibody.
authors.affiliation: Dept. of Pharmacy, Gifu University Hospital.
authors.forename: Hironori
authors.initials: H
authors.lastname: Fujii
authors.forename: Hirotoshi
authors.initials: H
authors.lastname: Iihara
authors.forename: Masashi
authors.initials: M
authors.lastname: Ishihara
authors.forename: Nobuhisa
authors.initials: N
authors.lastname: Matsuhashi
authors.forename: Takao
authors.initials: T
authors.lastname: Takahashi
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Yoshida
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Itoh
mesh_terms: D017486:Acneiform Eruptions / Q000139:chemically induced / Q000453:epidemiology*; D000368:Aged; D000369:Aged, 80 and over; D000911:Antibodies, Monoclonal / Q000009:adverse effects* / Q000627:therapeutic use; D000970:Antineoplastic Agents / Q000009:adverse effects* / Q000627:therapeutic use; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000473:pathology; D066246:ErbB Receptors / Q000276:immunology; D005076:Exanthema / Q000139:chemically induced / Q000453:epidemiology*; D005260:Female; D006801:Humans; D015994:Incidence; D008274:Magnesium / Q000097:blood*; D008275:Magnesium Deficiency / Q000139:chemically induced / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D000077544:Panitumumab; D012189:Retrospective Studies
chemical_list: D000911:Antibodies, Monoclonal; D000970:Antineoplastic Agents; D000077544:Panitumumab; C512478:EGFR protein, human; D066246:ErbB Receptors; D008274:Magnesium