title: Clinical relevance and utility of cetuximab-related changes in magnesium and calcium serum levels.
abstract: Hypomagnesemia and hypocalcemia are common adverse events during cetuximab treatment. The influence of the chemotherapeutic combination on serum levels is unknown and the predictive value is currently under discussion. This analysis investigated 79 patients who had received cetuximab for at least 6 weeks in the day clinic of the Comprehensive Cancer Center, University of Munich. Calcium and magnesium serum levels were analyzed weekly; tumor response and adverse events were followed. Thirty-eight patients had metastatic colorectal cancer (mCRC) and the predictive value of hypomagnesemia was tested in these patients. During therapy, calcium serum levels decreased to about 97% of the baseline levels and were maintained for the duration of treatment. Magnesium levels showed a significant time-dependent decrease. Serum levels of magnesium were lower when cetuximab was combined with a platinum derivative. After a treatment duration of 12 weeks, magnesium levels decreased to 70% in platinum-treated patients, whereas they decreased to only 90% of baseline in patients who did not receive platinum therapy. In patients treated for mCRC, a decrease of serum magnesium below 95% of the baseline levels 14 days after initiating treatment separated patients significantly in terms of survival times. Magnesium levels decrease in a time-dependent manner during cetuximab therapy. As hypomagnesemia was more prominent in patients receiving platinum agents, magnesium measurements may be advised in these patients. In mCRC patients treated with cetuximab, day-14 magnesium serum levels correlated with treatment efficacy.
authors.affiliation: Department of Internal Medicine III, Klinikum Grosshadern, University of Munich, Germany. sebastian.stintzing@med.uni-muenchen.de
authors.forename: Sebastian
authors.initials: S
authors.lastname: Stintzing
authors.forename: Doris
authors.initials: D
authors.lastname: Fischhaber
authors.forename: Charlotte
authors.initials: C
authors.lastname: Mook
authors.forename: Dominik P
authors.initials: DP
authors.lastname: Modest
authors.forename: Clemens
authors.initials: C
authors.lastname: Giessen
authors.forename: Christoph
authors.initials: C
authors.lastname: Schulz
authors.forename: Michael
authors.initials: M
authors.lastname: Haas
authors.forename: Stefan
authors.initials: S
authors.lastname: Boeck
authors.forename: Marlies
authors.initials: M
authors.lastname: Michl
authors.forename: Joachim
authors.initials: J
authors.lastname: Stemmler
authors.forename: Rüdiger P
authors.initials: RP
authors.lastname: Laubender
authors.forename: Volker
authors.initials: V
authors.lastname: Heinemann
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D061067:Antibodies, Monoclonal, Humanized / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use; D002118:Calcium / Q000097:blood*; D000068818:Cetuximab; D015331:Cohort Studies; D015179:Colorectal Neoplasms / Q000097:blood / Q000150:complications / Q000188:drug therapy*; D016903:Drug Monitoring; D005260:Female; D006801:Humans; D006996:Hypocalcemia / Q000209:etiology*; D015994:Incidence; D008274:Magnesium / Q000097:blood*; D008297:Male; D008875:Middle Aged; D017671:Platinum Compounds / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use; D051437:Renal Insufficiency / Q000150:complications; D012189:Retrospective Studies; D016019:Survival Analysis; D014883:Water-Electrolyte Imbalance / Q000139:chemically induced* / Q000453:epidemiology / Q000503:physiopathology
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents; D017671:Platinum Compounds; D008274:Magnesium; D000068818:Cetuximab; D002118:Calcium