title: Mismatch repair system (MMR) status correlates with response and survival in non-small cell lung cancer (NSCLC) patients.
abstract: Pre-clinical data suggested a relationship between inactivation of hMLH1 and hMSH2 and resistance to drugs like cisplatin and carboplatin, but not oxaliplatin. We then hypothesised that NSCLC showing loss of expression of the mismatch repair system (MMR), could be refractory to cisplatin-based, but not to oxaliplatin-based chemotherapy. Immunohistochemical expression of hMLH1 and hMSH2 was analysed on tumour samples from 93 advanced NSCLC, receiving chemotherapy with either cisplatin or oxaliplatin in combination with gemcitabine. Patients showing loss of hMLH1 or hMSH2 expression in > or = 50% of tumour cells were deemed MMR-negative (Group A), whereas cases with a normal hMLH1 or hMSH2 expression in > 50% of the tumour cells were defined MMR-positive (Group B). No differences in the response and progression rate were found in the whole patients population and in the gemcitabine/cisplatin group for both hMLH1 and hMSH2. In the gemcitabine/oxaliplatin group response rate was 38% and 0% (p=0.04) for patients with or without loss of hMSH2 expression. Median survival according to MMR status in Groups A and B, respectively was: 17 months versus 9 months for hMLH1 (p=0.031) and 10 months versus 9 months for hMSH2 (p=0.8330). Both the difference in response rate and in median survival observed according to MMR status seem to confirm what has been suggested by preclinical studies.
authors.affiliation: Clinica di Oncologia Medica, Azienda Ospedaliero-Universitaria Ospedali Riuniti e Università Politecnica delle Marche, Ancona, Italy.
authors.forename: Mario
authors.initials: M
authors.lastname: Scartozzi
authors.forename: Vittorio
authors.initials: V
authors.lastname: Franciosi
authors.forename: Nicoletta
authors.initials: N
authors.lastname: Campanini
authors.forename: Giovanni
authors.initials: G
authors.lastname: Benedetti
authors.forename: Fausto
authors.initials: F
authors.lastname: Barbieri
authors.forename: Giulio
authors.initials: G
authors.lastname: Rossi
authors.forename: Rossana
authors.initials: R
authors.lastname: Berardi
authors.forename: Roberta
authors.initials: R
authors.lastname: Camisa
authors.forename: Rosa Rita
authors.initials: RR
authors.lastname: Silva
authors.forename: Alfredo
authors.initials: A
authors.lastname: Santinelli
authors.forename: Andrea
authors.initials: A
authors.lastname: Ardizzoni
authors.forename: Lucio
authors.initials: L
authors.lastname: Crinò
authors.forename: Guido
authors.initials: G
authors.lastname: Rindi
authors.forename: Stefano
authors.initials: S
authors.lastname: Cascinu
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D020137:Base Pair Mismatch; D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy / Q000235:genetics / Q000401:mortality; D002352:Carrier Proteins / Q000378:metabolism; D002945:Cisplatin / Q000008:administration & dosage; D003841:Deoxycytidine / Q000008:administration & dosage / Q000031:analogs & derivatives; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D008175:Lung Neoplasms / Q000188:drug therapy / Q000235:genetics* / Q000401:mortality; D008297:Male; D008875:Middle Aged; D000070957:MutL Protein Homolog 1; D000070956:MutL Proteins; D009363:Neoplasm Proteins / Q000378:metabolism; D009687:Nuclear Proteins / Q000378:metabolism; D009944:Organoplatinum Compounds / Q000008:administration & dosage; D000077150:Oxaliplatin; D012189:Retrospective Studies; D015996:Survival Rate; D000093542:Gemcitabine
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; C501486:MLH1 protein, human; D009363:Neoplasm Proteins; D009687:Nuclear Proteins; D009944:Organoplatinum Compounds; C088996:PMS1 protein, human; D000077150:Oxaliplatin; D003841:Deoxycytidine; D000070957:MutL Protein Homolog 1; D000070956:MutL Proteins; D002945:Cisplatin; D000093542:Gemcitabine