Second-line (post-study) chemotherapy received by patients treated in the phase III trial of pemetrexed plus cisplatin versus cisplatin alone in malignant pleural mesothelioma.
BACKGROUND
A phase III trial in patients with malignant pleural mesothelioma demonstrated a survival advantage for pemetrexed plus cisplatin compared with single-agent cisplatin. Because post-study chemotherapy (PSC) may have influenced the outcome of the trial, we examined its use and association with survival.


METHODS
Eighty-four patients from the pemetrexed plus cisplatin arm and 105 patients from the single-agent cisplatin arm received PSC. Kaplan-Meier survival estimates were compared by treatment groups, and by PSC and non-PSC subgroups.


RESULTS
The percentage of patients receiving PSC was imbalanced between the treatment arms. Fewer pemetrexed plus cisplatin treated patients received PSC (37.2% versus 47.3%). A multiple regression analysis performed in this trial showed that PSC had a statistically significant correlation with prolonged survival (P <0.01), adjusting for baseline prognostic factors and treatment intervention. The adjusted hazard ratio for PSC over non-PSC subgroups was 0.56 (confidence interval 0.44-0.72).


CONCLUSIONS
PSC in malignant pleural mesothelioma was significantly associated with prolonged survival. It is not known whether the reduced risk of death was associated with PSC or whether patients who had prolonged survival tended to receive more PSC. The pemetrexed plus cisplatin treatment group had a statistically significant survival advantage even though fewer patients from that arm of the trial received PSC. The potentially beneficial role of PSC should be assessed in prospective trials.
Manegold
C
C
Heidelberg University Medical Center, Mannheim, Germany. Prof.Manegold@t-online.de
Symanowski
J
J
Gatzemeier
U
U
Reck
M
M
von Pawel
J
J
Kortsik
C
C
Nackaerts
K
K
Lianes
P
P
Vogelzang
N J
NJ
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D002945:Cisplatin / Q000008:administration & dosage / Q000627:therapeutic use*; D005260:Female; D005971:Glutamates / Q000008:administration & dosage*; D006147:Guanine / Q000008:administration & dosage / Q000031:analogs & derivatives*; D006801:Humans; D008297:Male; D008654:Mesothelioma / Q000188:drug therapy* / Q000401:mortality; D008875:Middle Aged; D000068437:Pemetrexed; D010997:Pleural Neoplasms / Q000188:drug therapy* / Q000401:mortality; D012189:Retrospective Studies
D005971:Glutamates; D000068437:Pemetrexed; D006147:Guanine; D002945:Cisplatin