Patients who received first-line carboplatin-based chemotherapy had a higher global QOL and fewer symptoms of fatigue, nausea and vomiting, appetite loss and constipation than those who received cisplatin-based chemotherapy. Our results, which showed fewer symptoms of nausea and vomiting with carboplatin-based chemotherapy, agreed with the results of previous studies (10
). Differences in the response rates and one-year survival were not significant when cisplatin- and carboplatin-based chemotherapy were compared. However, previous meta-analyses of RCTs comparing carboplatin- to cisplatin-based chemotherapy in advanced NSCLC (10
) showed a higher response rate with cisplatin-based chemotherapy, although the survival advantage was not significant with cisplatin-based chemotherapy. Thus, in comparison of the two chemotherapeutic strategies, survival, which was the primary outcome measure in the clinical trials, did not vary significantly between treatments, although there were significant differences in QOL that favored carboplatin-based chemotherapy.
Previous reports of the choice between cisplatin or carboplatin have addressed points of controversy and, consequently, possible equivalency in efficacy, superior toxicity profiles and convenience of administration have led to the predominant role of carboplatin in the marketplace for the treatment of advanced NSCLC (27
). The toxicity profile should help to guide decisions in choosing regimens (9
). While QOL questionnaires, such as the EORTC QLQ-C30, may assess not only lung cancer symptoms, including toxicity profiles in addition to global QOL, clinical parameters had significant effects on QOL in patients undergoing chemotherapy (29
). Thus, useful information for selecting suitable chemotherapeutic regimens may be obtained by QOL assessment. We found a significant difference in the Global QOL between the two regimens. We consider that it is important to evaluate QOL in addition to survival, response rate and toxicity in patients with advanced NSCLC. Various aspects of QOL may help physicians to deal with incurable patients with lung cancer in order to provide the most appropriate weight to potentially differing perceptions of QOL (30
). Future studies should include QOL as a treatment outcome for first-line treatment.
The main use of QOL assessments in clinical trials has been to provide an additional outcome measure when comparing various oncological treatment regimens (31
). For example, in a report of the effects on, or comparison of, survival and QOL in advanced NSCLC patients with regard to various treatments, Cullen et al
stated that the effect of mitomycin, ifosfamide and cisplatin (MIC) on survival, observed in each trial separately, was reinforced by the consistently significant treatment effect, which was not achieved at the expense of short-term QOL (32
). Bonomi et al
reported that paclitaxel combined with cisplatin produced a modest survival improvement compared to etoposide plus cisplatin, without producing negative effects on QOL (33
). In the present study, the survival rate was not significantly different when comparing cisplatin-to carboplatin-based chemotherapy. However, the patients who received carboplatin-based chemotherapy did have a higher QOL. QOL information is invaluable in understanding the full impact of the treatment differences on patient outcomes (34
However, there were certain limitations to this study. Firstly, this meta-analysis includes only a small number of subjects in comparison to a previous study (12
) (2,405 vs. 6,906 patients) since some of the trials failed to report any QOL measures. QOL is increasingly recognized as a major end-point in medical care (35
), and QOL in lung cancer is an important treatment outcome in addition to length of survival (36
). Nevertheless, there have been a few previous studies reporting QOL outcomes following such palliative treatment. This may lead to the collection of conservative p-values. However, our results suggest a significant association with certain QOL measures. We believe that we may be able to conduct statistically suitable analyses of the limited information we have available. Secondly, the literature published in 2002 was the earliest trial to provide QOL data, while in the previous study (12
), the earliest literature was published in 1990. However, considering that the results for survival and response rates were not significantly different from our study, variations in the year of publication may not elicit significant bias.
In conclusion, the numbers of trials of treatment of advanced NSCLC have increased, particularly when the main objective is to avoid disease progression. If QOL assessments are performed and QOL is included as a treatment outcome, the patients receiving the palliative chemotherapy will receive useful information regarding the selection of a suitable chemotherapy regimen, taking into consideration QOL.