To the best of our knowledge, this is the first systematic review to implement an EE of NAC and AC in cancer. We found that the EEs of NAC or AC dominant approaches for multiple cancer patients, are mixed, although 68% of studies revealed NAC as the dominant strategy. NAC is more cost-effective for pancreatic, head and neck, rectal, prostate, and cervical cancers, and colorectal liver metastases. NAC is cost-effective with lower cost and similar QALY in ovarian cancer, and there were no significant differences in cost and outcomes for lung cancer.
For high-risk patients (IV, age ≥ 75 years, comorbidity) with ovarian cancer, NAC was cost-effective with higher QALY and similar cost, with the opposite result for patients who are not high risk.28 In prostate cancer,34 NAC was the dominant strategy in high-risk patients (clinical stage T2c or T3, initial prostate-specific antigen levels ≥ 20 ng/mL, biopsy Gleason score (GS) ≥ 8 according to the D’Amico risk stratification system).40
Patient numbers at various stages (Table S 4 in the Supplement), revealed NAC as dominant among majority of patients at stage IV.
One study indicated NAC as prevalent with stage IV patients, while AC was dominant in stage III. One with a 65% stage IV patient proportion showed that NAC was cost-effective.
Thus, NAC is cost-effective in stage IV or high-risk patients because they have more complications or operational difficulties, which can offset AC’s surgery advantage.
Given the number and types of cancer research designs, it is difficult to synthesize and analyze all cancer types. Some studies use observational cohorts, with patient populations and data from the medical database. Only one RCT study and four population studies come from RCTs, probably because they are not cost effective in NAC and AC. In addition, the RCT for effective outcomes comparisons in NAC and AC lacked detailed cost information.
In addition, the literature conveys uncertainty regarding cost and efficacy. The efficacy results align with previously published research,41–48 demonstrating no significant advantages of NAC and AC for survival. The variation in efficacy was mostly due to the proportion of patients with different stages of cancer, which relates closely to survival time.49,50 Moreover, studies with different time horizons and consequences were measured in different units.
The cost variation can be attributed to several factors. The studies employed various designs and methods to measure and analyze cost differences, such as the phase-of-care and total cost estimation methods. Furthermore, with different assumptions, the cost categories included were different, as in Figure S 5 in the Supplement. Another driver could be the inclusion of studies from multiple countries and settings, as costs can vary country wise. We found that cost comparisons differ, even for the same cancer (Table 2). Some included studies assumed that AE costs were equal in NAC and AC, while Brandt et al. found that patients’ tolerance of NAC was better than that of AC in NSCLC.39 Similar results were also found in ovarian,51 breast,52 and gastric cancer.53 Therefore, we considered that chemotherapy AEs’ costs required inclusion in the model. Moreover, the quality of life (QOL) of patients experiencing NAC and AC must be different owing to different tolerances.51 We need to evaluate the utility value of NAC and AC, respectively, which are equivalent in the reviewed studies.
The comparison of the efficacy of NAC and AC in these eight types of cancer remained controversial, which showed that OS or PFS were not significantly different.41–48 Two treatment strategies are recommended by the NCCN.1 However, there are numerous systematic reviews about NAC and AC comparisons in multiple cancers. Burotto et al. showed that NAC and AC had no statistically significant difference in OS for breast or colorectal cancer.54 Our review analyzes the cost-effectiveness of NAC vs. AC from a broad scope and spectrum of disease, making the study more informative, relevant, and useful for clinical practice and medical decision-making.
Although EEs’ results are uncertain, the PSAs suggested that NAC was likelier to be cost-effective at each WTP level. Most possibilities of the dominant strategy in PSA were less than 60%, and the survival, recurrence rate, R0 rate, and QOL can change the results of cost-effectiveness analysis. Therefore, a study of the effect of NAC vs. AC should consider these outcomes.
In our review, stage IV or other high-risk cancer patients were more suitable for NAC. Therefore, subgroup analyses, such as in Forde et al.30,55 and Poonawalla et al.28 on NAC and AC EEs or other studies are necessary. Furthermore, the more elaborate the high-risk assessment before treatment, the more benefit patients received in medical decisions.
This review is constrained by the quantity and quality of the included studies, which may lead to inaccurate analysis and synthesis. The quality of reporting was high for most studies, but some failed to clearly define and report on perspectives, cost inputs, or study design elements of the economic model. In addition, 83% of included studies were based on observational data, which may have resulted in biased parameter estimates. Furthermore, this study is limited by summarizing results from published studies, thus potentially missing important unpublished data.