Survival, treatment regimens and medical costs of women newly diagnosed with metastatic triple-negative breast cancer

Individuals diagnosed with metastatic triple-negative breast cancer (mTNBC) suffer worse survival rates than their metastatic non-TNBC counterparts. There is little information on survival, treatment patterns, and medical costs of mTNBC patients in Asia. Therefore, this study aimed to examine 5-year survival, regimens of first-line systemic therapy, and healthcare costs of mTNBC patients in Taiwan. Adult females newly diagnosed with TNBC and non-TNBC as well as their survival data, treatment regimens and costs of health services were identified and retrieved from the Cancer Registry database, Death Registry database, and National Health Insurance (NHI) claims database. A total of 9691 (19.27%) women were identified as TNBC among overall BC. The 5-year overall survival rate of TNBC and non-TNBC was 81.28% and 86.50%, respectively, and that of mTNBC and metastatic non-TNBC was 10.81% and 33.46%, respectively. The majority of mTNBC patients received combination therapy as their first-line treatment (78.14%). The 5-year total cost in patients with metastatic non-TNBC and with mTNBC was NTD1,808,693 and NTD803,445, respectively. Higher CCI scores were associated with an increased risk of death and lower probability of receiving combination chemotherapy. Older age was associated with lower 5-year medical costs. In sum, mTNBC patients suffered from poorer survival and incurred lower medical costs than their metastatic non-TNBC counterparts. Future research will be needed when there are more treatment options available for mTNBC patients.

Cost-effectiveness analysis of atezolizumab in advanced triple-negative breast cancer

BACKGROUND

The IMpassion130 trial demonstrated that adding atezolizumab to nanoparticle albumin-bound (nab)-paclitaxel improved the survival of patients with untreated, advanced, programmed death ligand 1 (PDL1)-positive triple-negative breast cancer (TNBC). In view of the high cost of immunotherapy, it is important to examine its value with respect to both benefits and costs. In this study, the cost-effectiveness of atezolizumab/nab-paclitaxel combination therapy relative to nab-paclitaxel monotherapy was evaluated for the first-line treatment of advanced, PDL1-positive TNBC, from a healthcare system perspective.

METHODS

A three-state partitioned-survival model was developed to compare the clinical and economic outcomes of treatment with atezolizumab/nab-paclitaxel combination therapy with nab-paclitaxel monotherapy in patients with advanced TNBC. Clinical data were obtained from the IMpassion130 trial and extrapolated to 5 years. Health state utilities were retrieved from the literature, while direct costs (in Singapore dollars, S$) were sourced from public healthcare institutions in Singapore. The primary outcomes of the model were life years (LYs), quality-adjusted LYs (QALYs), costs and incremental cost-effectiveness ratios (ICERs). One-way and probabilistic sensitivity analyses and scenario analyses were conducted to explore the impact of specific assumptions and uncertainties.

RESULTS

Adding atezolizumab to nab-paclitaxel resulted in an additional 0.361 QALYs (0.636 LYs) at an ICER of S$324,550 per QALY gained. The ICER remained high at S$67,092 per QALY even when atezolizumab was priced zero. One-way sensitivity analysis showed that the ICER was most sensitive to variations in the cost of atezolizumab and the time horizon. Scenario analyses confirmed that the ICERs remained high even under extremely favourable assumptions.

CONCLUSIONS

Given the exceedingly high ICER, adding atezolizumab to nab-paclitaxel was unlikely to represent good value for money for the treatment of advanced PDL1-positive TNBC. Our findings will be useful in informing funding policy decisions alongside other considerations such as comparative effectiveness, unmet need and budget impact.

Decisions on Further Research for Predictive Biomarkers of High-Dose Alkylating Chemotherapy in Triple-Negative Breast Cancer: A Value of Information Analysis

OBJECTIVES

To inform decisions about the design and priority of further studies of emerging predictive biomarkers of high-dose alkylating chemotherapy (HDAC) in triple-negative breast cancer (TNBC) using value-of-information analysis.

METHODS

A state transition model compared treating women with TNBC with current clinical practice and four biomarker strategies to personalize HDAC: 1) BRCA1-like profile by array comparative genomic hybridization (aCGH) testing; 2) BRCA1-like profile by multiplex ligation-dependent probe amplification (MLPA) testing; 3) strategy 1 followed by X-inactive specific transcript gene (XIST) and tumor suppressor p53 binding protein (53BP1) testing; and 4) strategy 2 followed by XIST and 53BP1 testing, from a Dutch societal perspective and a 20-year time horizon. Input data came from literature and expert opinions. We assessed the expected value of partial perfect information, the expected value of sample information, and the expected net benefit of sampling for potential ancillary studies of an ongoing randomized controlled trial (RCT; NCT01057069).

RESULTS

The expected value of partial perfect information indicated that further research should be prioritized to the parameter group including "biomarkers' prevalence, positive predictive value (PPV), and treatment response rates (TRRs) in biomarker-negative patients and patients with TNBC" (€639 million), followed by utilities (€48 million), costs (€40 million), and transition probabilities (TPs) (€30 million). By setting up four ancillary studies to the ongoing RCT, data on 1) TP and MLPA prevalence, PPV, and TRR; 2) aCGH and aCGH/MLPA plus XIST and 53BP1 prevalence, PPV, and TRR; 3) utilities; and 4) costs could be simultaneously collected (optimal size = 3000).

CONCLUSIONS

Further research on predictive biomarkers for HDAC should focus on gathering data on TPs, prevalence, PPV, TRRs, utilities, and costs from the four ancillary studies to the ongoing RCT.