Radiation therapy after breast-conserving surgery: does hospital surgical volume matter? A population-based study in Taiwan

Effectiveness of tomotherapy vs linear accelerator image-guided intensity-modulated radiotherapy for localized pharyngeal cancer treated with definitive concurrent chemoradiotherapy: a Taiwanese population-based propensity score-matched analysis

OBJECTIVE

This study used a population-based propensity score (PS)-matched analysis to compare the effectiveness of tomotherapy-based image-guided intensity-modulated radiotherapy (referred to as T-IMRT) with that of linear accelerator based (referred to as L-IMRT) for clinically localized pharyngeal cancer (LPC, divided into nasopharyngeal cancer and non-nasopharyngeal cancer) with definitive concurrent chemoradiotherapy (CCRT).

METHODS

Eligible LPC patients diagnosed between 2007 and 2014 were identified among all citizens in Taiwan from the Health and Welfare Data Science Center database. A PS-matched sample based on the PS estimated from the covariables of interest was constructed to compare the effectiveness of T-IMRT with L-IMRT. In the primary analysis, overall survival (OS) was compared for assessment of effectiveness. We also evaluated freedom from local regional recurrence and pharyngeal cancer-specific survival and performed supplementary analyses.

RESULTS

The study population included 960 patients equally divided into two groups. OS did not differ significantly between the T-IMRT and L-IMRT groups (hazard ratio for death: 0.82, p = 0.15, 5-year OS rate: 79 and 74% for T-IMRT and L-IMRT, respectively), and there were no significant differences in the other endpoints or supplementary analyses.

CONCLUSION

For LPC patients treated with definitive CCRT, we found no significant difference in disease control or survival between the T-IMRT and L-IMRT groups. However, further studies, especially randomized trials or studies focusing on other dimensions, such as quality of life, are needed. Advances in knowledge: We provide the first population-based study, as well as the largest study, on the clinical effectiveness of T-IMRT compared with L-IMRT in conjunction with CCRT in LPC patients.

A Population-based Study of the Effectiveness of Stereotactic Ablative Radiotherapy Versus Conventional Fractionated Radiotherapy for Clinical Stage I Non-small Cell Lung Cancer Patients

Background

Stereotactic ablative radiotherapy (SABR) is a promising option for non-operated early-stage non-small cell lung cancer (NSCLC) compared to conventional fractionated radiotherapy (CFRT). However, results from conclusive randomized controlled trials are not yet available. The aim of our study was to explore the effectiveness of SABR vs. CFRT for non-operated early-stage NSCLC.

Patients and methods

We used a comprehensive population-based database to identify clinical stage I non-operated NSCLC patients in Taiwan diagnosed from 2007 to 2013 who were treated with either SABR or CFRT. We used inverse probability weighting and the propensity score as the primary form of analysis to address the nonrandomization of treatment. In the supplementary analyses, we constructed subgroups based on propensity score matching to compare survival between patients treated with SABR vs. CFRT.

Results

We identified 238 patients in our primary analysis. A good balance of covariates was achieved using the propensity score weighting. Overall survival (OS) was not significantly different between those treated with SABR vs. CFRT (SABR vs. CFRT: probability weighting adjusted hazard ratio [HR] 0.586, 95% confidence interval 0.264-1.101, p = 0.102). However, SABR was significantly favored in supplementary analyses.

Conclusions

In this population-based propensity-score adjusted analysis, we found that OS was not significantly different between those treated with SABR vs. CFRT in the primary analysis, although significance was observed in the supplementary analyses. Our results should be interpreted with caution given the database (i.e., nonrandomized) approach used in our study. Overall, further studies are required to explore these issues.

Impact of Preexisting Mental Illnesses on Receipt of Guideline-Consistent Breast Cancer Treatment and Health Care Utilization

This study determined the impact of preexisting mental illnesses on guideline-consistent breast cancer treatment and breast cancer-related health care utilization. This was a retrospective, longitudinal, cohort study conducted using data from the 2006-2008 Medicaid Analytic Extract files. The target population for the study consisted of female Medicaid enrollees who were aged 18-64 years and were newly diagnosed with breast cancer in 2007. Guideline-consistent breast cancer treatment was defined according to established guidelines. Breast cancer-related health care use was reported in the form of inpatient, outpatient, and emergency room visits. Statistical analyses consisted of multivariable hierarchical regression models. A total of 2142 newly diagnosed cases of breast cancer were identified. Approximately 38% of these had a preexisting mental illness. Individuals with any preexisting mental illness were less likely to receive guideline-consistent breast cancer treatment compared to those without any preexisting mental illness (adjusted odds ratio: 0.793, 95% confidence interval [CI]: 0.646-0.973). A negative association was observed between preexisting mental illness and breast cancer-related outpatient (adjusted incident rate ratio (AIRR): 0.917, 95% CI: 0.892-0.942) and emergency room utilization (AIRR: 0.842, 95% CI: 0.709-0.999). The association between preexisting mental illnesses and breast cancer-related inpatient utilization was statistically insignificant (AIRR: 0.993, 95% CI: 0.851-1.159). The findings of this study indicate that breast cancer patients with preexisting mental illnesses experience disparities in terms of receipt of guideline-consistent breast cancer treatment and health care utilization. The results of this study highlight the need for more focused care for patients with preexisting mental illness.