Impact of Wide Local Excision on Melanoma Patient Survival: A Population-Based Study

Introduction

Promoting standardization and quality assurance (QA) in oncology on the strength of real-world data is essential to ensure better patient outcomes. Wide excision after primary tumor biopsy is a fundamental step in the therapeutic pathway for cutaneous malignant melanoma (CMM). The aim of this population-based cohort study is to assess adherence to wide local excision in a cohort of patients diagnosed with CMM and the impact of this recommended procedure on overall and disease-specific survival.

Materials and Methods

This retrospective cohort study concerns CMM patients diagnosed in the Veneto region (north-east Italy) in 2017, included in the high-resolution Veneto Cancer Registry, and followed up through linkage with the regional mortality registry up until February 29th, 2020. Using population-level real-world data, linking patient-level cancer registry data with administrative records of clinical procedures may shed light on the real-world treatment of CMM patients in accordance with current guidelines. After excluding TNM stage IV patients, a Cox regression analysis was performed to test whether the completion of a wide local excision was associated with a difference in melanoma-specific and overall survival, after adjusting for other covariates.

Results

No wide excision after the initial biopsy was performed in 9.7% of cases in our cohort of 1,305 patients. After adjusting for other clinical prognostic characteristics, Cox regression revealed that failure to perform a wide local excision raised the hazard ratio of death in terms of overall survival (HR = 4.80, 95% CI: 2.05-11.22, p < 0.001) and melanoma-specific survival (HR = 2.84, 95% CI: 1.04-7.76, p = 0.042).

Conclusion

By combining clinical and administrative data, this study on real-world clinical practice showed that almost one in ten CMM patients did not undergo wide local excision surgery. Monitoring how diagnostic-therapeutic protocols are actually implemented in the real world may contribute significantly to promoting quality improvements in the management of oncological patients.

Quality management of cutaneous melanoma: impact on short-term outcomes and costs

Promoting standardization and quality assurance (QA) may guarantee better outcomes for patients and ensure a better allocation of healthcare system resources. The present study tested the association between process quality indicators of the clinical pathway for melanoma and both patient short-term mortality and budget utilization. Specific indicators were selected to assess quality of processes in different phases of the pathway as well as the pathway as a whole. Cox regression models were run for each phase to test the association between adherence to the quality indicator and overall mortality. A Tobit regression analysis was used to identify any association between adherence to the quality indicators and total costs over the two years after melanoma was diagnosed. This retrospective cohort study concerned 1,222 incident cases of melanoma in the Veneto Region (north-east of Italy). Adherence to the clinical pathway as a whole was associated with a significant decrease in risk of death (HR= 0.40; 95% CI: 0,19 -0,77). Adherence to quality processes in the diagnostic phase (HR= 0.55 95% CI: 0.31- 0.95) and surgical phase (HR= 0.33 95% CI: 0.16- 0.61) significantly reduced the hazard risk. Tobit regression revealed a significant increase in overall costs for patients who adhered to the whole pathway in comparison with those who did not (β= 2,393.24; p= 0.013). This study suggests that adherence to the quality of management of clinical pathways modifies short-term survival as well as mean cost of care for patients with cutaneous melanoma. Physicians should be encouraged to improve their compliance with clinical care pathways for their melanoma patients, and steadily growing associated costs emphasize the need for policy makers to invest exclusively in treatments of proven efficacy.

Kaposi's Sarcoma-Associated Herpesvirus Reactivation by Targeting of a dCas9-Based Transcription Activator to the ORF50 Promoter

CRISPR activation (CRISPRa) has revealed great potential as a tool to modulate the expression of targeted cellular genes. Here, we successfully applied the CRISPRa system to trigger the Kaposi's sarcoma-associated herpesvirus (KSHV) reactivation in latently infected cells by selectively activating ORF50 gene directly from the virus genome. We found that a nuclease-deficient Cas9 (dCas9) fused to a destabilization domain (DD) and 12 copies of the VP16 activation domain (VP192) triggered a more efficient KSHV lytic cycle and virus production when guided to two different sites on the ORF50 promoter, instead of only a single site. To our surprise, the virus reactivation induced by binding of the stable DD-dCas9-VP192 on the ORF50 promoter was even more efficient than reactivation induced by ectopic expression of ORF50. This suggests that recruitment of additional transcriptional activators to the ORF50 promoter, in addition to ORF50 itself, are needed for the efficient virus production. Further, we show that CRISPRa can be applied to selectively express the early lytic gene, ORF57, without disturbing the viral latency. Therefore, CRISPRa-based systems can be utilized to facilitate virus-host interaction studies by controlling the expression of not only cellular but also of specific KSHV genes.