Impact of Timely Treatment Initiation on Outcomes in Non-Small Cell Lung Cancer. A Registry Based Observational Study.

Abstract

Introduction: Lung cancer is the leading cause of cancer death in Australia, with evidence of unwarranted variation in clinical care. Timeliness recommendations have been made in international guidelines, although previous studies exploring the effect of timeliness on survival in NSCLC have revealed conflicting results. Method(s): We performed an observational cohort study of all cases of Stage I-II NSCLC in the Victorian Lung Cancer Registry (VLCR), between July 2011 and May 2023. Timeliness intervals were defined by the Australian Optimal Care Pathway for people with lung cancer. A diagnosis-to-treatment interval (DTI) of <14 days and referral-totreatment interval (RTI) of <42 were defined as timely. The effect of timeliness on overall survival was determined using Cox proportional hazards regression. Result(s): We identified 3,016 cases of Stage I-II NSCLC (52% Male). Patients receiving timely treatment (n=1,204, 42%) were younger (median 69 vs 72 years, p <0.001) and never smokers, with fewer comorbidities and better performance status. Patients undergoing surgical resection (n=1,989, 66%) were more likely to receive timely care, whereas those undergoing systemic treatment, radiotherapy, or referred to palliative care were less likely (p<0.001). Median overall survival to census date for timely DTI and RTI were 1,100 days (IQR 585, 1,815) and 1,337 (IQR 713, 2,077) respectively, vs untimely 1,439 (IQR 746, 2,203) and 1,033 (IQR 588, 1,653) p<0.001 Table 1. Both timely DTI and RTI were associated with significantly lower mortality risk (DTI HR 0.57, 95% CI 0.49-0.67, p <0.001, RTI HR 0.75 95% CI 0.63-0.9, p 0.002) Figure 1. Conclusion(s): Timely treatment of Stage I-II NSCLC was associated with improved survival, although most cases did not meet recommended timeliness intervals. With lung cancer screening soon to be implemented in Australia, there is a strong impetus to investigate the barriers to timely access to care and help guide future resource allocation..