Patterns of care for people with small cell lung cancer in Victoria, 2011–19: a retrospective, population‐based registry data study

To report stage‐specific patterns of treatment and the influence of management and treatment type on survival rates for people newly diagnosed with small cell lung cancer (SCLC).

Patterns of care for people with small cell lung cancer in Victoria, 2011-19: a retrospective, population-based registry data study Joanna Huang 1 , Wasek Faisal 2 , Margaret Brand 3 , Shantelle Smith 3 , Marliese Alexander 4,5 , Lisa Briggs 3 , Matthew Conron 5,6 , Mary Duffy 4 , Thomas John 4 , David Langton 3,7 , Jacqueline Lesage 3 , Michael MacManus 4 , Paul Mitchell 8 , Inger Olesen 9 , Phillip Parente 10,11 , Jennifer Philip 5 , Evangeline Samuel 1,12 , Javier Torres 13 , Craig R Underhill 14,15 , John R Zalcberg 1,3 , Susan Harden 3,4 , Rob Stirling 1,3,16 S mall cell lung cancers (SCLC) comprise 10-14% of all lung cancers. They are characterised by a rapid doubling time, a high growth fraction, and the early development of widespread metastases. 1,2 Most patients present with stage IV (extensive stage) disease, and median survival time without systemic therapy is 2-4 months. 3,4 Standard staging evaluation includes computed tomography (CT) imaging of the thorax and abdomen, CT or magnetic resonance imaging (MRI) of the brain, and fluorodeoxyglucose-positron emission tomography (FDG-PET). SCLC is amenable to chemotherapy and radiotherapy, but recurrence rates are high and SCLC is often resistant to subsequent lines of treatment, leading to a 5-year survival rate of less than 10%. 5 Chemotherapy has been the backbone of SCLC treatment for twenty years. 6,7 The results of randomised controlled trials of radiotherapy dominated practice until the emergence of immunotherapy agents. 8,9 The recent confirmation of the efficacy of immune checkpoint inhibitors such as atezolizumab and durvalumab has led to their adoption alongside chemotherapy for first line treatment of stage IV disease 10-12 (listed in the Pharmaceutical Benefit Scheme, March 2020 13 ).
Guideline-recommended treatment for limited stage (stages I-III) SCLC with good performance status is concurrent chemo-radiotherapy and, for relatively rare stage I disease, surgical resection or stereotactic ablative radiotherapy with adjuvant chemotherapy. Additional adjuvant management includes prophylactic cranial irradiation or brain MRI surveillance. If performance status is poor (Eastern Cooperative Oncology Group [ECOG] grades 2-4) because of SCLC, sequential chemotherapy with or without radiotherapy is recommended. For extensive stage (stage IV) disease with good performance status or poor performance status because of SCLC, treatment includes combination systemic therapy, including chemotherapy and immunotherapy, adjuvant thoracic radiotherapy, and palliative radiotherapy at symptomatic sites. When performance status is poor for reasons other than SCLC (disease of any stage), individualised and supportive care is recommended. Follow-up, including survivorship care Research planning, imaging surveillance, and smoking cessation, is integral to holistic care. 7 Only limited information on guideline adherence, patterns of care, and survival outcomes for people with SCLC are available. 14 A recent systematic review found that treatment options were limited and overall survival poor, but data were fragmented and inconsistently reported. 15 Unwarranted variation in care and important outcomes have been reported in Australia,16,17 particularly for people in lower socio-economic status areas 18 or rural areas, 19 as well as for Aboriginal and Torres Strait Islander people. 20 Evaluations of the quality of SCLC care should be based on disease-specific outcomes related to safe, timely, evidencebased and multidisciplinary, guideline-concordant treatment, patient-reported experience of care, and accessibility of care. Purpose-designed clinical quality registries can report key performance process and outcome measures in a timely manner, providing evidence of clinical performance in a learning health system. 21 Pattern of care studies are an important element of practice evaluation and health service research because they identify disparities in health care that affect outcomes, 22 stimulating quality improvement and innovations that reduce disparities in health care. We therefore investigated stage-specific patterns of treatment and the influence of management and treatment provision on survival rates for people newly diagnosed with SCLC in Victoria.

Methods
We analysed data provided by the Victorian Lung Cancer Registry (VLCR), a clinical quality registry that systematically collects process and outcomes data for all people with newly diagnosed lung cancer in Victoria. 23 We included patient characteristics, diagnostic method, treatment type (chemotherapy, radiotherapy, surgery), and survival time data for all people diagnosed with SCLC at nineteen Victorian health services and fifty hospitals during 11 April 2011 -18 December 2019, with follow-up to 5 March 2020.

Definitions
For SCLC staging, we used the International Association for the Study of Lung Cancer (IASLC) system, 24 respectively combining tumour node metastasis (TNM) stages I-III and IV with the older limited and extensive stage disease categories. Performance status was assessed with the ECOG scale for capacity for selfcare. 25 Overall survival was defined as time from date of diagnosis to date of death.

Statistical analysis
We summarise categorical data as numbers and proportions, normally distributed continuous data as means with standard deviation (SDs), and non-normally distributed continuous data as medians with interquartile ranges (IQRs). For categorical variables, the statistical significance of between-group differences was assessed in Fisher exact tests (when the expected frequency was lower than five per cell) or χ 2 tests. The statistical significance of between-group differences for continuous variables was assessed in Student t tests (normally distributed data) or Mann-Whitney U tests (non-normally distributed data). P < 0.05 was deemed statistically significant. Time from diagnosis Associations between treatments and demographic characteristics were assessed in logistic regression models and reported as odds ratios (ORs) with 95% confidence intervals (CIs). Associations between treatment and survival were assessed in Cox proportional hazards regression models and reported as hazard ratios (HRs) with 95% CIs.

Ethics approval
The Victorian Lung Cancer Registry is administered by the Monash University Department of Epidemiology and Preventative Medicine (National Mutual Acceptance ethics approval: HREC/16/Alfred/84) and managed in a governance structure based on Australian Committee on Safety and Quality in Healthcare principles. 26 The study reported in this article was approved as Monash University project 26764 (to October 2025).

Cancer management
The cases of 552 patients had been discussed at multidisciplinary meetings (55%) (Box 2). Presentations were less likely if the person was initially referred from a private hospital (26 of 124, 21% v from public hospitals 526 of 882, 60%; OR, 0.18; 95% CI, 0.11-0.28). A total of 377 people (37%) had received supportive care screening; 40 people with stage I-III disease (15%) and 295 with stage IV disease had been referred for palliative care (47%) (Box 2).
The median time from diagnosis to chemotherapy initiation was eight days (IQR, 5-18 days); the interval was less than fourteen days for 590 of 842 people for whom initiation time was known (70%

Discussion
We report information about patterns of care for a large group of people with SCLC. Of 1006 cases diagnosed in Victoria over Research eight and a half years, 628 people presented with stage IV disease, or 70% of those for whom staging information was available, similar to the 71% reported by an American study. 27 The overall chemotherapy treatment rate was high (84%; 89% for patients with staged disease), 71% of people with TNM I-III disease had received guideline-concordant chemo-radiotherapy, and treatment had been initiated within thirty days of diagnosis for 92% of patients. Performance status was not documented at diagnosis for 34% of people, and TNM staging for 11%; only 55% of cases were discussed at multidisciplinary meetings, and only 39% of patients were referred for palliative care.
Survival was significantly higher for people who commenced chemotherapy within fourteen days of diagnosis (overall: 32%), but chemotherapy was initiated within this timeframe for only 59% of patients. The reported impact of timeliness of care on outcomes for people with lung cancer is inconsistent, 28 and information regarding its importance for the treatment of people with SCLC is limited.
Emotional distress has been described as the sixth vital sign in oncology, 29 and overseas guidelines recommend longitudinal screening for distress during cancer treatment. 2 However, only 37% of patients in our study underwent supportive care screening. The availability of lung cancer nurse specialists is very limited in Australia; the Australian Lung Foundation recently reported that twelve full-time equivalent nurse specialists are available 30 to manage the 13 810 people who receive new lung cancer diagnoses each year. 31 Lung cancer nurse specialists could make major contributions to care by responding to patient distress, enhancing patient characterisation, improving communication with medical specialists and care coordination, and helping people navigate medical and social care pathways.
PET is the recommended SCLC staging modality for all people undergoing treatment with curative intent, but PET scans were recorded for only 42% of patients in our study. A 2012 systematic review found that PET-based staging can change management for 28% of patients with SCLC, increase the provision of life-prolonging radiotherapy, and avert unwarranted radiotherapy, thereby reducing unnecessary physical toxicity and expense. 32 PET scanning is not subsidised by Medicare for people with SCLC, and this is a major obstacle to best practice staging and reducing treatment costs for patients.
Optimal provision of appropriate active cancer treatment is crucial to maximising survival. Only 71% of people with limited stage (TNM I-III) SCLC received concurrent chemo-radiotherapy, despite its being the mainstay of treatment for patients with limited stage disease. Immune checkpoint inhibitors became available during the period covered by our study, and more detailed collection of oncologic treatment details (systemic anti-cancer therapy, radiotherapy, clinical trial participation) is needed.
Reporting of patterns of care for people with SCLC would be substantially enhanced by a purpose-built clinical dataset effectively linked with the Victorian Cancer Registry and administrative datasets. Such data linkage would support assessment of equity of outcomes, identify research and clinical performance deficits, and drive innovation in practice. 33 As the Australian SCLC clinical practice guidelines 34 are somewhat fragmentary, we propose an updated panel of quality indicators for confirmation in a national Delphi process (Box 6).

Limitations
Our study included the largest reported Australian cohort of consecutive patients with SCLC, and we analysed prospectively collected data linked with complete survival data. However, registry studies are subject to unmeasured confounding related to inconsistent data collection for variables such as biomarkers, patient frailty, treatment tolerance, and patient preferences; comprehensive treatment details are not recorded, nor assessments of patients' experience of treatment and satisfaction.
As the VLCR collects data on about 85% of all new Victorian lung cancer cases, selection bias is possible, as is information bias due Research to loss to follow-up caused by patient transfer between nonparticipating institutions; more comprehensive data linkage is needed. Further, the VLCR captures data on first-line treatment, but information on disease-free survival, disease recurrence, and subsequent lines of treatment is less complete. As there is no consensus about second-line treatment of people with SCLC, this limitation is probably of minor consequence.

Conclusions
Our patterns of care study provides evidence of deficits in the best practice management in the treatment of people with SCLC in Victoria. We identified opportunities for improving the level of nursing care, clinical characterisation of patents, supportive care screening, multidisciplinary meeting evaluation, and palliative care referral. A national registry of SCLC-specific management and outcomes data could improve the quality and safety of care in a learning health system.