Systemic therapy rates in patients with lung cancer have fallen short of published benchmarks, especially for people low income groups, according to a NSW study.

The study, published in the Asia-Pacific Journal of Clinical Oncology, comprised more than 1,000 patients with different types of lung cancer.

PBS claims data showed 45% of patients overall received chemotherapy including metastatic non-SCC (53%), metastatic SCC (35%), other specified or not-otherwise-specified histology (31%) and all-stage SCLC (79%).

Immune checkpoint inhibitors for lung cancer were first listed on the PBS in 2017 and, therefore, were not captured in the data for this analysis.

A multivariable analysis of factors associated with systemic therapy in the metastatic lung cancer cases found the incidence of systemic therapy decreased with older age.

Indicators of poor performance status including ED visits prediagnosis, comorbidities, and disability were also associated with a lower incidence of systemic therapy.

On the flip side, patients with a higher BMI, a diagnosis of SCLC, and less socioeconomic disadvantage were more likely to receive systemic therapy.

The investigators said their results were consistent with other Australian and international studies but rates of systemic therapy fell short of optimal utilisation.

“In 2010, it was estimated that 73% of SCLC and NSCLC patients would receive systemic therapy under perfect adherence to guidelines. In contrast, only 49% of SCLC and NSCLC cases in this sample received systemic therapy. Observed utilisation fell short of these targets for both metastatic NSCLC (51% observed use vs. 79% optimal use) and all SCLCs (79% observed use vs. 93% optimal use),” they said.

“Our findings suggest that systemic therapy was underutilised and highlight a gap in care that was pronounced for cases living in areas of socioeconomic disadvantage.”

“As treatment continues to innovate, disparities in care will likely translate to disparities in survival, emphasising the need for improved implementation in underserved populations,” they concluded.

Senior investigator on the study Dr Marianne Weber told the limbic socioeconomic disparities continued to make their mark on health care and outcomes.

“A study like this is another way of presenting the problem but we don’t really provide any answers and solutions. One of the things we would like to see is just more research around barriers and facilitators to treatment uptake.”

Dr Weber, a Senior Research Fellow and Stream lead for Lung Cancer Policy & Evaluation at the Daffodil Centre, said one surprise in their findings was remoteness wasn’t a significant predictor of whether patients received chemotherapy.

“Which I hope is a good news story,” she said.

Dr Weber, who is also on the advisory board for Lung Foundation Australia, said there may be good reasons, such as frailty or treatment preference, for why patients weren’t receiving systemic therapy.

“It’s difficult from a study like ours to determine which of the factors result in unwarranted variations in care.”

“One thing we would like to see is more patients actually making it to the clinic to receive optimal care which may come down to purely having better information about what treatments are available.”

“We would like to see investment in resources that can support shared decision making between patients and clinicians for lung cancer treatments. This is especially true now treatments have become a lot more sophisticated.”

She added that more specialised lung cancer nurses could also support patients and carers navigating the system, provide treatment information, and help manage symptoms.