High 30-day mortality rates in advanced cancer patients receiving checkpoint inhibitors show there is still a need for careful selection of patients for treatment, Australian researchers have shown.

Traditional chemotherapy has been associated with 30-day mortality rates of 8-18% in patients with advanced cancers and it had been hoped the more favourable side effect profile of checkpoint inhibitors would mean lower mortality rates for such patients, according to study investigators from the Calvary Mater Hospital in Newcastle, NSW.

But in a retrospective review of 601 patients treated with immunotherapy at the tertiary cancer centre between 2006 and 2018 they found that 76 (12.6%) died within 30 days of starting treatment.

The majority of deaths (86%) related to disease and one patient died of treatment-related pneumonia. The main cancers treated were melanoma (63%), lung cancer (20%) and bladder/urothelial (5%).

Possibly due to the small patient numbers, the study did not find any significant association between survival and patients characteristics, cancer type, immunotherapy type or ECOG performance status.

Presenting the findings at ASCO 2019 here in Chicago, study investigator Dr Hiren Mandaliya said the study was the first real world data on 30-day mortality after immunotherapy in advanced cancer.

Since the mortality rates were in a similar range to those seen with chemotherapy, the results emphasised the significance of careful selection of advanced cancer patients for immunotherapy, he said.

As with chemotherapy, the patients who are likely to have poor outcomes are those who are rapidly progressing, he told the limbic.

“If they have poor performance from the outset, they are not an ideal candidate [for immunotherapy], because this treatment takes a long time,” he said.

“And some of these patients already had second or third line treatment – those patients do poorly in any cancer setting, even with chemotherapy.

“We use these drugs [checkpoint inhibitors] because they are less toxic in general compared with traditional chemo – and that’s why we were hoping the [mortality] numbers would be less than 12% but we are still seeing that. So it’s still a case of careful selection of patients who are fit enough.”