Intraoperative dexamethasone may confer survival benefit in non-immunogenic cancers

The intraoperative administration of dexamethasone in patients with non-immunogenic cancers may have survival benefits, according to a retrospective cohort study from the US presented at Anesthesiology 2021.

Participants were 30,561 adults undergoing surgical resection for solid tumours at two academic centres in Boston, Massachusetts, US. Of these, 11,666 patients received intraoperative dexamethasone (mean 6.5 mg or 0.09 mg/kg). The mean age of dexamethasone recipients and non-recipients was 55.6 and 61.4 years, respectively, 77.8 and 54.8 percent, respectively, were female, and BMI was 27.6 and 28.1 kg/m², respectively. Patients had a Charlson Comorbidity Index score of 2 and the mean duration of surgery was 197 and 210 minutes, respectively.

At 1-year post-surgery, the incidence of all-cause mortality was significantly reduced among dexamethasone recipients vs non-recipients (1.8 percent vs 4.1 percent; adjusted odds ratio [adjOR], 0.79, 95 percent confidence interval [CI], 0.67–0.95; p=0.009). [Anesthesiology 2021, abstract A4224]

The reduced incidence was notable in the 23,921 patients with non-immunogenic cancers (1.4 percent vs 3.2 percent; adjOR, 0.74, 95 percent CI, 0.59–0.91; p=0.005). In contrast, there was no significant difference in 1-year mortality risk between dexamethasone recipients and non-recipients who had immunogenic cancers (4.2 percent vs 6.5 percent; adjOR, 0.97, 95 percent CI, 0.72–1.29; p=0.81).

Hyperglycaemia (>180 mg/dL) within 24 hours after surgery was assessed in 8,450 patients. The incidence was significantly more common among dexamethasone recipients vs non-recipients, but only among those who received high-dose dexamethasone (adjOR, 1.55, 95 percent CI, 1.32–1.82; p<0.001), and not among those who received low-dose dexamethasone (adjOR, 1.06, 95 percent CI, 0.88–1.28; p=0.54).

Surgical site infections within 7 days post-surgery were significantly reduced in both high- and low-dose dexamethasone recipients vs non-recipients (0.7 percent and 1.1 percent vs 1.8 percent; adjOR, 0.54, 95 percent CI, 0.38–0.78 and adjOR, 0.63, 95 percent CI, 0.48–0.83, respectively; p=0.001 for both vs non-recipients).

The incidence of major infective complications within 7 days post-surgery did not significantly differ between groups (0.9 percent [high dose] and 1.0 percent [low dose] vs 2.4 percent [non-recipient]; adjOR, 0.80; p=0.19 and adjOR, 0.77; p=0.07, respectively).

“Dexamethasone is administered intraoperatively to millions of patients each year to decrease the risk of nausea and vomiting after chemotherapy and surgery,” said the authors.

“Dexamethasone has positive and negative effects – it inhibits cancer growth, but also suppresses the immune system,” said senior author Dr Maximilian Schaefer, director of the Center for Anesthesia Research Excellence, Beth Israel Deaconess Medical Center, and Harvard Medical School, Boston, Massachusetts, US.

“Previous research has reported that in cancers in which the immune system controls cancer growth, the positive and negative effects of dexamethasone balance each other, so there is no benefit. Ours is the first large study to show that for a wide variety of cancers where the immune system does not play a major role, the positive effects seem to predominate,” he continued.

“[The results of the present study showed that the] intraoperative administration of dexamethasone is associated with decreased mortality within 1 year after oncologic surgery,” the authors said. The effect of dexamethasone appeared to be modified by tumour immunogenicity, where it was magnified in non-immunogenic cancers, and not evident in immunogenic cancers.

“These data support the administration of dexamethasone during oncologic surgery,” the authors noted.

“[P]hysician anaesthesiologists should feel more confident in administering dexamethasone to patients undergoing surgery for non-immunogenic cancers,” said Schaefer. “It not only helps with nausea, but it also may result in improved survival.”