Preop smoking ups postop complications for cancer surgery patients

Smoking within 4 weeks of cancer surgery translates to a higher number of complications after the procedure.

In a meta-analysis of 54 studies, the odds of postoperative complications among patients who smoked within 4 weeks preoperatively were higher by 31 percent than among those who ceased smoking for at least 4 weeks (odds ratio [OR], 1.31, 95 percent confidence interval [CI], 1.10–1.55; n=14,547 [17 studies]) and by 182.9 percent than among those who had never smoked (OR, 2.83, 95 percent CI, 2.06–3.88; n=9,726 [14 studies]). [JAMA Netw Open 2025;8:e250295]

Within the shorter term, the odds of postoperative complications did not significantly differ between patients who smoked within 2 weeks preoperatively and those who had stopped between 2 weeks and 3 months (OR, 1.19, 95 percent CI, 0.89–1.59; n=5,341 [10 studies]). Within the longer term, on the other hand, the odds were higher among people who smoked within a year of surgery than among those who had quit smoking for at least 1 year (OR, 1.13, 95 percent CI, 1.00–1.29; n=31,238 [13 studies]).

Adjusted analyses confirmed the key findings.

Smoking cessation

“Collectively, the findings from this review and the robust evidence demonstrating the benefits of smoking cessation emphasize the importance of providing early and effective cessation interventions for all people undergoing surgery,” the investigators said.

For instance, a recent review on multicomponent smoking cessation interventions (ie, combination of behavioural support and pharmacotherapy) showed that implementing these interventions at least 4 weeks before surgery helped reduce the risk of complications in noncancer surgical populations. [Anesth Analg 2024;doi:10.1213/ANE.0000000000007187]

However, the investigators acknowledged that the optimal time to stop smoking before surgery to minimize postoperative complications remains unclear. [Addict Behav 2024;148:107832]

“Although future randomized controlled trials can help determine the optimal timing of smoking cessation interventions in patients diagnosed with cancer, the present results suggest that smoking cessation for longer periods can maximize postoperative outcomes,” they said. “Early cessation interventions therefore play an important and cost-effective role in improving the outcomes of surgical populations and should be embedded within routine cancer care.” [Int J Surg 2022;104:106742]

The investigators additionally noted abundant evidence of reduced postoperative complications among people who have never smoked, reinforcing the significant health and economic benefits of comprehensive, population-level tobacco control programs that prevent people from initiating smoking.

“Surgical cancer treatments may be delayed for patients who smoke over concerns for increased risk of complications. Quantifying risks for people who had recently smoked can inform any trade-offs of delaying surgery,” they said.

Study characteristics

Most of the 54 studies included in the meta-analysis were conducted in either the US (n=20) or Japan (n=15). Lung cancer was the most commonly studied cancer type (n=27), and resection was the most frequent procedure. In terms of study type, one was a randomized clinical trial, two were case-control, and all others were observational. The pooled sample population comprised 39,499 cancer surgery patients.

The majority of the included studies examined more than one type of postoperative complication, including pulmonary (n=41), cardiovascular (52 percent), and wound complications (n=26) and mortality outcomes (n=25).

Smoking status and cessation were determined using self-reported information in many studies. This may have understated smoking behaviour as opposed to objective measures and, in turn, reduced the precision of the meta-analysis and underestimated the effects of cessation on postoperative complications, according to the investigators. “The findings from these meta-analyses could be a conservative estimate of the outcomes from recent smoking.”