In a prospective cohort study reported in The Lancet, the GlobalSurg Collaborative found that 30-day mortality after surgery for colorectal and gastric cancers, but not breast cancer, was higher in low- or middle-income countries vs high-income countries.¹ Among all patients, mortality rates following major complications were significantly higher in low- or middle-income countries vs high-income countries, with the difference only partly accounted for by patient or disease factors.

Ewen M. Harrison, PhD

The study was performed by the GlobalSurg Collaborative, a network of over 4,000 individuals across 82 countries, and the National Institute for Health Research Global Health Research Unit on Global Surgery. Ewen M. Harrison, PhD, of the National Institute for Health Research Global Health Research Unit on Global Surgery, Centre for Medical Informatics Usher Institute, University of Edinburgh, was the senior author.

Study Details

The study compared postoperative outcomes in 15,958 patients from 428 hospitals in 82 countries who underwent surgery for primary breast, colorectal, or gastric cancer, with enrollment occurring between April 2018 and January 2019. Among the studied countries, 30 were in Europe, 22 were in Africa, 17 were in Asia, 6 were in South America, 5 were in North America, and 2 were in Oceania.

The population consisted of 9,106 patients from 31 high-income countries, 2,721 patients from 23 upper-middle income countries, and 4,131 patients from 28 lower-middle income countries; income level was based on World Bank classification. In the three income categories, surgery was performed for breast cancer in 46%, 49%, and 69% of patients; for colorectal cancer, surgery was performed in 46%, 41%, and 23%; and for gastric cancer, surgery was performed in 8%, 11%, and 8%. The primary outcome was death or major complication (Clavien-Dindo grade III, IV, or V) within 30 days of surgery.

Major Complications and Mortality Rates

Patients in low- or middle-income countries were more likely to present with more advanced disease vs those in high-income countries. Hospitals in upper-middle–income and low-/lower-middle–income countries were less likely to have a postoperative care infrastructure (eg, designated postoperative recovery areas, consistently available critical care facilities, and available functioning computed tomography) and cancer care pathways (eg, tumor board, oncology services, and palliative care services).

Among 8,406 patients undergoing breast cancer surgery, the incidence of major complications at 30 days was 5.2% in high-income countries, 4.7% in upper middle-income countries, and 7.6% in low-/lower-middle–income countries. Risk was reduced in upper-middle–income countries vs high-income countries (odds ratio [OR] = 0.53, 95% confidence interval [CI] = 0.31–0.90). Mortality at 30 days was 0.1%, 0.2%, and 0.4%, with no significant differences between low- or middle-income countries vs high-income countries being observed.

Among 6,215 patients undergoing colorectal cancer surgery, the incidence of major complications at 30 days was 14.2% in high-income countries, 11.3% in upper middle-income countries, and 19.1% in low-/lower-middle–income countries, with no significant differences observed between low- or middle-income countries vs high-income countries. Mortality at 30 days was 2.3%, 4.3%, and 7.0%, with risk significantly increased in low-/lower-middle–income countries (OR = 4.59, 95% CI = 2.39–8.80) and upper-middle–income countries (OR = 2.06, 95% CI = 1.11–3.83) vs high-income countries.

Among 1,337 patients undergoing gastric cancer surgery, the incidence of major complications at 30 days was 14.8% in high-income countries, 9.2%% in upper-middle–income countries, and 18.6% in low-/lower-middle–income countries, with no significant differences observed between low- or middle-income countries vs high-income countries. Mortality at 30 days was 3.8%, 3.9%, and 10.1%, with significantly increased risk observed for low-/lower-middle–income countries (OR = 3.72, 95% CI = 1.70–8.16) vs high-income countries.

Risk of Death After Major Complications

Rates of death following a major complication were 17.5% in the high-income population, 38.4% in the upper-middle–income population, and 41.2% in the low-/lower-middle–income population. In a model in the total population accounting for patient factors and clustering by country and hospital, patients in upper-middle–income (OR = 3.89, 95% CI = 2.08–7.29) and low-/lower-middle–income groups (OR = 6.15, 95% CI = 3.26–11.59) had a significantly increased risk of dying after major complications vs the high-income group.

Patient performance status and emergency surgery were strong predictors of death after major complications. Patients with stage IV cancer had a greater likelihood of dying after major complications (OR = 1.80, P = .036) vs those with stage I disease, but no increased risk was observed for patients with stage II or III disease.

In a model of patients nested in hospitals, countries, and income groups, 60% of the variation in mortality outcome was explained by patient or disease factors and 40% by hospital, country, and country income group factors. A model including a postoperative care infrastructure showed that a significant proportion of excess mortality was associated with the absence of a postoperative care infrastructure in low-/lower-middle–income (OR = 1.19, 95% CI = 1.01–1.42; 20%) and upper-middle–income groups (OR = 1.19, 95% CI = 1.01–1.42; 22%). Additional analysis showed that the presence of a postoperative care infrastructure in the low-/lower-middle–income group (7–10 fewer deaths/100 major complications, number needed to treat = 10–14) and the upper-middle–income group (5–8 fewer deaths/100 major complications, number needed to treat = 13–20) was associated with reduced mortality after major complications.

The investigators concluded: “Higher levels of mortality after cancer surgery in [low- or middle-income countries] was not fully explained by later presentation of disease. The capacity to rescue patients from surgical complications is a tangible opportunity for meaningful intervention. Early death after cancer surgery might be reduced by policies focusing on strengthening perioperative care systems to detect and intervene in common complications.” 

DISCLOSURE: The study was funded by the National Institute for Health Research Global Health Research Unit. For full disclosures of all study authors, visit thelancet.com.

REFERENCE

1. Knight SR, Shaw CA, Pius R, et al: Global variation in postoperative mortality and complications after cancer surgery. Lancet 397:387-397, 2021.