Assessing the Rate of Postoperative VTE Among Patients With Stage IA NSCLC

Results of a single-center, prospective cohort study revealed incidence of postoperative venous thromboembolism (VTE) among patients with stage IA non-small cell lung cancer (NSCLC) was 7.3%, with age and postoperative day 1 D-dimer (D-D) value serving as independent risk factors for the complication. Findings were published in Thoracic Cancer.

VTE, which includes deep venous thrombosis (DVT) and pulmonary embolism (PE), is common among patients who undergo thoracic surgery and can increase risk of mortality, hospitalization costs, and complication rates, researchers explained.

The complication also typically occurs within 1 month of the operation with a prevalence of 8.1% to 23.1% reported in patients with lung cancer.

Although the number of patients with stage IA NSCLC undergoing thoracic surgery has increased in recent years, the risk stratification of postoperative VTE in these patients remains unclear.

To address this knowledge gap, researchers assessed the effectiveness of the Caprini risk assessment model (Caprini RAM) and explored the incidence and risk factors of postoperative VTE among a cohort of patients who received care at Beijing Chaoyang Hospital Affiliated with Capital Medical University between January 2017 and July 2021.

All study participants had primary lung tumors and underwent radical surgery, while patients with lung metastases, confirmed VTE prior to operation, or other potentially confounding conditions were excluded from the analysis.

Of the 314 patients included, 37.3% (n = 117) were male and median patient age was 57 years; 7.3% had postoperative VTE.

“A total of 99.0% (n = 311) of the patients underwent thoracoscopic surgery and 1.0% (n = 3) of the patients underwent thoracotomy, including wedge resection in 50 cases (15.9%), segment resection in 44 cases (14.0%), and lobectomy in 220 cases (70.1%),” authors wrote.

Analysis revealed:

• Significant differences in age, operation time, preoperative and postoperative day 1 D-D value, neuron-specific enolase value, forced expiratory volume in 1 second, maximum ventilation, carbon monoxide diffusion capacity, and pathological diameter were noted between those with and without VTE
• The incidence of VTE in patients under 60 years old (n = 189), 61–74 years old (n = 118), and over 75 years old (n = 7) was 3.2%, 12.7%, and 28.6%, respectively
• No significant difference in the incidence of VTE between patients with adenocarcinoma (n = 299) and squamous cell carcinoma (n = 13) (7.4% vs. 7.7%, P > 0.05)
• Age (95%CI, 1.056–1.216) and postoperative day 1 D-D value (95% CI, 1.125–1.767) were independent risk factors
• The incidence of VTE in the low-, medium-, and high-risk groups with Caprini scores was 0%, 7.3%, and 11.5%, respectively
• The area under the curve (AUC) of the Caprini score was 0.704 (P < .05)

The significant difference in incidence of postoperative VTE between stage IA1 and stage IA2 and no differences seen between IA1 and IA3, nor IA2 and IA3, could be due to the lower number of IA3 stage patients included. As such, “the correlation between tumor stage and VTE cannot be confirmed in stage IA patients,” researchers explained. On average patients experienced VTE within 1 week post operation.

Based on the findings, “Continuous monitoring of postoperative D-D levels of lung cancer patients can be performed to effectively evaluate the occurrence of VTE,” they wrote, adding prolonged operation time, increased bleeding and open surgery can increase the risk of VTE.

Furthermore, the Caprini score AUC of 0.704 suggests the diagnosis and prediction of this complication in patients with stage IA NSCLC can be improved upon.

The lack of long-term follow-up after discharge marks a limitation to this study, while it’s single-center nature could have introduced bias. Future multicenter studies are warranted to verify results, authors concluded.

Reference

Dong H, Liang X, Gao Y, et al. Postoperative venous thromboembolism after surgery for stage IA non-small-cell lung cancer: a single-center prospective cohort study. Thorac Cancer. Published online March 22, 2022. doi:10.1111/1759-7714.14373