Laparoscopic colectomies associated with decreased retrieval of 12 or more lymph nodes compared to open in elective colon cancer surgery

BACKGROUND: Colorectal cancer is the third most commonly diagnosed cancer worldwide. Lymph node (LN) retrieval is a key factor for pathologic staging and prognosis of colorectal cancer. Increase in number of LNs removal suggests improvement in tumour clearance and decrease in metastatic spread. Studies have suggested that excising 12 or more LNs during colectomy in patients with colon cancer is associated with improved survival. To date, there have been no studies to determine whether minimally invasive surgery affects the ability to retrieve 12+ LNs in elective colon cancer surgery. Therefore, we elected to determine whether a difference exists on the ability to retrieve 12+ nodes in elective colon cancer colectomies performed open versus laparoscopic. METHODS: The National Surgical Quality Improvement Program (NSQIP) Procedure Specific Colectomy database was analysed for the year 2014–2015. Inclusion criteria were colon cancer (ICD-9 Code 153.9), age greater than 18 years. Exclusion criteria were missing data. Data abstracted included patient demographics, type of operation performed and number of LNs retrieved. The patients were categorised based on their elective colon cancer colectomies such as laparoscopic or open. Binary logistic regression was used to identify confounding variables in the retrieval of 12+ LNs. RESULTS: After accounting for missing cases, a total of 18,792 patients with a diagnosis of colon cancer were analysed. Twelve or more LNs were retrieved in 88% (16,538) of patients, Among them, 2,516 patients underwent laparoscopic colectomy and 5,284 patients underwent open colectomy. The difference was not statistically significant for the average number of LNs retrieved among both the groups. Open operative approach compared to the laparoscopic approach was associated with 15% greater odds of retrieval of >12 LNs (OR 1.148; 95% CI (1.035–1.272); p = 0.008). CONCLUSION: The majority of colectomies such as open or laparoscopic are able to retrieve 12 or more LNs. However, there are greater odds of retrieving more than 12 LNs with the open approach compared to the laparoscopic approach. By allowing for more LN retrieval, open colectomies suggest improvement in tumour clearance and decrease metastatic spread. Additional research is needed to further investigate the specific factors influencing the ability to retrieve an adequate number of LNs, such as viewing angles provided with an open approach versus laparoscopic approach.