Disparities in Lymph Node Examination Following Esophagectomy

In a retrospective observational study of patients who underwent esophagectomy for cancer, only 28.7% of patients and <1 in 10 hospitals met the National Comprehensive Cancer Network (NCCN) benchmark of examining at least 15 lymph nodes. The researchers recommended that hospitals perform internal process improvement activities to better achieve guideline adherence [Arch Surg. 2012;147(6):505-511].

Esophageal cancer continues to pose significant diagnostic and therapeutic challenges with a generally poor prognosis. A crucial predictor of survival for patients undergoing esophagectomy for cancer is the presence of lymph node metastasis. Despite the current evidence, little is known about the quality of lymph node sampling in the United States. Therefore, the researchers conducted a study to evaluate the quality of lymph node examination following esophagectomy for cancer in the United States based on NCCN treatment guidelines (≥15 nodes) and to assess the association of patient, tumor, and hospital factors with the adequacy of lymph node examination.

Using the National Cancer Data Base, the investigators identified 38,741 patients who underwent a major surgical resection for esophageal or gastroesophageal junction cancer diagnosed from 1998 to 2007. Patients with stage 1 through stage III esophageal cancer undergoing esophagectomy who were not treated with neoadjuvant chemotherapy were enrolled. Exclusion criteria included patients with cervical esophagus lesions or stage IV disease who were not treated at the reporting facility, and/or insufficient data were available on the number of examined lymph nodes after resection. The primary end point was the rate of adequate lymph node examination (≥15 nodes).

The final study cohort included 13,955 patients from 639 hospitals (1998-2001: 4197 patients; 2002-2004: 5864 patients; and 2005-2007: 3934 patients). Of the 13,955 patients, 7646 (54.6%) were treated at academic centers (n=206) and 6349 (45.4%) at community centers (n=433). Overall, 4014 patients (28.7%) had at least 15 lymph nodes examined and 9981 patients (71.3%) had fewer than 15 lymph nodes examined. The proportion of patients with at least 15 lymph nodes examined increased from 23.5% to 34.4% during the study period.

At the hospital level only 45 centers (7%) examined a median of at least 15 lymph nodes. Among academic centers, the number of patients with at least 15 lymph nodes examined increased by 11.5% during the study period, while community centers exhibited a marginal increase at 9.7%.

From 1998 to 2007, the median number of nodes examined rose from 9 to 12 at academic centers and from 8 to 10 at community centers. In the most recent period (2005-2007), at least 15 nodes were examined in 38.9% of patients at academic centers, compared with 28.0% at community centers. Furthermore, high-volume centers had significantly more patients with at least 15 lymph nodes examined than low-volume centers (44.1% vs 29.3%).

On multivariable analysis, hospital type, surgical volume status, and geographic location remained significant predictors of having at least 15 lymph nodes examined. Patients in this group were either treated at academic or high-volume centers, or had stage II or III tumors. Patients were less likely to have at least 15 lymph nodes examined if they were treated in the South or Midwest, had more severe comorbidities, or had tumors in the lower esophagus.

The authors cited several limitations. Specific operative details were unknown, such as operative approach or the location of the removed lymph nodes. The study used retrospective data from a large multi-institutional database; therefore, coding inconsistencies or errors could have influenced the results. Further, it has been debated that the number of lymph nodes sampled during cancer surgery should not be considered a quality metric.

“There is opportunity for improvement in lymph node staging at most hospitals in the United States regardless of hospital type, volume status, or geographic locations,” concluded the researchers.