Temporal trends in lymph node assessment as a quality indicator in colorectal cancer patients treated at a high-volume Canadian centre

Background: Clinical practice guidelines have been developed to improve surgical quality and optimize cancer-specific survival. Adequate lymph node assessment (LNA) is a key quality indicator in patients with colorectal cancer (CRC) who undergo resection, and depends on both surgical technique and pathologic retrieval. National Cancer Institute (2001) and Cancer Care Ontario (2005) guidelines stipulate that a minimum of 12 LNs should be assessed. Methods: We examined compliance with this standard at our institution over time. Patients were grouped according to date of surgery: t1 (1997-2001), t2 (2002-2006), and t3 (2011-2016). Each group included consecutive patients who underwent resection of primary CRC at Mount Sinai Hospital, Toronto. Results: The entire study cohort comprised 1412 patients (62 3 female, 789 male, median age 65 yr [range 20-98]). There were no observed differences across time periods for patient (sex, age) or tumour (TNM stage, resection margin status) features. Adequacy of LNA markedly improved over time for both colon and rectal primary sites (p < 0.0001). Of note, the proportion of cases done urgently/emergently actually increased in t3 (9%) v. t1 (6%) and t2 (4%) (p = 0.04). Thirty-two cases in the t3 period did not have adequate LNA (18 rectal, 14 colon); 100% of rectal cases had received neo-adjuvant treatment, and the majority of colon cases were stage IV (57%) at the time of primary resection. Here, we show that the implementation of Cancer Care Ontario guidelines resulted in markedly improved lymph node assessment at a tertiary cancer centre. Conclusion: These results support the effectiveness of clinical practice guidelines in improving achievement of quality indicators for CRC surgery. Compliance with recommendations for adjuvant therapy in patients with node-positive disease requires further study.