Temporal Changes of Low Anterior Resection Syndrome Score after Sphincter Preservation: A Prospective Cohort Study on...

Background: There is a relative shortage of studies directly addressing the postoperative rectal cancer patients' evacuatory dysfunction, as estimated by the low anterior resection syndrome (LARS) score at repeated assessment time-points. The aim of the present study was to prospectively evaluate the incidence of LARS at predefined time intervals during the first 3 years after sphincter preserving rectal cancer surgery and to enlighten the effect of identified risk factors.Materials and methods: Seventy-eight patients, who remained alive and recurrence-free 2 years after (ultra-) low anterior resection were prospectively assessed at 6, 12, 18, 24, 30 and 36 months postoperatively, using the LARS score as bowel dysfunction outcome measure. All patients have completed the 2-year follow-up functional assessment, while 56 and 37 of them have been evaluated up to the 30^th and the 36^th postoperative month, respectively.Results: The proportion of patients with "major and minor" LARS significantly decreased during the first 3 evaluations (up to 18 months) (74% vs 62% vs 35%, p = 0.0001). The tumor distance from the anal verge and the neoadjuvant radiotherapy were identified as risk factors for high LARS score at 6 months (p < 0.03). The tumor distance remained as risk factor throughout the entire follow-up. All patients with high tumors were alleviated from symptoms reflecting "major" or "minor" LARS at 18 months. Most patients (90%) after radiotherapy showed a high LARS score in the first semester, but improved afterwards.Conclusion: Overall, the LARS score improves in the majority of patients after 18 months, with low tumor height and radiation adversely affecting them. Our results may be useful in more accurately define the postoperative "functional course" of rectal cancer patients and in aiding their consultation on expected functional outcome.