The Time Between Chemoradiation and Surgery for Rectal Carcinoma Negatively Influences Mesorectal Excision Quality

Total mesorectal excision quality (TMEq) is a prognostic factor associated with local recurrence in rectal adenocarcinoma. Neoadjuvant chemoradiotherapy (NCRT) reduces the risk of tumor recurrence, but may compromise TMEq. The time between NCRT and surgery (TTS) and how it influences TMEq and tumor control were evaluated. In prospective registry, 236 patients after NCRT and TME were analyzed. NCRT involved radiotherapy with 45 Gy to the pelvis, plus tumor boost dose 5.4 Gy with concurrent 5-fluorouracil infusion. NCRT was followed by TME after 9 weeks on average (median 9.4 ± SD 2.5). TMEq was parametrically analyzed by standard three-grade system. With median follow-up of 47.5 months, 3-year overall survival (OS) was 83.8%, disease-free survival (DFS) was 77.7%, and 6.4% was the rate of local recurrence (LR). TTS was not associated with OS, DFS, or LR. TMEq was found to be associated with LR in univariate analysis, but not in multivariate, where pathological tumor stage and resection margins remained dominant predictors. TMEq was negatively influenced by inferior location of the tumor, longer TTS, higher tumor and nodal stage, presence of tumor perforation, perineural invasion, and close/positive resection margins. Nonetheless, TTS remained a strong predictor of TMEq in multivariate analyses. TTS was proven to be an independent predictor of TMEq. With longer TTS, fewer complete TME with intact mesorectal plane were observed. However, TTS was not associated with survival deterioration or tumor recurrence. These were negatively influenced by other factors interfering with TMEq, especially by pathological tumor stage and resection margins.