Waiting Time following Neoadjuvant Chemoradiotherapy for Rectal Cancer: Does It Really Matter

Abstract

Background: Neoadjuvant chemoradiotherapy (CRT) is considered the standard approach before any surgical intervention for locally advanced rectal tumors and has been proven to significantly improve the local recurrence rates of rectal cancer. However, the optimal timing of surgical resection after neoadjuvant CRT remains debatable. Objective and Methods: We conducted a retrospective review of 65 consecutive patients with locally advanced rectal cancer who underwent preoperative CRT followed by surgical resection in order to evaluate the optimal time for surgical treatment. We used two alternative groups for analysis: patients who underwent surgery up to 6 weeks after CRT (n = 28) and those who underwent surgery 6 weeks or more after CRT (n = 27). Also, we compared patients who were operated on within 3 months (n = 39) with those who underwent surgical resection after more than 3 months (n = 16). Nonresponders to CRT were excluded from the analysis. Results: There was no statistically significant association between waiting period post CRT and radiological downstaging for any group (p > 0.05 for any association). Also, there was no association between recurrence of disease, cancer-related deaths, perineural invasion, or positive lymph node ratio and any waiting period up to 3 months (p > 0.05 for all associations). Conclusion: In this small exploratory study there was no evident difference in outcome according to timing of surgery, which suggests that further research in larger cohorts is warranted.

Implications of Prolonged Time to Pancreaticoduodenectomy After Neoadjuvant Chemoradiation

“…Optimal timing of surgery after neoadjuvant chemoradiotherapy has been explored for cancer of other organs such as rectal and esophageal cancers. 15,[17][18][19][20][21][22] Longer intervals in rectal cancer have been associated with increased tumor downstaging and higher rates of a complete pathologic response. 23 However, this advantage is counterbalanced by concerns of poor outcomes because of local tumor progression or the development of metastatic disease during the extended interval.…”

The Interplay among Radiation Therapy, Antibiotics and the Microbiota: Impact on Cancer Treatment Outcomes

“…These findings were also significant in patients experiencing fatigue post RT compared to non-fatigued patients. Other studies showed a rise in pro-inflammatory bacteria belonging to genus Sutterella (S. wadsworthensis and S. parvirubra) and decreased proportions of anti-inflammatory bacteria such as Faecalibacterium prausnitzii and Prevotella histicola, and additional members of the Firmicutes phylum, such as Lachnospira pectinoschiza, Roseburia intestinalis, and others [27,[60][61][62][63].…”

Optimal interval to surgery after chemoradiotherapy in rectal cancer

“…Ideally, surgery should take place at the time of optimal response to preoperative nCRT as the effects of the latter are time dependent. [13]…”

“…Evidence also suggested that a waiting interval beyond 8 weeks might increase fibrosis around the TME plane, potentially lead to intra-operative technical difficulties, and higher surgical morbidity. [13]…”