Longer Time Interval Between Completion of Neoadjuvant Chemoradiation and Surgical Resection Does Not Improve Downstaging of Rectal Carcinoma

Abstract

Perioperative morbidity is not affected by longer intervals. A longer interval between completion of neoadjuvant chemoradiation and surgical resection may not increase the tumor response rate of advanced rectal cancer in this cohort.

Neoadjuvant therapy for locally advanced rectal cancer

“…Следует отметить, что в настоящее время полная регрес-сия опухоли после неоадъювантного лечения является мощным прогностическим фактором, позитивно влияю-щим на послеоперационную безрецидивную выживае-мость больных. Это подтверждается данными крупных рандомизированных исследований [21][22][23]. Все они ука-зывают на улучшение результатов лечения с увеличением ответа опухоли на предоперационную терапию [24].…”

Usefulness of two independent histopathological classifications of tumor regression in patients with rectal cancer submitted to hyperfractionated pre-operative radiotherapy

“…This finding may prove to be of significance during planning of surgical treatment. The percentage of patients with "T-downstaging" in the group submitted to long-term radiotherapy and radiochemotherapy ranged from 23/88 (26.0%) to 15/20 (75.0%) [14,17,[20][21][22][23][24]27,[34][35][36]39,[46][47][48][49]51,52] . Among patients submitted to short-term preoperative radiotherapy "T-downstaging" ranged between 10/28 (35.7%) and 44/104 (43%) [11,14,18,19] .…”

“…Some authors studied "N-downstaging" parameter [17,20,[22][23][24][25][26]36,47] and showed its prognostic value [17] . The percentage of patients submitted to radiochemotherapy or radiotherapy with long time intervals between neo-adjuvant treatment and surgery, in which "N-downstaging" was noted, ranged from 13/26 (50.0%) to 38/42 (90.4%) [17,20,[22][23][24][25][26]36,47] . Tumor size decrease, 'sterilization' and lymph node atrophy are the classic effects of radiotherapy [20,44,45] .…”

“…The value of ypT parameter equal or higher than uT indicates lack of tumor regression [11,14,[17][18][19][20][21] . This parameter may also be applied to the regression of metastatic regional lymph nodes in rectal cancer, "N-downstaging" [17,20,[22][23][24][25][26] . Preoperative radiotherapy and radiochemotherapy evokes a rang e of mor phological chang es in the microscopic picture of rectal cancer including increased tumor necrosis, cellular and nuclear atypia, endocrine differentiation of tumor cells, increased stromal fibrosis, quantitative and qualitative changes of the stromal inflammatory exudates, formation of mucin pools, surface ulceration, peritumoral eosinophilic infiltrate, dysplastic and adenomatous changes (high-grade dysplasia, and lowgrade adenoma component in the intestinal mucosa) [5,27,28] .…”

Multi-modality Therapy for Rectal Cancer—Past, Present, and Future

“…60 Moreover, some studies have failed to demonstrate an association between an increased interval before surgery and improved pCR rates. 61 meeting from the first 32 patients reported a 33 % pCR rate with over a 90 % treatment compliance rate. 63 The mature study results from both the Timing Trial and the CONTRE trial are eagerly awaited, and will no doubt provide important information for the design and conduct of future neoadjuvant rectal cancer trials.…”