Glynne-Jones R, Mawdsley S, Novell JRThe clinical significance of the circumferential resection margin following preoperative pelvic chemo-radiotherapy in rectal cancer: why we need a common language. Colorectal Dis 8: 800-807
ABSTRACT The presence of microscopic tumour cells within 1 mm of the circumferential surgical resection margin (CRM) is the endpoint most strongly associated with local recurrence in rectal cancer and doubles the risk of developing distant metastases. Reporting on the CRM can monitor surgical quality assurance and over the past two decades has driven advances in surgical technique with the increasing use of total mesorectal excision. The aim of this review was to use the evidence from both phase II and phase III randomized trials of preoperative radiotherapy and chemoradiation in rectal cancer, to assess how often CRM involvement is currently documented and examine its utility as an early predictor of both disease-free and overall survival.
A literature search identified both randomized and nonrandomized trials of preoperative radiation therapy and chemoradiation therapy in rectal cancer since 1993. The aim was to find those studies, which documented the distance from the periphery of the tumour and the CRM. Small trials treating < 20 patients were excluded.
One hundred and eighty-seven phase II and 28 phase III trials of preoperative radiotherapy or chemoradiation were identified. Most trials documented the degree of response but only 10 of 187 phase II/retrospective studies and four of 28 phase III trials presented data on the achievement of a negative CRM. Few defined this early pathological endpoint prospectively with accurate measurements. However, the majority of studies did use the definition of <or= 1 mm as an involved CRM. Discussion Pathological parameters have been used as early endpoints to compare studies of preoperative radiotherapy or chemoradiation. It remains uncertain whether the degree of response to chemoradiation (e.g. complete pathological response, downsizing the primary tumour, sterilizing the regional nodes, tumour regression grades or residual cell density) or the achievement of a curative resection (uninvolved CRM) is the best early clinical endpoint. Retrospective studies in rectal cancer have confirmed a strong association between the presence of microscopic tumour cells within 1 mm of the CRM and increased risks of both local recurrence and distant metastases. However, as yet this early pathological endpoint lacks structured measurement and analysis techniques to control for intra- and inter-observer variation and has not been validated as a potential surrogate for local control and survival. Recommendations are made as to the most appropriate information, which should be documented in future trials.
The CRM status predicts outcome after surgery alone, preoperative radiotherapy and preoperative chemoradiation. Yet CRM status and its measurement has been poorly documented in the literature, and rarely as a prospective measure of outcome. The CRM should be measured and documented in all cases, using the definition of <or= 1 mm to denote an involved CRM. This definition should also be incorporated into future rectal cancer studies with the use of a standardized proforma.
- SourceAvailable from: Gyeong Hoon Kang
[Show abstract] [Hide abstract]
- "Local treatment approach such as postoperative radiotherapy or CRT has failed to compensate for positive CRM according to previous studies [2,4]. Systemic therapy may be required because positive CRM is related with high risk for distant metastasis as demonstrated in the current study as well as other studies [6,7,9,10,14]. EORTC 22921 showed that the tumor biology could be linked to the effect of chemotherapy . "
ABSTRACT: Circumferential resection margin (CRM) and distal resection margin (DRM) have different impact on clinical outcomes after preoperative chemoradiotherapy (CRT) followed by surgery. Effect and adequate length of resection margin as well as impact of treatment response after preoperative CRT was evaluated. Total of 403 patients with rectal cancer underwent preoperative CRT followed by total mesorectal excision between January 2004 and December 2010. After applying the criterion of margin less than 0.5 cm for CRM or less than 1 cm for DRM, 151 cases with locally advanced rectal cancer were included as a study cohort. All patients underwent conventionally fractionated radiation with radiation dose over 50 Gy and concurrent chemotherapy with 5-fluorouracil or capecitabine. Postoperative chemotherapy was administered to 142 patients (94.0%). Median follow-up duration was 43.1 months. The 5-year overall survival (OS), disease-free survival (DFS), distant metastasis-free survival (DMFS) rates, and locoregional control rates (LRC) were 84.5%, 72.8%, 74.2%, and 86.3%, respectively. CRM of 1.5 mm and DRM of 7 mm were cutting points showing maximal difference in a maximally selected rank method. In univariate analysis, CRM of 1.5 mm was significantly related with worse clinical outcomes, whereas DRM of 7 mm was not. In multivariate analysis, CRM of 1.5 mm, and ypN were prognosticators for all studied endpoints. However, CRM was not a significant prognostic factor for good responders, defined as patients with near total regression or T down-staging, which was found in 16.5% and 40.5% among studied patients, respectively. In contrast, poor responders demonstrated a significant difference according to the CRM status for all studied end-points. Close CRM, defined as 1.5 mm, was a significant prognosticator, but the impact was only prominent for poor responders in subgroup analysis. Postoperative treatment strategy may be individualized based on this finding. However, findings from this study need to be validated with larger cohort.BMC Cancer 12/2013; 13(1):576. DOI:10.1186/1471-2407-13-576 · 3.32 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: Colorectal cancer is one of the most common malignancies, and has become one of the main diseases that threaten people's health and influence the quality of people's life due to its rising incidence. With the significant improvements in adjuvant therapy for colorectal cancer and the refinements in surgical technique, the accurate preoperative staging becomes very important for clinical doctors to choose the optimal therapy. Imaging diagnosis plays an important role in the preoperative staging and postoperative assessment of colorectal cancer, providing the accurate information of the tumor for clinical doctors makeing treatment decisions and surveillance after surgery. Recently, rapid developments in imaging techniques and modifications of the machines provide magnetic resonance imaging (MRI) with great advantages and enhanced status in the evaluation of colorectal cancer.
- [Show abstract] [Hide abstract]
ABSTRACT: Surgical therapy of rectal carcinoma has advanced enormously since the 1990s. However, not only the surgical technique itself has improved; first and foremost has been the effort to adapt the radicality of the surgical approach to the individual patient. The objective is to avoid therapies that are either too aggressive or too conservative, while taking the patient’s unique situation into account. A surgery that is too radical may not further increase the chance of cure, but may ultimately result in a long-lasting and severe reduction in quality of life. If the therapy regimen is too conservative, an increased rate of recurrence will result and the patient’s long-term survival will be unavoidably reduced.