| Objective: |
Colorectal cancer is a major cause of cancer-related mortality worldwide. In Sweden approximately 4.500 patients are diagnosed with colon cancer annually and the numbers are increasing. Disease stage according to AJCC is the most important prognostic factor. Emergency presentation of colon cancer including obstruction, perforation, and haemorrhage comprises 17-26% of colon cancer cases in Sweden and in other countries. Roughly 70% of all emergencies are due to colonic obstruction, hereafter referred to as malignant obstruction. Patients who undergo emergency surgical resections for colon cancer have a higher overall 30- day morbidity (33%) and spend more days in the hospital. Furthermore, they have an increased 30- day (5%) and 90- day mortality (11%) compared to elective cases 1.3 and 2.5%, respectively. Other concerns about acute colon cancer resections are the short term and long term oncological outcomes. Long term oncological outcomes are significantly worse in terms of recurrence and death [6-8] where adjuvant chemotherapy does not appear to make a difference. Furthermore, decision making in the acute situation may be challenging for the individual surgeon, since it is not only the immediate postoperative morbidity and mortality to consider but also the oncological results.
Colon resection has been gold standard for acute malignant obstruction due to colon cancer. The concept of bridge-to-surgery for colon cancers was introduced assuming temporary decompression would improve postoperative and oncological outcomes. Stoma and self-expanding metallic stent (SEMS) are two options for bridge-to-surgery. It is theoretically appealing to create an elective procedure out of an emergency before cancer resection to allow decompression, treatment of unfavourable physiology and improve nutritional status. Moreover, this would concede qualified colorectal surgeons to perform the resection possibly with an increased use of minimally invasive surgery. From an oncological point of view this would allow better surgical specimens in terms of R0-resection, total mesocolic excision and higher lymph yield etc in the short term and possibly lower recurrences and better survival in the long term. Another attainable advantage of decompression would be that patients recover faster and would be accessible for adjuvant chemotherapy when needed.
Thus, there is a need for a prospective study regarding malignant colonic obstruction to evaluate how these patients are best dealt with. This study will collect data on all colon cancer causing acute obstruction regardless of location. To date we do not know how many patients that are treated with a bridge-to-surgery intent that eventually undergo a resectional procedure. |
| Aim: |
The aim of this prospective observational study is to evaluate primary resection for malignant obstruction of the colon compared to only decompression as first intervention regarding postoperative outcomes. We hypothesize that patients with malignant obstruction benefit from avoidance of emergency cancer resection, by a two-stage procedure, with decompression by a stoma or stent as first intervention, leading to decreased short-term morbidity and mortality and improved long-term oncological outcome. |
| Methods: |
This is an exploratory, prospective, longitudinal, non-interventional, multicentre study aiming to evaluate treatment of malignant colonic obstruction due to colon cancer. Baseline characteristics at diagnosis, first line treatment (resection, stoma or stent), complications, proportion of patients ultimately subjected to resectional surgery, type of operation, proportion of permanent stomas and short and long term oncological outcomes will be registered. All cases are to be registered on an intention-to-treat bases, i.e. if patients are allocated to stent or stoma initially but this fails, and the patient is resected instead, the patient is to be registered according to first objective and the reason for change registered.
Patients will be identified at participating emergency departments or hospital wards. For patients with suspected malignant colon obstruction a routine medical history will be taken, and the patients will undergo a clinical examination. Routine laboratory test such as haemoglobin, white blood cell count, creatinine, C-reactive protein, albumin and CEA will be obtained. CT abdomen will be performed before the acute surgical procedure. If findings are consistent with malignant colon obstruction the patient will be included. CT chest should preferably be performed preoperatively. The e-CRF admission form will be filled in. In case of urgent surgery preventing that informed consent can be achieved preoperatively informed consent may be retrieved later during the same hospital stay. Prospective registration additional to Swedish Colorectal Cancer Registry (SCRCR) base line characteristics and certain long-term outcomes will be performed. Foreign centres will need to use a e-CRF linked to SCRCR. the A screening list of all eligible patients at participating centres will be compulsory to allow analyses of demographics and registry data of the cohort of missed cases.
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| Reason for International Trial: |
This is a population –based observational study on patients with malignant colonic obstruction. Power calculations are not suitable for this study. In a randomized setting, 432 patients would have to be included in each group, in order to detect a reduction by half in the 90-day mortality of 11% when comparing resection versus bridge-to-surgery (significance level 5%, power 80). Since this is not a randomized study, an additional number of patients is necessary, because of the need to control the analysis for potential confounders. We aim to include an evaluate 1000 patients. Approximately 500 patients are subjected to emergency resections due to malignant obstruction annually in Sweden. We are looking for international collaboration to speed up study recruitment. We believe the topic is relevant in an international setting. |
