In general, embarking on an operative intervention in a patient with stage 4 rectal cancer in an elective setting is meaningful only if the operative risk is low and the patient has a reasonable life expectancy (at least 2–6 months) [7, 21, 24–29]. In an emergent setting however, the question to be answered is what intervention to offer as an operation may be the only therapy to improve short-term survival [21, 30]. Potentially life-threatening complications include obstruction, perforation and bleeding. The American Society of Colon and Rectal Surgeons (ASCRS) identifies three goals of treatment in the emergent setting: (1) prevent the immediate negative impact of complication such as sepsis and death, (2) achieve tumor control, and (3) allow for the initiation of adjuvant or systemic therapy [4]. Interventions should be individualized based on presenting symptom or symptoms, and available imaging and therapeutic modalities.

Traditionally, palliative resection was, and continues to be performed to prevent obstruction, bleeding and pain in asymptomatic or minimally symptomatic patients. However, it is not currently recommended that patients with asymptomatic tumors undergo routine resection, and systemic chemotherapy should be the primary treatment modality [4, 12]. Despite this, there continues to be a number of proponents for palliative resection in asymptomatic patients with more than two-thirds of patients who present with stage 4 colorectal cancer undergoing resection of the primary tumor according to a study based on the Surveillance, Epidemiology, and End Results (SEER) database [67]. Proposed advantages to palliative resection include improvement in quality of life, prevention of complications of the primary tumor such as obstruction, bleeding or pain as well as improvement in survival rates [8, 68]. Additionally, performing a palliative resection potentially avoids an emergent resection as it has been demonstrated that resection in an elective setting demonstrates a decrease in mortality when compared to resections in an emergent setting [44, 69–71].

Regardless of any proposed benefit, the resection of primary tumors on asymptomatic patients is not without potential risks. Morbidity rates from resections have been demonstrated to be as high as 23–48 % [72], and resections may actually worsen quality of life [30, 73] and lead to poorer survival rates [74]. Additionally, it has been argued that many patients will die from progression of systemic disease rather than the development of a primary tumor complication, and these patients need not undergo an invasive procedure [72, 73, 75]. In fact, a retrospective study by Patel et al. demonstrated that only 4.3 % of patients treated with neoadjuvant chemotherapy progress to complete obstruction and subsequent perforation [43]. In another study of patients undergoing chemotherapy for synchronous colorectal metastasis, only 7 % of patients required intervention for obstruction, perforation or bleeding [76]. Of most concern is that palliative resection delays the initiation of chemotherapy [67, 77]. It is clear that chemotherapy improves both quality of life and survival in patients with unresectable rectal cancer [78, 79]. Thus, interruption or postponement of this therapy to perform resection in an asymptomatic patient is currently not advised.

Despite the risks of resection, a number of retrospective studies have been performed evaluating palliative resection of the primary tumor. Cirocchi et al. recently performed a study for the Cochrane Collaboration evaluating survival in patients undergoing resection of an asymptomatic primary tumor versus chemotherapy. The authors evaluated seven retrospective studies summarized in Table 24.2 [80–86], and found no differences in overall survival and no significant reduction in risk of complication in the resection group [87]. In contrast, Stillwell et al. performed a meta-analysis of eight retrospective studies and found a significant survival benefit in patients undergoing resection of the primary tumor (p < 0.001), and a 7.3 times higher complication rate from the primary tumor in those treated with chemotherapy alone [88]. Recently, the National Surgical Adjuvant Breast and Bowel Project C-10 (NSABP C-10) published the results of their prospective trial evaluating the safety of Bevacizumab to systemic chemotherapy with infusional fluorouracil, leucovorin, and oxaliplatin (mFOLFOX6) as the initial treatment for stage 4 colon cancer. The authors found that 87 % of patients did not develop symptoms from the primary tumor over a median follow-up of 20.7 months. They concluded that asymptomatic patients should undergo initial systemic therapy as the rate of serious adverse events from the primary tumor is acceptably low and the majority of patients would avoid unnecessary surgery [89].

It has been widely acknowledged that the survival benefit seen in patients who have undergone palliative resection may be due to selection bias [4]. These patients tend to actually be symptomatic and physiologically fitter [30]. Moreover, the studies have all been retrospective reviews evaluating outdated chemotherapy regimens [4]. To address these issues, several prospective studies are currently underway. Although these are studies primarily addressing metastatic colon cancer, guidelines regarding management of late stage rectal cancer may be developed as a result. The University College Hospital in London, England has completed a phase III trial evaluating overall survival in patients with metastatic colorectal cancer receiving chemotherapy with and without surgery. Results have not yet been published [90]. The Dutch Colorectal Cancer Group (DCCG) is currently accruing patients with synchronous unresectable metastatic colorectal cancer to a randomized phase III trial investigating overall survival in patients undergoing resection of the primary tumor followed by systemic therapy compared to patients receiving systemic therapy alone [91]. Additionally, the SYNCHRONOUS trial is a multicenter, randomized controlled trial in Germany evaluating the safety and efficacy of resection of the primary tumor in patients with metastatic colon cancer prior to initiating systemic therapy. Primary endpoint is overall survival with secondary endpoints determining time-to-development of tumor-related complications and intervention required [92].

Most patients do not require emergent surgery and obtaining radiographic data becomes important in determining optimal treatment [93]. In addition to localizing the issue, determining the presence of carcinomatosis or ascites is essential as the presence of either is associated with unsuccessful surgery [94]. Nonoperative intervention is the preferred route in those patients with carcinomatosis or ascites, those who demonstrate poor performance status, or those with an unacceptably high operative risk.

Endoscopic-based therapies are an attractive alternative to operative intervention as they are less invasive and can be performed on an outpatient basis without general anesthesia. Endoscopic interventions are able to relieve obstructions, bleeding and/or pain rapidly and effectively. These are important considerations when electing to intervene on patients with limited life expectancy.