Key Concepts

• All patients with resected stage III, and most with high-risk stage II, colon cancer should be considered for adjuvant chemotherapy for 3–6 months.
• Adjuvant therapy for rectal cancer is more complex. Multiple options exist with regard to the order and timing of multimodal therapy.
• Patients with clinical stage II and III rectal cancer should be considered for preoperative radiotherapy and systemic chemotherapy for a total of 4–6 months of treatment.
• Radiotherapy used as an adjunct to proctectomy for rectal cancer is more effective and less toxic if it is given preoperatively, as compared to postoperative administration. Postoperative radiotherapy should be avoided if possible.
• Intensive postoperative surveillance has not been proven to be associated with improved survival, as compared to less intense surveillance or no surveillance.
• Surveillance is only indicated in patients who wish to undergo treatment for recurrent tumor, and who are candidates for liver, lung, and/or intestinal resection, and/or multidrug chemotherapy. Patient desires, age, and comorbidities should be considered prior to initiating a surveillance plan.
• Detection of asymptomatic liver metastasis and local regional recurrence are more likely to be amenable to curative-intent salvage resection than symptomatic recurrences, although it is unclear whether this strategy improves survival when compared with no surveillance.
• Use of carcinoembryonic antigen (CEA) testing and computed tomography (CT) scans is associated with increased detection of asymptomatic recurrence. However, there remains no evidence to support the use of other laboratory or image-guided testing in routine surveillance.
• Risk of locoregional recurrence is higher in patients with advanced rectal cancer compared to colon cancer. Risk factors include the omission of chemoradiotherapy, positive circumferential margin, and T4 and N2 histology.
• Surveillance after resection of stage I colorectal cancer remains controversial. Typically, colonoscopy to look for metachronous neoplasia is the only test recommended.