ACR Appropriateness Criteria: rectal cancer-metastatic disease at presentation

In 2009, an estimated 40,870 new cases of rectal cancer will be diagnosed in the USA. After decades of treating metastatic colorectal cancer (CRC) with 5-fluorouracil alone, newer agents have resulted in significant improvements in disease-free and overall survival rates. These improvements stem from combinations of newer cytotoxic agents and targeted therapies. Based on performance status and burden of disease, metastatic CRC patients are generally treated with either a curative or palliative intent. Curative paradigm patients often have low burden liver or lung metastases which are technically resectable. Patients with resectable colorectal liver metastases and no evidence of any extrahepatic metastases have impressive 5-year survival rates of 30%-70% following resection. Unfortunately, only 20%-30% of patients with colorectal liver metastases are candidates for resection at initial presentation. Patients with unresectable liver or lung metastasis are candidates for local therapies including radioablation, chemoembolization, radioembolization, and stereotactic radiation therapy. In select patients with metastatic CRC, neoadjuvant or adjuvant pelvic chemoradiation (CRT) is indicated to prevent local recurrence. Patients who have resectable metastatic disease with symptomatic, obstructive, Stage T3-4 and N1, or low-lying (