- Advancing age, inherited and acquired genetic susceptibilities, lifestyle choices, inflammatory bowel disease, type 2 diabetes mellitus, and environmental factors are associated with colorectal cancer risk.
- Regular use of aspirin and other nonsteroidal antiinflammatory drugs, calcium intake, and higher blood vitamin D levels may reduce risk of colorectal cancer, but they are not currently recommended for routine cancer prevention.
- Effective colorectal cancer screening programs incorporate regular examination of the entire colon starting at age 50 years for average-risk individuals. Colorectal adenomas can progress to cancer and should be removed.
- The histologic stage of colorectal cancer upon diagnosis—determined by depth of bowel invasion, lymph node involvement, and presence of metastases—is the most important prognostic factor for disease recurrence and survival.
- The treatment goal for stages I, II, and III colon cancer is cure; surgery should be offered to all eligible patients for this purpose. Six months of fluoropyrimidine-based adjuvant systemic therapy reduces the risk of cancer recurrence and overall mortality in patients with stage III and select populations with stage II colon cancer. An oxaliplatin-containing regimen further reduces risk as compared with fluoropyrimidine alone.
- Combined modality neoadjuvant therapy consists of fluoropyrimidine-based chemosensitized radiation therapy and surgery for patients with stage II or III cancer of the rectum and is considered standard of care to decrease risk of local and distant disease recurrence.
- Preoperative chemotherapy may reduce tumor size and convert unresectable disease to resectable disease in selected patients with metastatic colorectal cancer. This strategy offers the potential for prolonging overall survival and cure for metastatic disease.
- Chemotherapy is palliative for metastatic disease. A fluoropyrimidine with oxaliplatin or irinotecan improves survival compared to fluoropyrimidine monotherapy and should be offered to patients who are candidates for aggressive treatment. The ability for patients to receive all active cytotoxic agents (e.g., fluoropyrimidine, oxaliplatin, irinotecan) during the course of their disease improves their overall survival.
- Bevacizumab plus fluoropyrimidine-based chemotherapy as initial therapy for metastatic disease is considered standard of care and provides a survival benefit as compared with combination chemotherapy alone.
- The addition of cetuximab or panitumumab to initial treatment for KRAS wild-type advanced or metastatic disease may improve tumor response rates and survival. Individuals who have disease progression after initial therapy not containing an epidermal growth factor receptor (EGFR) inhibitor may benefit from cetuximab or panitumumab, either alone as a single agent or combined with other drugs. However, patients with codon 12 or 13 KRAS gene mutations should not receive cetuximab or panitumumab as these tumor mutations predict lack of treatment response.
On completion of the chapter, the reader will be able to:
Identify and discuss clinical risk factors associated with the development of colon cancer.
Recommend dietary and lifestyle interventions that patients can implement to decrease the risk of colon cancer.
Explain the role of inherited genetic mutations in the development of colon cancer.
Discuss the role of aspirin and nonsteroidal antiinflammatory drugs in the general population as chemopreventive agents for colorectal cancer.
Compare advantages and ...