Preoperative Workup, Staging, and Treatment Planning of Colorectal Cancer

Abstract Colorectal cancer (CRC) remains a leading cause of death in the United States. CRC is the second to third most common cancer globally and it impacts both genders. Screening initiatives are of paramount importance to eradicate the disease at a precancerous or early stage. Recommendations for screening are based on multiple factors including age, ethnicity, individual patient risk factors, and family history. Short- and long-term outcomes and survival data correlate with the stage of disease at the time of diagnosis emphasizing the need for appropriate baseline staging. Furthermore, stage of disease determines the necessity for any neoadjuvant or adjuvant therapy and provides recommendations for long-term oncologic follow-up. Preoperative workup includes physical examination, blood tests such as tumor markers and liver function tests, endoscopic evaluation, and cross-sectional imaging. In a select group of patients, genetic testing is part of the initial evaluation as it can impact the treatment plan, long-term follow-up, and testing of potential offspring. In general, surgical intervention remains the predominant treatment modality for stage I to III colon cancers with chemotherapy administration as adjuvant therapy for stages II to III to minimize recurrence or as a palliative modality for patients with stage IV disease. The treatment of rectal cancer remains more complex. Traditionally, early rectal cancer has been treated with surgical resection and locally advanced rectal cancer with neoadjuvant chemoradiation followed by surgical resection and postoperative chemotherapy. In the last decade, several protocols have been implemented to modify the neoadjuvant treatment with a trend toward more extended chemotherapy with the intent to further downstage the rectal cancer. Furthermore, the introduction of various protocols of total neoadjuvant chemoradiation may offer in a select group of patients with complete pathologic response, the possibility of observation without surgery. Finally, the management of stage IV CRC is in continuous evolution with the palliative goal of prolonging survival in most patients while offering the opportunity in some patients with limited metastatic disease to become potential candidates for resection of the primary lesion in addition to the metastatic disease.