Adjuvant chemotherapy for high-risk stage II and stage III colon cancer: timing of initiation and optimal duration.

The benefit of adjuvant chemotherapy has been clearly proven for patients with stage III (node-positive) and highrisk stage II colon cancer and consists to eradicating micrometastases that may be present during the time of surgical resection, reducing thereby the likelihood of disease recurrence and potentially increasing the cure rates after surgery. In this review, the appropriate timing of initiation and optimal duration of adjuvant chemotherapy are discussed. Current guidelines recommend an oxaliplatinbased regimen (FOLFOX: 5-fluorouracil with oxaliplatin or CapeOx: capecitabine with oxaliplatin) instead of 5-FU/LV (5-fluorouracil/leucovorin) for 6 months. For patients with a contraindication to oxaliplatin, a fluoropyrimidine-based regimen alone is an acceptable option. It should be initiated within 6-8 weeks from the time of surgical resection. Studies on reduced duration of fluoropyrimidine-based only regimens (bolus 5-FU/LV vs 5-FU) showed no significant difference in overall (OS) and disease free survival (DFS) benefits. However, the studies showed significantly lower toxicities for protracted venous infusion (PVI) 5-FU given for shorter duration. For oxaliplatin-based therapies, prospective trials failed to establish non-inferiority of 3 months compared to 6 months of oxaliplatin-based adjuvant therapy. The longterm data of the International Duration Evaluation of Adjuvant Chemotherapy (IDEA) collaboration for OS are not mature to date yet. Six months of oxaliplatin-based therapy still remain the standard of care. Decisions to shorten the duration of adjuvant oxaliplatin-based therapy should be dictated by drug tolerability, risk stratification of the disease, consideration of the value of decreased neurotoxicity at the cost of decreased DFS, and patient preference.

Surgical treatment for colorectal cancer in octogenarians and nonagenarians.

Advances in surgical techniques and perioperative care have improved cancer-related outcomes. However, there are still concerns regarding the safety of octogenarian and nonagenarian patients during surgery. Clinicians may be reluctant to perform a radical resection for colorectal cancer and administer adjuvant or palliative cytotoxic chemotherapy to octogenarian and nonagenarian patients. In the elderly, setting a primary goal based on multidisciplinary team discussions prior to treatment is important. The overall treatment scheme, risks, and potential benefits should be discussed with elderly patients and their families. In this review, we will discuss multidimensional aspects of colorectal cancer surgery for octogenarian and nonagenarian patients with respect to age-related physiological declines, preoperative assessments, appropriate surgical procedures, and short-term and oncologic outcomes. In this era of an aging society, clinicians should provide objective evidence to octogenarian and nonagenarian patients regarding estimated short-term and oncologic outcomes. However, there is a limited number of studies concerning outcomes following colorectal cancer surgery in octogenarians and nonagenarians. In the future, a prospective study with a larger cohort would be helpful to collect objective data on octogenarian and nonagenarian patients.