ONCOLOGY Vol 24 No 1_Suppl_1

In this supplement to Oncology, guest editor Axel Grothey from the Mayo Clinic, explores adjuvant therapy considerations in stage II colon cancer from different angles.

In the treatment of colon cancer today, the decision-making involved in the treatment of stage II disease is probably the most challenging aspect. The major question is whether or not these patients should receive postoperative adjuvant chemotherapy. Approximately 75% of stage II colon cancer is cured by surgery alone. For the remaining 25% of cases, there is great debate over whether adjuvant chemotherapy is sufficiently effective in enough patients to warrant the exposure to potentially toxic treatments. In the important QUASAR clinical trial, stage II patients were randomized to either fluorouracil (5-FU)-based therapy or observation. The results demonstrated an approximate 3% improvement in outcome for the 5-FU–treated patients. This leads to the assumption that treating all stage II patients with adjuvant chemotherapy is gross overtreatment, when essentially 97% of these patients will not benefit. Clearly the only way to approach this decision is through risk determination. In this article, I will describe the current state of defining high- and low-risk disease, which is mainly through histopathologic characteristics, as well as discuss emerging approaches such as molecular markers and genomic profiling

it is obvious that some patients with stage II cancers have excellent outcomes and do not require additional therapy, whereas other patients have cancers that biologically behave more like stage III tumors.Over the past years, our understanding of stage II colon cancer has made significant advances leading to a refinement in the identification of the patient population and the treatment options considered appropriate as adjuvant therapy in this setting.

Colon cancer is estimated to have accounted for 106,100 new cancer cases and 49,920 cancer-related deaths in 2009. Over half of these new diagnoses and deaths occur in individuals age 70 and older.

Approximately 150,000 new cases of colorectal cancer were expected for the year 2009 in the United States. Moreover, 49,920 deaths related to colorectal cancer were also predicted for the same year. The age-adjusted cancer death rates related to colorectal cancer have steadily declined over the past 2 decades. This improvement is a direct consequence of advances in prevention and treatment, including colorectal cancer screening, diagnostic tests, surgical technique, adjuvant therapies, and medical support.