LOS ANGELES – Treatment with neoadjuvant chemotherapy leads to significant downstaging in a selected group of patients with advanced colon cancer, results from a large registry study showed.
“Neoadjuvant chemotherapy is already established as a treatment strategy in several other types of cancers, such as breast cancer, gastric cancer, and rectal cancer,” lead study author Dr. Moniek Verstegen said at the annual meeting of the American Society of Colon and Rectal Surgeons. “It reduces tumor size and promotes resectability. In colon cancer, however, this treatment strategy is relatively new and not applied very often.”
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Preliminary results from the ongoing FOxTROT trial in the United Kingdom showed that preoperative chemotherapy for radiologically staged, locally advanced, operable primary colon cancer is feasible, with acceptable toxicity and perioperative morbidity, but long-term results are not yet available. The aim of the current study was to see how often neoadjuvant chemotherapy is used in the Netherlands for stage II and III colon cancer and to assess the tumor and nodal downsizing effects. Moreover, perioperative results and long-term outcomes were compared between those treated with neoadjuvant chemotherapy and those who were treated with adjuvant chemotherapy for locally advanced colon cancer.
The researchers searched the Netherlands Cancer Registry from 2008-2012 to identify 24,944 patients diagnosed with stage II and III colon cancer. Dr. Verstegen, a researcher in the department of surgery at Radboud University Medical Center, Nijmegen, Netherlands, reported results from 85 patients who received neoadjuvant chemotherapy and 2,216 who received adjuvant chemotherapy (the control group). Both groups were similar in terms of age (a median of about 65 years), gender, localization of the primary tumor, differentiation grade, morphology, and clinical T and N stage. Multivisceral resections were performed significantly more often in the neoadjuvant group, compared with the control group (21% vs. 5%, respectively; P less than .001). There were no differences between groups in the number of complete resections, nor in the rate of complications. Furthermore, no patient died within 30 days of neoadjuvant chemotherapy after surgery.
Tumor downstaging was observed in 47% of patients treated with neoadjuvant chemotherapy and there were three complete responses. At the same time, nodal downstaging was observed in 50% of patients treated with neoadjuvant chemotherapy. The 3-year overall survival was 73% in both groups.
Dr. Verstegen acknowledged certain limitations of the study, including its retrospective design and the lack of data on recurrences and disease-free survival. “Neoadjuvant chemotherapy seems to be a safe treatment strategy, since we have low postoperative morbidity and mortality rates,” she concluded. “We see comparable outcomes compared to the control group. Prospective trials are needed to confirm the safety and value of neoadjuvant chemotherapy.”
Dr. Verstegen reported having no financial disclosures.