Wednesday, July 1, 2009
More than 100 Memorial Sloan Kettering investigators shared their latest findings with oncologists from around the world at the annual meeting of the American Society of Clinical Oncology, which was held in Orlando May 29 through June 2.
More than 100 Memorial Sloan Kettering investigators shared their latest findings with oncologists from around the world at the annual meeting of the American Society of Clinical Oncology, which was held in Orlando May 29 through June 2. Following are two studies by Memorial Sloan Kettering investigators that were highlighted at the meeting.
Medical oncologist Vincent A. Miller reported that two targeted therapies, bevacizumab (Avastin®) and erlotinib (Tarceva®), can be administered together to delay disease progression in patients who have been treated with chemotherapy for non-small cell lung cancer (NSCLC).
The findings are the results of an international study led by Dr. Miller in which 768 patients with advanced NSCLC were treated initially with standard cytotoxic chemotherapy and bevacizumab. Those who did not progress continued taking bevacizumab but were randomized to receive erlotinib or placebo. Previous studies have shown that bevacizumab added to chemotherapy in NSCLC improves survival when compared with chemotherapy alone. In the present trial, patients stayed progression-free even longer if erlotinib was added to bevacizumab after initial chemotherapy.
Bevacizumab blocks angiogenesis, the process by which tumors gain access to new blood vessels, while erlotinib prevents tumor cells from receiving certain signals that induce them to grow or spread. “This is the first study to show that the addition of erlotinib to maintenance therapy prolongs progression-free survival in patients with advanced non-small cell lung cancer,” said Dr. Miller. “Knowing which patients will get the greatest benefit from the combination, based on the identification of biomarkers, will be an important next step in this research.” Both drugs cause fewer and generally less-severe side effects than standard chemotherapy agents do.
Surgical oncologist Philip B. Paty, Vice Chair for Clinical Research in the Department of Surgery, observed that a new treatment approach is warranted for patients with advanced colorectal cancer whose disease has already spread from the colon to other organs at the time of diagnosis.
Traditionally, such patients have been treated with surgery to remove the primary tumor in the colon. “We now know that the routine use of surgery in these patients is based on old thinking, and we’re beyond that,” Dr. Paty said. “Our default position should be not to operate, although there will always be individual exceptions.”
In a retrospective study, he and his colleagues analyzed 233 patients who had been diagnosed with metastatic colorectal cancer and treated with chemotherapy at Memorial Sloan Kettering. In 93 percent of these patients, the primary tumor did not cause any complications that required it to be removed.
The investigators considered a number of factors, including the tumor’s initial location, its extent of spread, and whether bevacizumab had been added to the chemotherapy. None of these correlated with a patient’s need for surgical intervention. “If the primary tumor is not causing symptoms such as bleeding or blockage, we’ve found these patients are best treated with chemotherapy,” Dr. Paty commented. “By moving straight to chemotherapy, patients can start treatment for all disease sites without delay and avoid the risk of surgical complications.”