According to results recently presented at an annual meeting of the American Society of Clinical Oncology (ASCO), continuous maintenance therapy may improve survival among patients with metastatic colorectal cancer.
Colorectal cancer remains the second leading cause of cancer-related deaths in the United States. Metastatic colorectal cancer refers to cancer that has spread from its site of origin to distant sites in the body. Patients with metastatic colorectal cancer may be treated with initial therapy. Cancer may either shrink or completely regress following initial therapy. Unfortunately, the majority of patients with metastatic colorectal cancer will ultimately experience a progression of their cancer following initial therapy.
What is maintenance therapy in cancer?
Following the primary treatment of cancer doctor may recommend additional treatment with “maintenance therapy.” The goal of maintenance therapy is not to cure the cancer but to “maintain” a remission or prevent or delay the cancer’s return if the cancer is in remission after initial treatment. Some doctors believe the term “continuous therapy” is more appropriate since the cancer is essentially being treated on an ongoing basis.
Why is maintenance therapy used?
- To prevent or delay the cancer’s return if the cancer is in remission after initial treatment. Maintenance therapy is generally approved for use where it has been demonstrated in clinical trials to prolong survival for a specific cancer, leukemia, or lymphoma.
- Sometimes maintenance therapy is used to slow the growth of advanced cancer after initial treatment. This can help shrink the cancer, which is called a “partial remission.” In this situation, maintenance therapy is not used to cure the cancer, but it can lengthen a person’s life.
What types of maintenance therapy are there?
Maintenance therapy can be chemotherapy, hormone therapy, precision cancer medicines or immunotherapy drugs.
Maintenance therapy refers to therapy that is used following initial therapy, when a patient’s cancer is stable and not exhibiting signs of progression. The role of maintenance therapy and its optimal scheduling for metastatic colorectal cancer is under review. Researchers have been evaluating the optimal role of maintenance therapy among patients with colorectal cancer. Because chemotherapy is associated with side effects, researchers are interested in finding the optimal scheduling of therapy; such a program would reduce side effects while maintaining survival benefits.
Maintenance Therapy in Colon Cancer
Researchers recently conducted a clinical trial referred to as the OPTIMOX2 trial in which continuous maintenance therapy was evaluated among patients with metastatic colorectal cancer. This trial included 202 patients with metastatic colorectal cancer who were initially treated with Eloxatin® (oxaliplatin)-based chemotherapy. One group of patients was then treated with continuous maintenance chemotherapy (same as initial chemotherapy without Eloxatin) while the other group was treated again once their disease progressed.
- Overall survival was 26 months for those treated with maintenance therapy compared with 19 months for those not treated with maintenance therapy.
- Progression-free survival was improved for patients treated with maintenance therapy.
- During maintenance therapy fewer than 10% of patients experienced severe side effects
The researchers concluded that maintenance therapy may improve survival for patients with metastatic colorectal cancer as compared with re-introduction of chemotherapy at disease progression. However, it is important for patients to speak with their physician regarding their individual risks and benefits of maintenance therapy, as side effects are inherent with the use of chemotherapy.
References: Maindrault-Goebel F, et al. Final Results of OPTIMOX2, a Large Randomized Phase II Study of Maintenance Therapy or Chemotherapy-Free (CFI) after FOLFOX in Patients with Metastatic Colorectal Cancer (MRC): A GERCOR Study. Proceedings from the 2007 annual meeting of the American Society of Clinical Oncology (ASCO). Abstract #4013.
