Dennis Citrin, MD, PhD
Ten years ago, Dennis Citrin, MD, PhD watched as patients with metastatic non–small cell lung cancer died, despite treatment, 6 to 12 months after diagnosis.
These days, through the use of chemotherapies (eg, carboplatin, paclitaxel, pemetrexed) and targeted treatments (eg, bevacizumab) the doctor is able to usher many of them into remission.
It’s a transformation that has, in turn, created the need for longer-term treatment strategies—not just for patients with NSCLC, but for those with other solid tumor types in which prognoses have improved, said Citrin, MD, Phd, of the Cancer Treatment Centers of America.
Increasingly, the oncology community is looking to meet that need with maintenance therapy (MT), a strategy that involves immediately following a successful first-line treatment with a component of the same regimen (continuation maintenance), or with a different therapy that is effective and well-tolerated (switch maintenance).
“When it comes to more common solid tumors like breast, colorectal, or ovarian, the goal of initial treatment is to get the disease under control so it’s not causing symptoms or discomfort and, more than that, to prolong survival,” said Citrin, who practices at his organization’s Midwestern Regional Medical Center in Zion, Illinois. “Having said that, you can’t keep patients with these cancers in remission without continued treatment, and that’s the whole idea behind maintenance therapy.”
Heather Wakelee, MD
Without some of the newer, less-toxic cancer medications, MT wouldn’t be a workable strategy, particularly in NSCLC, noted Heather Wakelee, MD, assistant professor of Medicine in the Division of Oncology at Stanford University, in California.
“Why haven’t we done maintenance before? It’s because we were focused on platinum-based doublet chemotherapy in treating NSCLC, and you can’t give doublets indefinitely, nor can you give taxanes indefinitely,” Wakelee said. “It’s only because we have drugs that you can continue, from a toxicity standpoint, that this question has really come up.”
MT, which can include cytotoxic drugs, targeted therapies, hormonal or other anticancer treatments, has long been established in blood cancers, including acute lymphocytic leukemia and acute myeloid leukemia; once in remission after induction therapy, those patients get MT for 2 or 3 years to protect against their cancer’s return.1
Debu Tripathy, MD
While the concept of MT remains under investigation in many types of solid tumors, the strategy has been adopted for eligible patients in some breast cancers—although doctors don’t always refer to it as MT, said Debu Tripathy, MD, co-leader of the Women’s Cancers Program and a professor of Medicine at the Norris Comprehensive Cancer Center at the University of Southern California in Los Angeles.
In early-stage breast cancers, where cure is the goal, patients often undergo a fixed number of chemotherapy cycles, followed by what some consider maintenance with hormonal drugs or trastuzumab for a prespecified length of time. In advanced or metastatic disease, where the aim is to slow disease progression, there are fewer rules for what a regimen should contain or how long it should last, except that both initial and maintenance therapies usually continue until disease progression, Tripathy added. In that setting, maintenance treatments vary based on a tumor’s size, its responsiveness to treatment, and the severity of the side effects a patient experiences, Tripathy said.