In an exciting revelation, proof now exists that adding chemotherapy to the standard treatment of radiation can improve life expectancy in people with certain slow-growing brain tumors.
New study on chemotherapy and brain cancer
The findings, which come from a long-term study of patients who took part in a trial that began in 1998, show that years may be added to the lives of such patients.
The study followed subjects who were treated for grade 2 gliomas — tumors that begin in certain brain cells called glial cells and are relatively slow-growing.
Previous results from the trial had showed that adding chemotherapy to the standard treatment of radiation can help keep tumors from progressing. This followup proves that it prolongs peoples’ lives as well.
Dr. Jan Buckner, lead researcher and chair of the oncology department at the Mayo Clinic in Rochester, Minnesota claims, “Until now, there hasn’t been any therapy known to improve life expectancy for these patients.”
In the United States, nearly 23,000 adults were diagnosed with brain cancer in 2015, according to the U.S. National Cancer Institute (NCI). Grade 2 gliomas brain cancer accounts for 5 to 10 percent of adult brain cancers, disproportionately affecting younger adults.
The study, published in the April 7 issue of the New England Journal of Medicine and funded by the NCI, recruited 251 patients between 1998 and 2002.
Half of the patients were randomly assigned to six weeks of radiation therapy followed by chemotherapy that included a trio of drugs: procarbazine, CCNU and vincristine. The remaining participants received the radiation therapy alone. When possible, participants underwent surgery to remove some of the cancer before undergoing radiation.
The patients ranged in age, but were typically around 40 years old.
Five extra years?
At the end of the study period it was discovered that although 55 percent of the study group had died from the disease, the patients who had received chemo typically survived for 13 years, versus eight years averaged by those who had received radiation alone.
“An extra five years,” Buckner said. “That’s a significant difference.”
Director of neuro-oncology at the University of California San Francisco Medical Center, Dr. Susan Chang, agreed.
“We should celebrate that we have a treatment that can prolong these patients’ lives,” said Chang, who is also associate editor of Cancer.Net, the cancer information website run by the American Society of Clinical Oncology (ASCO).
“But at the same time,” she continued, “we have to recognize that there’s a need for less toxic treatments.”
Noted in the study was that chemotherapy patients often had drops in their blood cell counts, leaving them vulnerable to potentially serious infections. Side effects such as nausea, vomiting, constipation and weight loss were also commonly reported.
Due to the length of time needed to run the study, changes to treatments now exist, and less-toxic chemo drugs are more readily available and are generally preferred by doctors. With that said, the newer drugs may need to go through their own similar trials to determine if the same results will prevail.
It is also important to recognize that not all patients given the chemo treatment benefited. As Chang points out, not all grade 2 glioma patients are the same. For reasons that are currently not understood, some patients respond well to treatments that others do not.
Going forward, the hope is to better understand the tumors at a molecular level. Such advancements could lead to drugs that go beyond chemotherapy and specifically target abnormalities on the tumor cells.
“We want to be able to hit the tumor, and not the normal tissue,” Chang said.
For now, Buckner suggested that glioma patients talk with their doctors about whether chemo is right for them.