Combination Therapy Doesn't Help Head, Neck Cancers
Study finds disappointing results when adding potent drug to radiation
MONDAY, May 20, 2002 (HealthDayNews) -- Adding the powerful cancer drug cisplatin to radiation therapy doesn't seem to improve the outlook over radiation alone in people with head and neck tumors.
That's the surprising and disappointing early return from an ongoing study comparing the two therapies. The research leaders stress the latest results are interim, and many patients hadn't reached the crucial two-year mark when the data was analyzed. However, the initial trends suggest the combination's benefits will be minimal at best.
"People are always looking for things to do for patients," says Dr. Arlene Forastiere, of Johns Hopkins University's Kimmel Cancer Center and a co-chair of the study team. "We may be able to find a subset of patients that [the combination] helps, but right now, to our surprise, we're not seeing positive results."
Head and neck tumors -- such as those of the voice box, throat and mouth -- strike nearly 29,000 Americans a year, killing 7,400, according to the American Cancer Society. The disease is particularly nasty, lethal within five years for more than half of people in whom it's diagnosed.
The standard of care for these tumors has been to remove them surgically, and then use radiation to kill off residual cancer cells and prevent tumors from returning. For people who aren't good candidates for surgery, doctors use cisplatin -- a platinum-based compound prescribed for lung, breast, bladder and other cancers -- and radiation.
Cisplatin plus radiation has also worked in patients with other forms of cancer, including tumors of the uterus and esophagus, says Dr. Jay S. Cooper, a radiation expert at New York University Medical Center and another co-chair of the study team.
So, researchers wondered with good reason if adding cisplatin to radiation might improve the prognosis for head and neck tumor patients who qualify for surgery.
The latest evidence, reported this weekend at a meeting of the American Society of Clinical Oncology in Orlando, Fla., suggests the answer to that question is a qualified no.
Beginning in 1995, Forastiere, Cooper and their colleagues at clinics across the country have followed 407 people who had surgery to remove head and neck tumors. Of those, all received radiation and roughly half were given up to three doses of cisplatin to augment that treatment.
After an average of 27 months of follow-up, outcomes in the two groups were similar. Tumors had returned in 26 percent of the patients who received radiation alone and in 20 percent of those in the other group -- but that difference wasn't statistically significant.
Survival rates were also essentially identical, 63 percent in the combined treatment group versus 57 percent in the radiation group.
Patients who took cisplatin were more likely to be cancer-free during the follow-up period -- 54.2 percent versus 42.5 percent. However, that gain came at a price: The drug is highly toxic, and only 58 percent of patients were able to tolerate all three doses. Serious side effects from the drug were more than twice as common as with radiation alone. These included nausea, vomiting, mouth soreness and low blood counts.
Three people in the cisplatin group died of complications possibly linked to the drug, compared with no treatment-related deaths in those receiving only radiation.
Forastiere thinks cisplatin's harshness may explain the disappointing results. "Maybe the postoperative population just doesn't tolerate the treatment as well," she says.
Even so, the researchers aren't ready to call the combination therapy a total bust. Roughly a third of their patient population hadn't been followed for two years when the data were collected last October. The first 24 months are a critical time for the return of tumors, and it?s the period when most patients suffer relapses. However, she says, even if the drug performs better in these people than it did in the others, the overall results are unlikely to change markedly.
The researchers are considering lower doses of cisplatin to make it more palatable to patients. They're also looking to newer, high-tech cancer drugs that might supplement radiation, ones that target cancer cells directly.
"We're just going to have to wait and be patient to see if [cisplatin plus radiation] is really effective," Cooper says. "But whether it is or it isn't, the concept that using modest doses of chemotherapy to enhance the effectiveness of radiation seems to be a valid paradigm."