Proton Therapy May Have Benefit in Treating Advanced Head and Neck Cancers
Improvement with proton beam therapy compared with photon intensity-modulated radiation therapy.
Proton beam therapy compared with photon intensity-modulated radiation therapy (IMRT) may be associated with better outcomes in patients with malignant diseases of the nasal cavity and paranasal sinuses, according to a systemic review and meta-analysis.
Researchers at the Mayo Clinic reported in Lancet Oncology that charged particle therapy resulted in better locoregional control, disease-free survival (DFS), and overall survival in both treatment-naïve patients and those with recurrent disease.1
“I think it is good news. It appears that patients treated with proton therapy had better control and survival compared [with] photon IMRT,” said study author Robert Foote, MD, who is a radiation oncologist at the Mayo Clinic in Rochester, Minnesota.
Dr. Foote and his colleagues identified 539 studies of nasal cavity and paranasal sinus tumors through various databases and 41 studies met the criteria for their analyses. The median follow-up was 38 months (range: 5 to 73 months) for the charged particle group and 40 months (range: 14 to 97 months) for the photon therapy group.
The researchers found that DFS was significantly higher at 5 years for patients receiving charged particle therapy compared with the photon therapy group (72% vs 50%, respectively). The tumor control rates were similar between the two groups at 5 years. However, tumor control was higher for the charged particle therapy group than for the photon therapy group at longest follow-up (81% vs 64%, respectively).
“It is a very challenging group of patients to treat because of the location of the tumor and it is difficult for the surgeons to get clear negative margins and it is difficult to give adequate doses of radiation,” Dr. Foote said in an interview with Cancer Therapy Advisor. “Protons appear to be able to provide a better control rate.”
Dr. Foote and his colleagues caution that prospective studies are warranted and they point out that this analysis included a heterogeneous population of patients with head and neck cancer and heterogeneous delivery techniques.
Radiation oncologist David Sher, MD, an assistant professor at Rush University in Chicago, Illinois, said that this analysis is important but is really just a first step at looking at these different therapies for these types of tumors. “The authors did a valiant job to deal with confounders, but due to the challenges of reviewing retrospective data, it is difficult to draw conclusions about these technologies. The patient populations were quite different,” explained Dr. Sher.
He said that proton therapy appears to be especially promising for certain head and neck cancers. However, Dr Sher indicated that much more research is needed before any strong conclusions can be made.
“When you talk about head and neck cancer you are talking about different diseases and different types of cancers in different locations. So you can't say one therapy is better than another for all of them. Proton therapy radiation plans will always look better. They do spare more normal tissue. Whether that leads to better control and better quality of life, we don't know,” Dr. Sher told Cancer Therapy Advisor. “There are no studies looking at quality of life and that is such a big issue [for] these patients.”
Currently, there is a phase 2/3 randomized trial comparing the two approaches for the treatment of oropharyngeal cancer of the head and neck.2 Radiation oncologist Jeffrey Bradley, MD, director of the S. Lee Kling Center for Proton Therapy at the Siteman Cancer Center in St. Louis, Missouri, said that while proton therapy may be overmarketed for some tumor types, that is not the case with head and neck tumors.
“It hasn't been oversold at all for head and neck. It is underutilized and undersold in head and neck cancers and [head and neck cancer] is probably one of the sites where there is an advantage,” Dr. Bradley noted in an interview with Cancer Therapy Advisor.
- Patel SH, Wang Z, Wong WW, et al. Charged particle therapy versus photon therapy for paranasal sinus and nasal cavity malignant diseases: a systematic review and meta-analysis. 2014;15(9):1027-1038.
- ClinicalTrials.gov. Intensity-modulated proton beam therapy (IMPT) versus intensity-modulated photon therapy (IMRT). NLM Identifier: NCT01893307. Bethesda, MD: National Library of Medicine. http://clinicaltrials.gov/ct2/show/NCT01893307. Accessed August 12, 2014.