Stereotactic Body Radiation Therapy in Older Cancer Patients

The incidence of cancer increases with age, creating new challenges as the global population grows older. Challenges of treating cancer in elderly patients include co-morbid disease and the patient’s ability to tolerate standard therapies. Some elderly patients are not offered radiotherapy due to concerns about how they will tolerate treatment. Stereotactic body radiation therapy (SBRT) and hypofractionated schedules that enable fewer but larger doses per treatment make radiation a more acceptable option for elderly patients for whom long treatment schedules requiring multiple hospital visits may not be favorable. Recent technological advances in imaging and radiation treatment planning have enabled the precise, safe delivery of high doses per treatment session. Recent data support the use of SBRT and hypofractionated regimens in older patients across multiple tumor sites.

The role of SBRT is well established in patients with early-stage, non-small cell lung cancer (ES-NSCLC) who are medically inoperable. However, there is limited information on the efficacy and toxicity profile of SBRT in older adults. Personal experience suggests that many elderly patients can be treated with SBRT with excellent results and those formal evaluations of the outcomes of SBRT in this patient population—who is often under-represented in clinical trials and other studies—is needed.

Formal Evaluation

To that end, the Elekta Lung Research Group, an international collaboration of physicians and physicists, including Meredith Giuliani, MBBS, FRCPC, MEd, recently undertook a multi-institutional, retrospective cohort study of 1,000 patients. Published in the International Journal of Radiation Oncology, Biology and Physics, the study found that SBRT for the treatment of ES-NSCLC appears to be as safe and effective for patients aged 80 years and older as it is for younger patients (Table). No differences in local recurrences, regional recurrences, distant metastases, and cancer-specific survival (CSS) were observed between the two groups. Serious toxicity and 90-day mortality rates were very low in both groups, with no statistically significant differences.

The results of this study are in line with a recent 772-patient study from the MD Anderson Cancer Center, which compared the effectiveness of SBRT in patients younger than 75 and patients aged 75 and older. The results showed no differences between the groups in time-to-progression, CSS, or toxicity rates in patients. There was a similar overall survival (OS) at 2 years, with improved OS at 5 years for patients younger than 75. No grade 4 or 5 toxicities were seen in patients aged 75 or older.

Important Considerations

“These studies fill an important knowledge gap in the management of NSCLC in elderly patients, and additional prospective studies are warranted to address important questions, including the role of SBRT in operable elderly patients and the effects of treatment on elderly patients’ quality of life,” says Inga Grills, MD, a radiation oncologist at Beaumont Hospital and co-author of the ES-NSCLC study.

The Elekta Lung Research Group plans to play an important role in addressing these research questions through continued collaboration with leading cancer institutions and lung cancer experts around the world. The studies cited above demonstrate that assumptions that elderly cancer patients won’t tolerate or benefit from radiation therapy do a disservice to these patients. Additionally, they indicate  that SBRT is a highly effective treatment with a favorable toxicity profile in elderly patients with ES-NSCLC.

Based on the results of this study, Giuliani and colleagues urge clinicians to consider patients with early-stage lung cancers, regardless of their age, for treatment of their cancer. Decisions about treatment should be based on a case-by-case evaluation that includes factors other than age, such as co-morbidities, performance status, risk-benefit, and patient preference. The results of the ES-NSCLC study will hopefully inspire the medical community to educate itself and others involved in elder care about the role that SBRT and radiotherapy more broadly can play in treating older cancer patients.