Many patients receiving palliative radiation therapy to the bone or chest for metastatic non–small cell lung cancer (NSCLC) may be receiving a greater number of treatments and higher doses than are supported by current evidence, according to a Cancer Care and Outcomes Research and Surveillance Consortium (CanCORS) study reported in the Journal of Clinical Oncology by Aileen B. Chen, MD, MPP, of Dana-Farber Cancer Institute and Brigham and Women’s Hospital, Boston, and colleagues.^₁

As reviewed by the authors, available evidence indicates that single-fraction radiotherapy for uncomplicated bone metastases is effective in most patients; no difference in pain relief has been observed between single-fraction (5–15 Gy total dose) and multifraction (1530 Gy in 3–10 fractions) radiotherapy, although retreatment has been more common in patients receiving single-fraction radiotherapy. Most data indicate that shorter, lower-dose radiotherapy to the chest (eg, 10–35 Gy in 1–10 daily or 16 twice-daily fractions) produces palliation of symptoms equivalent to higher-dose treatment with less treatment-related adverse effects. Though analyses also suggest a potential small short-term survival advantage for modestly higher palliative doses (over about 30 Gy in 10 fractions), significantly higher doses have not been adequately tested.

Study Details

The CanCORS study analyzed palliative radiotherapy use in 1,574 patients diagnosed with metastatic NSCLC between 2003 and 2005; patients were from participating CanCORS sites in Northern California, Los Angeles County, North Carolina, Iowa, or Alabama or were receiving care in any of 10 Veterans Administration sites or 5 large health maintenance organizations. The median age of the cohort was 68 years, and 65% were male. Median survival following metastatic diagnosis was 4.7 months, with 20% of patients remaining alive at 15 months, the end of the observation period.

Overall, 895 patients (57%) had at least one visit with a radiation oncologist after diagnosis of metastatic disease, with 780 patients (87% of those with visits and 50% of the total cohort) receiving at least one course of radiotherapy. Among those receiving radiotherapy, 22% received radiation to the brain, 21% to the chest, and 12% to the bone. Among all patients, 51% received at least one course of chemotherapy after diagnosis, 6% had surgery for the primary tumor, and 6% had surgery for a metastatic site.

Factors Associated with Radiotherapy

On multivariate analysis, there were no significant associations of receipt of radiotherapy with sex, marital status, race, comorbidity, or insurance type. Patients receiving systemic chemotherapy (56% vs 42% of those not receiving chemotherapy, odds ratio [OR] = 1.66, P < .001) and those who had surgery for a metastatic site (65% vs 49% of those not receiving such surgery, OR = 1.90, P = .006) were more likely to receive radiotherapy. Older patients (39% of patients aged > 80 years vs 61% of patients aged < 55 years, OR = 0.47, P = .003) and those receiving surgery for the primary site (36% vs 50% of those not receiving such surgery, OR = 0.41, P < .001) were less likely to receive radiotherapy.

Fraction and Dose Findings

Among 194 patients receiving palliative radiotherapy to the bone with a known number of fractions, 50% received 6 to 10 treatments, 20% received 5 or fewer, and 6% received a single fraction. Among 206 patients receiving a known dose, 49% received between 21 and 30 Gy. Among 297 patients receiving palliative radiotherapy to the chest with a known number of fractions, 42% received more than 20 fractions. Among 319 with a known dose, 65% received more than 30 Gy and 33% received more than 50 Gy.

Several factors were associated with number of fractions and dose on multivariate analysis. Patients treated within integrated networks (ie, staff model HMOs or the Veterans Administration network) received an average of 3.4 fewer fractions (P = .001) and a dose 4.0 Gy lower (P = .049) to the bone than those not in an integrated network; these patients also received 2.9 fewer fractions (P = .047) and a dose 4.8 Gy lower (P = .04) to the chest.

Patients with greater comorbidity scores tended to receive higher doses to the bone (overall P = .005) with no difference in number of fractions. Patients receiving chemotherapy after diagnosis received 7.0 more fractions and a dose 11.3 Gy higher to the chest (both P < .001) than patients not receiving chemotherapy.

Conclusions

The authors concluded, “Palliative [radiotherapy] is frequently used in patients with metastatic NSCLC and has clearly demonstrated ability to improve quality of life in those patients. However, treatment can incur significant time and monetary costs for patients with limited life expectancy. We found that a substantial proportion of patients treated to the bone or chest receive higher doses and more fractions than clinical trial data supports.”

They continued, “Our observation that patients treated in integrated networks receive lower total doses and fewer fractions suggests that provider characteristics, organizational structures and processes, and/or financial incentives may influence clinical practice. However, further study is necessary to clarify the reasons for the extent of overly intensive care and to develop strategies for bringing evidence and practice into better alignment.” ■

Disclosure: Dr. Jennifer Malin has been compensated for employment or a leadership position at WellPoint. All other authors of the study reported no potential conflicts of interest.

Reference

1. Chen AB, Cronin A, Weeks JC, et al: Palliative radiation therapy practice in patients with metastatic non-small-cell lung cancer. J Clin Oncol. January 7, 2013 (early release online).