RADIATION THERAPY BENEFITS SOME OLDER PATIENTS WITH BREAST CANCER

Clinicians might want to offer radiation therapy to some older women (70 to 79 years of age) with early breast cancer because it lowers the risk for recurrence and subsequent mastectomy, according to a new American observational study.

The study of women in a "real-world" setting shows a benefit for radiation therapy after lumpectomy in this older patient population. This finding is in contrast to findings from a previous clinical trial, which prompted clinical guidelines to no longer recommend radiation therapy in this group.

The study, published online August 13 in Cancer, showed that at 10 years, radiation therapy was associated with a lower absolute risk for mastectomy in the same breast, compared with no radiation therapy (3.2% vs 6.3%).

This translates into a statistically significant relative reduction of two thirds in the risk for subsequent mastectomy (hazard ratio, 0.33; P < .001).

Most of the women (87.6%) in the 7403-patient cohort, derived from the Surveillance, Epidemiology, and End Results (SEER)–Medicare database, were treated with radiation therapy. A small percentage of the total population had a recurrence; only 174 patients (2.4%) underwent mastectomy in the same breast after initial surgery during the study period (1992 to 2002), which had a median follow-up of 7.2 years.

These findings led the study authors to conclude that radiation therapy is "associated with a greater likelihood of ultimate breast preservation for most older women with early breast cancer."

The study did not assess overall survival. Instead, it was designed to determine whether adjuvant radiation therapy reduced the risk for mastectomy in women with stage I estrogen-receptor (ER)-positive breast cancer.

In effect, the study is an analysis of radiation therapy in routine practice. The use of radiation therapy in older women with early breast cancer was also studied in the major clinical Cancer and Leukemia Group (CALGB) 9343 trial.

In that randomized trial, radiation therapy resulted in a statistically nonsignificant 50% relative reduction in the risk for subsequent mastectomy. The absolute risk at 10 years was 4% for those who did not receive radiation therapy, compared with 2% for patients who did receive radiation therapy. There was no significant difference in survival between the 2 groups.

On the basis of the CALGB findings, the influential National Comprehensive Cancer Network (NCCN) adjusted its treatment guidelines, and now no longer recommends radiation therapy after lumpectomy in older women with ER-positive early breast cancer who are receiving endocrine therapy.

However, Benjamin Smith, MD, from the University of Texas M.D. Anderson Cancer Center in Houston, lead author of the current study, stopped short of saying the NCCN guidelines need to be reversed.

"I think the national guidelines, while well intended and important, may gloss over the certain nuances needed for making critical decisions with patients," he said in a press statement. "Our study may shed additional light on some of those nuances, and provides data that physicians can use when talking to their patients about whether to go forward with radiation."

Dr. Smith and his coauthors also acknowledge that randomized trials such as CALGB 9343 are "the gold standard of clinical evidence." But they point out that such trials "often do not have sufficient power to permit meaningful subgroup analyses, making it difficult to determine which subgroups of patients are more or less likely to benefit from the therapy under consideration."

The study authors suspect that there are differences between a "motivated clinical trial population" and the "general population" of women with ER-positive early breast cancer. For example, poor compliance with endocrine therapy is "common" in the general population, the authors report. Thus, they hypothesized (correctly) that radiation therapy would be even more beneficial in routine practice than it was in the CALGB trial.

Selecting Patients

The findings from the current study, with its subset analyses of clinicopathologic features, can help clinicians identify which patients are more or less likely to benefit from radiation therapy, suggest the authors.

For instance, in subset analyses, the study authors found that radiation therapy provided no benefit for patients 75 to 79 years of age without high-grade tumors who had a pathologic lymph node assessment (P = .80); however, for all other subgroups, radiation therapy was associated with an absolute reduction in risk for mastectomy that ranged from 4.3% to 9.8% at 10 years.

Which patient groups are more likely to benefit?

The study authors highlighted several groups, including patients with high-grade early breast cancers, who had a 6.7% absolute reduction in the 10-year risk for mastectomy; patients who undergo the less sophisticated clinical lymph node assessment (4.9% absolute reduction); and any patient 70 to 74 years of age (3.8% absolute reduction). These types of patients had some of the most pronounced benefits from radiation therapy, followed by most patients with other clinicopathologic features.

This study is not the only recent effort on radiation therapy in older women with early breast cancer by the study authors.

They recently published a paper on a nomogram that converts clinical data into estimates of mastectomy-free survival, as reported by Medscape Medical News (J Clin Oncol. 2012;30: 2837-2843). The tool aims to help clinicians refine their advice about radiation therapy to older women with early breast cancer.

In an editorial that accompanied the nomogram paper (J Clin Oncol. 2012;30:2809-2811), an expert suggested that nomograms might be a step forward in the ongoing effort to refine decision making about radiation therapy in this setting.

However, the nomogram needs validation, said David Wazer, MD, from the Tufts University School of Medicine in Boston, Massachusetts, and the Alpert Medical School of Brown University in Providence, Rhode Island.

In the meantime, Dr. Wazer advised clinicians to check out the modeling tool on the IBTR! Web site, which predicts 10-year risk for in-breast recurrence both with and without radiation therapy. The modeling tool, which uses clinical trial (randomized and not) data but not observational study data, is the "most reliable" of the available risk-assessment tools, he said.

A portion of this study was funded by a research grant from Varian Medical Systems. The study was also supported by the Department of Health and Human Services and the National Cancer Institute. The authors have disclosed no relevant financial relationships. Dr. Wazer reports being a consultant to Advanced Radiation Therapy.

BOUTIS SPEAKING-IMAGING IN ADVANCED CANCER

The use of high-cost diagnostic imaging "steadily increased" in Medicare patients with advanced cancers from 1995 to 2006, which raises concerns about overuse in this setting, according to a new study.

In the second half of the study period (2002 to 2006), the use of scanning was especially zealous, with 95.9% of patients undergoing a high-cost diagnostic imaging procedure and an average of 9.79 scans per patient, despite their limited survival times, report the study authors, led by Yue-Yung Hu, MD, MPH, from Brigham and Women's Hospital in Boston, Massachusetts.

The analysis, which was restricted to patients with stage IV breast, colorectal, lung, or prostate cancer, waspublished online July 31 in the Journal of the National Cancer Institute.

The types of scans analyzed were computed tomography, magnetic resonance imaging, positron emission tomography, and nuclear medicine.

The increasing use of big-ticket scans is not simply the result of vulnerable patients being overscanned, suggest a pair of experts in an accompanying editorial"The use of high-cost imaging found in this study may seem excessive," write K. Robin Yabroff, PhD, and Joan L. Warren, PhD, from the National Cancer Institute in Bethesda, Maryland. "Yet, assessing the appropriateness of care for patients with advanced disease is complex."

Part of the problem, say the editorialists, is that guidelines in the United States are "largely silent about the use of advanced imaging tests for ongoing evaluation" of patients with these advanced cancers "in the absence of symptoms."

This is in stark contrast to guidelines for early-stage disease, which make recommendations about "when to use (and when not to use)" advanced imaging for surveillance, they write.

Not surprisingly, the study authors found that from 1995 to 2006, the proportion of stage IV cancer patients imaged increased by 4.6% and the proportion of early-stage (stages I and II) cancer patients imaged decreased by 2.5%.

Evidence-based guidelines for these newer imaging technologies are needed, the editorialists assert. This is especially true because there is "limited evidence that advanced imaging improves patient outcomes, compared with older less expensive technologies," they note, referring to ultrasound and radiograph.

Nevertheless, guidelines can be developed.

In the United Kingdom, the National Institute for Clinical Excellence has issued "do not do" recommendations for some high-cost imaging in patients with advanced cancer, the editorialists report.

In their study, Dr. Hu and colleagues shed some light on the current situation in the United States.

It does not appear that physicians with financial incentives to scan are running up medical bills. In a previous study (Health Aff. 2008;27:1491-1502), increases in advanced imaging were observed in managed care, where there is no profit motive, according to the editorialists. Thus, the trend toward increased use is probably a combination of the "widespread availability of imaging machines, malpractice concerns, patient demand, and critically, the technological imperative," they write.

Costs for Imaging Rising Faster Than for Total Cancer Care

The study authors were inspired to review patterns of use in the United States because previous research found that "Medicare expenditures for high-cost diagnostic imaging have risen faster than those for total cancer care."

Dr. Hu and colleagues reviewed claims data from the Surveillance, Epidemiology, and End Results (SEER)–Medicare database for the 4 types of big-ticket scans. They found more than 100,000 patients diagnosed with stage IV breast, colorectal, lung, or prostate cancer during the study period.

They looked at imaging performed during 3 periods of time during the course of the disease: the diagnostic period, the last month of life, and the continuing-care phase (the interval between the diagnosis period and the last month of life).

The majority of patients with stage IV cancer received advanced imaging in the diagnostic (90.4%) and continuing-care (75.3%) phases. About a third of patients received advanced imaging in the last month of life (34.3%).

The purposes of scanning in the continuing-care phase of advanced care are "more diverse" than in the other 2 phases, according to the editorialists.

Imaging results can inform decisions about the continuation or modification of treatment, symptom management, and hospice referral, they write. "The incremental benefits of advanced imaging compared with older less expensive technologies for informing clinical decisions may vary for each of these different purposes," they add.

"In situations where high-cost imaging is used to evaluate response to third- or fourth-line therapies, evaluation of appropriateness extends to the decision to continue treatment of patients with poor prognoses," the editorialists explain.

Thus, identifying the appropriateness of advanced imaging for these clinical decisions requires a better understanding of how imaging can improve care, the editorialists explain. In other words, there is much work to be done in this field.

Despite many areas of concern, there is some good news, say the editorialists. In 2009 and 2010, the period after that evaluated by Dr. Hu and colleagues, the use of high-cost imaging for Medicare beneficiaries has declined slightly, according to recent report on Medicare payment policy.