Older Patients With Breast Cancer Still Overtreated With RT -- Why?

Pam Harrison

October 11, 2017

ANN ARBOR, Michigan — A large proportion of surgeons in the United States and even a good percentage of radiation oncologists still insist on treating women aged 70 years and older with adjuvant radiotherapy after they undergo lumpectomy for early-stage breast cancer. This is despite overwhelming evidence that adjuvant radiotherapy provides no survival benefit and very little protection against recurrence compared with no radiation.

The finding comes from a nationwide survey of surgeons and radiation oncologists published online in the Annals of Surgical Oncology.

"In the last 30 to 40 years, we've learned the value of doing less," Dean Shumway, MD, University of Michigan, Ann Arbor, said in a statement.

"[But] 60 percent of patients older than age 80 still receive radiation, so the [aim] of this study was to investigate how physicians view the option of omitting radiotherapy, with the goal of understanding more about why practice patterns haven't changed," he added. 

"The finding we didn't expect was that surgeons are generally more uncomfortable with the idea of omitting radiation than radiation oncologists are — it's viewed as a departure from the standard of care — and since the population is aging, this is going to be an issue that affects more women," Dr Shumway indicated.

No Benefit From Radiation  

Two large studies have shown that the addition of radiotherapy has no benefit for most older women who undergo lumpectomy and then endocrine therapy.  

In 2004, the Cancer and Leukemia Group B (CALGB) 9343 trial showed that adjuvant radiotherapy can be safely omitted in women age 70 years and older who have small, estrogen receptor–positive breast cancer treated with lumpectomy and tamoxifen.

Again in 2015, investigators involved in the PRIME II trial reported similar findings in women 65 years of age and older with early breast cancer followed out to 5 years.

In other words, 90% of patients such as those involved in these two trials do not benefit from radiation and do well with lumpectomy alone, provided they take endocrine therapy for 5 years.

"These studies have widely been interpreted as establishing breast-conserving surgery with omission of radiotherapy as a reasonable option for similar women who receive endocrine therapy," Dr Shumway and colleagues write.

And indeed, 96% of radiation oncologists included in the current survey indicated that they were familiar with findings from at least the CALGB 9343 study.

Why No Change in Practice?

To find out why practice has changed so little despite the publication of these two pivotal trials — and despite radiation oncologists seeming to be familiar with them — Dr Shumway and colleagues mailed an eight-page questionnaire to 879 surgeons and 713 radiation oncologists who routinely treat breast cancer in the United States.

"We evaluated physicians' attitudes and general knowledge by asking respondents to rate their agreement with statements such as 'Adjuvant radiation improves survival for elderly patients with early-stage breast cancer treated with lumpectomy'," the investigators note.

They also explored physicians' knowledge and recommendations regarding omission of radiotherapy in older patients with favorable-prognosis breast cancer by using various clinical vignettes.

Results showed that 40% of surgeons and 20% of radiation oncologists felt that omitting radiotherapy after lumpectomy was "unreasonable" (P < .001).

"Nearly a third of surgeons (29%) and 11% of radiation oncologists erroneously associated radiotherapy in older women with improvement in survival," the researchers add.

A "nontrivial minority" of both groups overestimated remaining life expectancy in such patients, while almost a third of surgeons and 19% of radiation oncologists overestimated the risk for locoregional recurrence as being at least 15% after 10 years if radiation therapy were omitted.

Importantly, those who wrongly attributed a survival benefit from radiotherapy and who overestimated remaining life expectancy were more than 6 times more likely to find the omission of adjuvant radiotherapy in this patient population as unreasonable.

Moreover, "one-third of surgeons and radiation oncologists would continue to recommend adjuvant radiotherapy even for an unhealthy 81-year-old," the  investigators write.

Concern Over Legal Liability

Almost half of the surgeons surveyed were concerned about legal liability issues if radiotherapy were omitted and patients subsequently developed a local recurrence, as were about one quarter of radiation oncologists.

Fifteen percent of radiation oncologists were also concerned about the financial repercussions that could occur if they did not offer radiotherapy to this patient population.

Approximately half of radiation oncologists pointed out that it's really a patient's decision to undergo radiotherapy and that patients often want to be treated more aggressively, even if the benefit is small.

Almost half of respondents indicated that it's more effort to convince patients they don't need radiotherapy than it is to recommend it, the investigators add.

As the authors point out, the surgeon is usually the first physician to discuss treatment options with patients with breast cancer and thus is the one most likely to set expectations, including the expectation that radiotherapy will be needed after lumpectomy.

This is why the investigators suggest that targeting surgeons may well be key to reducing aggressive care in older women with early-stage breast cancer.

"Our study provides a detailed view into the physician perspective on how the decision is made to omit radiotherapy and we hope this insight will be useful in improving delivery of individualized care for older women with early-stage breast cancer," Dr Shumway concluded.

This work was supported by a grant from the Conquer Cancer Foundation, the Breast Cancer Research Foundation, and intramural pilot project funding from the Cancer Surveillance and Outcomes Research Team and  by the National Cancer Institute of the National Institutes of Health. Dr Shumway has disclosed no relevant financial relationships.

Ann Surg Oncol. Published online July 26, 2017.  Abstract

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