Accelerated partial breast irradiation (APBI) using multicatheter brachytherapy in patients with early-stage breast cancer was not inferior to conventional whole breast irradiation (WBI), according to a phase III study presented at the 2015 American Society for Radiation Oncology (ASTRO) Annual Meeting.

The long-term follow-up results showed that the rates of overall survival (OS), disease-free survival (DFS), and local control among patients who underwent APBI were comparable with results in whole breast irradiation.

The multicenter, European, noninferiority study is the first phase III trial proving noninferiority of APBI compared with WBI for select patients with early-stage breast cancer. To date, it is the most comprehensive study comparing these techniques.

“The results of our study show that, at present, multicatheter brachytherapy is an attractive and viable APBI treatment option for low-risk breast cancer patients after breast-conserving surgery,” said lead author Vratislav Strnad, MD, PhD, professor of Radiation Oncology at University Hospital Erlangen, Germany, who presented the results at ASTRO.

From April 2004 to July 2009, the multicenter phase III study enrolled 1184 patients from 16 centers in Europe. Patients had early-stage breast cancer (stages 0, I, and IIa), were aged 40 years or older, and treated with breast-conserving surgery. Patients were randomized to conventional WBI (50 Gy with tumor bed boost of 10 Gy for about 7 weeks) or APBI using interstitial multicatheter brachytherapy for 5 days. Median age was 62 years, and about 50% of patients were younger than 60 years.

Baseline disease and demographic factors were similar for the two groups. At a median follow-up of 6.6 years, 5-year local recurrence rates were 1.4% for APBI versus 0.9% for WBI; 5-year second primary ipsilateral breast cancers were found in 1.1% versus 0.9%, respectively; 5-year DFS rates were 95% versus 94.5%, respectively; 5-year OS rates were 97.3% versus 95.6%, respectively. Local and regional recurrence rates were similar between the two cohorts for all age groups and all tumor types independent of the type of subsequent therapies that patients received.

“The results were not totally surprising, because...results of several smaller phase II trials showed low recurrence rates after breast-conserving surgery and APBI in comparison to WBI,” said Strnad.

“What is surprising, however, is how clear the results are. Our favorable results are in contrast to the disappointing and controversial results reported from other studies that used other APBI techniques, such as intraoperative and external-beam radiation therapy.”

Standard WBI uses external-beam radiation and treats the entire breast and surrounding chest area for several weeks, followed by a boost of radiation to the tumor bed. Many women choose mastectomy in hopes of avoiding WBI, largely due to the duration of treatment and fears of side effects, Strnad said.

APBI with multicatheter brachytherapy delivers effective radiation dose directly to the tumor, shortening the time of treatment to 4 or 5 days, while limiting side effects of radiation exposure to normal adjacent tissue in the heart, lungs, and skin. The shortened time to treatment with APBI is particularly attractive for elderly patients, working women, and women who travel distances to a radiation treatment facility, he explained.

Strnad noted that prior recommendations were for APBI to be used in older patients—those aged older than 50 or 60 years, but this study showed excellent results in all age groups, including those aged 40 years and older. Longer follow-up is needed to analyze recurrence rates beyond 5 years in different subgroups based on age, according to Strnad.

Catherine C. Park, MD, professor and chair, Department of Radiation Oncology, University of California, San Francisco, who moderated the press conference where the data were presented, commented that the patients in this study were highly selected and that APBI was studied with several techniques.

“In the United States, multicatheter brachytherapy is not widely available," Park explained. "External-beam radiation is the most widely used technique for partial breast radiation."

Strnad V. Accelerated partial breast irradiation using sole interstitial multicatheter brachytherapy versus whole breast irradiation for early breast cancer: 5-year results of a randomised phase III trial — Part I: Local control and survival results. Presented at: 2015 ASTRO Annual Meeting; October 18-21, 2015; San Antonio, TX. Abstract LBA 7.

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Accelerated partial breast irradiation (APBI) using multicatheter brachytherapy in patients with early-stage breast cancer was not inferior to conventional whole breast irradiation (WBI), according to a phase III study presented at the 2015 American Society for Radiation Oncology (ASTRO) Annual Meeting.


Partial Breast Irradiation as Effective as Conventional Therapy

Two studies presented at SABCS refined knowledge about how to prevent lymphedema in patients with breast cancer. In one study, manual lymph node drainage (MLD) failed to prevent lymphedema, whereas exercise was beneficial. A second study showed that a progressive weight-lifting program was effective in preventing lymphedema.

	Lymphedema, the buildup of fluids that can develop in fatty tissues of the arm, breast, or chest after surgery or radiation therapy, cannot be cured once it starts, according to the American Cancer Society. As a result, the ACS emphasizes strategies aimed at preventing lymphedema from developing and recognizing early signs of swelling so that steps can be taken to control it.

	Lead author Nele Devoogdt, MD, University Hospitals Leuven, Belgium, said clinicians recommend different modalities for preventing lymphedema, such as avoiding lymph restriction, preventing weight gain, and exercise. 

	“In Belgium, we use MLD, as well, and no study thus far has evaluated it on its own,” she said. MLD is similar to massage therapy, but the skin is stretched to improve resorption of lymph and to increase lymph transport, creating a pathway from axilla to axilla from the affected arm to the healthy arm.

	“Manual lymph drainage applied immediately after axillary lymph node dissection was not effective in preventing lymphedema, while exercise initiated immediately after surgery will prevent it,” said Devoogdt.

	An earlier study showed that the combination of information and exercise therapy was more effective at preventing lymphedema than taking no measures, and a second study found that the combination of information, exercise therapy, and MLD was better than taking no measures to prevent lymphedema.

	In the current study, researchers enrolled 160 women scheduled to undergo axillary lymph node dissection on one side. Their arms were measured prior to surgery. The women were randomized to receive a combination of guidelines or information on preventing lymphedema, exercise therapy, and MLD (n = 79) or a combination of guidelines and exercise but no MLD (n = 81).

	Devoogdt said the guidelines were presented during exercise therapy. A total of 29 exercise sessions were given, and MLD was performed 1 to 3 times per week following exercise for an average of 34 sessions. After surgery, arm volume was measured at months 1, 3, 6, and 12. Patients who developed lymphedema had the affected arm bandaged and wore an elastic sleeve.

	At all time points, more patients in the group receiving MLD developed lymphedema. At 3 months, 7% of patients in the MLD arm had lymphedema versus 5% in the non-MLD arm; at 6 months, rates of lymphedema were 12% versus 10%, respectively; and at 12 months, 23% of patients who underwent MLD had lymphedema compared with 18% of patients who did not. The time it took for patients to develop arm lymphedema was similar in both groups, as was the increase in arm volume, assessments of mental and physical quality of life, and functional problems, Devoogdt said.

	 “This study is a good addition to what has been a data-free zone,” said Hiram S. Cody, III, MD, Memorial-Sloan Kettering Cancer Center, New York, New York, who moderated the session.

	A second study presented at the symposium showed that weightlifting might help prevent lymphedema after treatment for breast cancer. Kathryn Schmitz, PhD, of the University of Pennsylvania’s Abramson Cancer Center, Philadelphia, previously reported that exercise limits lymphedema symptoms. In the new study of 154 breast cancer survivors without lymphedema, a slowly progressive weight-lifting program reduced the risk of developing lymphedema by 35% over 1 year.

	With the weight-lifting program, only 11% of women developed lymphedema versus 17% of women in the control group who did not change their typical level of physical activity. The effects of the weight-lifting intervention were even more robust among women who had ≥5 lymph nodes surgically removed; these women had a nearly 70% reduction in lymphedema, with 7% of the weight-lifting group versus 22% of the control arm experiencing lymphedema.

	These findings contradict the common assumption that women should avoid lifting anything heavier than 5 pounds after cancer treatment. The key to the weight-lifting program in this study is that it was slowly progressive. Participants enrolled at a fitness center for 1 year and attended twice-weekly 90-minute sessions for 13 weeks.

	Sessions were led by certified fitness professionals, who explained how to use free weights and machines. The weights were increased slowly for each exercise if there was no change in arm symptoms. For the remaining 49 weeks, participants exercised independently. They were monitored monthly for changes in arm circumference and self-reported any new symptoms each week.

	In summarizing what this study means, Schmitz noted that lymphedema is a common yet dreaded consequence of breast treatment. “Women worry that they will recover from cancer only to be plagued by this condition that limits their ability to function at home and work. Our study shows that they now have a weapon to reduce their risk of lymphedema and at the same time reap the many other health rewards of weight lifting that they may have missed out on due to decades of advice to avoid lifting so much as a grocery bag or their purse,” she said. 

Two studies presented at SABCS refined knowledge about how to prevent lymphedema in patients with breast cancer.

Bonnie Gillis

Articles

Partial Breast Irradiation as Effective as Conventional Therapy

Exercise, Weight-Lifting Help in Preventing Lymphedema