Shorter, stronger radiation course works in noninvasive breast cancer
Accelerated external-beam radiotherapy is a viable treatment option for ductal carcinoma in situ (DCIS), suggest recent study results.
The current standard of treatment for DCIS, an early-stage and noninvasive form of breast cancer, is lumpectomy followed by 5 to 6 weeks of whole breast radiation, affirmed a statement from the American Society for Radiation Oncology (ASTRO) that accompanied the latest research findings. The use of an accelerated form of radiation that increases the strength of the dose per treatment throughout fewer treatment sessions has been well-established as effective against invasive breast cancers, but not against DCIS.
Silvia C. Formenti, MD, a radiation oncologist at New York University School of Medicine, New York, New York, and colleagues conducted two consecutive clinical trials to determine whether accelerated radiation treatment would garner good results in women with DCIS. The team's findings were published in ASTRO's International Journal of Radiation Oncology, Biology, Physics (2012;83:e159-e164).
The first trial used whole breast irradiation of 42 Gy (2.8 Gy in 15 fractions), and the second trial used whole breast irradiation of 40.5 Gy (2.7 Gy in 15 fractions) with an additional daily boost of 0.5 Gy to the surgical cavity. Between 2002 and 2009, 59 women were enrolled in the first protocol and 86 in the second after undergoing lumpectomy. Median age was 56 years, and 65% of the women were postmenopausal at the time of treatment.
At 5 years' median follow-up (range, 2.6 to 105.5 months), only six patients (4.1%) experienced ipsilateral breast recurrence. In three of those women, the cancer recurred at the original DCIS site. New contralateral breast cancers arose in three cases (one DCIS and two invasive carcinomas).
The recurrence rate was comparable to the recurrence rate of 5% to 10% recorded in randomized trials for patients receiving standard radiation.
Of 125 women providing cosmetic self-assessment at least 2 years after treatment, 91% reported good-to-excellent outcomes and 9% reported fair-to-poor outcomes.