Fox Chase Cancer Center researchers have presented preliminary results of a clinical trial in which women received a two-week shorter course of radiation therapy than the current standard following a lumpectomy. The study was presented at the annual Charles A. Coltman Jr. San Antonio Breast Cancer Symposium.
Radiation therapy daily for six or seven weeks after a lumpectomy is the standard course of treatment for many women with breast cancer who have had breast-sparing surgery, called a lumpectomy.
"The length of time for radiation treatment is a major inconvenience to many women," said Gary Freedman, M.D., a radiation oncologist at Fox Chase Cancer Center and lead author of the study. "For some, it is a barrier that leads them to choose mastectomy instead of breast conservation."
In an effort to reduce the burden of treatment on women, Freedman and his colleagues at Fox Chase Cancer Center are studying a four-week course of radiation using IMRT (intensity-modulated radiation therapy) with an incorporated boost. A boost is a higher dose of radiation given to the site of the original tumor where the lumpectomy was done. This boost usually prolongs the radiation one to two weeks. In this phase II trial, the boost is given each day during the same four weeks the breast is treated.
At the San Antonio meeting, Freedman presented data on skin toxicity, or the effect the radiation has on the skin. Thirty-eight patients have completed radiation. Researchers have collected date from 28 women six weeks after the completion of treatment. The median age of the patients in the study was 55.
The toxicity to the skin was measured using a terminology called grades. Zero is the lowest level of side effects. Grade 1 is mild redness or dryness of the skin, and grade 2 is more moderate or severe redness from radiation or moist peeling of the skin folds of the breast. Grade 3 represents more severe skin reactions.
By the end of treatment week four, six patients (16%) had a grade 0 toxicity, 26 (68%) patients had grade 1 toxicity and six (16%) patients had grade 2 toxicity. There was no grade 3 or higher skin toxicity. Six weeks after radiation, the grade 2 skin toxicity was resolved for all women.
"Our study shows that IMRT for four weeks does cause side effects to the skin, but the level is milder than expected and considered acceptable," explained Freedman. "What's more, these results are comparable to the side effects seen in studies of conventional six-weeks of radiation."
Data is also being collected on tumor recurrence, cosmesis and quality of life.
"This radiation schedule may represent an alternative both to longer six- to seven-week standard whole-breast radiation and the more radically shortened one-week partial-breast treatment schedules," Freedman said.