A British research study followed more than 2,000 women for five years has found that targeting the tumor site, rather than the entire breast, was just as effective for women with early stage ductal breast cancer.
The results (open data) were published in The Lancet.
The participants were aged 50 years or older and had undergone breast-conserving surgery for unifocal invasive ductal adenocarcinoma of grade 1–3: tumor of 3 cm or less (pT1–2), zero-to-three positive axillary nodes (pN0–1), and minimum microscopic margins of non-cancerous tissue of 2 mm or more.
The three groups:
- 674 patients were analysed in the whole-breast radiotherapy (control) group
- 673 in the reduced-dose group
- 669 in the partial-breast group
The primary outcome measure was local relapse. The study assumed a 2·5% incidence of local relapse at five (5) years with whole-breast radiotherapy.
After a median follow-up of 72·2 months (IQR 61·7–83·2), local relapse had been reported for 18 patients, nine (1%) of whom were in the whole-breast group, three (<1%) in the reduced-dose group, and six (1%) in the partial-breast group… Four regional relapses were reported: one in the whole-breast group, one in the reduced-dose group, and two in the partial-breast group…
Our 5-year results confirm that local relapse was scarce across all trial groups and that non-inferiority was shown for both partial-breast and reduced-dose radiotherapy.
Original source: The Telegraph (2 August 2017)