Breast Cancer Research最新文献

Background: Accelerated partial breast irradiation (APBI) has shown non-inferior local control compared to whole breast irradiation, but the optimal external-beam regimen is unclear. This study compares two APBI schedules used at our institution: 38.5 Gy in 10 twice-daily fractions and 28.5 Gy in 5 once-daily fractions delivered every other day.

Methods: This retrospective, single-institution study includes post-menopausal women with ductal carcinoma in-situ (DCIS) and early-stage hormone receptor positive invasive breast cancer who underwent lumpectomy followed by APBI and endocrine therapy. Outcomes of interest include ipsilateral breast tumor recurrence (IBTR), disease-free survival (DFS), overall survival (OS), radiation toxicities (graded by CTCAE v5.0), and physician-reported (Harvard scale) cosmetic outcomes.

Results: A total of 399 patients were eligible: 142 in the 38.5 Gy group and 257 in the 28.5 Gy group. The median age was 66 years. Most patients had T1 tumors or DCIS (97.4%), were treated with 3D-conformal radiation (99.2%) in the prone position (96.0%), and initiated adjuvant endocrine therapy (86.0%). With a median follow-up of 3.4 years, 3-year IBTR was low and comparable (1% for 38.5 Gy vs. 2% for 28.5 Gy; P = 0.46). Three-year DFS was 99% vs. 98% (P = 0.79) and OS was 99% in both groups (P = 0.53). For acute toxicity, grade 1-2 dermatitis was significantly more common in the 38.5 Gy group (61.7% vs. 28.6%, P < 0.01). For late toxicity at 1-year post-treatment, grade 1-2 skin hyperpigmentation (79.5% vs. 32.4%, P < 0.01) and fibrosis (81.6% vs. 51%, P < 0.01) were significantly more common in the 38.5 Gy group than 28.5 Gy group, respectively. No grade ≥ 3 acute or late toxicities were observed. Cosmetic outcomes were similarly excellent. At 1 year, excellent or good cosmesis was observed in 99% of patients in the 38.5 Gy group and 98% in the 28.5 Gy group (P = 0.15), and at 3 years in 97.3% and 94.1%, respectively (P = 0.83).

Conclusions: Both regimens-38.5 Gy in 10 twice-daily fractions and 28.5 Gy in 5 once-daily fractions-delivered using 3D-conformal technique in the prone position yielded excellent 3-year outcomes. Nonetheless, the 28.5 Gy regimen demonstrated a lower incidence of acute and late toxicity and may be preferable in this patient population given its lower skin toxicity and increased convenience. Longer follow-up is warranted to confirm these findings.

Background: Oestrogen-receptor positive breast cancer patients are typically treated with adjuvant endocrine therapy (AET), some develop AET resistance. Previous research suggests mammographic density (MD) may represent an imaging biomarker, with fewer local or distant recurrences occurring with decreasing MD. We investigate whether reduction in MD after 1 and/or 3 years is associated with improved breast cancer specific survival (BCSS), metastasis-free survival (MFS) or disease-free survival (DFS).

Methods: This retrospective cohort study was generated from a Mammo-50 trial subset. Participants taking AET (cases) and controls were included. MD was assessed in the AET group using a 0-100% visual analogue scale (VAS). Readers scored mammograms at diagnosis, 1 year and 3 years post-surgery. A decrease in MD was defined as ≥10% reduction from diagnosis. A second reader reviewed paired mammograms and assessed whether there had been a temporal change in MD.

Results: Data from 1364 cases and 367 controls were included. Median VAS MD was approximately 30% for cases and controls at all time-points; 20% showed decreased MD at 1 year and 21% at 3 years for both cases and controls. Of the AET group, 23 died from breast cancer and 33 developed metastases during follow-up (median 8.7 years post-surgery). The 5-year BCSS rate was 99.6% (95%CI:97.4-99.9) versus 98.3% (95%CI:97.2-98.9) for those with and without a ≥10% reduction in MD at 1 year, p=0.35. The 5-year MFS rate for those with and without a ≥10% reduction in MD at 1 year was 94.2% (95%CI:90.7-96.4) versus 93.6% (95%CI:92.0-95.0) respectively; p=0.47. The 5-year DFS rate for those with a ≥10% reduction in MD at 1year was 92.4% (95% CI:88.5-94.9) versus 92.6% (95%CI:90.8-94.0); p= 0.47. Similar results for BCSS, MFS and DFS were seen for those with and without a ≥10% reduction in MD at 3 years and for those assessed as having a definite reduction in MD compared to those who had not at both 1 and 3 years.

Conclusion: Reduction in MD had no significant association with rates of BCSS, MFS or DFS. Change in MD was not shown to be a useful prognostic indicator in women over 50 years, treated with AET.