Baseline gut microbiota as a predictive marker for the efficacy of neoadjuvant chemotherapy in patients with early breast cancer: a multicenter prospective cohort study in the Setouchi Breast Project-14.

PURPOSE: Various studies have demonstrated the causal relationship between gut microbiota and efficacy of chemotherapy; however, the impact of gut microbiota on breast cancer has not been fully elucidated. This study aimed to evaluate the associations between the gut microbiota before neoadjuvant chemotherapy and its consequent efficacy in breast cancer. METHODS: This prospective observational study included patients who received neoadjuvant chemotherapy for primary early breast cancer at eight institutions between October 1, 2019, and March 31, 2022. We performed 16S rRNA analysis of fecal samples and α and ß diversity analyses of the gut microbiota. The primary endpoint was the association between the gut microbiota and pathological complete response (pCR) to neoadjuvant chemotherapy. RESULTS: Among the 183 patients, the pCR rate after neoadjuvant chemotherapy was 36.1% in all patients and 12.9% (9/70), 69.5% (41/59), and 29.6% (16/54) in those with the luminal, human epidermal growth factor receptor 2, and triple-negative types, respectively. The α diversity of the gut microbiota did not significantly differ between patients with pCR and those without pCR. Among the gut microbiota, two species (Victivallales, P = 0.001 and Anaerolineales, P = 0.001) were associated with pCR, and one (Gemellales, P = 0.002) was associated with non-pCR. CONCLUSION: Three species in the gut microbiota had potential associations with neoadjuvant chemotherapy efficacy, but the diversity of the gut microbiota was not associated with response to chemotherapy. Further research is needed to validate our findings.

Lung Oligometastasis of Breast Cancer: Prospective Cohort Study of Treatment Strategies (SBP-06).

While local treatment of metastases is considered to be unrelated to prognosis, previous studies have suggested that local treatment of isolated lung metastases may have positive prognostic impact. We designed this prospective cohort study to investigate the clinical situation and its outcomes. We enrolled patients with fewer than 3 lung nodules suspected of being oligometastases after curative breast cancer surgery. Treatments, including local and systemic therapy, were selected by the physician and patient in consultation. The primary outcome was overall survival (OS); secondary outcomes were the efficacy and the safety of the surgery for lung oligometastases. Between May 2015 and May 2019, 14 patients were enrolled. Resection of lung nodules (metastasectomy) was performed in 11 (78.6%) of 14 patients, and one of these cases was diagnosed as primary lung cancer. Metastasectomies were all performed employing video-assisted thoracic surgery (VATS) without perioperative complications. Systemic therapies were administered to all patients except one. The respective 3-year and 5-year OS rates of patients with lung oligometastases were 91.6% and 81.5%, respectively. Progression occurred in 6 patients: 3 of the 10 with metastasectomy and all 3 without this surgical procedure. Lung metastasectomy was worthwhile as a diagnostic evaluation and may provide long-term benefit in some patients.

The effect of exercise and educational programs for breast cancer patients on the development of breast cancer-related lymphoedema: secondary endpoint from a randomized controlled trial in the Setouchi Breast Project-10.

BACKGROUND: Although the association between higher physical activity and preventive effect on breast-cancer-related lymphoedema (BCRL) has been reported, it is unclear what intervention is optimal. We aimed to investigate the effect of exercise and educational programs on BCRL development. METHODS: This study was a secondary endpoint analysis from a prospective randomized controlled trial. We enrolled patients with stage 0-III breast cancer from March 2016 to March 2020 and randomly assigned them to the control (n = 111), education (n = 115), or exercise (n = 104) group. As secondary endpoint, we assessed the incidence of and preventive effect on BCRL at 12 months post-intervention. RESULTS: There were no significant differences in the incidence of BCRL at 12 months post-intervention between the exercise and control groups (9.8% and 10.8%, P = 0.83) and the education and control groups (11.6% and 10.8%, P = 1.00). There were no significant differences in time to BCRL onset from the day of surgery between the exercise and control groups (event rate at 12 months: 20.7% and 17.2%, log-rank, P = 0.54) and the education and control groups (18.8% and 17.2%, log-rank, P = 0.57). The multivariable analyses indicated that axillary dissection and obesity significantly increased the risk of BCRL [hazard ratio (HR): 2.36, 95% confidence interval (CI) 1.52-3.67 and HR: 1.68, 95% CI 1.07-2.63, respectively]. CONCLUSIONS: The intervention did not decrease the risk of BCRL, and axillary dissection and obesity were the risk factors of BCRL. TRIAL REGISTRATION NUMBER: UMIN000020595 at UMIN Clinical Trial Registry.