Survival outcome and reduction rate of Ki-67 between pre- and post-neoadjuvant chemotherapy in breast cancer patients with non-pCR.

The research question of this investigation is whether the reduction rate of Ki-67 after neoadjuvant chemotherapy (NAC) could indicate a survival in patients with non-pCR. A total of 455 patients had received NAC, and subsequent surgery was analyzed retrospectively. Patients with non-pCR were divided into three subgroups according to Ki-67 change: High-reduction (the absolute value of Ki-67 was reduced by >80 % compared with that prior to NAC), Low-reduction (the absolute value of Ki-67 was reduced by 0-80 % compared with that prior to NAC), and Increase group (the absolute value of Ki-67 was increased compared with that prior to NAC). The relapse-free survival (RFS) rates were compared among subgroups. pCR was achieved in 93 patients (20.4 %). In patients with non-pCR, the median reduction rate of Ki-67 was 60 %. A total of 15 % of patients were in the High-reduction, 63 % in the Low-reduction, and 22 % in the Increase group. The median follow-up period was 64.5 months. The 5-year RFS rates among the three groups were significantly different (p < 0.0001), and the differences were also observed in the HER2 (p = 0.033), triple-negative (p = 0.034), and luminal-like subtypes (p = 0.001). Patients in the High-reduction group showed comparable RFS to that of patients with pCR (p = 0.363). In patients with non-pCR, the reduction rate of Ki-67 after NAC significantly predicted RFS regardless of cancer subtypes. Therefore, patients who are non-pCR but who achieve a high reduction of Ki-67 can be expected to have a favorable prognosis similar to that of patients with pCR.

Disseminated Carcinomatosis of the Bone Marrow from Occult Breast Cancer Responding to a Sequence of Endocrine Therapy.

Patients with cancer of unknown primary (CUP) are generally treated with chemotherapy. Bone marrow involvement suggests an advanced stage, and CUP with disseminated carcinomatosis of the bone marrow (DCBM) appears to have a dismal prognosis. However, our case of CUP with DCBM was successfully treated with a sequence of endocrine therapy over a long period. A woman presenting with low back pain was found to have multiple bone metastasis without an identifiable primary tumor on imaging studies. Blood tests revealed anemia and thrombocytopenia. A bone marrow biopsy was performed and showed relatively uniform small cells, strongly positive for estrogen receptor and progesterone receptor expression. We considered chemotherapy to be risky due to bicytopenia and an aromatase inhibitor, letrozole, was initiated. The patient's symptoms and laboratory findings gradually improved and bone lesions almost disappeared on FDG-PET/CT after 1 year of treatment. After 2 years on letrozole, hemoglobin levels and platelet counts had been gradually decreasing. Although she had no symptoms and no significant changes were observed on a CT scan, disease progression was highly likely. Thus, second-line treatment with fulvestrant and palbociclib was commenced, and hemoglobin levels and platelet counts were restored to within the normal ranges. She currently continues to receive fulvestrant and palbociclib over a year later. CUP complicated with DCBM might be metastatic occult breast cancer, and endocrine therapy can be a valuable treatment option if tumors express hormone receptors.