The efficacy of neoadjuvant chemotherapy and survival in older patients with stages II to III triple-negative breast cancer

Background. Breast cancer (BC) maintains the leading position in the structure of the morbidity and mortality from malignancies. Triple-negative BC (TNBC) is the most aggressive subtype among all types of BC. The adequate and timely initiation of neoadjuvant chemotherapy (NAC) determines the further prognosis of the disease in case of early and locally advanced TNBC. Patients over 60 years old are the special subgroup, but it has not been previously considered separately. Aim. To determine the efficacy of NAC and survival in elderly patients with stages II to III TNBC. Materials and methods. Since 2014, 92 patients with histologically verified early and locally advanced TNBC have received NAC, followed by surgery ± adjuvant therapy. NAC was conducted under the following scheme: cisplatin 75 mg/m2 on day 1, paclitaxel 80 mg/m2 on days 1, 8 and 15 of 28-day cycle, for six cycles. After the end of NAC, patients underwent surgery and a follow-up assessment of the degree of therapeutic pathomorphism in the primary tumor and regional lymph nodes. Further on, the correlation analysis was carried out between clinical characteristics and the degree of therapeutic pathomorphism. Results. We analyzed the data from the 92 patients, 22 (23.9%) patients of them were in older age group. At the time of disease diagnosis, the patients older than 60 years of age had a greater involvement of regional lymph nodes (N3: 40.9% vs. 20.0%, p<0.05). Women older than 60 years of age received statistically and significantly less volume of the planned NAC (65.7% vs. 22.7%, p<0.05). This could be due to the significantly more frequent toxicity: nephropathy (54.5% vs 17.1%, p<0.05) and polyneuropathy (22.7% vs. 17.1%, p=0.054). We noted the lower frequency of the achieving complete clinical (28.6% vs. 41.4%, p=0.654) and pathomorphological response (51.6% vs 71.7%, p<0.05), that could be associated with both late diagnosis of the disease and incomplete volume of planned NAC. The local progression (45.5% vs. 22.9%, p<0.05), as well as the visceral metastases (36.4% vs. 17.1%, p<0.05) were more common identified characteristics in women older than 60 years of age. Women older than 60 years of age had worse survival rate (both, relapse-free and overall survival, p<0.05). We also received data concerning different localizations of metastasis in patients of different age groups: the predominant lesion of the central nervous system (50%) in patients younger than 60 years of age and liver damage (40%) in patients 60 years of age and older. Conclusions. The results of our analysis show significant differences in the efficacy, tolerability and long-term results of the treatment of older patients and require the conversion of the views on the course of the disease in patients over 60 years of age.

triple-negative breast cancer, elderly age, neoadjuvant chemotherapy, complete pathomorphism, prognosis for triple-negative breast cancer