Relative dose intensity of the neoadjuvant chemotherapy in elderly patients with breast cáncer.

Intensidad de dosis relativa de la quimioterapia neoadyuvante en pacientes ancianas con cáncer de mama.

Background: Breast cancer is the most frequent malignant tumor in the world. People older than 65 years represent a group, which gathers most of the deaths and survivors of this disease. It has been published previously that elderly people often receive a suboptimal cancer treatment. Objetive: Describe dose intensity of the neoadjuvant chemotherapy in the elderly people, the factors that modify this parameter or the consequences of having suboptimal dose intensity. Methods: This is an observational study descriptive retrospective of breast cancer patients older than 65 years old that received neoadjuvant chemotherapy in the Instituto Nacional de Cancerología between 2013 and 2015. We did a medical record review and estimated the summation dose intensity with the previously published Hryniuk’s formula. We also did an exploratory bivariate analysis to find conditions that could modify the dose intensity value. Results: Between august of 2013 and september of 2015, 72 patients were included. 44.4% of the patients presented in stage IIIB. The most frequent used chemotherapy scheme was AC-T in 45.8% of cases. El 38.8% reached the threshold of 85% or more. The global pathological complete response was of 16.39%. The biggest pathological response was in patient with overexpression of HER2 the response was 23.5%, and the triple negative subgroup was 23% and luminal was 11.36%. Conclusion: Our study supports the fact that elderly people often receive a suboptimal antineoplastic treatment. We couldn’t demonstrate a demographic or clinic factor that could influence the dose intensity of this population, nevertheless we found a trend towards a lower complete pathological response in the lowest dose intensities especially in the most chemo sensitive tumors.