Critically short telomeres and toxicity of chemotherapy in early breast cancer

// Miguel Quintela-Fandino 1 , Nora Soberon 2 , Ana Lluch 3 , Luis Manso 4 , Isabel Calvo 5 , Javier Cortes 6, 7 , Fernando Moreno-Antón 8 , Miguel Gil-Gil 9 , Noelia Martinez-Jánez 7 , Antonio Gonzalez-Martin 10 , Encarna Adrover 11 , Raquel de Andres 12 , Gemma Viñas 13 , Antonio Llombart-Cussac 14 , Emilio Alba 15 , Silvana Mouron 1 , Juan Guerra 16 , Begoña Bermejo 3 , Esther Zamora 6 , Jose Angel García-Saenz 8 , Sonia Pernas Simon 9 , Eva Carrasco 17 , María José Escudero 17 , Ruth Campo 17 , Ramón Colomer 18 , Maria A. Blasco 2 1 Breast Cancer Clinical Research Unit, CNIO-Spanish National Cancer Research Center, Madrid, Spain 2 Telomeres and Telomerase Group, Molecular Oncology Programme, CNIO-Spanish National Cancer Research Center, Madrid, Spain 3 Medical Oncology Department, Hospital Clinico Universitario, Valencia, Spain 4 Medical Oncology Department, Hospital 12 de Octubre, Madrid, Spain 5 Medical Oncology Department, Hospital de Montepríncipe, Madrid, Spain 6 Medical Oncology Department, Hospital Vall d´Hebron, Barcelona, Spain 7 Medical Oncology Department, Hospital Ramón y Cajal, Madrid, Spain 8 Medical Oncology Department, Hospital Clinico San Carlos, Madrid, Spain 9 Medical Oncology Department, Institut Catala d'Oncologia-IDIBELL, L'Hospitalet de Llobregat, Barcelona, Spain 10 Medical Oncology Department, MD Anderson Cancer Center, Madrid, Spain 11 Medical Oncology Department, Hospital General de Albacete, Albacete, Spain 12 Medical Oncology Department, Hospital Lozano Blesa, Zaragoza, Spain 13 Medical Oncology Department, Institut Catala d'Oncologia-Hospital Dr. Josep Trueta, Girona, Spain 14 Medical Oncology Department, Hospital Arnau de Vilanova, Valencia, Spain 15 Medical Oncology Department, Hospital Clínico Universitario Virgen de la Victoria, Málaga, Spain 16 Medical Oncology Department, Hospital Universitario de Fuenlabrada, Fuenlabrada, Spain 17 GEICAM, Madrid, Spain 18 Medical Oncology Department, Hospital Universitario La Princesa, Madrid, Spain Correspondence to: Miguel Quintela-Fandino, email: mquintela@cnio.es Maria A. Blasco, email: mblasco@cnio.es Keywords: telomere length, critically short telomeres, breast cancer, weekly paclitaxel, toxicity Received: October 25, 2016 Accepted: January 27, 2017 Published: February 21, 2017 ABSTRACT Cumulative toxicity from weekly paclitaxel (myalgia, peripheral neuropathy, fatigue) compromises long-term administration. Preclinical data suggest that the burden of critically short telomeres (< 3 kilobases, CSTs), but not average telomere length by itself, accounts for limited tissue renewal and turnover capacity. The impact of this parameter (which can be modified with different therapies) in chemotherapy-derived toxicity has not been studied. Blood from 115 treatment-naive patients from a clinical trial in early HER2-negative breast cancer that received weekly paclitaxel (80 mg/m2 for 12 weeks) either alone or in combination with nintedanib and from 85 healthy controls was prospectively obtained and individual CSTs and average telomere lenght were determined by HT Q-FISH (high-throughput quantitative FISH). Toxicity was graded according to NCI common toxicity criteria for adverse events (NCI CTCAE V.4.0). The variable under study was “number of toxic episodes” during the 12 weeks of therapy. The percentage of CSTs ranged from 6.5%–49.4% and was directly associated with the number of toxic events (R 2 = 0.333; P < 0.001). According to a linear regression model, each 18% increase in the percentage of CSTs was associated to one additional toxic episode during the paclitaxel cycles; this effect was independent of the age or treatment arm. Patients in the upper quartile (> 21.9% CSTs) had 2-fold higher number of neuropathy ( P = 0.04) or fatigue ( P = 0.019) episodes and >3-fold higher number of myalgia episodes ( P = 0.005). The average telomere length was unrelated to the incidence of side effects. The percentage of CSTs, but not the average telomere size, is associated with weekly paclitaxel-derived toxicity.