Abstract P6-11-07: Impact of chemotherapy on the health related quality of life among elderly patients with localized breast cancer: Findings from the prospective CANTO cohort

Abstract Background: The incidence of breast cancer (BC) increases with age. However, there appears to be a trend that elderly patients with BC receive less than the standard treatment compared to younger ones and this leads to poorer outcomes. The aim of this work was to assess whether chemotherapy has a differential impact on the health related quality of life (HRQOL) of elderly patients with BC, compared to younger ones. Methods: CANTO (NCT 01993498) is a multicenter prospective observational study (26 centers in France) whose main objective is to study the chronic toxicities of anticancer treatments in 12,000 women with localized stages I to III BC. HRQOL was assessed at baseline and at the end of acute treatments (surgery +/- radiotherapy +/- chemotherapy) using the EORTC-QLQ-C30 questionnaire and its BC specific module, the EORTC-QLQ-BR23. HRQOL at the end of acute treatments of patients aged 70 and over treated by chemotherapy was compared to that of the youngest ones. Multivariable mixed linear model was used to assess the determinants of HRQOL for the dimensions with minimal clinically important differences; defined as a mean difference of at least 5 points in HRQOL scores; between younger and older patients. Results: 3079 patients were included in the CANTO cohort from March 2012 to December 2014 and treated by chemotherapy. The mean age at diagnosis was 53 years and 7.3% of this population was ≥70 years old. Older and younger patients treated by chemotherapy were similar for the disease stage at diagnosis (p=0.7869), the tumor histology (p=0.07), the SBR grade (p=0.2350) and the HER2 status (p=0.4268). However, elderly patients treated by chemotherapy were more likely to be overweight (p<0.0001), with lower general health status (p=0.0001), had more comorbidities (p=0.0001). Elderly had shorter duration of treatment by chemotherapy (p<0.004) and were less often treated with taxanes regimens (p<0.0001). At the end of the treatment, the proportion of patients with at least one toxicity (p=0.58), toxicities at the general (p=0.82), cutaneous (p=0.77) or gastro-intestinal levels (p=0.88), did not differ between younger and older patients. However elderly had more neurological (p=0.003) and arterio-veinous (p<0.0001) toxicities with more frequent dose reduction (p=0.01). At the end of acute treatments, HRQOL was similar for 18 of the 23 dimensions of EORTC-QlQ-C30 and EORTC-QlQ-BR23 questionnaires between older patients and younger ones. A more pronounced deterioration in the elderly, between end of treatment HRQOL scores and baseline HRQOL scores, was seen for the appetite loss (Mean Difference (MD) = +9.65) and upset by hair loss (MD= +16) symptoms scale. However, body image (MD=8.75), dyspnea (MD= -6.98) and financial difficulties (MD= -7.08) were less deteriorated in elderly. In multivariable analyses, after adjustment on comorbidities, the stage of the disease, the tumor histology, the type of chemotherapy, the occurrence of toxicities and dose reduction, age was not an independent predictive factor of HRQOL for body image, dyspnea, appetite loss, upset by hair loss and financial difficulties. Conclusions: results of this study did not show a differential impact of chemotherapy on the HRQOL of elderly BC patients compared to the younger ones. Citation Format: Sandrine Dabakuyo Yonli, Oumar Billa, Olivia Dialla, Florence Joly, Sarah Dauchy, Charles Cecile, Cedric Lemogne, Patrick Soulie, Marie-Ange Mouret-Reynier, Carole Tarpin, Mario Campone, Sophie Guillermet, Jean-Marc Ferrero, Sylvie Giacchetti, Florence Lerebours, Suzette Delaloge, Anne-Laure Martin, Sibille Everhard, Charles Coutant, Fabrice Andre, Patrick Arveux. Impact of chemotherapy on the health related quality of life among elderly patients with localized breast cancer: Findings from the prospective CANTO cohort [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P6-11-07.