Abstract P1-17-06: Long-term incidence of taxane induced peripheral neuropathy in early breast cancer patients, a real world, single centre experience exploring effects on health related quality of life
Authors: Blackley Elizabeth F , Kesper Megan G , Savas Peter , Devitt Bianca 
Published: March 2020

Abstract
Background: Addition of taxanes to adjuvant chemotherapy provides survival benefit in patients with early breast cancer (EBC). Intensifying adjuvant regimens with taxanes leads to increased toxicity, including higher rates of sensory peripheral neuropathy (sPN).
Prevalence of chemotherapy induced peripheral neuropathy (CIPN) in trials varies with reported rates of 15 - 30%. Up to 15% of patients report persistent CIPN 1-3 years post treatment with associated adverse impact on quality of life (QOL). There is limited data reporting rates of CIPN and QOL beyond 3 years. We assessed rates of persistent sPN in real world patients with EBC treated with adjuvant taxanes and its effect on QOL.
Methods: Patients who received adjuvant taxane for EBC at a metropolitan health service in the preceding 10 years were identified from hospital records and invited to participate. Data was collected at a single time point using the EORTC Quality of Life (QLQ30) and Chemotherapy-Induced Peripheral Neuropathy (CIPN20) questionnaires. Demographic, co-morbid and treatment details were collected from medical records.
Raw scores were linearly transformed to a 0 to 100 scale with higher scores indicating higher functioning, QOL and levels of symptomatology. Prevalence was determined using a binary model of no or any sPN and cases grouped into no/mild or moderate/severe for further analysis. Groupwise comparisons were performed with parametric and non-parametric tests. Analysis of covariance was used to fit models incorporating comorbid factors such as diabetes with time point of assessment as the covariate.
Results: 176 of 250 questionnaires were returned, a response rate of 71%. Median age was 59 (range 30-88 years) with 52% of respondents receiving paclitaxel vs 47% docetaxel containing regimens. Median time from completion of taxane was 30 months (range 6-120 months). 11 patients (6%) had known diabetes and 50 (26%) had at least one other known risk factor for neuropathy.
The prevalence of CIPN across all time points was 74.4%, much higher than seen in historical trials.
Table 1: Incidence of sensory neuropathy (all grades) by time from chemotherapyTime bracket (months)N= (176)PN (%)No PN (%)6-246352 (82.5)11 (17.5)25-486347 (74.6)16 (25.4)49-1205032 (64%)18 (36%)
QOL scores were lower in patients with moderate/severe sPN, with a median global QOL scaled score of 50 vs 75 in patient with no/mild sPN (p = 0.0062). Increasing sPN score was associated with lower QOL score controlling for time from chemotherapy (standardised beta co-efficient -0.28).
In an analysis of covariance, diabetes was the only significant comorbid factor associated with higher sPN scores. In the final model incorporating diabetes, miscellaneous other sPN risk factors and time from chemotherapy, diabetes was associated with increased sPN scores with a small effect size (p = 0.03).
Paclitaxel was associated with higher sPN scores than docetaxel (p 0.0001) with significant interaction of paclitaxel with diabetes independent of other sPN risk factors and time from chemotherapy (p = 0.02). Paclitaxel was associated with higher sPN scores in diabetic patients (adjusted mean score in diabetic patients 46.7 v 20.9 in non-diabetic receiving paclitaxel, p = 0.001).
Conclusion: CIPN is significantly more prevalent in this real world cohort than reported in historic data, with persistent sPN having a negative correlation with QOL out to 10 years. Higher rates of paclitaxel-associated sPN in diabetic patients could inform decision making on adjuvant chemotherapy.
Citation Format: Elizabeth F Blackley, Megan G Kesper, Peter Savas, Bianca Devitt. Long-term incidence of taxane induced peripheral neuropathy in early breast cancer patients, a real world, single centre experience exploring effects on health related quality of life [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 P1-17-06.