The most common dose limiting toxicity (DLT) associated with paclitaxel is axonal sensorineural peripheral neuropathy (PN). PN is likely caused by disruption of microtubules within the axons to peripheral nerves. (Hasmats, 2012) PN can impair quality of life and functional capacity and a major concern is the unpredictable time course of PN onset and duration. (Mustafa 2017). Our objective was to identify if there are factors that pre-dispose patients to experiencing PN as a result of paclitaxel.
We identified patients from the chemotherapy booking database who had received paclitaxel chemotherapy between 1/1/2015 and 31/12/2017. Using the electronic medical record system we were able to identify patients that met the following inclusion criteria, female diagnosed with Stage I-III breast cancer who received neoadjuvant or adjuvant weekly paclitaxel. We recorded time (weeks) till developing PN that required dose modification, interruption or cessation and number of cycles of paclitaxel completed. We also established patients' modifiable and non modifiable factors that may correlate with increased risk of PN including smoking status, ethnicity(Asian, White, Black, European, Pacific Island), age, medical co-morbidities of rheumatalogical or neurological condition and diabetes. A Multi variant analysis was then performed to assess for statistically significant factors modifying a patient's risk of developing PN.
Our study identified 127 patients that met the inclusion criteria and of these patients, 72 (56.7%) required dose modification/cessation/interruption due to PN, with only 8 of these patients proceeding to complete 12 cycles of Paclitaxel. The median time till developing PN requiring cessation of Paclitaxel was 11 weeks.
The group that was significantly impacted by PN and completed 9 or less cycles consisted of 44 patients; 7 (15.9%) were aged less than 40, 22 (50%) were of caucasian/european ethnicity, 7 (15.9%) had a pre-existing diagnosis of diabetes, 11 (25%) were current or recent ex-smokers.
There was no statistically significant correlation between PN and the identified modifiable and non-modifiable risk factors, in all groups, assessed by multi variant analysis.
In our center 50.4% of patients with ESBC do not complete 12 cycles of paclitaxel due to PN. No clear association with modifiable or non-modifiable factors was identified. The only correlation between developing PN was number of cycles completed which is consistent with published data. (Tnabe, 2013)