PATIENTS AND METHODS
Case records of women with localized breast cancer treated in our center over a 4-year period were retrospectively reviewed. Further information was collected from records of patients with localized breast cancer who received docetaxel treatment in the adjuvant or neoadjuvant setting. Data on patients’ age, menopause status, body surface area (BSA), clinical presentation, biologic characteristics of the tumors, comorbidities, and concomitant medications were recorded. BSA is calculated from the height and weight of patients and forms the basis for calculation of the dose of the chemotherapy administered in each patient. Data on the chemotherapy treatment regimen (ie, 5-fluorouracil, epirubicin, cyclophosphamide-docetaxel [FEC-D] with or without trastuzumab), number of cycles, docetaxel dose, use of granulocyte colony-stimulating factor (G-CSF), and patient recorded pain (Edmonton Symptom Assessment Scale [ESAS] or other reported pain in a scale or descriptive manner in a medical or nursing note) associated with chemotherapy cycle were also extracted.
A total of 102 breast cancer patients who received docetaxel in the (neo)adjuvant setting from 2011 to 2015 were identified. After initial review, 26 patients were excluded because of incomplete documentation of adverse effects in their records, leaving 76 patients for further chart evaluation. Nine patients were further excluded because of the presence of a chronic pain syndrome antecedent to chemotherapy and with no increase after docetaxel use or because of first use of G-CSF concomitant with the first docetaxel cycles, making assertion or exclusion of docetaxel-associated M-AS impossible. Thus, 67 patients were included in this review (Figure 1).
Pain evaluations were performed using the ESAS. ESAS is a valid and reliable assessment tool for the assessment of nine common symptoms experienced by cancer patients.4 Pain, graded on a scale of 0 (no pain) to 10 (worst possible pain), is one of the symptoms assessed on the ESAS tool and was used in combination with descriptive clinical assessments for determining the development of taxane-induced M-AS. Patients’ ESAS scores for pain were recorded at each cycle of their FEC and docetaxel treatment. Patients were considered to have the M-AS if they developed musculoskeletal pain of more than 3 in the scale in the absence of previous pain or if their pain increased for at least two numbers in the scale if pain was present before the docetaxel administration (eg, due to previous G-CSF use).
The effectiveness of treatment of M-AS was based on a combination of decreased ESAS pain scores from Cycle 4 to Cycle 5, as well as additional clinical documentation provided in the chart notes of treatment efficacy or reduced pain in subsequent cycles. The effectiveness of treatment was defined as complete if there was a disappearance of pain or decrease to mild (ESAS Scores 1–3) if initially severe (ESAS Scores 7–10). Partial effectiveness was defined as decrease of the pain intensity from severe to moderate (ESAS Scores 4–6) or from moderate to mild.
The χ2 test was used for the statistical comparison of categorical variables in the two groups of patients, ie, without M-AS (control) and with M-AS. The two-tailed t-test was used for comparison of means of continuous variables. Statistics were performed using calculators available online (http://www.socscistatistics.com and http://graphpad.com).
The study has been approved by the Ethics Committee of Sault Area Hospital, Ontario, Canada. In view of the retrospective nature of the study, no individual patient consent was required.