Elderly patients especially those in excess of years of age
Elderly patients, especially those in excess of 70 years of age, are often quite fragile; such fragility may be secondary to aging or comorbidity. In this “susceptible” patient population, the negative influence of ET-adverse events on patient adherence to a medication regimen can be elevated. This may occur because the drug toxicities could more significantly impact elderly patients with a declining quality of life, compared with the general population. Therefore, the tolerance of and adherence to adjuvant oral endocrine therapy has become an important issue as we continue to treat this patient population and hopefully improve survival. However, there has been limited literature discussing this topic. Therefore, we retrospectively analyzed the completion of and tolerance to adjuvant oral endocrine therapy in elderly early breast cancer patients in a single medical center in Taiwan.
Methods and materials The pathologic diagnosis of HR-positive primary breast cancer was confirmed by pathologists, based on the customary criteria at that time. Axillary ionomycin node sampling or dissection could be performed depending upon the surgeon\'s judgment. Additionally, adjuvant chemotherapy would be recommended if a high risk of recurrence was involved. The choice of chemotherapy regimens, such as modified CMF or anthracycline-based regimens, was also dependent on the decision of each physician. Adjuvant radiotherapy would be suggested if certain factors were present including partial mastectomy, >3 positive lymph node involvement, positive surgical margins, tumor size ≥5 cm or skin involvement. Oral endocrine therapy was given for patients with HR-positive breast tumors, and the choice of tamoxifen or AI again was based on the decision of the physician. Furthermore, administration of adjuvant treatment, including chemotherapy, radiotherapy and ET, would be discussed with the patients and their families. We obtained the ages of the patients, the year of diagnosis, TNM stage, status of ER, PR and HER2 and histologic grading from primary chart review. The duration of oral endocrine therapy, causes of discontinuation, and the switches of medications were also recorded. Data was summarized as N (%) for categorical variables, and medians with interquartile ranges (IQR; 25–75%) for continuous characteristics. We used the Chi-square test to compare parameters between different subgroups, and Fisher\'s exact test for comparisons with small event numbers. Statistic assessments were considered as significance when the p value was less than 0.05. SPSS 22.0 software (SPSS Inc., Chicago, USA) was used for statistic analysis.
Results A total of 269 female elderly patients over the age of 70 were registered and diagnosed with HR-positive operable primary breast cancer, with a median age of 75 (IQR 72–78). The median follow-up period was 76.4 months. Only 88 patients (32.7%) had no known systemic underlying diseases. One hundred and ninety-four patients (72.1%) had both positive ER and PR, and 55 patients (20.4%) had positive ER but negative PR. There were 21 patients (7.8%) who showed positive PR but negative ER. Other patients\' baseline characteristics, including the year of diagnosis, TNM stage, HER2 status and histologic grading, were shown in Table 1.
The completion rate and the time of discontinuation of oral endocrine therapy in elderly patients One hundred and thirty-three patients took a complete course of oral adjuvant ET. The completion rate of adjuvant oral ET was 49.4% in the intention-to-treat patients in our study, which would increase to 56.7% if only patients willing to initiate ET were taken into account. Neither patients with a larger tumor size (T2-T4), positive lymph node involvement, higher histologic grade (grade 2/3), positive HER2 status, known systemic disease, of younger age, nor a complete adjuvant chemotherapy showed a significantly higher completion rate (p = 0.08, 0.46, 0.27, 0.12, 0.50, 0.46, and 0.87, respectively, using the Chi-square test). However, patients with a completed adjuvant radiotherapy presented with a significantly higher rate of a complete ET: 58.8% versus 27.4, p = 0.04. Ninety-eight patients (37.4%) had an ET duration of less than 5 years, 64 patients (24.8%) took oral endocrine agents less than two years, and 38 patients (14.1%) never initiated medication at all (Table 2).