Efficacy of reduced dose of pegfilgrastim in Japanese breast cancer patients receiving dose-dense doxorubicin and cyclophosphamide therapy.

BACKGROUND: This retrospective study aimed to evaluate the efficacy of a 3.6-mg dose of pegfilgrastim for primary prophylaxis in Japanese breast cancer patients receiving dose-dense chemotherapy. METHODS: Patients treated with adjuvant or neoadjuvant chemotherapy for early-stage breast cancer at the Tokyo-West Tokushukai Hospital were included in this analysis. Because 6 mg pegfilgrastim has not yet been approved for use in Japan, we compared the outcomes of a dose-dense doxorubicin and cyclophosphamide regimen plus 3.6 mg pegfilgrastim support with a conventional dose epirubicin and cyclophosphamide regimen. The incidence of febrile neutropenia, relative dose intensity, dose delay, dose reduction, regimen change and hospitalization because of neutropenia were assessed. RESULTS: From November 2013 to March 2016, 97 patients with stage I-III invasive breast cancer were analyzed (dose-dense doxorubicin and cyclophosphamide plus 3.6-mg pegfilgrastim group, n  =  41; epirubicin and cyclophosphamide group, n  =  56; median ages, 49.0 and 48.5 years, respectively). Febrile neutropenia occurred during the first chemotherapy cycle in 7 of 56 patients (12.5%) in the epirubicin and cyclophosphamide group and 0 of 41 patients in the dose-dense doxorubicin and cyclophosphamide group (P  =  0.02). The average relative dose intensities were 97.9% and 96.8%, respectively (P  =  0.28), with corresponding dose delay rates of 4.9% (2/41) and 16.1% (9/56), respectively (P  =  0.11) and dose reduction rates of 0% (0/41) and 7.1% (4/56), respectively (P  =  0.16). CONCLUSIONS: Our results indicate the efficacy of a 3.6-mg pegfilgrastim dose for the primary prevention of febrile neutropenia in dose-dense doxorubicin- and cyclophosphamide-treated Japanese breast cancer patients.

Impact of young age on local control after partial breast irradiation in Japanese patients with early stage breast cancer.

BACKGROUND: Partial breast irradiation (PBI) is an alternative to whole breast irradiation (WBI) for breast-conserving therapy (BCT). A randomised phase 3 trial demonstrated that PBI using multicatheter brachytherapy had an equivalent rate of local recurrence, disease-free survival, and overall survival as compared to WBI. However, limited data are available on PBI efficacy for young patients with breast cancer. METHODS: We evaluated consecutive patients with Tis-2 (≤ 3 cm) N0-1 breast cancer who underwent BCT. For PBI, patients received radiotherapy using multicatheter brachytherapy in an accelerated manner with a dose of 32 Gy in eight fractions over 5-6 days. For WBI, patients received an external beam radiation therapy that was applied to the entire breast with a total dose of 50 Gy in fractions of 2 Gy for 5 weeks. Two hundred seventy-four patients with 278 lesions received PBI; 190 patients with 193 lesions received WBI. RESULTS: Patients aged <50 years including 98 women with 99 lesions receiving PBI and 85 women with 85 lesions receiving WBI were selected. Ipsilateral breast tumor recurrence rate was 3.0 and 2.4 % by PBI and WBI, respectively (P = 0.99). There was no significant difference in 4-year probability of disease-free survival (97.6 and 91.4 % for PBI and WBI, respectively; P = 0.87). CONCLUSIONS: This is the first report of PBI efficacy in young patients in Asia. Although it is a nonrandomized retrospective chart review of a small cohort of patients with a relatively short follow-up period, PBI may be a better option than WBI following BCS in some young patients with breast cancer.

Comparison of radiation dose to the left anterior descending artery by whole and partial breast irradiation in breast cancer patients.

PURPOSE: Breast conserving surgery (BCS) followed by whole breast irradiation (WBI) is the standard of care for breast cancer patients. However, there is a risk of coronary events with WBI therapy. In this study, we compared the radiation dose in the left anterior descending artery (LAD) in patients receiving partial breast irradiation (PBI) with WBI. MATERIAL AND METHODS: We evaluated consecutive patients who underwent adjuvant radiotherapy after BCS between October 2008 and July 2014. Whole breast irradiation patients received 50 Gy in fractions of 2 Gy to the entire breast. Partial breast irradiation was performed using multicatheter brachytherapy at a dose of 32 Gy in eight fractions. The mean and maximal cumulative doses to LAD were calculated. The radiotherapeutic biologically effective dose of PBI was adjusted to WBI, and radiation techniques were compared. RESULTS: Of 379 consecutive patients with 383 lesions receiving radiotherapy (151 WBI and 232 PBI lesions), 82 WBI and 100 PBI patients were analyzed. In WBI patients, the mean and maximal cumulative doses for left-sided breast cancer (2.13 ± 0.11 and 8.19 ± 1.21 Gy, respectively) were significantly higher than those for right-sided (0.37 ± 0.02 and 0.56 ± 0.03 Gy, respectively; p < 0.0001). In PBI patients with left-sided breast cancer, the doses for tumors in inner quadrants or central location (2.54 ± 0.21 and 4.43 ± 0.38 Gy, respectively) were significantly elevated compared to outer quadrants (1.02 ± 0.17 and 2.10 ± 0.29 Gy, respectively; p < 0.0001). After the adjustment, the doses in PBI patients were significantly reduced in patients with tumors only in outer quadrants (1.12 ± 0.20 and 2.43 ± 0.37 Gy, respectively; p = 0.0001). CONCLUSIONS: Tumor control and dose to LAD should be considered during treatment since PBI may reduce the risk of coronary artery disease especially in patients with lateral tumors in the left breast.

[Factors affecting adherence of breast cancer patients to adjuvant hormonal therapy and validation of the evaluation method].

BACKGROUND: The long-term use of hormonal therapy is important for the treatment of patients with breast cancer. Therefore, we evaluated the methods used for measuring adherence and examined factors that influence compliance. Our goal was to improve overall adherence to the treatment. METHODS: Retrospective analyses by using electronic medical records and questionnaires were performed on 294 patients with breast cancer. The patients were classified into 2 groups based on the mean number of days when a dose was missed over a period of 28 days: group A(range, 0-3 days, n=272)and group B (range, B4 days, n=22). Factors that may influence adherence, including age, duration of hormonal therapy, the drug administered in hormonal therapy, the surgical method, axillary lymph node dissection, and adjuvant chemotherapy, were compared between both groups. RESULTS: The adherence rates calculated from electronic medical records and questionnaires were similar. The proportion of patients younger than 50 years was 30% in group A and 50% in group B(p<0.05). Additionally, there was a difference in the duration of hormone therapy(752 days vs 981 days in groups A and B, respectively; p< 0.05). Additional factors that are related to low-risk cancer-related procedures, such as breast conserving surgery, may also be linked to poor adherence. CONCLUSION: Young age and long duration of hormonal therapy are possibly related to poor adherence. Therefore, pharmacists should identify and manage these patients to increase adherence.

Altered cupular mechanics: a cause of peripheral vestibular disorders?

It has taken many decades to arrive at today's concept of cupula mechanics in the stimulation of endolymphatic flows on the hair cells in the ampullae of the semicircular canal. While Steinhausen assumed free swing-door movement of the cupula in the 1930s, Hillman was the first to demonstrate firm cupula attachment to the ampulla wall as a physiological necessity in the 1970s. In contrast to the present clinical concepts of acute peripheral vestibular functional disorders (circulatory disturbances, viral or bacterial infection, altered electrolytes in the endolymph), this study examines the extent to which an impaired attachment mechanism can trigger peripheral vestibular disorders. For this purpose, we used a pigeon model (n = 8), in which mechanical detachment of the cupula from the ampulla wall was achieved by means of a targeted pressure increase in the ampulla of the lateral semicircular canal. In two additional animals the labyrinth was completely destroyed on one side in order to directly compare partial and complete vestibular disorders. In this way partial damage to the lateral semicircular canal ampulla presents a clinical picture whose symptoms are very similar to those of an idiopathic vestibular disorder in humans. Their intensity and course of compensation differ markedly from the symptoms of complete vestibular destruction. Subsequent histological examination revealed that the hair cells remained intact during the experimental detachment of the cupula. Our results thus show that only altered cupula mechanics seem to trigger the clinical picture of a peripheral vestibular disorder. This may result in completely new approaches to differential diagnosis and the therapy of vestibular neuronitis.