Investigation of genotoxicity risk and DNA repair capacity in breast cancer patients using anastrozole.

OBJECTIVE: Breast cancer is the most common cancer in women worldwide and the incidence increases in postmenopausal women. Anastrozole is a non-steroidal (type II), third-generation aromatase inhibitor (AI) that is used in the treatment of postmenopausal estrogen-related breast cancer. Several studies have been conducted to assess the efficacy, safety, and superiority of AIs to tamoxifen; however, a literature search did not reveal a study that investigated the genotoxic potential of AIs. The aim of this study was to investigate the possible DNA damage risk profile and individual DNA repair capacity of patients using anastrozole with the modified alkaline comet assay in order to contribute to public health and health economics. METHODS: Women diagnosed with breast cancer after menopause comprised the study group. Six patients who had taken anastrozole for at least 6 months were retrospectively enrolled, and 12 patients who had not yet received treatment were prospectively enrolled as a control group. Peripheral blood lymphocytes were used to measure oxidized DNA damage using formamidopyrimidine DNA-glycosylase (FPG) and endonuclease III (endo III) in a modified comet assay. Individual DNA repair capacity was evaluated with the comet assay after a hydrogen peroxide (H2O2) challenge to examine the difference in DNA damage susceptibility. RESULTS: Analysis of DNA damage, oxidative base damage, susceptibility to DNA damage, and repair capacity revealed no significant difference between the control group and the patients taking anastrozole (p>0.05). Susceptibility to H2O2 damage was observed to increase with age (p<0.05). CONCLUSION: According to the results obtained in this study, anastrozole did not contribute to oxidative DNA damage. An H2O2 challenge with the comet assay is useful to evaluate circumstances of increased vulnerability to damage, such as aging and cancer.

Decreased DNA repair gene XRCC1 expression is associated with radiotherapy-induced acute side effects in breast cancer patients.

DNA repair plays a critical role in response to ionizing radiation (IR) and developing of radiotherapy induced normal tissue reactions. In our study, we investigated the association of radiotherapy related acute side effects, with X-ray repair cross complementing group 1 (XRCC1) and Poly (ADP-ribose) polymerase 1 (PARP1) DNA repair gene expression levels, their changes in protein expression and DNA damage levels in breast cancer patients. The study included 40 women with newly diagnosed breast cancer; an experimental case group (n=20) with acute side effects and the control group (n=20) without side effects. For gene and protein expression analysis, lymphocytes were cultured for 72 h and followed by in vitro 2 Gray (Gy) gamma-irradiation. For detection of DNA damage levels, lymphocytes were irradiated with in vitro 2 Gy gamma-rays and followed by incubation for 72 h. XRCC1 mRNA and protein expression levels were significantly higher in controls than in experimental cases (P=0.020). In terms of DNA damage levels, an increased frequency of micronucleus (MN) was observed in experimental cases versus controls, but this association was not significant (P=0.206). We also observed a significant negative correlation between MN frequency and XRCC1 protein levels in experimental (r=-0.469, P=0.037) vs control (r=-0.734, P<0.001). Our results suggested that decreased XRCC1 expression levels might be associated with the increased risk of therapeutic IR-related acute side effects in patients with breast cancer.

A cross-sectional survey of the diagnosis and management of bone metastasis in breast cancer patients in Turkey.

PURPOSE: This study aimed to report the practice of managing breast cancer with bone metastasis in Turkey and to determine the adherence to the British Association of Surgical Oncology (BASO) guidelines. METHODS: This multicenter, cross-sectional epidemiological survey was conducted in 38 centers across Turkey. Data from 1,026 breast cancer patients with bone metastases (mean age 54.0 ± 11.9 years) were analyzed. RESULTS: Over 30 % of patients had a diagnosis of metastatic breast cancer (stage IV) at the time of primary diagnosis. The imaging modalities used for diagnosing bone metastases were bone scintigraphy (57.8 %), radiography (22.8 %), and bone survey (4.4 %). Tumor markers were detected in 94.9 %, and markers of bone metabolism were measured in 90.4 % of patients. A total of 3.5 % of patients underwent surgery for bone metastasis, 26.4 % underwent palliative chemotherapy (most commonly docetaxel + capecitabine), and 56.5 % endured radiotherapy. Most patients (96 %) also received bisphosphonate. Radiography, bone scintigraphy, and CT were the main imaging tools used for postoperative follow-up of bone metastasis. Our results were >95 % in line with the BASO guidelines for the management of bone metastasis, except that interventional procedures, such as biopsy, were applied less frequently in our survey. CONCLUSIONS: The diagnosis and management practices of breast cancer with bone metastasis in Turkey were generally compatible with international guidelines. However, the awareness and knowledge of physicians on the current guidelines should be increased, and equipment for the appropriate interventional procedures should be provided in every clinic to obtain optimal and standard management of bone metastases.

Guideline implementation for breast healthcare in low- and middle-income countries: treatment resource allocation.

A key determinant of breast cancer outcome is the degree to which newly diagnosed cancers are treated correctly in a timely fashion. Available resources must be applied in a rational manner to optimize population-based outcomes. A multidisciplinary international panel of experts addressed the implementation of treatment guidelines and developed process checklists for breast surgery, radiation treatment, and systemic therapy. The needed resources for stage I, stage II, locally advanced, and metastatic breast cancer were outlined, and process metrics were developed. The ability to perform modified radical mastectomy is the mainstay of locoregional treatment at the basic level of breast healthcare. Radiation therapy allows for consideration of breast-conserving therapy, postmastectomy chest wall irradiation, and palliation of painful or symptomatic metastases. Systemic therapy with cytotoxic chemotherapy is effective in the treatment of all biologic subtypes of breast cancer, but its provision is resource intensive. Although endocrine therapy requires few specialized resources, it requires knowledge of hormone receptor status. Targeted therapy against human epidermal growth factor receptor 2 (anti-HER-2) is very effective in tumors that overexpress HER-2/neu receptors, but cost largely prevents its use in resource-limited environments. Incremental allocation of resources can help address economic disparities and ensure equity in access to care. Checklists and allocation tables can support the objective of offering optimal care for all patients. The use of process metrics can facilitate the development of multidisciplinary, integrated, fiscally responsible, continuously improving, and flexible approaches to the global enhancement of breast cancer treatment.

Breast radiation therapy guideline implementation in low- and middle-income countries.

Radiation therapy plays a critical role in the management of breast cancer and often is unavailable to patients in low- and middle-income countries (LMCs). There is a need to provide appropriate equipment and to improve the techniques of administration, quality assurance, and use of resources for radiation therapy in LMCs. Although the linear accelerator is the preferred equipment, telecobalt machines may be considered as an acceptable alternative in LMCs. Applying safe and effective treatment also requires well trained staff, support systems, geographic accessibility, and the initiation and completion of treatment without undue delay. In early-stage breast cancer, standard treatment includes the irradiation of the entire breast with an additional boost to the tumor site and should be delivered after treatment planning with at least 2-dimensional imaging. Although postmastectomy radiation therapy (PMRT) has demonstrated local control and overall survival advantages in all patients with axillary lymph node metastases, preference in limited resource settings could be reserved for patients who have >or=4 positive lymph nodes. The long-term risks of cardiac morbidity and mortality require special attention to the volume of heart and lungs exposed. Alternative treatment schedules like hypofractionated radiation and partial breast irradiation currently are investigational. Radiation therapy is an integral component for patients with locally advanced breast cancer after initial systemic treatment and surgery. For patients with distant metastases, radiation is an effective tool for palliation, especially for bone, brain, and soft tissue metastases. The implementation of quality-assurance programs applied to equipment, the planning process, and radiation treatment delivery must be instituted in all radiation therapy centers.

Effects of prolongation of overall treatment time due to unplanned interruptions during radiotherapy of different tumor sites and practical methods for compensation.

The prescribed total radiation dose should be administered within a specific time. In daily clinical practice, however, unplanned treatment interruptions resulting in prolongation of the overall treatment time are predictable. The present review evaluated the existing published data regarding the affect of the prolongation of the overall treatment time on the tumor control rate and outcome of patients with head-and-neck, lung, and uterine cervical cancer and other treatment sites. In most studies, including the planned interruption (split-course) schedules, as well as the retrospective studies analyzing the role of overall treatment time, a detrimental effect from the treatment break on the outcome was evident. This is suggestive of the deleterious effect of accelerated repopulation of tumor clonogens. In particular for the cancers of the head and neck for which the evidence is the strongest for such a consequence, even a 1-day interruption resulted in a decrease in the local control rate by 1.4%. Although the increased number of gaps was associated with a negative outcome, the data are contradictory concerning the effect of the number of gaps. The main recommendation is to exert all efforts to retain the planned irradiation schedule; however, existing data have shown that interruptions that effect the programmed time-course for irradiation need to be compensated for. This is to ensure biologic equivalence in treatment efficacy compared with uninterrupted regimens with respect to cancer site and stage. Practical methods for compensation using radiobiologic modeling and their limitations are also discussed.

Skeletal muscle: an unusual site of distant metastasis in gastric carcinoma.

UNLABELLED: Gastric cancer metastatic to skeletal muscle is an unusual entity. Surgery, systemic chemotherapy, or radiotherapy to the metastatic mass can be treatment options for achiving palliation. CASE REPORT: A patient with multiple skeletal muscle metastases that occurred during follow-up after gastrectomy and adjuvant chemo-radiotherapy is reported. Magnetic resonance imaging (MRI) demonstrated soft-tissue masses involving the posterior right paralumbar and posterior left paradorsal muscles. Biopsy showed metastatic infiltrating adenocarcinoma. The patient did not respond to palliative chemotherapy. Palliative radiotherapy was administered to the painful mass. Based on this case, the diagnosis of muscle metastases and treatment options for palliation are discussed.

Breast cancer in limited-resource countries: an overview of the Breast Health Global Initiative 2005 guidelines.

Breast cancer is the most common cause of cancer-related death among women worldwide, with case fatality rates highest in low-resource countries. Despite significant scientific advances in its management, most of the world faces resource constraints that limit the capacity to improve early detection, diagnosis, and treatment of the disease. The Breast Health Global Initiative (BHGI) strives to develop evidence-based, economically feasible, and culturally appropriate guidelines that can be used in nations with limited health care resources to improve breast cancer outcomes. Using an evidence-based consensus panel process, four BHGI expert panels addressed the areas of early detection and access to care, diagnosis and pathology, treatment and resource allocation, and health care systems and public policy as they relate to breast health care in limited-resource settings. To update and expand on the BHGI Guidelines published in 2003, the 2005 BHGI panels outlined a stepwise, systematic approach to health care improvement using a tiered system of resource allotment into four levels-basic, limited, enhanced, and maximal-based on the contribution of each resource toward improving clinical outcomes. Early breast cancer detection improves outcome in a cost-effective fashion assuming treatment is available, but requires public education to foster active patient participation in diagnosis and treatment. Clinical breast examination combined with diagnostic breast imaging (ultrasound +/- diagnostic mammography) can facilitate cost-effective tissue sampling techniques for cytologic or histologic diagnosis. Breast-conserving treatment with partial mastectomy and radiation therapy requires more health care resources and infrastructure than mastectomy, but can be provided in a thoughtfully designed limited-resource setting. The availability and administration of systemic therapies are critical to improving breast cancer survival. Estrogen receptor testing allows patient selection for hormonal treatments (tamoxifen, oophorectomy). Chemotherapy, which requires some allocation of resources and infrastructure, is needed to treat node-positive, locally advanced breast cancers, which represent the most common clinical presentation of disease in low-resource countries. When chemotherapy is not available, patients with locally advanced, hormone receptor-negative cancers can only receive palliative therapy. Future research is needed to better determine how these guidelines can best be implemented in limited-resource settings.

Breast cancer in limited-resource countries: treatment and allocation of resources.

Treating breast cancer under the constraints of significantly limited health care resources poses unique challenges that are not well addressed by existing guidelines. We present evidence-based guidelines for systematically prioritizing cancer therapies across the entire spectrum of resource levels. After consideration of factors affecting the value of a given breast cancer therapy (contribution to overall survival, disease-free survival, quality of life, and cost), we assigned each therapy to one of four incremental levels--basic, limited, enhanced, or maximal--that together map out a sequential and flexible approach for planning, establishing, and expanding breast cancer treatment services. For stage I disease, basic-level therapies are modified radical mastectomy and endocrine therapy with ovarian ablation or tamoxifen; therapies added at the limited level are breast-conserving therapy, radiation therapy, and standard-efficacy chemotherapy (cyclophosphamide, methotrexate, and 5-fluorouracil [CMF], or doxorubicin and cyclophosphamide [AC], epirubicin and cyclophosphamide [EC], or 5-fluorouracil, doxorubicin, and cyclophosphamide [FAC]); at the enhanced level, taxane chemotherapy and endocrine therapy with aromatase inhibitors or luteinizing hormone-releasing hormone (LH-RH) agonists; and at the maximal level, reconstructive surgery, dose-dense chemotherapy, and growth factors. For stage II disease, the therapy allocation is the same, with the exception that standard-efficacy chemotherapy is a basic-level therapy. For locally advanced breast cancer, basic-level therapies are modified radical mastectomy, neoadjuvant chemotherapy (CMF, AC, or FAC), and endocrine therapy with ovarian ablation or tamoxifen; the therapy added at the limited level is postmastectomy radiation therapy; at the enhanced level, breast-conserving therapy, breast-conserving whole-breast radiation therapy, taxane chemotherapy, and endocrine therapy with aromatase inhibitors or LH-RH agonists; and at the maximal level, reconstructive surgery and dose-dense chemotherapy and growth factors. For metastatic or recurrent disease, basic-level therapies are total mastectomy for ipsilateral in-breast recurrence, endocrine therapy with ovarian ablation or tamoxifen, and analgesics; therapies added at the limited level are radiation therapy and CMF or anthracycline chemotherapy; at the enhanced level, chemotherapy with taxanes, capecitabine, or trastuzumab, endocrine therapy with aromatase inhibitors, and bisphosphonates; and at the maximal level, chemotherapy with vinorelbine, gemcitabine, or carboplatin, growth factors, and endocrine therapy with fulvestrant. Compared with the treatment of early breast cancer, the treatment of advanced breast cancer is more resource intensive and generally has poorer outcomes, highlighting the potential benefit of earlier detection and diagnosis, both in terms of conserving scarce resources and in terms of reducing morbidity and mortality. Use of the scheme outlined here should help ministers of health, policymakers, administrators, and institutions in limited-resource settings plan, establish, and gradually expand breast cancer treatment services for their populations.

Radiotherapy for breast cancer in countries with limited resources: program implementation and evidence-based recommendations.

Radiotherapy is an essential part of the multimodality treatment of breast cancer. Applying safe and effective treatment requires appropriate facilities, staff, and equipment, as well as support systems, initiation of treatment without undue delay, geographic accessibility, and completion of radiotherapy without undue prolongation of the overall treatment time. Radiotherapy can be delivered with a cobalt-60 unit or a linear accelerator (linac). In early stage breast cancer, radiotherapy is an integral part of breast-conserving treatment. Standard treatment includes irradiation of the entire breast for several weeks, followed by a boost to the tumor bed in women age 50 years or younger or those with close surgical margins. Mastectomy is an appropriate treatment for many patients. Postmastectomy irradiation with proper techniques substantially decreases local recurrences and improves survival in patients with positive axillary lymph nodes. It is also considered for patients with negative nodes if they have multiple adverse features such as a primary tumor larger than 2 cm, unsatisfactory surgical margins, and lymphovascular invasion. Many patients present with locally advanced or inoperable breast cancer. Their initial treatment is by systemic therapy; after responding to systemic therapy, most will require a modified radical mastectomy followed by radiotherapy. For those patients in whom mastectomy is still not possible after initial systemic therapy, breast and regional irradiation is given, followed whenever possible by mastectomy. For patients with distant metastases, irradiation may provide relief of symptoms such as pain, bleeding, ulceration, and lymphedema. A single fraction of irradiation can effectively relieve pain from bone metastases. Radiotherapy is also effective in the palliation of symptoms secondary to metastases in the brain, lungs, and other sites. Radiotherapy is important in the treatment of women with breast cancer of all stages. In developing countries, it is required for almost all women with the disease and should therefore be available.

The effects of tamoxifen on radiation-induced pulmonary fibrosis in Wistar albino rats: results of an experimental study.

This study was performed to evaluate the effects of tamoxifen on pulmonary fibrosis, given concurrently with or after irradiation in Wistar albino rats. Twenty-one female Wistar albino rats were randomized into three groups. The first group (Group A) had tamoxifen, which was started after the completion of irradiation. The second group (Group B) had tamoxifen concomitant with irradiation. The third group (Group C) had only thoracic irradiation and did not receive tamoxifen. Whole lungs were irradiated to a total dose of 30Gy in ten fractions with Co60. Tamoxifen was continued until the animals were sacrificed 16 weeks after the start of irradiation. As an end point the percentage of lung with fibrosis for each rat was quantified with image analysis of histological sections of the lung. Groups were compared using the one-way ANOVA method and Bonferroni post hoc test. The mean percentage values of fibrosis were 10.03 for Group A, 36.81 for Group B, and 3.87 for group C (P<0.001). When the percentages of fibrosis were compared for each group, the difference was statistically significant between Group A and Group B (P<0.001) and between Group B and Group C (P<0.001). Concomitant use of tamoxifen appears to increase radiation-induced pulmonary fibrosis and it seems more convenient to delay tamoxifen until the completion of irradiation.

Toxicity and survival results of a phase II study investigating the role of postoperative chemo-radioimmunotherapy for gastric adenocarcinoma.

BACKGROUND AND PURPOSE: To investigate the role of postoperative concomitant chemo-radioimmunotherapy in gastric adenocarcinoma patients. PATIENTS AND METHODS: 59 patients, who underwent total or subtotal gastrectomy, with lymph node involvement, positive microscopic surgical margins or serosal involvement were included in the study. Radiotherapy started concomitantly with chemotherapy and levamisole. Extended-field radiotherapy was given to gastric bed and regional lymphatics via two anterior-posterior/posterior-anterior fields. A total dose of 45 Gy in 25 fractions with a fraction size of 1.8 Gy was planned. In 28 patients (48%) with positive surgical margins a 10-Gy boost dose was given to the anastomosis site. An adjuvant i.v. bolus of 450 mg/m(2)/day 5-fluorouracil (5-FU) was administered concomitantly during the first 3 days and at the 20th day of irradiation. After completion of radiotherapy, i.v. boluses of 450 mg/m(2)/day 5-FU and 25 mg/m(2)/day rescuvorin were continued for 6 months once a week. Levamisole 40 mg/day orally was started at the 1st day of radiotherapy and also continued for 6 months. Median follow-up was 37 months (7-112 months). RESULTS: Median survival was 23 months. Overall 3- and 5-year survival rates amounted to 35% and 14%, respectively. Median survival of the patients with positive surgical margins was 22 months. The 3- and 5-year locoregional control rates were 59% and 55%, respectively. The most common toxicity was upper gastrointestinal system toxicity, which was observed in 42 patients (71%). Four patients (7%) died on account of early toxic effects, and six (10%) could not complete treatment. CONCLUSION: Although 48% of the study population involved patients with microscopic residual disease, the survival results as a whole were satisfactory. However, due to high toxicity, radiotherapy must be delivered with the most proper techniques along with adequate nutrition and supportive care.

The effect of treatment interruptions in the postoperative irradiation of breast cancer.

OBJECTIVE: There is much evidence for the detrimental effect of treatment interruptions on tumor control, particularly in head and neck cancer. In order to determine the outcome of the treatment interruptions in postoperative irradiation of breast cancer, 853 female patients treated between 1990 and 1999 inclusive were retrospectively analyzed. METHODS: Locally advanced breast cancer patients who received neoadjuvant chemotherapy were not included in the study. Five hundred and forty-six patients (64%) treated with mastectomy and 307 patients (36%) with breast-conserving surgery were analyzed. A total dose of 50 Gy (46--54 Gy) was given to the chest wall/breast and regional lymph nodes in 1.8- to 2-Gy daily fractions, 5 times per week. A 14-Gy (10- to 20-Gy) photon or electron boost was given to the tumor bed of the patients with breast-conserving surgery. Unplanned treatment interruptions occurred in 741 (87%) of the patients and the median duration of the gaps was 13 days (1--91 days). A total of 348 patients (41%) had no treatment break or interruptions of 1 week or less, whereas 505 patients (59%) had treatment interruptions of more than 1 week. The locoregional control (LC) and overall survival (OS) rates were estimated with the Kaplan-Meier method. A Cox proportional hazard regression model was used to evaluate the influence of host- and treatment-related factors on LC and OS (age, menopausal status, histological subtype, grade, hormonal receptor status, pT stage, pN stage, type of surgery, adjuvant treatment, number of gaps and duration of gaps). RESULTS: For all patients LC rates for 5 and 10 years were 95 and 87%, respectively, and OS rates were 78% for 5 years and 62% for 10 years. LC rates for the group of patients with no treatment break or interruptions of 1 week or less, for 5 and 10 years were 94 and 90%, whereas the LC rates for 5 and 10 years were 89 and 86%, for the group of patients with interruptions of more than 1 week (p=0.019). Treatment interruptions of more than 1 week and premenopausal status appeared to be independent adverse prognostic factors in multivariate analyses affecting the LC (p=0.043 and p=0.005, respectively). The OS rates for the patients without treatment interruptions or interruptions of 1 week or less were also significantly better than for the patients with treatment interruptions of more than 1 week (p=0.026) in multivariate analyses. CONCLUSION: Interruptions more than 1 week during postoperative irradiation of breast cancer adversely affect the treatment outcome.

Pentoxifylline in the treatment of radiation-related pelvic insufficiency fractures of bone.

The reported incidence of bone complications after radiation therapy is quite low. The most commonly seen bone complication is insufficiency fractures of the pubis and sacrum. Treatment of insufficiency fractures consists of conservative care, and mineral replacement may be useful. The resolution of symptoms takes at least one year with these treatments. Vascular damage has an important role in the etiology of late radiation injury in normal tissues. Progressive ischemic changes further weaken the bone structure, which can cause fractures, and healing is also delayed. Pentoxifylline is a methylxanthine derivative that is shown to increase tissue blood flow. Here, we present a 63-year-old male patient with pelvic insufficiency fractures due to postoperative pelvic irradiation for rectal adenocarcinoma. The patient received pelvic radiotherapy to a total dose of 50.4 Gy with concomitant 5-FU. Six months after the completion of radiotherapy, the patient presented with severe pelvic pain. Pelvic magnetic resonance imaging (MRI) demonstrated abnormal signal intensity with insufficiency fractures at the sacrum and bone marrow edema near the fractures, but not an abnormal intensity that revealed bone metastases. Neither distant nor locoregional recurrence was observed at his work-up. The final diagnosis was insufficiency fractures of the pelvic bones owing to irradiation, and pentoxifylline (400 mg, 3 times daily, peroral, 1,200 mg/day) was used for eight months as treatment. Dramatic clinical improvement was obtained in six months, and objective healing was revealed with MRI. We concluded that pentoxifylline is a cost-effective drug with minimal adverse effects in treating radiation damage of bone.