TREATMENT RELATED LATE SIDE EFFECTS IN PATIENTS WITH BREAST CANCER

Abstract

Breast cancer is the most common cancer diagnosed among women in the United States, accounting for nearly 1 in 3 cancers. It is also the second leading cause of cancer death among women after lung cancer. Approximately 232,340 new cases of invasive breast cancer and 39,620 deaths are expected among US women in 2013. Approximately 79% of new cases and 88% of breast cancer deaths in 2013 will occur among women aged 50 years and older. In addition to invasive breast cancers, about 64,640 new diagnoses of in situ breast cancer are expected among US women in 2013 (Siegel and Jemal 2013). In Egypt, It is the most frequent occurring cancer according to Aswan Governorate Statistics in 2008, with 247 cases 21.5% of all cancers, more in females above 50 years old. And the second most frequent occurring according to Damietta statistics in 2009 (231 cases 15.8% of all cancers) after liver cancer (417 cases 28.5% of all cancers) more in females above 55 years old. But the most frequent in females (NCRPE, 2009). Age, family history, early menarche, late menopause, nulliparity, late age at first full-term pregnancy and use of hormone replacement therapy (HRT) are well-established risk factors for the development of breast cancer (McPherson et al., 2000). Summary  90  The diagnosis of breast cancer is based on clinical examination in combination with imaging, and confirmed by pathological assessment (Senkus et al., 2013). The ‘Gold Standard’ treatment for breast cancer is a complete surgical excision of the tumour and staging of the axillary lymph nodes, followed by appropriate combinations of adjuvant therapies (Wyld and Reed, 2007). These treatments are individualized for each patient, often with the treatment plan developed through the input of a multidisciplinary team. Ideally, choices between treatment options should be informed by extensive evidence, based mainly on evidence from randomised trials and encapsulated in published treatment guidelines (NBCC 2006). Breast care specialists rank the detection of treatment related morbidity the most important reason for follow-up care for women with breast cancer (Khatcheressian et al., 2006). Early detection and improved treatment have dramatically increased the life expectancy of women with breast cancer, leading to overall 5-year survival rates of 98% for local-stage disease and 84% for regional-stage disease (Soerjomataram et al., 2008; Cancer Facts and Figures 2008). Women with BC now represent the largest female cancer survivor group in the United States (Burstein and Winer, 2000). This is creating new challenges for the health care system, with medical concern shifting from initial treatment to Summary  91  survivorship and the responsibility for care shifting from oncologists to primary care providers (Hewitt et al., 2006). Breast cancer patients face long-term side effects following surgery and radiation therapy. The most common complications of local therapy are due to axillary surgery and/or axillary radiation, which can affect the nerves and lymph vessels of the axilla. Patients may develop numbness, weakness, pain, loss of range of motion, or arm swelling (Peppercorn et al., 2005). Although the beneficial effect of postoperative radiotherapy for breast cancer is well documented, this treatment may be related to a number of complications. Among significant long-term irradiation sequelae are cardiac and lung damage, lymphedema, brachial plexopathy, impaired shoulder mobility and second malignancies (Senkus-Konefka and Jassem, 2006). Patients may experience lasting sequelae of systemic therapy, including fatigue, ovarian failure with associated menopausal symptoms, neuropathy, weight gain, psychological distress, and sexual dysfunction. Late complications include an increased risk of leukemia (generally estimated to occur in less than 0.5% of women after an anthracycline-based regimen), osteoporosis from premature ovarian failure, and a slightly increased risk of cardiac dysfunction secondary to anthracyclines (Senkus-Konefka et al., 2006). Summary  92  In fifteen to twenty-five percent of breast cancer, there is an over expression of HER2 protein in the cancer cells, indicating a high risk of recurrence. Trastuzumab is a humanized monoclonal antibody against HER2 protein. When given concomitantly or after adjuvant chemotherapy for 12 months as adjuvant treatment for early HER2-positive breast cancer, trastuzumab reduced the risk of recurrence by approximately 50%and the risk of death by approximately 30% and. However, cardiotoxicity is the most adverse effect of trastuzumab (Tan-Chiu et al., 2005). Adjuvant endocrine therapy for early-stage breast cancer may involve 5-10 years of treatment; thus, many of the issues in follow-up concern the side effects or complications of ongoing therapy. These can include hot flashes and other menopausal symptoms, sexual dysfunction, muscle aches, and psychological distress. Patients on tamoxifen face an increased risk of thromboembolic disease, uterine cancer, and possibly cerebrovascular events. Fortunately, the incidence of such complications remains low. Patients on aromatase inhibitors face an increased risk of osteoporosis and fracture (Senkus- Konefka et al., 2006).