Cognitive function in breast cancer patients prior to adjuvant treatment

Prophylactic cranial irradiation in advanced breast cancer: a case for caution

PURPOSE

Prophylactic cranial irradiation (PCI) has a well-recognized role in the treatment of leukemia and small-cell lung cancer. Clinical utility has yet to be determined for breast cancer, where an emerging group at high risk of brain metastasis has fuelled consideration of PCI.

METHODS AND MATERIALS

In reviewing our experience with PCI as part of a complex protocol for advanced breast cancer, we present descriptive data on late central nervous system outcomes in those receiving PCI. After high-dose anthracycline-based induction chemotherapy, Stage IIIB/IV breast cancer responders underwent tandem autologous marrow transplantation. Those in continued remission were referred for PCI. Whole-brain radiotherapy was delivered by usual means, at 36 Gy in 20 fractions.

RESULTS

Twenty-four women, with median age 45 (28-61), were enrolled between 1995 and 1998. Disease was largely metastatic (79%), and 75% were previously exposed to chemotherapy or hormonotherapy. Ten patients received PCI, at a median of 13.4 (11.8-16.5) months from study entry. Six patients developed brain metastases, 2 despite PCI. Striking functional decline was documented in 3 patients (at 9 months, 4 years, and 5 years post-PCI), including one previously high-functioning woman requiring full care for posttreatment dementia.

CONCLUSIONS

We present a series of advanced breast cancer patients treated prophylactically with whole-brain radiotherapy following an aggressive chemotherapy regimen. Although the therapeutic benefit of PCI is not ascertainable here, we describe brain metastases occurring despite PCI and serious long-term neurobehavioral sequelae in PCI-treated patients. Any further investigation of PCI in high-risk breast cancer will need to be approached with caution.

Fatigue and sleep during cancer and chemotherapy: translational rodent models

The frequent occurrence of fatigue and disturbed sleep in cancer survivors and the negative effect of these symptoms on quality of life and clinical outcome underscore the need to identify mechanisms that cause cancer-related fatigue, with a view toward developing more effective treatments for this problem. Human studies of fatigue and disturbed sleep are limited by high interindividual genetic and environmental variability, difficulties with behavioral or reporting compliance, and the subjective nature of the problems. Although animal models also must overcome the barrier of assessing fatigue and sleep disturbance in the absence of obvious objective clinical markers, animal studies are easier to control and standardize than are studies of people. Moreover, animal models are crucial to the identification and understanding of underlying disease mechanisms. This review describes the need for, the feasibility of, and several possible approaches to measuring fatigue in animal models of cancer and to relating such measures to disturbed sleep, immune function, and other potential mechanisms. Developing and using animal models to better understand fatigue and disturbed sleep related to cancer and its treatment has an enormous potential to expand the knowledge base and foster hypotheses necessary for the future development and testing of interventions.