© 2005 Oxford University Press
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IN THIS ISSUE
Neoadjuvant Versus Adjuvant Treatment for Breast CancerNeoadjuvant therapy for breast cancer appears to reduce the extent of local surgery. To evaluate whether neoadjuvant therapy also affects disease progression end points, Mauri et al. (p. 188) conducted a meta-analysis of randomized trials that compared the clinical end points of patients treated with neoadjuvant therapy and patients treated with the same regimen given as adjuvant therapy. They found no statistically significant difference between the neoadjuvant and adjuvant therapy arms in terms of death, disease progression, or distant disease recurrence. However, neoadjuvant therapy was associated with an increased risk of locoregional disease recurrence, especially in trials in which more patients in the neoadjuvant arm received radiation therapy without surgery.
In an editorial, Davidson and Morrow (p. 159) note that surgery will remain an essential part of early breast cancer management until patients with a complete pathologic response to neoadjuvant therapy can be reliably identified. The early identification of patients who will and will not respond to systemic chemotherapy may decrease toxicity in those who respond and allow those who do not respond to receive more effective therapy.
Sun Exposure and Cancer Risk
Melanoma incidence and survival are positively associated, both geographically and temporally. Solar elastosis, a histologic indicator of cutaneous sun damage, has also been associated with better melanoma survival. Berwick et al. (p. 195) evaluated the association between measures of skin screening and death from cutaneous melanoma by following case subjects from a population-based study. The authors found that melanoma thickness, mitoses, ulceration, and anatomic location on the head and neck were positively associated with melanoma death. They also found that sunburn, high intermittent sun exposure, skin awareness, and solar elastosis were inversely associated with death from melanoma, and that skin awareness and solar elastosis were independently and inversely associated with death, even after adjusting for melanoma thickness, mitoses, and head and neck location. The authors conclude that sun exposure is associated with increased survival from melanoma.
The worldwide incidence of malignant lymphomas has increased in recent decades, and it has been suggested that the rise may be the result of increasing exposure to ultraviolet (UV) radiation. To investigate this hypothesis, Smedby et al. (p. 199) carried out a population-based case–control study in Denmark and Sweden in which they obtained detailed information on history of UV exposure and other risk factors for lymphoma from 3740 lymphoma patients and 3187 population controls. The authors found that increased exposure to UV radiation was associated with a decrease, rather than an increase, in the risk of non-Hodgkin lymphoma. Increased UV exposure was also associated, albeit more weakly, with a decreased risk of Hodgkin lymphoma. The authors discuss several possible biologic explanations for the inverse association between UV exposure and lymphoma, including UV-induced modulation of the immune system and photo-initiation of vitamin D production.
In an editorial, Egan et al. (p. 161) discuss how the results of Berwick et al. and Smedby et al. provide new evidence that sunlight may have a beneficial influence on both cancer incidence and outcome and hypothesize that vitamin D may be a critical mediator in the relationship between sunlight and cancer.
Inadequate Lymph Node Evaluation in Colorectal Cancer
Adequate lymph node evaluation is required for proper staging of colorectal cancer, and the number of lymph nodes examined is associated with survival. Baxter et al. (p. 219) used data from the National Cancer Institute's Surveillance, Epidemiology, and End Results program to determine the proportion of colorectal cancer patients in the United States who receive adequate lymph node evaluation. The authors found that, among all patients, the median number of lymph nodes examined was nine (below the recommended minimum number of 12) and that only 37% of all patients received adequate lymph node evaluation. Although the proportion of patients receiving adequate lymph node evaluation increased from 32% in 1988 to 44% in 2001, the majority of patients with colorectal cancer still received inadequate lymph node evaluation. Given that demographic variables, particularly patient age and geographic location, are associated with adequate lymph node evaluation, the authors conclude that local surgical and pathologic practice patterns may affect adequacy of lymph node evaluation.
Body Mass Index and Risk of Malignant Lymphoma
The incidence of non-Hodgkin lymphoma and the prevalence of obesity are increasing throughout the world. A suggested positive association between obesity and the risk of non-Hodgkin lymphoma prompted Chang et al. (p. 210) to investigate this relationship in a population-based case–control study in Scandinavia. They found that body mass index was not associated with the overall risk of non-Hodgkin lymphoma or Hodgkin lymphoma or with the risk of most major lymphoma subtypes evaluated. The authors conclude that excess weight does not appear to be associated with an increased risk of malignant lymphoma and that the growing prevalence of obesity is unlikely to be an important contributor to the increasing incidence of non-Hodgkin lymphoma.
Imaging Angiogenesis
Clinical trials of new drugs that target the angiogenic vasculature of tumors require rapid and effective biomarkers to establish drug dosage and monitor clinical response. Because antiangiogenic and antineovascular therapies are designed to affect the abnormal blood vessels found in tumors, changes in blood volume, blood flow, or other hemodynamic parameters may be promising biomarkers that herald a positive clinical response to therapy. Miller et al. (p. 172) review the validity and reproducibility of different imaging methods, including positron emission tomography, x-ray computed tomography, magnetic resonance imaging, ultrasound, and optical imaging, that have been used for imaging angiogenic vasculature. They discuss the analytic methods used to derive various hemodynamic parameters and the imaging methods that are most likely to have the sensitivity and reliability required for monitoring responses to cancer therapy and describe ways in which imaging has been used in clinical trials to date.
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