Breast Cancer 2002: Where Do We Stand?
Authors: P. A. Ganz
Journal: CA A Cancer Journal for Clinicians (2002)

Breast cancer is the most common cancer in women, accounting for about one third of all incident cancers of women in the United States.1 However it is neither the leading cause of cancer death, nor is it the most common cause of overall mortality among women (which is cardiovascular disease). These facts seem to elude the public at large, including the media. News stories abound recounting women's experiences with breast cancer. When a recent controversial meta-analysis appeared in Lancet regarding the efficacy of mammographic screening in reducing mortality2 the lay press responded with many more articles, including several editorials and op-ed pieces. In preparing for this editorial, I ran a Web search using the terms “breast and cancer.” It yielded 1,770,000 hits in 0.22 seconds. A search for “heart attack” yielded only about 140,000 more hits! My question is why is public interest in breast cancer so intense and in what ways do the articles in this issue of CA reflect medicine and society? In effect, where do we stand? Breast cancer affects women of all ages and races.3 During the past two decades, screening for breast cancer has become widespread through campaigns by various health organizations including the American Cancer Society. There is no question that these efforts have raised public awareness of the disease and decreased the social stigmatization associated with a breast cancer diagnosis. In addition, breast cancer often strikes upper-middle class women, many of whom have become vocal advocates for increased research on its causes, prevention, and treatment. Further, as the baby boom generation ages and becomes at risk for breast cancer, increasingly more people in their 40s and 50s personally know someone who has had breast cancer. With improvements in imaging technology and diagnostic procedures, more than half of all breast cancers are localized to the breast and a sizable number of new cases are non-invasive cancers.1,3 For this reason, it is important that women receive optimal and appropriate treatment for these very tiny and often nonpalpable breast tumors. In addition, as noted by the authorship listing by Morrow, et al. in this issue of CA, management of early-stage breast cancer is truly multidisciplinary. Key clinicians who interact during the treatment decision-making phase are the surgeon, radiologist, pathologist, and radiation oncologist. Medical oncologists are often involved early on as well if the tumor is large and neoadjuvant chemotherapy is being considered. Close coordination among the pathologist, surgeon, and radiologist is required during surgical procedures, and findings from the pathologic examination of the tissue are critical for subsequent treatment decision-making on the part of medical and radiation oncologists. The paper by Morrow and colleagues is especially important in that authors articulate a clear standard of care for handling of the tumor specimen, for its pathological evaluation and reporting, and to determine whether the tumor is invasive or non-invasive. In an ongoing study of a population-based sample of breast cancer patients in Los Angeles County, CA, our research group has noted substantial variations in the pathologic reporting of findings from both breast biopsies and definitive surgery results in over 2,000 cases of breast cancer. Pathology-report contents form the cornerstone of treatment decision-making for breast cancer, and therefore careful pathologic evaluation is a critical element in ensuring quality of care for people with breast cancer. In their paper on management of invasive breast cancer, Morrow and colleagues provide an excellent state-of-the-art review of issues related to management of invasive breast cancer ranging from breast-conserving surgery, clinical evaluation of the patient, pathological assessment, the role of radiation therapy, neoadjuvant therapy, and post-operative adjuvant therapy. This paper is particularly important for its attempt to delineate important quality-of-care indicators such as clear surgical margins, determination of estrogen and progesterone receptors, technical aspects of the surgical procedure, management of the axillary nodes, and follow-up care after primary breast cancer management. In addition, the authors have included important patient-focused concerns related to surgery and adjuvant therapy, and highlight the importance of patient participation at various points in the treatment continuum. These guidelines rely on a review of a substantial body of literature (that is comprehensively referenced) as well as the expertise of the panelists, and thus should be considered for widespread adoption by practitioners caring for women with breast cancer and/or for health-outcomes evaluations of the quality of breast cancer care. Also in this issue of CA, Calle and colleagues touch on another hot topic in breast cancer—the role environmental factors play (in particular, the use of pesticides) in the risk for breast cancer. During the latter half of the twentieth century, epidemiologists documented a small but steady increase in breast cancer incidence.3 Many studies have attempted to link this observation to environmental causes, such as the widespread use of organochlorine pesticides. As reviewed by Calle, et al. evidence for the linkage of breast cancer rates to organochlorine exposure is, at best, uncertain. Although known risk factors for breast cancer (e.g., aging, reproductive history, exogenous hormones, family history, and radiation exposure) provide a modest explanation for the risk of developing breast cancer in individual women, dramatic changes in the health and behaviors of women are a more likely explanation for the increasing incidence of the disease at the population level (e.g., better nutrition leading to earlier menarche, delayed or no childbearing, and postmenopausal hor-mone replacement therapy). Women would like to have a ready explanation as to why they may be at risk for breast cancer, as would their physicians. And many women who do develop the disease want to know why they personally were affected. Unfortunately we are seldom able to provide a simple answer to the individual woman sitting in our office. What does the future have in store? Clearly, all of the medical and societal influences briefly discussed here will still be at play in the years to come. But, there is hope that we will have better ways of examining breast tumors to predict both their seriousness and level of risk of dissemination using gene expression profiles and other molecular techniques.4,5 This is of increasing importance as the size of tumors at the time of detection decreases and the rate of detection of non-invasive cancer increases. While all breast cancers respond to adjuvant therapies with the same relative reduction in risk of recurrence, absolute benefits of treatment diminish as the size of the tumor decreases.6,7 Since there are some data that suggest detrimental effects from adjuvant therapy in terms of physical and sexual functioning,8–10 better specificity in selection of women in need of adjuvant treatment is a critical issue. On the prevention front, we need to optimize our decision-making about who is a candidate for chemoprevention strategies. Refining our risk models beyond the Gail Model will be important.11,12 Clearly, women with preneoplastic changes in the breast are most likely to benefit from tamoxifen therapy13 where the benefit is most evident in those lesions containing the estrogen receptor. Hopefully, new chemoprevention approaches that modify preneoplastic changes through other molecular targets will be identified and tested in future trials.14 Current strategies, such as the STAR trial, are aimed at reducing chemoprevention toxicities, but may still miss high-risk individuals. Thus, the three articles in this issue of CA highlight progress we have made as well as challenges we face in the prevention, detection, and treatment of breast cancer. We should be proud of the fact that although breast cancer is the most common cancer in women, mortality rates from the disease are declining and treatments are being refined to reduce morbidity and decrease the impact of a cancer diagnosis on quality of life. However, it would be far better if we could improve our understanding of who is truly at risk for the disease so we could either diminish those risks or apply highly-effective preventive strategies in the target population. That is what the future has in store.