Re: “Pilot Trial of a Computerized Decision Aid for Breast Cancer Prevention”

To the Editor: The article in the March ⁄ April 2007 volume: ‘‘Pilot Trial of a Computerized Decision Aid for Breast Cancer Prevention’’ by Ozanne et al. (1) raises issues of the most effective way to prevent invasive breast cancer. That article as well as most contemporary literature focuses on chemoprevention (2). In contrast, in two previous articles (3,4), we have emphasized that the most effective way to prevent invasive breast cancer is to detect and excise ductal carcinoma in situ through widespread mammographic screening. When cancers have an in situ phase that precedes invasion (colorectal, gastric, vulva, esophagus, cervical, head and neck, melanoma, etc.) it has been demonstrated that the removal of the in situ preinvasive phase prevents the later development of invasive cancers. Yet, somehow, because of the drug administration bias of the breast cancer community, we have failed to acknowledge that the same disease progression applies in breast cancer: removal of ductal carcinoma in situ detected by mammographic screening has led to a striking increase in the incidence of ductal carcinoma in situ (5) and subsequent prevention of invasive ductal cancers by their surgical excision. In Rhode Island, there has been a 280% increase in the incidence of ductal carcinoma in situ between 1987 and 2004 (6). Over time, continual removal of such preinvasive lesions will decrease the subsequent incidence of invasive breast cancer (7). A recent change in the modeling of incidence of cancers has been published (8) in the annual 2007 statistical report on cancer. This new modeling, more accurate because it is now based on 86% of the United States population rather than the SEER registry that includes only 14–26%, has demonstrated that the incidence of invasive breast cancer peaked about the year 2000 and is now significantly and continuously trending downwards. With extensive mammographic screening, breast cancer mortality in the United States peaked about 1990 and has declined significantly since that time, an almost 40% decline in the state of Rhode Island between 1988 and 2004. Now, in addition, invasive breast carcinoma incidence is declining, both these mortality and incidence trends fully consistent with widespread mammography leading to excision of smaller invasive cancers and the frequently discovered preinvasive ductal carcinoma in situ. There are many logical biological explanations about why removing preinvasive ductal carcinoma in situ will prevent later invasive breast cancer (4), all consistent with similar conclusions in other organ site cancers mentioned previously. Why this intuitive, logical, biologically plausible assumption, only mentioned occasionally in the literature, has not been explicitly accepted more widely is a puzzling demonstration of ‘‘group thinking’’ about the pharmacologic priority of preventing invasive breast cancer. We again urge the breast cancer community to acknowledge the fact that repeated excisions year after year of DCIS (>20% of all breast ‘‘cancers’’) will lead to a decline in later invasive disease incidence. This decline in invasive breast cancer would occur fairly promptly in high grade ductal carcinoma in situ with a rapid evolution (±5 years), but may be delayed for 10–20 years or more in grade I or II DCIS because of the more prolonged evolution of such non-high grade DCIS to invasive ductal cancer, as demonstrated by reports describing the much later appearance of invasive ductal carcinoma after biopsy only of DCIS (9). The bias towards a pharmacological approach to breast cancer prevention undoubtedly reflects the medical profession’s preoccupation with drugs, and the intense publicity and lobbying efforts by the pharmacologic industry, both in congress and the oncologic community. We hope members of the breast cancer oncology community will appreciate a further logical Address correspondence and reprint requests to: Blake Cady, MD, Professor of Surgery, Brown Medical School, 593 Eddy Street, APC 435, Providence, RI 02903, USA, or e-mail: bcady123@comcast.net.