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Breast cancer in women with palpable breast cysts
COMMENTARY
CORRESPONDENCE Breast cancer in women with palpable breast cysts Sir—J M Dixon and colleagues’ (May 22, p 1742)1 study adds to the body of evidence that palpable breast cysts are associated with an increased risk of breast cancer and shows that younger women are at increased risk. However, it does not address the important question of what are the other differences between women with palpable breast cysts who developed breast cancer compared with those who did not. The investigators did not report data on the risk and protective factors for breast cancer and more detailed information on the biochemical content of the cyst. In the methods they state that details were collected on menstrual status, previous benign disease, family history, parity, age at first pregnancy, and use of pill and hormone replacement therapy. However, they do not report these data or compare the two groups of women to find potential epidemiological differences, and thus clues to the pathogenesis of breast cancer in women with a history of breast cysts. The study involved collection of fluid from all cysts, which was analysed for the content of sodium and potassium ions, but the researchers should also have done a more detailed biochemical analysis. A profile of the type and amount of sex hormone and the relative amounts of growth factors associated with epithelial-cell proliferation, such as epidermal growth factor,2 in each cyst would have provided information on the biochemical environment and the level of proliferative stimulus present within the breast cysts. Such detailed information could have identified a pattern in women with a history of breast cysts who go on to develop breast cancer3 and as a result potentially lead to the formulation of a biochemical screening test. A prospective study of routine histological assessment of palpable breast cysts assesses that the type and concentration of sex hormones and proliferative growth factors in the cysts, together with collection of relevant personal and family history, should be considered. No study to date has combined all this information to try and differentiate between cystic breast disease that is a marker for breast
THE LANCET • Vol 354 • August 21, 1999
cancer from that which it is not. Such a study would also answer the question of whether cysts or associated hyperplastic lesions increase the risk of breast cancer.4 This information is vital if an attempt is to be made to stratify women with breast cysts into risk groups for breast cancer and to thus identify women who will potentially benefit from early mammographic screening. *Carlo Palmieri, Helena Linardou Department of Medical Oncology, Charing Cross Hospital, London W6 8RF, UK 1
Dixon JM, McDonald C, Elton RA, Miller WR, on behalf of the Edinburgh Breast Group. Risk of breast cancer in women with palpable breast cysts: a prospective study. Lancet 1999; 353: 1742–45. 2 Ness JC, Sedghinasab M, Moe RE, Tapper D. Identification of multiple proliferative growth factors in breast cyst fluid. Am J Surg 1993; 166: 237–43. 3 Tapper D, Cajdusek C, Moe R, Ness J. Identification of a unique biological tumour marker in human breast fluid and breast cancer tissue. Am J Surg 1990; 159: 473–78. 4 Dupont WD, Page DL. Risk factors for breast cancer in women with proliferative breast disease. N Engl J Med 1985; 312: 146–51.
Sir—Before there is a public outcry for intensive mammographic screening for women with breast cysts, in response to J M Dixon and colleagues’ report,1 I would like to draw attention to an important potential artefact. Most breast cysts are not painful, not progressive, and spontaneously regress. It is therefore possible for women to live their life in blissful ignorance of the fact that they have a palpable cyst in the breast. These women would be those who do not examine their breasts and do not have a heightened awareness of breast cancer. By contrast, the women who present with cysts in the breast are those who may practise selfexamination and be breast-cancer aware. These two groups of women are likely to be very different in terms of other risk factors. Those who present with cysts are likely to be of a higher social class or with a family history of breast cancer. Those women who are unaware of their cysts are likely to be of a lower social class without a family history of breast cancer. In other words, the presentation of a benign lump in the clinic may be a surrogate marker of
established risk factors, such as a family history or the postponement of the first pregnancy, in women who are more likely to be breast aware and breast selfexaminers. I believe Dixon and colleagues’ report is seriously flawed because it does not describe the demography of their population with cystic disease. Unless I can be convinced that those women who present to the Edinburgh clinic with breast cysts have no other excess risk factors, I will continue to reassure and discharge my patients with a diagnosis of a simple cyst, rather than add them to the growing list of the worried well. Michael Baum Department of Surgery, Royal Free and University College Medical School, University College London, London W1P 7DL, UK 1
Dixon JM, McDonald C, Elton RA, Miller WR, on behalf of the Edinburgh Breast Group. Risk of breast cancer in women with palpable breast cysts: a prospective study. Lancet 1999; 353: 1742–45.
Sir—The classification by J M Dixon and colleagues1 of the two main types of breast cyst is based on the peculiar biochemical composition of the breast cyst fluid and the morphological examination of its cellular component. Type I secretory cysts have higher concentrations of potassium ions, lower content of sodium and chlorine, and a higher concentration of steroid hormones, growth factors, and gross cystic disease fluid proteins than type II transudative cysts.2,3 The morphological features of type I cysts show the presence of actively synthesising and secreting apocrine cells, whereas type II cysts are lined by flattened cells with a low metabolic activity.3 These studies and previous reports shed light on the natural history of the two types of cyst and strengthen the epidemiological evidence about the increased risk of breast cancer in women with type I cysts.2,4 Although the relation between gross breast cystic disease and carcinoma is much debated, this disease is a subject worthy of thorough epidemiological and clinical discussion.5 Several studies have assessed the relation between gross breast cystic disease and breast
677
CORRESPONDENCE Breast cancer in women with palpable breast cysts Sir—J M Dixon and colleagues’ (May 22, p 1742)1 study adds to the body of evidence that palpable breast cysts are associated with an increased risk of breast cancer and shows that younger women are at increased risk. However, it does not address the important question of what are the other differences between women with palpable breast cysts who developed breast cancer compared with those who did not. The investigators did not report data on the risk and protective factors for breast cancer and more detailed information on the biochemical content of the cyst. In the methods they state that details were collected on menstrual status, previous benign disease, family history, parity, age at first pregnancy, and use of pill and hormone replacement therapy. However, they do not report these data or compare the two groups of women to find potential epidemiological differences, and thus clues to the pathogenesis of breast cancer in women with a history of breast cysts. The study involved collection of fluid from all cysts, which was analysed for the content of sodium and potassium ions, but the researchers should also have done a more detailed biochemical analysis. A profile of the type and amount of sex hormone and the relative amounts of growth factors associated with epithelial-cell proliferation, such as epidermal growth factor,2 in each cyst would have provided information on the biochemical environment and the level of proliferative stimulus present within the breast cysts. Such detailed information could have identified a pattern in women with a history of breast cysts who go on to develop breast cancer3 and as a result potentially lead to the formulation of a biochemical screening test. A prospective study of routine histological assessment of palpable breast cysts assesses that the type and concentration of sex hormones and proliferative growth factors in the cysts, together with collection of relevant personal and family history, should be considered. No study to date has combined all this information to try and differentiate between cystic breast disease that is a marker for breast
THE LANCET • Vol 354 • August 21, 1999
cancer from that which it is not. Such a study would also answer the question of whether cysts or associated hyperplastic lesions increase the risk of breast cancer.4 This information is vital if an attempt is to be made to stratify women with breast cysts into risk groups for breast cancer and to thus identify women who will potentially benefit from early mammographic screening. *Carlo Palmieri, Helena Linardou Department of Medical Oncology, Charing Cross Hospital, London W6 8RF, UK 1
Dixon JM, McDonald C, Elton RA, Miller WR, on behalf of the Edinburgh Breast Group. Risk of breast cancer in women with palpable breast cysts: a prospective study. Lancet 1999; 353: 1742–45. 2 Ness JC, Sedghinasab M, Moe RE, Tapper D. Identification of multiple proliferative growth factors in breast cyst fluid. Am J Surg 1993; 166: 237–43. 3 Tapper D, Cajdusek C, Moe R, Ness J. Identification of a unique biological tumour marker in human breast fluid and breast cancer tissue. Am J Surg 1990; 159: 473–78. 4 Dupont WD, Page DL. Risk factors for breast cancer in women with proliferative breast disease. N Engl J Med 1985; 312: 146–51.
Sir—Before there is a public outcry for intensive mammographic screening for women with breast cysts, in response to J M Dixon and colleagues’ report,1 I would like to draw attention to an important potential artefact. Most breast cysts are not painful, not progressive, and spontaneously regress. It is therefore possible for women to live their life in blissful ignorance of the fact that they have a palpable cyst in the breast. These women would be those who do not examine their breasts and do not have a heightened awareness of breast cancer. By contrast, the women who present with cysts in the breast are those who may practise selfexamination and be breast-cancer aware. These two groups of women are likely to be very different in terms of other risk factors. Those who present with cysts are likely to be of a higher social class or with a family history of breast cancer. Those women who are unaware of their cysts are likely to be of a lower social class without a family history of breast cancer. In other words, the presentation of a benign lump in the clinic may be a surrogate marker of
established risk factors, such as a family history or the postponement of the first pregnancy, in women who are more likely to be breast aware and breast selfexaminers. I believe Dixon and colleagues’ report is seriously flawed because it does not describe the demography of their population with cystic disease. Unless I can be convinced that those women who present to the Edinburgh clinic with breast cysts have no other excess risk factors, I will continue to reassure and discharge my patients with a diagnosis of a simple cyst, rather than add them to the growing list of the worried well. Michael Baum Department of Surgery, Royal Free and University College Medical School, University College London, London W1P 7DL, UK 1
Dixon JM, McDonald C, Elton RA, Miller WR, on behalf of the Edinburgh Breast Group. Risk of breast cancer in women with palpable breast cysts: a prospective study. Lancet 1999; 353: 1742–45.
Sir—The classification by J M Dixon and colleagues1 of the two main types of breast cyst is based on the peculiar biochemical composition of the breast cyst fluid and the morphological examination of its cellular component. Type I secretory cysts have higher concentrations of potassium ions, lower content of sodium and chlorine, and a higher concentration of steroid hormones, growth factors, and gross cystic disease fluid proteins than type II transudative cysts.2,3 The morphological features of type I cysts show the presence of actively synthesising and secreting apocrine cells, whereas type II cysts are lined by flattened cells with a low metabolic activity.3 These studies and previous reports shed light on the natural history of the two types of cyst and strengthen the epidemiological evidence about the increased risk of breast cancer in women with type I cysts.2,4 Although the relation between gross breast cystic disease and carcinoma is much debated, this disease is a subject worthy of thorough epidemiological and clinical discussion.5 Several studies have assessed the relation between gross breast cystic disease and breast
677