***TASK*** the task is to summarize an input biomedical literature in six sentences 
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    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
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    Input: CONTEXT The Women 's Health Initiative trial of combined estrogen plus progestin was stopped early when overall health risks , including invasive breast cancer , exceeded benefits . Outst and ing issues not previously addressed include characteristics of breast cancers observed among women using hormones and whether diagnosis may be influenced by hormone effects on mammography . OBJECTIVE To determine the relationship among estrogen plus progestin use , breast cancer characteristics , and mammography recommendations . DESIGN , SETTING , AND PARTICIPANTS Following a comprehensive breast cancer risk assessment , 16 608 postmenopausal women aged 50 to 79 years with an intact uterus were r and omly assigned to receive combined conjugated equine estrogens ( 0.625 mg/d ) plus medroxyprogesterone acetate ( 2.5 mg/d ) or placebo from 1993 to 1998 at 40 clinical centers . Screening mammography and clinical breast examinations were performed at baseline and yearly thereafter . MAIN OUTCOME MEASURES Breast cancer number and characteristics , and frequency of abnormal mammograms by estrogen plus progestin exposure . RESULTS In intent-to-treat analyses , estrogen plus progestin increased total ( 245 vs 185 cases ; hazard ratio [ HR ] , 1.24 ; weighted P<.001 ) and invasive ( 199 vs 150 cases ; HR , 1.24 ; weighted P = .003 ) breast cancers compared with placebo . The invasive breast cancers diagnosed in the estrogen plus progestin group were similar in histology and grade but were larger ( mean [ SD ] , 1.7 cm [ 1.1 ] vs 1.5 cm [ 0.9 ] , respectively ; P = .04 ) and were at more advanced stage ( regional/metastatic 25.4 % vs 16.0 % , respectively ; P = .04 ) compared with those diagnosed in the placebo group . After 1 year , the percentage of women with abnormal mammograms was substantially greater in the estrogen plus progestin group ( 716 [ 9.4 % ] of 7656 ) compared with placebo group ( 398 [ 5.4 % ] of 7310 ; P<.001 ) , a pattern which continued for the study duration . CONCLUSIONS Relatively short-term combined estrogen plus progestin use increases incident breast cancers , which are diagnosed at a more advanced stage compared with placebo use , and also substantially increases the percentage of women with abnormal mammograms . These results suggest estrogen plus progestin may stimulate breast cancer growth and hinder breast cancer diagnosis OBJECTIVES To analyze prospect ively the association between hormone replacement therapy ( HRT ) and mortality in women before old age . DESIGN AND METHODS A group of 11,667 women ( 91 % of the age cohort of the area ) aged 52 - 62 years from the population -based Kuopio Osteoporosis Risk Factor and Prevention Study were followed for 7 years in 1994 - 2001 . Information about HRT use and health events was obtained from two repeated question naires in 1989 and 1994 . Information about deaths and causes of death from the follow-up period was obtained from the Statistics Finl and . Cox 's proportional-hazards models were used to calculate risk of death related to the use of HRT . RESULTS At the start of follow-up , 2203 women had used HRT > 5 years , 3945 women < or = 5 years and 5519 women had never used it . During the follow-up , 361 deaths occurred . Compared with non-users of HRT , the adjusted hazard ratio ( HR ) of death from any cause was 1.05 ( 95 % confidence interval ( CI ) 0.80 - 1.36 ) in women who used HRT < or = 5 years and 1.06 ( 95 % CI 0.78 - 1.46 ) in women who used HRT > 5 years . The adjusted HR for coronary heart disease ( CHD ) mortality in women who used HRT < or = 5 years was 0.79 ( 95 % CI 0.36 - 1.73 ) , and in women who used HRT > 5 years , 2.16 ( 95 % CI 0.93 - 4.98 ) . For breast cancer mortality the adjusted HR for < or = 5 years of HRT use was 0.96 ( 95 % CI 0.32 - 2.82 ) and 2.62 ( 95 % CI 0.98 - 7.00 ) for > 5 years of HRT use . CONCLUSIONS History of HRT use does not affect overall or CHD mortality in women . More than 5 years of HRT use may increase the risk of breast cancer mortality Of 256 patients with breast cancer diagnosed between 1972 and 1981 , 102 have died ( mortality , 39.8 % ) . More hormone users had negative axillary nodes ( 57.1 % ) than did nonusers ( 41.8 % ) . The mortality of the hormone users ( 22.2 % ) was significantly lower ( p less than or equal to 0.01 ) than that of the nonusers ( 45.5 % ) . In 162 patients whose diagnosis of breast cancer was made prior to 1979 , the 5-year survival rate in hormone users was 76.2 % compared to 48.1 % in nonusers . During the prospect i ve phase of the study from 1975 to 1981 , the lowest incidence of breast carcinoma ( 67.3:100,000 ) was observed in the estrogen-progestogen users and was significantly lower than that of the untreated group ( 342.3:100,000 ) and lower than that expected from both the Third National Cancer Survey and the National Cancer Institute System for Electronic Evaluation and Retrieval ( SEER ) data ( p less than or equal to 0.01 ) . Estrogen therapy does not increase the risk of mammary malignancy , but added progestogen significantly decreases the risk BACKGROUND Hormone replacement therapy ( HRT ) is typically avoided for women with a history of breast cancer because of concerns that estrogen will stimulate recurrence . In this study , we sought to evaluate the impact of HRT on recurrence and mortality after a diagnosis of breast cancer . METHODS Data were assembled from 2755 women aged 35 - 74 years who were diagnosed with incident invasive breast cancer while they were enrolled in a large health maintenance organization from 1977 through 1994 . Pharmacy data identified 174 users of HRT after diagnosis . Each HRT user was matched to four r and omly selected nonusers of HRT with similar age , disease stage , and year of diagnosis . Women in the analysis were recurrence free at HRT initiation or the equivalent time since diagnosis . Rates of recurrence and death through 1996 were calculated . Adjusted relative risks were estimated by use of the Cox regression model . All statistical tests were two-sided . RESULTS The rate of breast cancer recurrence was 17 per 1000 person-years in women who used HRT after diagnosis and 30 per 1000 person-years in nonusers ( adjusted relative risk for users compared with nonusers = 0.50 ; 95 % confidence interval [ CI ] = 0.30 to 0.85 ) . Breast cancer mortality rates were five per 1000 person-years in HRT users and 15 per 1000 person-years in nonusers ( adjusted relative risk = 0.34 ; 95 % CI = 0.13 to 0.91 ) . Total mortality rates were 16 per 1000 person-years in HRT users and 30 per 1000 person-years in nonusers ( adjusted relative risk = 0.48 ; 95 % CI = 0.29 to 0.78 ) . The relatively low rates of recurrence and death were observed in women who used any type of HRT ( oral only = 41 % of HRT users ; vaginal only = 43 % ; both oral and vaginal = 16 % ) . No trend toward lower relative risks was observed with increased dose . CONCLUSION We observed lower risks of recurrence and mortality in women who used HRT  after breast cancer diagnosis than in women who did not . Although residual confounding may exist , the results suggest that HRT after breast cancer has no adverse impact on recurrence and mortality Summary Nine hundred and eighty-four breast cancer patients were interviewed regarding exogenous hormonal use . This represents a r and om sample of breast cancer patients in Southern Sweden referred to the Department of Oncology at Lund for treatment between 1978 and 1997 ( excluding 1980 and 1981 ) with a 100 % follow-up . Ever-use of  hormone replacement therapy ( HRT ) prior to diagnosis was significantly associated with a longer overall survival in women with their breast cancer diagnosed at ages 45 and above , relative risk ( RR ) of dying 0.73 ( 95 % confidence interval ( CI ) 0.62–0.87 ; P = 0.0005 ) . Ever use of HRT prior to breast cancer diagnosis was significantly positively associated with overall longer survival after adjustment for T-stage , N-stage , M-stage , year of diagnosis and age at diagnosis , RR of dying 0.78 ( 95 % CI 0.65–0.93 ; P = 0.006 ) .  Hormone replacement therapy use and oestrogen receptor positivity were independently significantly associated with overall longer survival , P = 0.005 and P < 0.0001 , respectively , in one model . HRT use and progesterone receptor positivity were also independently significantly associated with longer overall survival , P = 0.003 and P = 0.0003 , respectively , in another model . The mode of diagnosis was known in 705 women . Mammography screening was not more common among HRT users compared with never-users , where this information was available . Both  mammography screening  and HRT use were independently associated with longer survival , P = 0.002 and P = 0.038 respectively It is well known that a family history of breast cancer is an important risk factor for the disease . A critical issue is how to advise patients with a family history of breast cancer about perimenopausal and postmenopausal use of hormone replacement therapy ( HRT ) . Hoskins and colleagues [ 1 ] have provided guidelines on assessment and counseling of women with such a history , including a recommendation that they avoid exogenous estrogens . A considerable body of literature has discussed the association of HRT and risk for breast cancer . Interpretation of available data is not consistent : Two meta-analyses [ 2 , 3 ] found a positive association , and two others [ 4 , 5 ] found no association . More recent studies have not clarified the issue [ 6 - 8 ] . Findings on increased risk in women with a family history of breast cancer have been more consistent . A meta- analysis [ 3 ] of five studies that had examined the issue suggested that the risk for breast cancer associated with HRT  was elevated among women without a family history of breast cancer ( relative risk [ RR ] , 1.5 [ 95 % CI , 1.2 to 1.7 ] ) but was even greater among women with a family history ( RR , 3.4 [ CI , 2.0 to 6.0 ] ) . Of the studies not included in the meta- analysis , some [ 9 - 12 ] but not all [ 6 , 7 , 13 ] reported similar observations . Beyond the issue of the effects of HRT on the incidence of breast cancer , further consideration of the concomitant effect of HRT on risk for death is warranted . A recent report from the Nurses ' Health Study [ 8 ] suggests that hormonal therapy lasting at least 5 years is associated with a 45 % increase in the rate of death from breast cancer . Analytic epidemiologic studies suggest that women who receive HRT have a significantly lower risk for death , primarily because of protection against cardiovascular disease [ 14 - 17 ] . Thus , it is important to examine all-cause mortality when considering the risks and benefits of HRT use [ 18 ] , especially among women with a family history of breast cancer . As part of the Iowa Women 's Health Study , a prospect i ve cohort study of 41 837 women who were 55 to 69 years of age at baseline in 1986 , data were collected on self-reported family history of breast cancer in first-degree relatives and on history of HRT use . These data were used to examine the risks for postmenopausal breast cancer , case fatality , and total mortality . Methods The Iowa Women 's Health Study Cohort Participants in the Iowa Women 's Health Study were selected from a r and om sample of all women between 55 and 69 years of age who had a valid Iowa driver 's license in 1985 [ 19 ] . This sampling frame comprised approximately 94 % of female Iowa residents in that age range . The primary purpose of the study was to examine the association of obesity and body fat distribution with the incidence of cancer and mortality rate . A total of 41 837 women returned a mailed question naire ( response rate , 42.7 % ) . Three follow-up question naires mailed in October 1987 , August 1989 , and June 1992 were used to collect information on incident self-reported disease and each participant 's current residence . Only minor demographic differences were seen at baseline between respondents and nonrespondents [ 20 ] . Nonrespondents have subsequently been found to have a higher 5-year incidence of cancer and rate of death ( primarily death from diseases related to smoking ) [ 21 ] . The incidence of breast cancer , however , was similar among respond 
    Output:
    
Postdiagnosis HRT use also showed a beneficial effect on breast cancer survival .
In the subgroup analyses , we found that patients who were current users at diagnosis or who received combined hormone therapy  before diagnosis seemed to show more benefit from HRT use .
In conclusion , the average effect of HRT use seems not harmful to breast cancer survival .