***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: PURPOSE To determine whether a diet low in fat and high in fruits , vegetables , and fiber may be protective against prostate cancer by having an impact on serial levels of serum prostate-specific antigen ( PSA ) . METHODS Six hundred eighty-nine men were r and omized to the intervention arm and 661 to the control arm . The intervention group received intensive counseling to consume a diet low in fat and high in fiber , fruits , and vegetables . The control group received a st and ard brochure on a healthy diet .  PSA in serum was measured at baseline and annually thereafter for 4 years , and newly diagnosed prostate cancers were recorded . RESULTS The individual PSA slope for each participant was calculated , and the distributions of slopes were compared between the two groups . There was no significant difference in distributions of the slopes ( P = .99 ) . The two groups were identical in the proportions of participants with elevated PSA at each time point . There was no difference in the PSA slopes between the two groups ( P = .34 ) and in the frequencies of elevated PSA values for those with elevated PSA at baseline . Incidence of prostate cancer during the 4 years was similar in the two groups ( 19 and 22 in the control and intervention arms , respectively ) . CONCLUSION Dietary intervention over a 4-year period with reduced fat and increased consumption of fruits , vegetables , and fiber has no impact on serum PSA levels in men . The study also offers no evidence that this dietary intervention over a 4-year period affects the incidence of prostate cancer during the 4 years The relationship between risk of prostate cancer  and dietary intake of energy , fat , vitamin A , and other nutrients was investigated in a case-control study conducted in Ontario , Canada . Cases were men with a recent , histologically confirmed diagnosis of adenocarcinoma of the prostate notified to the Ontario Cancer Registry between April 1990 and April 1992 . Controls were selected r and omly from assessment lists maintained by the Ontario Ministry of Revenue , and were frequency-matched to the cases on age . The study included 207 cases ( 51.4 percent of those eligible ) and 207 controls ( 39.4 percent of those eligible ) , and information on  dietary intake  was collected from them by means of a quantitative diet history . There was a positive association between energy intake and risk of prostate cancer , such that men at the uppermost quartile level of energy intake had a 75 percent increase in risk . In contrast , there was no clear association between the non-energy effects of total fat and monounsaturated fat intake and prostate cancer risk . There was some evidence for an inverse association with saturated fat intake , although the dose-response pattern was irregular . There was a weak ( statistically nonsignificant ) positive association between polyunsaturated fat intake and risk of prostate cancer . Relatively high levels of retinol intake were associated with reduced risk , but there was essentially no association between dietary β-carotene intake and risk . There was no alteration in risk in association with dietary fiber , cholesterol , and vitamins C and E. Although these patterns were evident both overall and within age-strata , and persisted after adjustment for a number of potential confounding factors , they could reflect ( in particular ) the effect of nonrespondent bias A rising level of prostate-specific antigen ( PSA ) , after primary surgery or radiation therapy , is the hallmark of recurrent prostate cancer and is often the earliest sign of extraprostatic spread in patients who are otherwise asymptomatic . While hormonal therapy may slightly extend survival in a minority of patients , it is not curative and produces side effects including hot flashes , decreased libido , and loss of bone mass . Alternatively , dietary modification may offer an important tool for clinical management . Epidemiologic studies have associated the Western diet not only with prostate cancer incidence but also with a greater risk of disease progression after treatment . Conversely , many elements of plant-based diets have been associated with reduced risk of progression . However , dietary modification can be stressful and difficult to implement . We therefore conducted a 6-month pilot clinical trial to investigate whether adoption of a plant-based diet , reinforced by stress management training , could attenuate the rate of further PSA rise .  Urologists at the University of California , San Diego , and San Diego Veterans Affairs Medical Centers recruited 14 patients with recurrent prostate cancer . A pre-post design was employed in which each patient served as his own control . Rates of PSA rise were ascertained for each patient for the following periods : from the time of posttreatment recurrence up to the start of the study ( pre study ) and from the time immediately preceding the intervention ( baseline ) to the end of the intervention ( 0 - 6 months ) . There was a significant decrease in the rate of PSA rise from pre study to 0 to 6 months ( P < .01 ) . Four of 10 evaluable patients experienced an absolute reduction in their PSA levels over the entire 6-month study . Nine of 10 had a reduction in their rates of PSA rise and an improvement of their PSA doubling times . Median PSA doubling time increased from 11.9 months ( pre study ) to 112.3 months ( intervention ) . These results provide preliminary evidence that adoption of a plant-based diet , in combination with stress reduction , may attenuate disease progression and have therapeutic potential for clinical management of recurrent prostate cancer Epidemiological studies have shown an inverse association between dietary intake of lycopene and prostate cancer risk . We conducted a clinical trial to investigate the biological and clinical effects of lycopene supplementation in patients with localized prostate cancer . Twenty-six men with newly diagnosed prostate cancer were r and omly assigned to receive a tomato oleoresin extract containing 30 mg of lycopene ( n = 15 ) or no supplementation ( n = 11 ) for 3 weeks before radical prostatectomy . Biomarkers of cell proliferation and apoptosis were assessed by Western blot analysis in benign and cancerous prostate tissues . Oxidative stress was assessed by measuring the Peripheral blood lymphocyte ONA oxidation product 5-hydroxymethyl-deoxyuridine ( 5-OH-mdU ) . Usual  dietary Intake  of nutrients was assessed by a food frequency question naire at baseline . Prostatectomy specimens were evaluated for pathologic stage , Gleason score , volume of cancer , and extent of high- grade prostatic intraepithelial neoplasia . Plasma levels of lycopene , insulin-like growth factor-1 , insulin-like growth factor binding protein-3 , and prostate-specific antigen were measured at baseline and after 3 weeks of supplementation or observation . After intervention , subjects in the intervention group had smaller tumors ( 80 % vs 45 % , less than 4 ml ) , less involvement of surgical margins and /or extra-prostatic tissues with cancer ( 73 % vs 18 % , organ-confined disease ) , and less diffuse involvement of the prostate by high- grade prostatic intraepithelial neoplasia ( 33 % vs 0 % , focal involvement ) compared with subjects in the control group .  Mean plasma prostate-specific antigen levels were lower in the intervention group compared with the control group . This pilot study suggests that lycopene may have beneficial effects in prostate cancer . Larger clinical trials are Warranted to investigate the potential preventive and /or therapeutic role of lycopene in prostate cancer BACKGROUND Multivitamin supplements are used by millions of Americans because of their potential health benefits , but the relationship between multivitamin use and prostate cancer is unclear . METHODS We prospect ively investigated the association between multivitamin use and risk of prostate cancer ( localized , advanced , and fatal ) in 295,344 men enrolled in the National Institutes of Health (NIH)-AARP Diet and Health Study who were cancer free at enrollment in 1995 and 1996 . During 5 years of follow-up , 10,241 participants were diagnosed with incident prostate cancer , including 8765 localized and 1476 advanced cancers . In a separate mortality analysis with 6 years of follow-up , 179 cases of fatal prostate cancer were ascertained . Multivitamin use was assessed at baseline as part of a self-administered , mailed food-frequency question naire .  Relative risks ( RRs ) and 95 % confidence intervals ( CIs ) were calculated by use of Cox proportional hazards regression , adjusted for established or suspected prostate cancer risk factors . RESULTS No association was observed between  multivitamin use and risk of localized prostate cancer . However , we found an increased risk of advanced and fatal prostate cancers ( RR = 1.32 , 95 % CI = 1.04 to 1.67 and RR = 1.98 , 95 % CI = 1.07 to 3.66 , respectively ) among men reporting excessive use of multivitamins  ( more than seven times per week ) when compared with never users . The incidence rates per 100,000 person-years for advanced and fatal prostate cancers for those who took a multivitamin more than seven times per week were 143.8 and 18.9 , respectively , compared with 113.4 and 11.4 in never users . The positive associations with excessive multivitamin use were strongest in men with a family history of prostate cancer or who took individual micronutrient supplements , including selenium , beta-carotene , or zinc . CONCLUSION These results suggest that regular multivitamin use is not associated with the risk of early or localized prostate cancer . The possibility that men taking high levels of multivitamins along with other supplements have increased risk of advanced and fatal prostate cancers is of concern and merits further evaluation PURPOSE The effects of a low-fat diet or a low-fat diet with the addition of a soy supplement were investigated in a pilot Phase II study for asymptomatic , hormonally naive prostate cancer patients with rising prostate-specific antigen ( PSA ) levels . EXPERIMENTAL DESIGN A two-step intervention was implemented . During step 1 patients were begun on a low-fat diet with a goal to reduce fat intake to 15 % of total daily calories . On PSA progression , a soy protein supplement was added to the diet ( step 2 ) . The primary end point was PSA reduction by 50 % . Secondary end points were PSA doubling time and time to progression ( TTP ) . Serum was analyzed for changes in the sex hormone and insulin-like growth factor ( IGF-I ) axes . RESULTS Among 18 evaluable patients , ( median follow-up on study 10.5 months ) , no patient on either step had a PSA reduction by 50 % at any time . There was a trend toward a longer PSA doubling time ( P = 0.06 ) and a prolongation in estimated median TTP of approximately 3 months ( P = 0.018 ) during step 2 compared with step 1 of the study . During step 1 , free testosterone levels decreased by 5 % ( P < 0.01 ) , and during step 2 , IGF-I levels increased by 22 % ( P = 0.02 ) . CONCLUSIONS A low-fat diet with the subsequent addition of a soy supplement did not result in a significant decline in PSA levels . The addition of soy protein had a modest effect on TTP . A potentially undesirable effect associated with the administration of soy was an increase in IGF-I serum levels The purpose of this study was to determine the effects of soy protein isolate consumption on circulating hormone profiles and hormone receptor expression patterns in men at high risk for developing advanced prostate cancer . Fifty-eight men were r and omly assigned to consume 1 of 3 protein isolates containing 40 g/d protein : 1 ) soy protein isolate ( SPI+ ) ( 107 mg/d isoflavones ) ; 2 ) alcohol-washed soy protein isolate ( SPI- ) ( < 6 mg/d isoflavones ) ; or 3 ) milk protein isolate ( 0 mg/d isoflavones ) . For 6 mo , the men consumed the protein isolates in divided doses twice daily as a partial meal replacement . Serum sample s collected at 0 , 3 , and 6 mo were analyzed for circulating estradiol , estrone , sex hormone-binding globulin , and rostenedione , and rostanediol glucuronide , dehydroepi and rosterone sulfate , dihydrotestosterone , testosterone , and free testosterone concentrations by RIA . Prostate biopsy sample s obtained pre- and postintervention were analyzed for and rogen receptor ( AR ) and estrogen receptor-beta expression by immunohistochemistry . At 6 mo , consumption of SPI+ significantly suppressed AR expression but did not alter estrogen receptor-beta expression or circulating hormones . Consumption of SPI- significantly increased estradiol and and rostenedione concentrations , and tended to suppress AR expression ( P = 0.09 ) . Although the effects of SPI- consumption on estradiol and and rostenedione are difficult to interpret and the clinical relevance is uncertain , these data show that AR expression in the prostate is suppressed by soy protein isolate consumption , which may be beneficial in preventing prostate cancer OBJECTIVES Epidemiological studies have shown significant relationships between the use of dietary components and prostate cancer incidence and mortality . Large studies of primary prevention , which confirm these findings , are desirable but costly and difficult to design . The present tertiary prevention study reports on the effect of a dietary supplement in comparison with placebo on the rate of increase of prostate-specific antigen ( PSA ) . METHODS 49 patients with a history of prostate cancer and rising PSA levels after radical prostatectomy ( n = 34 ) or radiotherapy ( n = 15 ) 
    Output:
    
Although conclusive evidence is limited , the current data are indicative that a diet low in fat , high in vegetables and fruits , and avoiding high energy intake , excessive meat , excessive dairy products and calcium intake , is possibly effective in preventing PC .
The dietary recommendations for patients diagnosed with PC are similar to those aim ing to reduce their risk of PC