**3.4 Clinical studies in prostate cancer**

Mills et al., (1989), through the Seventh Day Adventist men study, showed a link between low prostate cancer risk and frequent tomato consumption, along with beans, lentils and peas, raisins, dates, and other dried fruit. Giovannucci et al., (2007) performed an analysis on data from the Health Professionals study and found that higher tomato sauce (assumed to be lycopene) intake correlated inversely with prostate cancer incidence; indeed, this was only one of four factors (in addition to African American race, positive family history, and alpha-linolenic acid intake) that predicted for incidence and advanced prostate cancer.

In a small, randomized trial of 30mg lycopene supplementation over 3 weeks prior to prostatectomy, margin positivity at surgery was reduced by lycopene, though no other endpoints were affected (Kucuk et al., 2001). The study was extremely small, and no conclusions can be drawn.

Zhang et al., (2010) recently reported a study in 41 men with localized prostate cancer given 10mg lycopene once a day. Seventy percent of men had a reduced slope of PSA rise, and 21% had a decrease in their PSA levels. However, scant details were available for the study, and we do not know whether there were confounding variables; further, this would appear to be the same patient population as in a previous publication (Barber et al., 2006). In a study of 41 men with localised prostate cancer (Barber et al., 2006) given 20 mg lycopene daily, nearly 70% of patients had a slower rate of PSA rise post-treatment. A study in 20 consecutive men with hormone refractory prostate cancer treated with lycopene 10mg daily had shown a response rate (complete and partial) of 35% (Ansari et al., 2004). However, this phenomenal response rate has not been able to be repeated. Indeed, Vaishampayan et al., (2007) reported a study in 38 men with hormone sensitive and resistant cancer randomized to the lycopene alone arm and found only PSA stabilization, without any patient qualifying for a partial response. Adding soy isoflavones (to men randomized to the other arm) did not appear to improve outcome. Another study in 46 patients with androgen-independent prostate cancer prescribed 15mg lycopene daily found only one patient with a PSA response; toxicity included mainly grade 1-2 diarrhea, nausea, flatulence, and abdominal distension (Jatoi et al., 2007).
