The SWENOTECA-MIR prospective multicenter study aims to assess the clinical value of miR-371a-3p as a novel marker in metastatic germ cell tumor patients undergoing retroperitoneal lymph node dissection (RPLND), to predict the presence of viable residual tumor. A total of 114 patients (86 nonseminomas, 28 seminomas) who underwent surgery for presumed metastatic disease pre-chemotherapy (primary RPLND), and post-chemotherapy RPLND were included. The expression of miR-371a-3p was evaluated using RT-digital droplet PCR before and after RPLND. Pre- and post-operative miR-371a-3p levels were statistically compared, and optimism-corrected performance calculations compared with conventional serum tumor markers. Associations were evaluated by logistic regression. Patients who underwent primary RPLND were categorized into seminoma and nonseminoma groups. Among the seminoma patients (n = 24) undergoing primary RPLND, all had normal conventional markers. Six patients received adjuvant treatment before surgery. miR-371a-3p exhibited a sensitivity of 74%, specificity of 100%, PPV of 100% and NPV of 21% for viable tumor. The levels of miR-371a-3p significantly decreased after surgery. In the nonseminoma group (n = 18) treated with primary RPLND, 22% had elevated conventional markers, and 3 had received prior adjuvant treatment. miR-371a-3p showed a sensitivity of 34%, specificity of 88%, PPV of 67% and NPV of 62% for the primary nonseminoma patients. No association was observed between stage or prior adjuvant treatment, and the outcome of the miR-test. In the post-chemotherapy group (n = 72), the miR-371a-3p sensitivity was 9%, reducing to 0 when excluding patients with seminoma (n = 4). Teratomas and benign histology were essentially negative. Our study highlights miR-371a-3p as a fairly sensitive and highly specific marker for pre-chemotherapy seminomas, outperforming conventional markers. However, in pre-chemotherapy non-seminomas as well as in post-chemotherapy patients, we observed low sensitivity and no significant differences in miR-371a-3p levels before and after surgery, suggesting limited utility for miR-371a-3p in this context.

Phytoestrogens have been suggested to have an anti-proliferative role in prostate cancer, potentially by acting through estrogen receptor beta (ERβ) and modulating several hormones. We primarily aimed to investigate the effect of a phytoestrogen intervention on hormone concentrations in blood depending on the ERβ genotype. Patients with low and intermediate-risk prostate cancer, scheduled for radical prostatectomy, were randomized to an intervention group provided with soybeans and flaxseeds (∼200 mg phytoestrogens/d) added to their diet until their surgery, or a control group that was not provided with any food items. Both groups received official dietary recommendations. Blood samples were collected at baseline and endpoint and blood concentrations of different hormones and phytoestrogens were analyzed. The phytoestrogen-rich diet did not affect serum concentrations of testosterone, insulin-like growth factor 1, or sex hormone-binding globulin (SHBG). However, we found a trend of decreased risk of increased serum concentration of estradiol in the intervention group compared to the control group but only in a specific genotype of ERβ (p = 0.058). In conclusion, a high daily intake of phytoestrogen-rich foods has no major effect on hormone concentrations but may lower the concentration of estradiol in patients with prostate cancer with a specific genetic upset of ERβ.