Real-world prostate-specific antigen response and progression to castration-resistant prostate cancer among men with metastatic castration-sensitive prostate cancer treated with apalutamide: a multi-institutional study in the Chu-shikoku Japan Urological Consortium.

BACKGROUND: Japanese men receiving apalutamide often experience skin-adverse events (AEs), possibly requiring treatment interruption or dose reduction. However, concerns have arisen regarding the impact of these adjustments on the efficacy of apalutamide. Our study evaluated the efficacy, safety, and persistence of apalutamide in men with metastatic castration-sensitive prostate cancer (mCSPC). METHODS: We retrospectively reviewed the medical records of 108 men with mCSPC from 14 Japanese institutions. The primary outcomes were the efficacy of apalutamide: prostate-specific antigen (PSA) response (50%, 90% and < 0.2 decline) and progression to castration-resistant prostate cancer (CRPC). The secondary outcomes were the skin-AE and compliance of apalutamide. RESULTS: PSA50%, PSA90% and PSA < 0.2 declines were observed in 89.8, 84.3 and 65.7%, and the median time to CRPC progression was not reached. PSA < 0.2 decline and an initial full dose of apalutamide were significantly associated with a longer time to CRPC. The most common AE was skin-AE (50.9%), and there was no association between the occurrence of skin-AE and the time to CRPC (P = 0.72). The median apalutamide persistence was 29 months, which was longer in the initial full dose recipients than in the reduced dose recipients. The dosage is reduced in about 60% of patients within the first year of treatment in the initial full dose recipients. CONCLUSIONS: Our findings indicate the effectiveness of apalutamide in Japanese men with mCSPC, despite a substantial portion requiring dose reduction within a year among the initial full dose recipients.

Health-related quality of life in the first year after laparoscopic radical prostatectomy compared with open radical prostatectomy.

OBJECTIVE: To assess health-related quality of life in the first year after laparoscopic radical prostatectomy compared with that after open radical prostatectomy. METHODS: The subjects were 105 consecutive patients with localized prostate cancer treated with laparoscopic radical prostatectomy between January 2011 and June 2012. Health-related quality of life was evaluated using the International Prostate Symptom Score, Medical Outcome Study 8-Items Short Form Health Survey (SF-8) and Expanded Prostate Cancer Index Composite at baseline and 1, 3, 6 and 12 months after surgery. Comparisons were made with data for 107 consecutive patients treated with open radical prostatectomy between October 2005 and July 2007. RESULTS: The International Prostate Symptom Score change was similar in each group. The laparoscopic radical prostatectomy group had a better baseline Medical Outcome Study 8-Items Short Form Health Survey mental component summary score and a better Medical Outcome Study 8-Items Short Form Health Survey physical component summary score at 1 month after surgery. In Expanded Prostate Cancer Index Composite, obstructive/irritative symptoms did not differ between the groups, but urinary incontinence was worse until 12 months after surgery and particularly severe after 1 month in the laparoscopic radical prostatectomy group. The rate of severe urinary incontinence was much higher in the laparoscopic radical prostatectomy group in the early period. Urinary bother was worse in the laparoscopic radical prostatectomy group at 1 and 3 months, but did not differ between the groups thereafter. Urinary function and bother were good after nerve sparing procedures and did not differ between the groups. Bowel and sexual function and bother were similar in the two groups. CONCLUSION: Urinary function in the first year after laparoscopic radical prostatectomy is worse than that after open radical prostatectomy.

DCK is frequently inactivated in acquired gemcitabine-resistant human cancer cells.

Although gemcitabine is the most effective chemotherapeutic agent against pancreatic cancer, a growing concern is that a substantial number of patients acquire gemcitabine chemoresistance. To elucidate the mechanisms of acquisition of gemcitabine resistance, we developed gemcitabine-resistant cell lines from six human cancer cell lines; three pancreatic, one gastric, one colon, and one bile duct cancer. We first analyzed gemcitabine uptake using three paired parental and gemcitabine resistant pancreatic cancer cell lines (PK-1 and RPK-1, PK-9 and RPK-9, PK-59 and RPK-59) and found that uptake of gemcitabine was rapid. However, no DNA damage was induced in resistant cells. We further examined the microarray-based expression profiles of the cells to identify genes associated with gemcitabine resistance and found a remarkable reduction in the expression of deoxycytidine kinase (DCK). DCK is a key enzyme that activates gemcitabine by phosphorylation. Genetic alterations and expression of DCK were studied in these paired parental and derived gemcitabine-resistant cell lines, and inactivating mutations were found only in gemcitabine-resistant cell lines. Furthermore, siRNA-mediated knockdown of DCK in the parental cell lines yielded gemcitabine resistance, and introduction of DCK into gemcitabine-resistant cell lines invariably restored gemcitabine sensitivities. Mutation analyses were expanded to three other different paired cell lines, DLD-1 and RDLD-1 (colon cancer cell line), MKN-28 and RMKN-28 (gastric cancer cell line), and TFK-1 and RTFK -1 (cholangiocarcinoma cell line). We found inactivating mutations in RDLD-1 and RTFK-1 and decreased expression of DCK in RMKN-28. These results indicate that the inactivation of DCK is one of the crucial mechanisms in acquisition of gemcitabine resistance.