Proton Therapy for Localized Prostate Cancer: Long-Term Results From a Single-Center Experience.

PURPOSE: Although proton therapy is controversial, it has been used to treat localized prostate cancer over the past 2 decades. The purpose of this study is to examine the long-term efficacy and toxicity of proton therapy for localized prostate cancer. METHODS AND MATERIALS: This was a retrospective observational study of 2021 patients from 2003 to 2014 at a single institution. Patients were classified using the risk groups defined by the National Comprehensive Cancer Network guidelines, version 4.2019. Ninety-eight percent of the patients received 74 Gy (relative biological effectiveness) in 37 fractions. Fifty-one and 6% of the patients received neoadjuvant and adjuvant androgen deprivation therapy, respectively. The outcomes were the time of freedom from biochemical relapse and the time to late toxicity by the National Cancer Institute Common Terminology Criteria for Adverse Events, version 4.0. The outcomes were estimated using the Kaplan-Meier method and were analyzed using multivariable Cox proportional hazards models. RESULTS: The median follow-up period was 84 months (interquartile range, 60-110). The 5- and 10-year freedom from biochemical relapse rates were 100% and 100%, 99% and 88%, 93% and 86%, 90% and 79%, 88% and 68%, and 76% and 63% for the very low, low, favorable intermediate, unfavorable intermediate, high, and very high-risk groups, respectively. Patients with higher risk experienced biochemical relapse after shorter periods. The 5-year rates of grade 2 or higher late genitourinary and gastrointestinal toxicity were 2.2% and 4.0%, respectively. The results of multivariable analyses indicate that younger patients more often experienced biochemical relapse. CONCLUSIONS: This study demonstrates the favorable biochemical controls of proton therapy even in advanced localized prostate cancer patients with a low incidence of late toxicities, supporting the feasibility of conducting prospective clinical trials. The risk groups defined by the National Comprehensive Cancer Network guidelines, version 4.2019, are useful to classify patients with localized prostate cancer. Our findings might suggest the necessity to develop a treatment strategy that accounts for the patient's age.

Long-term outcomes in patients treated with proton therapy for localized prostate cancer.

The aim of this retrospective study was to report long-term clinical outcomes in patients treated with proton therapy (PT) for localized prostate cancer. Between 2001 and 2014, 1375 consecutive patients were treated with PT. Patients were classified into prognostic risk groups based on the National Comprehensive Cancer Network criteria. Freedom from biochemical relapse (FFBR), cancer-specific survival (CSS) and incidence of late gastrointestinal (GI)/genitourinary (GU) toxicities were calculated. Multivariate analysis was performed to identify clinical prognostic factors for FFBR and late toxicities. The median follow-up period was 70 months (range, 4-145 months). In total, 99% of patients received 74 Gy (relative biologic effectiveness [RBE]); 56% of patients received neoadjuvant androgen deprivation therapy. For the low-, intermediate-, high-, and very high-risk groups, 5-year FFBR was 99% (95% confidence intervals [CI], 96-100%), 91% (95% CI, 88-93%), 86% (95% CI, 82-89%), and 66% (95% CI, 53-76%), respectively, and 5-year CSS was 100% (95% CI, 100-100%), 100% (95% CI, 100-100%) , 99% (95% CI, 97-100%), and 95% (95% CI, 94-98%), respectively. Patient age, T classification, Gleason score, prostate-specific antigen, and percentage of positive cores were significant prognostic factors for FFBR. Grade 2 or higher GI and GU toxicities were 3.9% and 2.0%. Patient age was a prognostic factor for both late GI and GU toxicities. This study represents the largest cohort of patients treated with PT for localized prostate cancer, with the longest follow-up to date. Our results demonstrate that the biochemical control of PT is favorable particularly for high- and very high-risk patients with lower late genitourinary toxicity and indicates the necessity of considering patient age in the treatment protocols.

Treatment results of alternating chemoradiotherapy for nasopharyngeal cancer using cisplatin and 5-fluorouracil--a phase II study.

The present study was conducted to evaluate the therapeutic results of alternating chemoradiotherapy for locally advanced nasopharyngeal cancer. The subjects were 87 patients with stage II-IVB nasopharyngeal cancer. Alternating chemoradiotherapy was performed; initially, chemotherapy was administered, and then radiotherapy (wide field), chemotherapy, radiotherapy (shrinking field), and chemotherapy were alternately performed. For chemotherapy, 5-FU at a dose of 800 mg/m2/24 h was intravenously administered for 5 days (days 1-5), and CDDP at a dose of 50 mg/m2/24h for 2 days was administered on day 6 and 7. The scheduled courses of alternating chemoradiotherapy were completed in 70 (80%) of 87 patients. Although 1 patient developed a transient neurological disturbance induced by hyper-ammonemia by metabolism of 5-FU, no severe adverse effects were noted in any other patients. In these 87 patients, the overall 5-year survival rate was 83% (95% confidence interval: 74-92%), and the progression free survival rate was 75% (95% CI: 66-85%). This method of alternating chemoradiotherapy yielded higher or at least similar survival rates and lower toxicities than concurrent chemoradiotherapy, and is worth trying in a randomized controlled study to compare with concurrent chemoradiotherapy.

Gargling with tea catechin extracts for the prevention of influenza infection in elderly nursing home residents: a prospective clinical study.

OBJECTIVES: To evaluate the effects of gargling tea catechin extracts on the prevention of influenza infection in elderly nursing home residents. DESIGN: A prospective study conducted for 3 months from January to March 2005. SETTINGS/LOCATION: A nursing home in Japan. SUBJECTS: A total of 124 elderly residents of at least 65 years of age were enrolled in the study. Seventy-six residents (83 +/-8.2 years, mean +/-standard deviation; 24 men, 52 women) gargled with tea catechin extract (catechin group) and were compared with 48 age- and sex-matched residents who gargled without tea catechin extracts (control group). All the residents were vaccinated with an influenza vaccine until early December 2004. INTERVENTIONS: catechin group: gargling with the tea catechin extract solution (200 microg/mL catechins, 60% of catechins comprise epigallocatechin gallate); control group: gargling without the catechin extract solution. In both groups, gargling was performed three times daily for 3 months. OUTCOME MEASURES: The incidence of influenza infection during the study was compared between the two groups. A safety evaluation was conducted to observe adverse events during the study. RESULTS: The incidence of influenza infection was significantly lower in the catechin group (1.3%, one resident) than in the control group (10%, five residents) calculated by multivariate logistic regression analysis (p = 0.028; odds ratio, 15.711; 95% confidence interval, 1.883-399.658). No adverse events, such as respiratory tract irritation, an obstruction, or allergic bronchial spasm, were observed during the study. CONCLUSIONS: This prospective study demonstrating the effect of catechin gargling on the prevention of influenza infection in the elderly is the first to be reported in the literature. Further randomized, controlled studies are needed to confirm the effects of catechin gargling on the prevention of influenza infection.