Cancer‐specific mortality of high‐risk prostate cancer after carbon‐ion radiotherapy plus long‐term androgen deprivation therapy

Abstract

The treatment outcomes of patients with high‐risk localized prostate cancer (PC) after carbon‐ion radiotherapy (CIRT) combined with long‐term androgen deprivation therapy (LTADT) were analyzed, and compared with those of other treatment modalities, focusing on PC‐specific mortality (PCSM). A total of 1247 patients were enrolled in three phase II clinical trials of fixed‐dose CIRT between 2000 and 2013. Excluding patients with T4 disease, 608 patients with high‐risk or very‐high‐risk PC, according to the National Comprehensive Cancer Network classification system, who received CIRT with LTADT were evaluated. The median follow‐up time was 88.4 months, and the 5‐/10‐year PCSM rates were 1.5%/4.3%, respectively. T3b disease, Gleason score of 9–10 and percentage of positive biopsy cores >75% were associated with significantly higher PCSM on univariate and multivariate analyses. The 10‐year PCSM rates of patients having all three (n = 16), two (n = 74) or one of these risk factors (n = 217) were 27.1, 11.6 and 5.7%, respectively. Of the 301 patients with none of these factors, only 1 PCSM occurred over the 10‐year follow‐up (10‐year PCSM rate, 0.3%), and significant differences were observed among the four stratified groups (P <0.001). CIRT combined with LTADT yielded relatively favorable treatment outcomes in patients with high‐risk PC and very favorable results in patients without any of the three abovementioned factors for PCSM. Because a significant difference in PCSM among the high‐risk PC patient groups was observed, new categorization and treatment intensity adjustment may be required for high‐risk PC patients treated with CIRT.

Preliminary result of carbon-ion radiotherapy using the spot scanning method for prostate cancer

“…In the case of T3b prostate cancer, the ipsilateral seminal vesicles were included in the CTV [22]. Prophylactic pelvic lymph node area was not included in the CTV [23]. Planning target volume (PTV) 1 was created by adding anterior and lateral margins of 10 mm and a posterior margin of 5 mm to the CTV.…”

Carbon Ion Therapy: A Modern Review of an Emerging Technology

“…Similarly, patients with high risk or very high risk prostate cancer who received CIRT with long term androgen deprivation therapy had a 10-year prostate cancer specific mortality rate of 4.3%. The 10-year incidence of grade 2 GU toxicity was 11.7%, with grade 3 GU toxicity occurring in 0.5% of patients (84).…”

Estimating the Number of Patients Eligible for Carbon Ion Radiotherapy in the United States

“…The number of patients eligible for CIRT was then estimated for each disease site, based on inclusion criteria from previously published protocols and retrospective studies from Germany and Japan. The following disease sites were included: glioblastoma (based on the CLEOPATRA protocol, using CIRT as a boost [17]), hepatocellular carcinoma (PROMETHEUS-01 protocol/NCT01167374 [18]), cholangiocarcinoma (J-CROS study [19]), locally advanced pancreatic cancer (PHOENIX and CIPHER/NCT03536182 studies [9]), early and locally advanced non-small cell lung cancer (multiple retrospective studies [20][21][22][23]), localized prostate cancer (multiple retrospective studies [23][24][25][26]), soft tissue sarcomas (multiple retrospective studies [27,28]) and head and neck cancers, including salivary gland cancers (COSMIC protocol/NCT01154270 [29]), sinonasal cancers (NCT01220752 and retrospective studies [30]) and nasopharyngeal cancers (multiple retrospective studies [31,32]). Further histologic classification (such as adenoid cystic carcinoma or mucosal melanoma) of the general disease sites was possible given the limitations of the various databases used ( Table 1).…”