Nationwide Japanese Prostate Cancer Outcome Study of Permanent Iodine-125 Seed Implantation (J-POPS).
BACKGROUND
To evaluate the safety and efficacy of brachytherapy with permanent iodine-125 seed implantation (PI) for prostate cancer. The nationwide Japanese Prostate Cancer Outcome Study of Permanent Iodine-125 Seed Implantation (J-POPS) has continued since July 2005. This manuscript presents the rationale, J-POPS study design, and the characteristics of initial participants enrolled in this study from July 2005 to June 2007.


METHODS
All participants were treated with PI in accordance with the American Brachytherapy Society recommendations. The primary outcome measure was biochemical progression-free survival. Progression-free survival, overall survival, cause-specific survival, longitudinal changes in health-related quality of life, disease-specific quality of life, the International Prostate Symptom Score, and the incidence of adverse events were also investigated as secondary outcome measurements.


RESULTS
Overall, 6,927 patients were enrolled by the end of 2010, that is approximately 40 % of all cases treated around the country. During the first 2 years, 2,354 participants were enrolled and 2,339 were actually treated with PI. The age range of participants was 45 to 89 years (median 69 years) and their risk classifications were 1,037 (44.3 %) at low risk, 1,126 (48.1 %) at intermediate risk, and 134 (5.7 %) at high risk, in addition to 16 participants whose classification was unknown. Of all patients, 76.6 % were treated with PI without external beam radiation therapy and 49.3 % received neoadjuvant hormone therapy.


CONCLUSIONS
The J-POPS, a nationwide prospective cohort study that enrolled approximately 40 % of all PI cases in Japan, will provide highly reliable evidence, including outcomes and quality of life, after long-term follow-up.
Department of Urology, National Hospital Organization Tokyo Medical Center, 2-5-1 Higashigaoka Meguro-ku, Tokyo, 152-8902, Japan, saitoshr@netjoy.ne.jp.
Shiro
S
Saito
Kazuto
K
Ito
Atsunori
A
Yorozu
Manabu
M
Aoki
Hirofumi
H
Koga
Takefumi
T
Satoh
Toshio
T
Ohashi
Naoyuki
N
Shigematsu
Shinichiro
S
Maruo
Takashi
T
Kikuchi
Shinsuke
S
Kojima
Takushi
T
Dokiya
Masanori
M
Fukushima
Hidetoshi
H
Yamanaka
D000230:Adenocarcinoma / Q000097:blood / Q000532:radiotherapy* / Q000628:therapy; D000368:Aged; D000369:Aged, 80 and over; D000726:Androgen Antagonists / Q000627:therapeutic use; D001918:Brachytherapy / Q000009:adverse effects / Q000379:methods*; D003131:Combined Modality Therapy; D018572:Disease-Free Survival; D006801:Humans; D007457:Iodine Radioisotopes / Q000009:adverse effects / Q000627:therapeutic use*; D007564:Japan; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000097:blood / Q000532:radiotherapy* / Q000628:therapy; D011788:Quality of Life; D011829:Radiation Dosage; D015996:Survival Rate
D000726:Androgen Antagonists; D007457:Iodine Radioisotopes; D017430:Prostate-Specific Antigen