Changes in the Clinicopathological Demographics of Vulvar Cancer in Japan: Increasing Oldest-Old, Stage Shifting, and Decreasing Cohort-Level Survival †

Shin Nishio; Koji Matsuo; Takeo Shibata; Satoshi Yamaguchi; Hiroyuki Kanao; Kazuhiro Takehara; Nobuhiro Kado; Akiko Tozawa; Hideki Tokunaga; Tatsuya Matsunaga; Hisamori Kato; Koji Horie; Akira Kikuchi; Takayuki Enomoto; Mikio Mikami

doi:10.3390/jcm8122081

Changes in the Clinicopathological Demographics of Vulvar Cancer in Japan: Increasing Oldest-Old, Stage Shifting, and Decreasing Cohort-Level Survival ^†

J Clin Med. 2019 Nov 29;8(12):2081. doi: 10.3390/jcm8122081.

Authors

Shin Nishio¹, Koji Matsuo², Takeo Shibata³, Satoshi Yamaguchi⁴, Hiroyuki Kanao⁵, Kazuhiro Takehara⁶, Nobuhiro Kado⁷, Akiko Tozawa⁸, Hideki Tokunaga⁹, Tatsuya Matsunaga¹⁰, Hisamori Kato¹¹, Koji Horie¹², Akira Kikuchi¹³, Takayuki Enomoto¹⁴, Mikio Mikami¹⁵

Affiliations

¹ Department of Obstetrics and Gynecology, Kurume University School of Medicine, Kurume, Fukuoka 830-0011, Japan.
² Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, University of Southern California, Los Angeles, CA 90033, USA.
³ Department of Health Management, Tokai University, Hiratsuka, Kanagawa 259-1292, Japan.
⁴ Department of Gynecologic Oncology, Hyogo Cancer Center, Akashi, Hyogo 673-0021, Japan.
⁵ Department of Gynecologic Oncology, Cancer Institute Hospital of JFCR, Tokyo 135-0063, Japan.
⁶ Department of Gynecologic Oncology, National Hospital Organization Shikoku Cancer Center, Matsuyama, Ehime 791-0245, Japan.
⁷ Department of Gynecologic Oncology, Shizuoka Cancer Center, Shizuoka 411-0934, Japan.
⁸ Department of Obstetrics and Gynecology, St. Marianna University School of Medicine, Kawasaki, Kanagawa 216-8511, Japan.
⁹ Department of Obstetrics and Gynecology, Tohoku University School of Medicine, Sendai, Miyagi 980-8574, Japan.
¹⁰ Department of Obstetrics and Gynecology, Yokohama City University Hospital, Yokohama, Kanagawa 236-0004, Japan.
¹¹ Department of Gynecology, Kanagawa Cancer Center, Yokohama, Kanagawa 241-8515, Japan.
¹² Department of Gynecology, Saitama Cancer Center, Saitama 362-0806, Japan.
¹³ Department of Gynecology, Niigata Cancer Center Hospital, Niigata 951-8133, Japan.
¹⁴ Department of Obstetrics and Gynecology, Niigata University School of Medicine, Niigata 951-8510, Japan.
¹⁵ Department of Obstetrics and Gynecology, Tokai University Hospital, Isehara, Kanagawa 259-1193, Japan.

Abstract

Background: To examine trends in the clinicopathological characteristics of vulvar cancer in Japan.

Methods: This is a nationwide retrospective study examining consecutive women with vulvar cancer between 2001 and 2010 in Japan (n = 1061). Temporal trends in demographics, tumor characteristics, and survival were assessed by cohort-level analysis. The National Cancer Institute's Surveillance, Epidemiology, and End Result Program was used for external validation (n = 10,154).

Results: The number of oldest-old women aged ≥80 years significantly increased (from 18.0% in 2001 to 30.6% in 2010; 70.5% relative increase) in the study period. A stage shift was observed, with stage I disease decreasing from 43.0% to 34.0% (21.0% relative decrease), and tumors with distant metastases increasing from 23.2% to 35.6% (53.3% relative increase, p < 0.05). The number of women who underwent surgical treatment decreased from 84.0% to 69.7% (17.0% relative decrease), whereas utilization of radiotherapy increased from 34.4% to 43.2% (25.7% relative increase) over time (p < 0.05). In the cohort-level analysis, the five-year survival rates significantly decreased from 2001 to 2010 (p < 0.05), specifically, 66.9% to 51.0% for progression-free survival (23.7% relative decrease), 79.5% to 67.9% for cause-specific survival (14.6% relative decrease), and 74.9% to 62.3% for overall survival (16.9% relative decrease). In the patient-level analysis, oldest-old women were less likely to undergo surgical treatment and were independently associated with decreased survival (p < 0.05). In the US cohort, the number of oldest-old women (25.2% to 27.8%) and the five-year cause-specific survival rate (81.8% to 79.9%) remained unchanged during the study period (p > 0.05).

Conclusion: Demographics and outcomes of vulvar cancer in Japan significantly changed during the study period. An increasing oldest-old population and a stage shift to more metastatic disease resulted in a cohort-level decrease in survival rates.

Keywords: Japan; demographics; elderly; survival; trends; vulvar cancer.