Trends in Cancer Coverage in Japanese Newspapers
Authors: Yukiko Kishi, Soichiro Nagamatsu, Morihito Takita, Yuko Kodama, Akiko Hori, Nobuyo Hatanaka, Tamae Hamaki, Eiji Kusumi, Kazuhiko Kobayashi, Tomoko Matsumura, Koichiro Yuji, Hiroto Narimatsu, Yuji Tanaka, Masahiro Kami
Journal: Journal of Clinical Oncology (2008)

Cancer has been the leading cause of death since 1981 in Japan, 1 and the public is seeking information on cancer.Cancer information can be divided into two categories: general cancer information regarding therapies and specialized hospitals, and specific information regarding patients' conditions.The mass media deliver the former, general information, which has a considerable influence on citizens.The estimated audience for a television program with an audience rating of 8.3% is approximately 3 million (NHK Broadcasting Culture Research Institute), 2 whereas the circulation of each major newspaper is between 2.2 and 10 million.Newspapers may be effective for providing correct and easy-to-understand information on cancer to the public.Because no one has investigated the influence of cancer articles in newspapers thus far, we investigated cancer-related articles in newspapers to reveal trends in public interest in health care.In this study, we investigated the number of cancer-related articles published from 1992 to 2007 using Nikkei Telecom 21, the largest newspaper database in Japan.Of the registered newspapers, five major newspapers-Asahi, Mainichi, Yomiuri, Sankei, and Nihon Keizai (Nikkei)-were chosen, which account for 27 million official subscribers.In those newspapers, the number of cancer-related articles was counted.We used "cancer," "malignant tumor," and "malignant neoplasm" as keywords to search for cancer-related articles.We included three types of Japanese characters to express cancer, or gan (hiragana, katakana, and Chinese characters).Next, the annual change in the number of cancer-related articles in the newspapers was recorded and analyzed.This was compared with the number of times that the cancer-related keywords occurred in the newspapers in 2007.In addition, each word that was seen in more than 100 articles was traced to identify the trend from 1992 to 2007.The total number of articles in the five major newspapers targeted is shown in Figure 1A.The annual number of articles registered in the database started to increase in the early 1990s, but it remained almost constant after 2000.After 2000, the annual numbers of articles registered from Asahi, Yomiuri, and Mainichi were approximately three times the numbers of those from Nihon Keizai and Sankei.The number of cancer-related articles in the five major newspapers targeted is shown in Figure 1B.The annual number of cancer-related articles registered in the database started to increase in the early 1990s, but it remained almost constant after 2000.After 2000, the numbers of such articles registered from Asahi, Yomiuri, and Mainichi and those from Sankei were respectively about three times and two times the number of those from Nihon Keizai.The ratio of cancer-related articles to total articles remained stable during the study period (Fig 2).The ratio in Asahi and Yomiuri newspapers tended to decrease, whereas in Nihon Keizai and Sankei newspapers, it tended to increase.The ratio re-