Japan's National Cancer Center for the first time on Aug. 9 released data showing the relative five-year survival rate of cancer patients at 188 hospitals around Japan -- roughly half the number of institutions serving as bases for cancer treatment.
The results showed a wide variation in the survival rates for lung cancer and liver cancer patients at different institutions, while the differences in breast cancer survival rates were relatively small.
Center officials are calling for people to take the results into consideration when receiving cancer treatment to gauge the characteristics of each hospital, while stressing they do not indicate which hospitals are the best.
The center analyzed 214,469 cancer cases at 209 of 425 designated cancer treatment hospitals in Japan that were aware of the survival rates for at least 90 percent of their patients. Of these, 188 institutions agreed to the release of individual data.
The figures include the five-year survival rates by hospital for five main types of cancer (stomach, intestinal, liver, lung and breast cancer), along with patients' approximate age and the stage of the cancer. However, the survival rates do not take into account the stage of the cancer when it was first treated, or the specific age of patients at that point, so the results do not necessarily reflect superiority in treatment.
The survival rate for lung cancer patients after five years was 68.9 percent at the top institution, while the corresponding figure at the hospital with the lowest rate was 2.3 percent. It is believed this is because the survival rate of this type of cancer largely depends on the stage of the cancer when treated, and late-stage cancer patients tend to accumulate at central hospitals in various regions. The highest and lowest figures for liver cancer were 71.6 percent and 15.8 percent, respectively.
The announcement of the survival rate by hospital stemmed from requests from groups representing patients. Fumihiko Wakao, director of the Center for Cancer Control and Information Services at the National Cancer Center, commented that the results are not at a level conducive to patients' selection of a hospital, but added, "We were able to put out something people can refer to, enabling them to see what type of cancer patients are common at which hospital, and accordingly, what the treatment results are like."
The relative five-year survival rate is calculated by dividing the percentage of people diagnosed with cancer who are still alive after five years by the percentage of other ordinary Japanese who are still alive then, so as to exclude deaths from illnesses other than cancer and accidents, and provide a more accurate picture of the effectiveness of treatment.
The results are available in Japanese on a cancer information website operated by the National Cancer Center at: http://ganjoho.jp/reg_stat/statistics/brochure/hosp_c_reg_surv.html