Expectations for cancer genomic medicine for biliary tract cancer in Japan

In Japan, biliary tract cancer is not a rare cancer, and more than 20,000 people are diagnosed with biliary tract cancer annually. Biliary tract cancer is the ninth most common cancer in men and the seventh most common cancer in females. In addition, the prevalence of biliary tract cancer has begun to increase in the 50s. Biliary tract cancer is more common among the elderly in their 70s and 80s. Bile duct cancer and papillary carcinoma are more common in men. On the other hand, gallbladder cancer is more common in females. Recently, in Japan, long-term use of dichloromethane and dichloropropane in the printing business is considered to be the cause of the onset of bile duct cancer.

In the clinical stage, if bile duct cancer is a surgically resectable lesion, surgical treatment is the treatment of choice. For bile duct cancer, the surgical method is not fixed. Surgical treatment is selected according to the location of the onset of bile duct cancer and the spread of the cancer. Combination chemotherapy with gemcitabine and cisplatin has been established as standard treatment for bile duct cancer. In particular, combination chemotherapy with gemcitabine and cisplatin is being given to patients with bile duct cancer who are difficult to surgically resect. However, the response rate with these antitumor agents is low, and the 5-year survival rate for bile duct cancer is 21.8%.

During the period from December 2019 to December 2021, treatment methods for total of 1298 cases (Ncc oncopanel test: 294 cases, F1CDx test: 995 cases) were examined in cancer genomic medicine at a national university in Japan. Of these, a total of 25 cases of bile duct cancer (Ncc oncopanel test: 4 cases, F1CDx test: 21 cases) were subjected to cancer genomic testing. From the test results, pathogenic variants were found in the factors of BAP1, STK11, BARM1, IDH1, and TP53. Antineoplastic agents targeting each pathogenic variant have been prescribed.

The prognosis for biliary tract cancer is extremely poor, and currently available treatments are very limited. In the future, oncogene panel tests should be actively introduced as tests for biliary tract cancer, and clinical trials of antitumor agents targeting pathogenic variants should progress.

Disclosure of potential conflicts of interest
The authors declare no potential conflicts of interest.

Cancer medical specialist doctor
Doctor specializing in emerging infectious diseases

Published in Science at December 18, 2021. by Kyoto@takumaH