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Lhasa Carcinogenicity Database

A vital source of long-term carcinogenicity study data. 

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  • The Lhasa Carcinogenicity Database (LCDB) was founded on the now retired, Carcinogenic Potency Database (CPDB).
  • The Lhasa Carcinogenicity Database is a widely used, free resource containing the results of animal cancer tests. 
  • Since 2016, Lhasa Limited has used its knowledge in the field of user experience to add new functionality, building on the excellent work of the team behind the original CPDB database.
  • The LCDB is a vital source of long-term carcinogenicity study data. 


The CPDB was an invaluable resource containing the results of 6,529 chronic, long-term animal cancer studies on 1,547 chemicals. 

In 2016, Lhasa Limited recognised the potential risk of losing such a valuable resource and adopted the database to continue the public benefit that it offered. 


Lhasa Carcinogenicity Data

The Lhasa Carcinogenicity Database (LCDB) contains all data from the original CPDB database and has since been supplemented with additional data. In some cases, after careful validation, chemicals which were considered to be distinct, have been merged into a single entry. For example, compounds with studies using either commercial or technical grade chemicals, or the same compound at different purities, were distinct entries with different unique identifiers in the CPDB. Lhasa has considered these studies as being related to the same chemical, and so has recorded the information in a single entry, with the relevant information about grade/purity added. With the addition of new data, the LCDB is a structure searchable repository of 7,745 long-term carcinogenicity studies covering 1,726 chemicals.


Lhasa TD50

One of the key uses of the CPDB was to provide a numerical description of carcinogenicity potency (TD50), estimated for each set of tumour incidence data reported in the CPDB. The Gold TD50 provides a “standardized quantitative measure that can be used for comparisons and analyses of many issues in carcinogenesis”.

Lhasa Limited has calculated its own TD50 values based on the same data used for the Gold TD50. Both values are available in the Lhasa Limited Carcinogenicity database and a paper has been published describing the methodology used by Lhasa’s scientists.

Read more about the comparing CPDB and Lhasa TD50 values in the Lhasa Carcinogenicity Database, in this blog piece.

The Future

Lhasa Limited intends to continue maintaining the Carcinogenicity Database by searching the literature, gathering studies and compounds, and estimating the Lhasa TD50. Lhasa Limited intends to keep this resource online and freely available for the foreseeable future.

Features and Benefits 

  • Vital source of long-term carcinogenicity study data - The Lhasa Carcinogenicity Database is a searchable repository of 7,745 long-term carcinogenicity studies covering a total of 1,726 chemicals.
  • Structure searchable – The ability to easily build complex queries around both structures and associated data, which allows for the retrieval of specific information, aiding decision support and improving productivity.
  • Freely available online – There is no need to install the database, it can be easily accessed online at any time.
  • Reproducible TD50 provided – Lhasa Limited has created its own TD50 from the data, based on Gold’s methods. For data from the CPDB, both the Lhasa TD50 and Gold TD50 are provided 
  • Actively maintained – The only freely available resource of its kind, the database will continue to be maintained to ensure its continued availability.  
  • Attractive user interface – The redesigned user interface is clear, intuitive and has facilitated greater ease of access by enabling substructure and similarity-based structure queries.


Key References 

Peto, R., Pike, M.C., Bernstein, L., Gold, L.S., and Ames, B.N.; ‘The TD50: A proposed general convention for the numerical description of the carcinogenic potency of chemicals in chronic-exposure animal experiments’; Environmental Health Perspectives; 58: 1-8; (1984).

Sawyer, C., Peto, R., Bernstein, L., and Pike, M.C.; ‘Calculation of carcinogenic potency from long-term animal carcinogenesis experiments’; Biometrics; 40: 27-40; (1984).

Thresher, T., Gosling J, P., Williams, R.; 'Generation of TD50 values for carcinogenicity study data'; Toxicology Res; 8: 696-703; (2019).

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