Is the word cantora the same in Brazilian and European Portuguese?

Yes

The word "cantora" is identical in meaning, grammar, and spelling in both Brazilian and Continental Portuguese. The only difference is pronunciation. In Brazilian Portuguese, the vowels are generally more open and the rhythm is more melodic. In Continental Portuguese, unstressed vowels are often "reduced" or shortened, making the syllables sound more closed or clipped.

Brazilian Portuguese

1. Ela é uma cantora de muito sucesso. (She is a very successful singer.)
2. Eu adoro a voz dessa cantora. (I love this singer's voice.)
3. A cantora vai fazer um show amanhã. (The singer is going to perform a show tomorrow.)
4. Ela começou a carreira como cantora. (She started her career as a singer.)
5. Você conhece essa cantora? (Do you know this singer?)

European Portuguese

1. Ela é uma cantora de muito sucesso. (She is a very successful singer.)
2. Eu adoro a voz desta cantora. (I love this singer's voice.)
3. A cantora vai dar um concerto amanhã. (The singer is going to perform a concert tomorrow.)
4. Ela começou a carreira de cantora. (She started her career as a singer.)
5. Tu conheces esta cantora? (Do you know this singer?)