Where to get genetic testing

Hi,

My dad had been recently diagnosed wiht NSCLC brain Metastases. He is not in UK but i had samples of tissues. Please can anyone recommend where in London to send the sample for genetic testing? 

He has been a fighter so far but it breaks my heart seeing my dear dad, a man who used to be a professional athelete and always the healthest in the family, suffering. I don't want to loose him.

Please help! Thank you very much!