In today's Waikato Times there's the following headline: Faith healers attack cancer, injuries with prayer.
Unfortunately it's not really possible to assess the claims being made for the power of prayer - because those attending this new clinic are advised to continue with regular medical treatment. So - in the event of someone's health improving, it's not really possible to assess which treatment modality did the work... For example, I'm always a bit sceptical of claims along the lines of 'I had X tumours prior to the clinic's treatment, & now I have only Y' (where Y<X). If the tumour numbers were confirmed (before & after the treatment) by radiography/surgery, then the outcome is good for the patient, however it was achieved - but I'd like to see the supporting evidence for the original claim. Plus some indication of what other treatements the patient was also having - you'd hope that someone diagnosed with a large number of tumours would be referred rather promptly for surgery, radiotherapy or chemotherapy (or a combination of those). In which case, which treatment modality actually had the desired effect? Without that sort of supporting evidence, these testimonials remain at the level of anecdote.
Similarly, claims that the clinic has high success rates for its 'treatment' of cancer are not backed up with any data, so again, they cannot be properly evaluated. (I guess this particular practice may not be covered by the Medicines Act as it offers a 'service' rather than a product...)
Note - prayer may well have a profound psychological effect for some people, & I'm not arguing against that. What I am saying is that extraordinary claims along the lines of 'prayer can cure cancer' do need to be backed up by extraordinary evidence.
Update: You might also be interested in this more extended discussion by the Silly Beliefs team.