1,2 My BCa was papillary type but I know a few people who had only flat type (CIS).
BCG works well particularly for CIS. A study by Southwest Oncology Group in 2000 describes that 68.1% of CIS
patients had complete response after 6 months, but the complete response increased to 83.8% when the BCG maintenance was done.
3. When BCG does not work, a patient and the doctor need to review which route - bladder preservation or removal of bladder is better strategy for the patient.
Bladder preservation strategy for non muscle invasive BCa.
If BCG does not work well, some doctor will try BCG+Interferon. I know a coupe people that BCG alone did not respond, but BCG+Interferon have worked and they are in NED for a couple years now. I know some urologist chooses Intravesical chemotherapy when BCG did not work, but I do not know what criteria urologist the urologist uses when intravesical chemotherapy is chosen.
Also recently, Immunotherapy drug (injection) was approved by FDA to be used for those high risk non invasive BCa patients who did not respond well to BCG treatment.
4. When a person is diagnosed with BCa for the first time, 5% are already metastasized, 20% are muscle invasive.
By luck, your dad BCa was non-muscle invasive and the study says it is very treatable. Typically BCG therapy will last 3 years and your dad will go through cystoscopy several times. It should become a kind of routine.
Best wishes
