Hi Clyde,
Do you have the pathology report from the initial TURBT? It's good to make a file for all the medical records.
From what you described what you saw "a small red spot" what the urologist described "superficial and caught early", I think your prognosis looks good.
I too have a habit going down a rabbit hole to find relevant information over the internet. There are so many sites and there are many research papers on bladder cancers, sometimes with conflicting results. I will be careful not just taking in some number or a statement straight as it may confuse you more. I usually first refer to the American Urology Association guidelines to urologists for the treatment of NMBIC (non-muscle-invasive bladder cancers). Treatment is based upon the Risk Stratification as shown in table 4. Most NMIBCs are papillary type, which grows up into the lumen (empty area) of the bladder. The stages of NMBIC for papillary type has T0, Ta and T1, depending on how deep it has progressed. The grade for papillary type NMIBC is LG(low grade) and HG (high grade). The grade indicates how much cancer cells look different from normal cells. CIS has its unique stage and grade, which is Tis.
Link to AUA
www.auanet.org/guidelines/bladder-cancer-non-muscle-invasive-guideline
Table 4 categorizes NMBICs into low risk, intermediate-risk, and high risk. All CIS is high risk, accordingly the recommended treatment is BCG. T1HG is high risk, accordingly the recommended treatment is also BCG. TaHG, if it is not recurrence, is intermediate risk, so the recommended treatment is intravesical chemotherapy or BCG but shorter period than high risk.
Attached are the histology of normal bladder and CIS. In the normal bladder, all cells look uniformed. Umbrella cells (top layer) stretched out to protect urine to come inside. There is a think layer called the basement membrane just below the basal cell (bottom layer). This is like a glue between epithelial cells and lamina propria (connective tissue).
Another picture is CIS. Notice that cells are very abnormal-looking compared to normal bladder cells. But, if you look below the basal cells (bottom layer), they have not crossed the basement membrane into lamina propria (the connective tissue). This is the typical feature of CIS. But, CIS is known to progress to the Lamina propria layer and into the muscle layer. I assume that when your urologist said that your CIS was early stage and superficial, the urologist meant that your CIS had not crossed the basement brane.
So, the question is why when the behavior of CIS tends not to go up like a papillar type and not go under beyond the basement membrane to lamina propria (T1 area), but indeed if not treated it tends to progress to lamina propria and muscle layer. A clue is found by its genomic analysis. P53, which is known as a tumor suppressor gene is often found in muscle-invasive cancers. P53 is rarely mutated Low-Grade NMIBCs but P53 mutation is often found in CIS. It is also noted P53 mutation is also found in high-grade papillary type bladder cancers.
See gene mutations of MIBC.
In terms of the treatment for CIS, there have been several studies. The largest random study was done in 2005
by the European Organization for the Research and Treatment of Cancer.
pubmed.ncbi.nlm.nih.gov/15947584/
203 of 293 (68.1%) patients who received Intravesical BCG had a complete response.
158 of 203 (51.5%) patients who received Intravesical chemotherapy had a complete response.
Because every cancer is different even among CIS and every patient is different, Some patients do not respond well to BCG treatment. In such a case, there is an option of early cystectomy or several options for bladder preservation treatment.
