King Charles cancer battle continuing into 2025 - Oncologist explains why this reveals disease's sinister side

We were told The King's cancer was early and potentially curable but the latest announcement from The Palace reveals a more sinister side to his diagnosis.

Although it has not been officially announced "precisely what cancer King Charles' has been diagnosed with, it is very likely to be bladder cancer. The announcement that treatment is extending well into 2025 tells us more about the precise type he has - with some concern.

From the course of events early in 2024, it appeared that his bladder cancer was picked up by chance, after the biopsy of his prostate for a separate condition called Benign Prostatic Hyperplasia (BPH). This was very fortunate as his bladder cancer could have grown for many months without being noticed until a more advanced stage.

The usual first sign of bladder cancer is blood in the urine (Haematuria). It is well established that the earlier the cancers are picked the better the prognosis especially whether the cancer has grown into the muscle bladder wall. The treatments for bladder cancers which have or have not spread into the muscle wall are significantly different.

As well as CT scans, to determine the treatments pathways, the pathologist would have scrutinised biopsy sample down the microscope. The pathologist would have been able to tell how aggressive the cancer was (the grade), whether it had grown through the muscle wall or whether it is in more than one location in the bladder (the stage). These issues are very important as they determine whether the cancer is defined as early or not. As The King did not have radiotherapy or removal of his bladder, fortunately, he would not have had "muscle invasive disease" (i.e he had early cancer).

There are, however, different types of early cancers and it appears The King's has some concerning features, requiring longer treatments. Earlier in the year, the urologist would have removed his cancer from the inside lining of the bladder via a cystoscope inserted under a general anaesthetic. Immediately after the removal, during the same procedure, the urologist would have installed a single infusion of a chemotherapy called Mitomycin C.

To prevent the cancer growing back, a course of additional (adjuvant) treatment would have been recommend by the multidisciplinary team looking after him. The exact type of additional treatment would have depended on the grade of the cancer (how aggressive it looks down the microscope).

Patients with both low and high grade cancers receive a course of local bladder treatments every week for six weeks after the initial operation. These have been shown to significantly improve the chance of cure. These weekly treatments involve instilling a liquid treatment into the bladder. The procedures are given as an outpatient so don't require an over-night stay. Most often, they are carried out by a highly trained urology nurse involving the insertion of a small catheter into the bladder with lubrication but without anaesthetic. Once instilled the catheter is removed and the patient is encouraged to walk around and not pass water for 1-2 hours before it's passed naturally. Afterwards, to reduce the inevitable cystitis symptoms the patients are encouraged to drink up to two litres of water to dilute the urine.

If the tumour is low grade and in one place only, six weekly bladder installations would have been the only treatment. As the King's treatments are continuing, then his tumour was either likely to be in more than one location in the bladder (multifocal) or be a higher grade, or both. If low grade, but multifocal, after the first six weeks, he would require a "top up" of three weekly mitomycin C chemotherapy intravesical infusions every six months for 18 months.

If high grade, instead of further mitomycin C, the King would have received six weekly infusions of a TB vaccine called BCG. This is known to be more effective for more aggressive tumours - it is first clinical form of immunotherapy used in medicine and is still relevant today. It works by stimulating the immune defences in the lining of the bladder. This up-regulated immune reaction then kills early cancer cells. Although the prognosis is still good, these higher grade tumours do have a higher chance of coming back. Because of this, patients with these cancers have three weekly top-ups of intravesical BCG every six months for three years.

Whatever the treatment pathway, the urologist will be keeping an eye on the bladder via a flexible cystoscopy at regular intervals to spot any recurrence. These do not involve a general anaesthetic but does cause some inconvenient and sometimes troublesome cystitis symptoms for a few days.

On top of medical and surgical treatments, there is some evidence for dietary and lifestyle strategies which can also help speed up recovery from these treatments and reduce the risk of relapse. Fortunately, the King is fit for his age and has a good diet, eating an avocado every day, is a non-smoker, is not overweight and is physically active.

As well as these, the factors which help the prognosis include quitting smoking (if relevant), improving gut health, stopping late night snacking and high processed sugar intake, ensuring adequate vitamin D levels, avoiding dietary and environmental chemicals, exercising at least three hours a week, trying to get a good night's sleep, avoiding ultra-processed foods, and boosting the intake of phytochemical rich foods.

These prolonged treatments will be uncomfortable for King Charles and will have an impact on the practicalities of royal duties but fortunately the prognosis remains good.