Prostate cancer treatments improved by research
11 November 2021
About 10,000 men in Sweden are diagnosed with prostate cancer every year. This makes it our most common cancer. Over the past 15 years, great progress has been made in terms of diagnostics and treatment options.
“Prostate cancer can vary enormously. You could actually say that it’s several distinct diseases,” says Pär Stattin, Professor of Urology at Uppsala University. He is also the registrar and chairman of the National Prostate Cancer Register of Sweden (NPCR).
In his profession, he has closely followed developments in prostate cancer care. Since he qualified as a urologist in 1992, there has been dramatic progress in methods of diagnosis and treatment with radiotherapy (radiation therapy), surgery and drugs.
“In the past, a higher proportion of men were diagnosed with advanced cancer, and to some extent we actually treated the ‘wrong’ patients in the 1990s and 2000s. That is, we treated many men with low-risk cancer too aggressively,” he says.
“Low-risk cancer” refers to small, slow-growing malignant tumours that may not show symptoms for several decades. Since the median age for prostate cancer diagnosis is 70 years, this means that treatment is unnecessary in most cases because the majority of men will never develop any symptoms. Men with low-risk cancer and long life expectancy can be monitored actively by means of regular check-ups. If the tumour shows signs of starting to grow, surgery or radiotherapy can be offered.
Men thought to have a short life expectancy owing to other illnesses and old age are monitored closely. If the cancer shows signs of beginning to grow or spread (metastasise), drugs to delay its progression are administered in the form of hormone therapy.
More radical treatments
On the other hand, the most malignant tumours always require more radical treatments.
Methods of tackling aggressive cancer affecting only the prostate have been refined. Today, non-invasive, robot-assisted laparoscopy (“keyhole surgery”)is used for prostate removal. Radiotherapy has also been developed and now much more focused treatment is provided, with fewer side effects.
“Another advance is that the radiotherapy is given for a shorter time, which is good, especially for patients who live a long way from the hospital where they’re treated,” Stattin says.
Locally advanced prostate cancer means that the cancer has spread outside the prostate capsule (the outer layer of the gland). Men with this diagnosis were seldom given curative treatment in the early 2000s, but there has been a sharp increase since then. Today, some 80% of these men receive curative treatment, usually with a combination of radiotherapy and hormone treatment. An Uppsala University study based on NPCR data, published in 2020, showed that mortality from prostate cancer for men with this diagnosis aged 65–74 was halved between 2000 and 2016.
Hormon therapy slows down the cancer
In roughly 10% of men with prostate cancer, it has already spread to the bones (bone metastasis) by the time of diagnosis. Then, until 2004, the only available treatment used to be hormone therapy, usually in the form of gonadotropin-releasing hormone (GnRH) analogue injections. This treatment lowers the testosterone level, thereby slowing down the cancer. Despite low testosterone levels, however, tumour cells eventually start growing, and at this stage the cancer is known as “castration-resistant”.
In 2004, the first study was published showing that chemotherapy prolongs the lives of men with castration-resistant prostate cancer. Since then, many new treatments that extend the lifespan for patients with metastatic prostate cancer have been developed. Now, various combinations of local radiotherapy, chemotherapy and new hormone treatments can be given along with GnRH straight after diagnosis.
Bone-seeking radioactive isotopes to target skeletal metastases are used in another technique developed in recent years to treat prostate cancer once it has spread. Radium-223 has proved to extend these men’s lives, and the latest addition is treatment with Lutetium-177.
“This is just the beginning of a development that is making prostate cancer a disease that is normally treatable. And if a cure isn’t possible, the patient can still live for many years with it under control and a good quality of life,” Stattin says.
To enable early detection of prostate cancer, even before it gives symptoms, organised prostate cancer testing is now being successively introduced in Sweden. Accordingly, all men in certain age groups are being systematically offered prostate-specific antigen (PSA) testing.
Until a couple of years ago, every man with an elevated PSA level promptly underwent a prostate biopsy. This resulted in far too much low-risk cancer being diagnosed. The Swedish National Care Programme now recommends first using magnetic resonance imaging (MRI) to investigate men with high PSA and then, if it reveals a suspected tumour, taking a biopsy. If the MRI is normal, on the other hand, the investigation is closed.
“So a paradigm shift is under way, in terms both of early diagnosis and of treating metastatic prostate cancer. In the future, I believe we’ll be able to more reliably identify the men who truly need treatment. And we’ll be able to tailor it for each man, while avoiding diagnosing cancer that has a low risk of affecting his life.”
Facts about the National Prostate Cancer Register (NPCR)
Launched in 1998, the NPCR covers approximately 95% of all new prostate cancer cases. For every one, an accurate description of the man’s illness, the treatment he has received, the hospital and the surgeon who operated on him may be found. The ultimate goal of the NPCR’s activities is for every man in Sweden with prostate cancer to get the right treatment at the right time, regardless of where he lives. With its particulars of 250,000 patients, the NPCR provides a unique foundation for prostate cancer research. Since 2010, more than 200 scientific articles based on NPCR data have been published.