What is Theranostics, Cancer Cells, Theranostics Singapore, Dr Andrew Tan

What Is Theranostics?

Theranostics is a viable method of treating cancer, especially when the cancer cells have spread or are at a more advanced stage and are unable to respond to other treatments.

While there is still a lot of potential to replicate the procedure for other types of cancers, to date, theranostics has shown success mostly in treating liver cancer, metastatic prostate cancer, and neuroendocrine tumours.

Who Invented Theranostics?

The term theranostics was invented in 2002 by John Funkhouser, who was the Chief Executive Officer of PharmaNetics at the time. The term is essentially a combination of the word “therapeutics” and “diagnostics” – a portmanteau describing the PharmaNetics business model for developing diagnostic tests to identify cancer cells and the application of specific therapies.

What Is Theranostics in Nuclear Medicine?

Theranostics in nuclear medicine, or nuclear theranostics, refers to a specific type of cancer treatment.

It targets infection sites by first using diagnostic imaging or a radioactive drug to identify if target receptors are present on cancer cells, followed by a second radioactive drug to deliver therapy to treat the primary tumour and any advanced or metastatic tumours.

Does Nuclear Medicine Have Side Effects?

Only small amounts of radioactive material, known as radiopharmaceuticals or radiotracers, are used in nuclear medicine. These radiopharmaceuticals emit radiation that travels a short and safe distance, which is why very few people experience side effects or allergic reactions from nuclear medicine tests.

Any adverse reactions or side effects are usually mild and need little to no medical treatment. Generally, you should not feel much difference after the radiotracers are administered.

What Is the Theranostic Approach?

The theranostic approach is personalised, using both diagnosis and therapy tools as part of the treatment.

Theranostics in the Treatment of Cancer

Theranostics eliminates the need for multiple procedures to treat cancer, which reduces delays in treatment and improves patient care. In the diagnosis stage, PET scan imaging is used to locate specific targets known as tumour receptors or target receptors present on tumour cells.

As for the therapy stage, once these targets are visible on the scan, a radioactive drug will be injected into the body. This drug is used to treat tumours by selectively targeting the tumour cells and avoiding healthy areas. The radioactive drug that is not utilised or cannot reach the target will be passed out of the body.

What Is Metastatic Prostate Cancer?

Metastatic prostate cancer is an advanced stage of prostate cancer where cancer cells have spread to other parts of the body. It occurs when cells break away from the tumour in the prostate.

During the metastatic stage, these cancer cells usually break away and travel through the lymphatic system in the lymph nodes and the bones or through the bloodstream to other parts of the body.

What Is the Survival Rate for Metastatic Prostate Cancer?

The survival rate of prostate cancer entirely depends on the various stages of cancer. The staging system uses three different aspects of tumour growth – tumour, nodes, and metastasis. Patients whose prostate cancer has spread to other areas like the bones, liver or lymph nodes are in the metastasis stage and may need more advanced treatment.

According to the American Society of Clinical Oncology, about one-third of patients with metastatic prostate cancer will survive for more than five years.

Can Metastatic Prostate Cancer Be Cured?

There are many types of treatment available to slow down the spread of metastatic prostate cancer. Your doctor or oncologist will develop a treatment plan that takes into account your symptoms, stage of cancer, and general health.

What Are the Treatment Options Available For Metastatic Prostate Cancer?

Radiation therapy: External radiation therapy shrinks the tumour in the prostate or kills any new metastasised cancer cells in other areas.

Hormone therapy: This form of therapy lowers the production of male sex hormones, which can help prevent the spread of cancer cells.

Chemotherapy: Chemotherapy prevents cancer cells from multiplying. Patients usually receive chemotherapy once the prostate cancer has stopped responding to hormone therapy.

Immunotherapy: This form of therapy triggers and boosts the immune system to attack cancer cells. Immunotherapy filters immune cells out of the body and stimulates them at a lab to target prostate cancer. These cells are then reinfused back into the patient’s body intravenously (IV).

Bisphosphonate therapy: Patients with prostate cancer that has spread to the bones may undergo bisphosphonate therapy which blocks a bone cell from breaking down other parts of the bone.

How Is Theranostics Used to Treat Metastatic Prostate Cancer?

Radium 223 (Xofigo) is a radioactive drug used in a theranostics procedure to treat castrate-resistant Prostate Cancer, symptomatic Bone Metastases and no known Visceral Metastatic Disease.

The aim of the therapy is to control the bony metastases and to reduce symptoms of bony pain (if present).

Lutetium 177 PSMA is another radioactive drug that is used to treat metastatic castrate resistant prostate cancer, and can target all prostate cancer lesions as long as they express the PSMA ligand on the cell surface.

What Is Hepatocellular Carcinoma (HCC)?

Hepatocellular carcinoma (HCC), also known as primary liver cancer, is a complex heterogeneous cancer. When diagnosing this form of cancer, the choices for treatment will depend heavily on the extent of the cancer and the severity of the underlying chronic liver disease.

What Is the Survival Rate for Hepatocellular Carcinoma?

As Hepatocellular carcinoma is generally diagnosed late in its course, its median survival rate is approximately 6 to 20 months from the time of diagnosis. Globally, it is the 6th most common cancer, and it has become the 2nd most common cause of cancer-related mortality.

Can Hepatocellular Carcinoma Be Cured?

If caught early, it can sometimes be cured with surgery or a transplant. In more advanced cases, it often cannot be cured, but consistent treatment and support can help you live longer, with an improved quality of life.

What Are the Treatment Options Available For Hepatocellular Carcinoma?

There are two types of treatments for Hepatocellular carcinoma; curative and non-curative treatment options.

Curative treatment options include partial liver resection or hepatectomy, local ablation, and liver transplantation, which may provide a high probability of long-term survival.

Non-curative treatment options can be administered when patients are no longer suitable for curative treatment options due to the severity of the disease and condition of the liver or individual’s overall fitness capacity.

Non-curative treatment options that may prolong life are transarterial chemoembolisation (TACE), selective internal radiation therapy (SIRT) with yttrium-90 and systemic therapy. These treatment options are also occasionally used as a neoadjuvant treatment to downstage patients for curative therapy.

How Is Theranostics Used to Treat Hepatocellular Carcinoma?

In theranostics procedures, Yttrium-90 SIRT therapy, a form of Selective Internal Radiation Therapy (SIRT), can be used to treat liver cancer. Yttrium-90 SIRT therapy aims to reduce the size of inoperable tumours that cannot be removed in surgery and/or decrease the number of abnormal cells in the liver. Occasionally, a successful Yttrium-90 SIRT treatment may make it plausible for tumours to be removed surgically.

This form of radiation therapy targets and damages the cancer cells in the liver, reduces the size of the tumours, and prevents the cancer from metastasising further. It is administered via an injection of Yttrium-90 into the main blood vessels in the liver.

What Are Neuroendocrine Tumours (NETs)?

Neuroendocrine tumours (NETs) or neuroendocrine neoplasms (NENs) are rare tumours that develop in cells of the neuroendocrine system.

The World Health Organization (WHO) groups neuroendocrine tumours according to three main categories of tumour grade:

Well-differentiated neuroendocrine tumours, further subdivided into tumours with benign and those with uncertain behaviour
Well-differentiated (low grade) neuroendocrine carcinomas with low-grade malignant behaviour
Poorly differentiated (high grade) neuroendocrine carcinomas, which are the large cell neuroendocrine and small cell carcinomas.

What Is the Survival Rate for Neuroendocrine Tumours?

According to a study conducted on NETs patients from 1973 to 2014, the median survival duration was 41 months. Out of 73,782 NETs patients, the 1-, 3-, 5-, and 10-year overall survival rates were 72.8%, 52.7%, 39.4%, and 18.1%, respectively.

However, general statistics on survival rates must be viewed within the proper context. Your physician should conduct further prognosis depending on your condition.

Can Neuroendocrine Tumours Be Cured?

There are treatments available to prevent the tumours from spreading further. In some cases, neuroendocrine tumours are dormant, small and slow-growing. Studies have shown that slow-growing tumours, when diagnosed early and with proper treatment, can reduce symptoms and limit spreading.

What Are the Treatment Options Available For Neuroendocrine Tumours?

The treatment of neuroendocrine tumours depends on the prognosis and diagnosis of your condition. Treatment options depend on the grade of tumour, which part of the body it originated from, the level of aggressiveness, and how advanced it has spread to distant parts of the body.

How Is Theranostics Used to Treat Neuroendocrine Tumours?

In theranostics procedures to treat neuroendocrine tumours, Lutetium-177 Octreotate therapy (Lu-Octreotate) can be considered a radioactive drug to target radiation on cancer cells without damaging much of the healthy tissue.

Also referred to as Peptide Receptor Radionuclide Therapy (PRRT), Lu-Octreotate therapy combines octreotate, a manufactured form of the naturally produced hormone somatostatin, and lutetium-177, a compound that releases radiation into a tumour.

This theranostic procedure kills abnormal cells, which in turn reduces the size of the NETs tumour from growing further and multiplying. This may mean that the tumour will be relatively dormant for longer periods of time, but it does not mean that NETs can be cured completely.