Pituitary Gland Tumour: Treatment Approaches

The pituitary gland, located at the base of the brain, is in charge of a large portion of the body’s hormonal symphony. However, when a tumour disrupts this balance, the effects can be profound, impacting everything from metabolism to vision. Treatment for pituitary tumours necessitates a precise, multifaceted strategy, regardless of whether the growth is modest and benign or a hormone-producing powerhouse. This content mentions all the cutting-edge treatment options available for pituitary tumours. Additionally, it offers insights into pituitary tumour diagnosis, factors influencing the treatment approach, potential side effects, and complications if left untreated.

Understanding Pituitary Tumours

A pituitary gland tumour is basically an abnormal growth of the pituitary gland, and most pituitary tumours are benign, i.e., not cancerous. These benign pituitary tumours are termed pituitary adenomas. They generally arise from the anterior pituitary gland (which accounts for approximately 15% of intracranial neoplasms). These benign tumours, when spread to the bones of the skull or the sinus cavity below the pituitary gland, are referred to as invasive pituitary adenomas. In rare cases, if the pituitary tumour metastasises, it is termed pituitary carcinoma.

The exact cause of pituitary tumours is still unknown, but it is most likely due to genetic abnormalities and alterations. Possible causes that pose a risk of pituitary tumours include syndrome conditions, such as multiple endocrine neoplasia type 1 (MEN 1), carney complex, isolated familial acromegaly, X-LAG syndrome, succinate dehydrogenase-related familial pituitary adenoma, neurofibromatosis type 1, and von hippel–lindau syndrome.

It takes approximately 5 to 7.5 years for the pituitary tumour to grow from the time of diagnosis to the occurrence of the first metastasis. The pituitary tumour surgery success rate in India is comparatively high than pituitary carcinoma survival rate.

Pituitary Tumour Diagnosis

There are ample of diagnostic and imaging tests performed for pituitary tumour diagnosis. The tests are usually performed at the time of initial diagnosis, before surgery, during the recovery phase, and in unforeseen circumstances. These tests provide insight into the type, size and location of the tumour. Additionally, these advanced imaging techniques and specific tests help identify the type of pituitary tumour, allowing for targeted treatment.

The following are the diagnostic methods to detect pituitary tumours:

• Blood and urine test
• CT scans
• MRI of the pituitary
• Eye exam
• Visual field exam
• Biopsy
• Neurological exam
• High-dose dexamethasone suppression test
• Low-dose dexamethasone suppression test
• Venous sampling for pituitary tumours
• Laboratory tests, such as Immunohistochemistry, Immunocytochemistry and Light and electron microscopy

Factors Affecting Pituitary Tumour Treatment

The prognosis and treatment options depend on the following factors:

• Type and size of tumour
• Exact location of the tumour in the body
• Whether the tumour is benign or malignant
• Type of hormone being released by the tumour
• Whether the tumour is just diagnosed or reoccurred
• Type of hospital
• Medical history

Pituitary Tumour Treatment Options

Surgery, chemotherapy, radiation therapy, hormonal replacement therapy, and drug therapy are the options for pituitary tumour treatment. The size and location of the tumour, the type of tumour, the patient’s medical history, and the patient’s diagnostic results determine the kind of treatment plan. Treatment may be a single option or a combination of surgery, therapies, and medications. Additionally, new options of treatment for pituitary tumours in India are under clinical trials.

A specialised and skilled team of doctors and other medical professionals is required to treat and manage pituitary tumours. The team of doctors who treat pituitary tumours includes a neurosurgeon, endocrinologist, otolaryngologist, ophthalmologist, radiation oncologist, surgical oncologist, and medical oncologist. Other medical professionals required are physician assistants (PAs), nurses, psychologists, rehabilitation specialists, therapists, and other health professionals. Let’s understand the pituitary tumour treatment options one by one in detail:

1. Surgery

Pituitary tumours can be surgically treated via transsphenoidal surgery, endoscopic transsphenoidal surgery, or craniotomy. Transsphenoidal surgery is the primary treatment for many pituitary tumours, although the type of surgery to be performed depends on the type, size, and exact location of the tumour.

a. Transsphenoidal surgery: This kind of surgery involves inserting the instruments into a portion of the brain by first making an incision (cut) beneath the upper lip or between the nostrils and then passing through the sphenoid bone—a butterfly-shaped bone at the base of the skull—to reach the pituitary gland. The pituitary gland is directly above the sphenoid bone. This pituitary adenoma surgery technique is used for 95% of the cases. The chances of complete tumour removal are high in the case of microadenoma and comparatively low if the tumour is large. Pituitary macroadenoma treatment is basically done via combination of surgery and therapies.

b. Transsphenoidal surgery when involves inserting an endoscope through an incision (cut) made at the back of the inside of the nose and then through the sphenoid bone to reach the pituitary gland termed Endoscopic transsphenoidal surgery. An endoscope is a thin, tube-like instrument with a light source and a viewing lens used for removing tumour tissue.

c. Craniotomy: In this case, the tumour is removed through an opening made in the skull. This transcranial surgery is performed in rare conditions, such as when the adenomas are too large to be removed through the sinus cavity.

2. Chemotherapy

In the case of pituitary carcinomas, chemotherapy may be used as palliative treatment. Drugs are given in chemotherapy to stop the growth of cancer cells, either by killing them or preventing them from dividing. Temozolomide is the recommended first-line chemotherapy drug. It is an oral alkylating agent that exerts its pharmacologic effect by deoxyribonucleic acid (DNA) methylation, resulting in irreversible DNA damage. Depending on the type of pituitary gland tumour being treated, chemotherapy may be systemic or regional.

a. Systemic Chemotherapy: When chemotherapy is administered orally or injected into a muscle or vein, the medication enters the bloodstream and can reach cancer cells throughout the body.

b. Regional chemotherapy: When chemotherapy is administered directly into the cerebrospinal fluid, an organ, or a body cavity, such as the abdomen, the drugs primarily affect cancer cells in those areas.

Note: Palliative Treatment typically helps relieve symptoms and reduce suffering caused by life-threatening diseases. It does not treat or cure a disease.

3. Radiation Therapy

High-energy radiations (e.g., X-rays) are used in machines to kill cancer cells or check their growth. This method works well for controlling the development of a tumour. A single, powerful radiation treatment is directed straight at the tumour via a machine. To maintain the head motionless during radiation treatment, a rigid head frame is attached to the skull in this instance. No surgery is involved in this process. Usually, a session lasts between 15 to 30 minutes.

Before the therapy, a patient undergoes imaging tests and scans to determine the exact shape, size, and location of the tumour. The planning sessions, usually referred to as simulations, determine the correct angles for aiming the radiation beams, the shape of the beams and the proper dose of radiation.

It is recommended:

• When surgery is not feasible for some reason
• In case of recurring tumours
• Symptoms caused due to the tumour are not controlled with medicines

Fractionated or stereotactic are the two ways to give radiation therapy, but generally, in cases of pituitary tumours, stereotactic radiosurgery is often performed. Although it largely depends on the patient’s medical condition.

a. Fractionated radiation therapy: In this approach, the total dose of radiation is divided (fractionated) into smaller doses, which are typically administered 5 times a week over 4 to 6 weeks to minimise brain damage.

b. Stereotactic radiosurgery: This type of treatment doesn’t involve surgery and is also known as stereotactic radiosurgery, radiosurgery, or radiation surgery. It delivers a large, precise radiation dose to the tumour area, either in one treatment session (for SRS) or in a few sessions (for SRT). Radiosurgery targets the tumour precisely, limiting the radiation exposure to nearby structures and the rest of the brain. Gamma knife, cyberknife, LINAC machines, and proton beams are types of SRS.

4. Hormone Replacement Therapy

Pituitary tumours are frequently treated with hormone replacement therapy (HRT) to address the hormonal imbalances brought on by the tumour’s effect on pituitary function. If the tumour results in hypopituitarism, a condition in which the pituitary gland produces insufficient amounts of these hormones, HRT can help replace thyroid hormones, cortisol, and sex hormones. The individual’s needs and the hormones impacted determine the precise course of treatment. Frequent monitoring is necessary to modify treatment and guarantee successful symptom management.

5. Drug therapy/Medications

This treatment option is generally used to prevent the pituitary tumour from functioning, thereby reducing the production of excessive hormones. Hence, it is typically considered in cases of functioning pituitary tumours.

Controlling pituitary hormone hypersecretion is as mandatory in patients with pituitary cancer as in any patient with a functional pituitary tumour. For patients with lactotroph tumours, dopamine agonists, such as cabergoline, can be given at high doses. In patients with hypercortisolism, steroidogenesis inhibitors, such as metyrapone or ketoconazole (11-beta-hydroxylase inhibitor and antifungal agent, respectively), are crucial to avoid morbidity and mortality from excess cortisol. Finally, for somatotrophic tumours, somatostatin analogs (octreotide), growth hormone receptor antagonists (pegvisomant), or dopamine agonists can be continued at the maximally tolerated doses. The following table provides an overview of medicines taken in different pituitary adenoma cases:

Note: Treatment given post-surgery to lower the risk of cancer recurrence, is called as adjuvant therapy.

Side Effects of Pituitary Adenoma Treatment

It is estimated that 60% of people develop hypopituitarism after surgery or radiation therapy. It is a condition in which the gland stops or lowers the production of one or more pituitary hormones. However, this condition is treatable with hormone-replacement medications.

Complications related to surgery include bleeding, cerebrospinal fluid leaks, meningitis, or diabetes insipidus.

Side effects of dopamine agonists include nausea, vomiting, dizziness or sometimes increased compulsive behaviour.

Side effects of radiation therapy include pituitary hormonal deficiency, impaired fertility, and vision loss or brain injury (rare).

Complications of an Untreated Pituitary Adenoma

If pituitary adenomas are left untreated, they can cause serious health issues, particularly in cases of macroadenomas and functioning adenomas.

If left untreated, pituitary adenomas can lead to a very rare complication called pituitary apoplexy. It is a severe condition that requires medical attention. It occurs when the tumour suddenly enlarges and causes bleeding into the pituitary gland or blocks the blood supply to the pituitary gland. Symptoms associated with this condition are severe headache, eye muscle paralysis, loss of peripheral vision, and acute adrenal insufficiency.

Best Hospital for Pituitary Tumour Treatment in India

The following is the list of best hospitals for pituitary tumour surgery in India alongwith other treatment options:

• Medanta – The Medicity, Gurgaon
• Fortis Memorial Research Institute, Gurgoan
• Institute of Brain and Spine (IBS), Delhi
• Tata Memorial Hospital, Mumbai
• Apollo Hospital, Chennai
• Rajiv Gandhi Cancer Institute and Research Centre, Delhi
• Nanavati Max Super Speciality Hospital, Mumbai
• All India Institute of Medical Sciences, Delhi
• Manipal Hospital, Delhi
• BLK-Max Super Speciality Hospital, Delhi
• Medicover Hospital, Hyderabad

Best Doctors for Pituitary Tumour Treatment in India

The following table mentions the list of best doctors or can say, pituitary adenoma specialists across India for pituitary tumour treatment:

Get in touch with Cancer Rounds to get assitance for personlised treatment plans, connect with best pituitary tumour specialist, and treatment cost estimate.