What is a Neuroendocrine Tumor? Here's everything you need to know about the rare Cancer

Bollywood actor Irrfan Khan, who was battling against neuroendocrine cancer since 2018, passed away today i.e.on April 29 in Mumbai. The actor was recently admitted in the Intensive Care Unit (ICU) of Kokilaben Dhirubhai Ambani Hospital for his colon infection treatment. The news of his sudden demise was confirmed by filmmaker Shoojit Sircar via a tweet. He tweeted, "My dear friend Irfaan. You fought and fought and fought. I will always be proud of you.. we shall meet again.. condolences to Sutapa and Babil.. you too fought, Sutapa you gave everything possible in this fight. Peace and Om shanti. Irfaan Khan salute."

When the actor was diagnosed with a neuroendocrine tumor in 2018, it came as a rude shock to the entire entertainment industry. What exactly is neuroendocrine tumor aka (NET)? The tumors form in the cells that interact with the nervous system or in glands that produce hormones. These cells which are known as neuroendocrine cells are present in the entire body, however, the tumors are mostly found in the gastrointestinal tract. These tumors are also found in the lungs, pancreas, and adrenal glands. As per the report of the National Cancer Institute, there has been a five-fold increase in the NET cases from 1973 to 2004.

Read on to know the signs, types, cause, stages and treatment of neuroendocrine tumor:

What are the signs and symptoms?
Many times NETs don't show signs in the beginning stage and that's why it is sometimes hard to diagnose it. The symptoms of NET are wide-ranging as they are based on the location of the tumor.

Following are the common ones:
unexplained weight loss
pain
constant fatigue
diarrhea and other gastrointestinal issues
increased thirst
frequent urination
dizziness and shakiness
high blood pressure
fatigue
flushing
swelling in the feet and ankles

Types
Doctors may classify NETs depending on the origin sites. They may use terms such as GI NET, pancreatic NET and lung NET among others. Their size and how quickly they grow varies. While some are malignant others can be cancerous.

Stages
Neuroendocrine tumors are staged as per the TNM staging system i.e. tumor (T), node (N), metastasis (M). As per World Health Organization (WHO,), well-differentiated neuroendocrine tumors are grade 1 and 2 and poorly-differentiated neuroendocrine tumors fall in grade 3)

Treatments
Treatment for NETs depends on the type and stage of the disease. Common treatment options opted by doctors are surgery (to remove the primary tumor), chemotherapy, hormone therapy, targeted therapy, interventional radiology, peptide receptor radionuclide therapy (PRRT) and radiation therapy (this is done when surgery is difficult) among others.

Diagnosis
Cancer experts use following tools which are designed for diagnosing tumors:
Lab tests
Biopsy
ERCP
CT scan
MRI
Laparoscopy

Cause
The exact cause of NETs is not clear yet.