Through ultrasound, needle biopsy, computed tomography and magnetic resonance imaging, early thyroid cancers can be identified and treated. (Claire Sheprow/AP)

Think of cancer and you probably think of the most publicized ones: breast, colon, prostate. But one cancer that got a lot of attention in the Canadian Cancer Society's 2008 cancer statistics report was thyroid cancer, the most rapidly increasing cancer in Canada.

Thyroid cancer develops in the thyroid, a butterfly-shaped gland located at the base of the neck. It is responsible for producing hormones that regulate metabolism, such as how quickly you burn calories and how much energy you have.

What's worrying health experts is that thyroid cancer rose by more than five per cent a year in both sexes between 1995 and 2004, according to the Canadian Cancer Society (CCS).

Since 1997, thyroid cancer cases have been growing by 10 per cent per year in women aged 20 to 39. (Ian Jackson/CP)

Since 1997, thyroid cancer cases have been growing by 10 per cent per year in women aged 20 to 39. "It is increasing dramatically," says Loraine Marrett, a CCS researcher in Toronto. "Thyroid cancer is a big driver in this age group."

The CCS estimates that in 2008, there will be 4,300 new cases of thyroid cancer reported in Canada, with 890 men and 3,400 women being diagnosed with the disease. It predicts 180 deaths. Regionally, Ontario and New Brunswick are thyroid cancer hotspots, with 1,850 and 670 cases projected this year.

Thyroid cancer: good prognosis

When a fluid-filled nodule develops in the thyroid, it can be benign or cancerous. While benign nodules vastly outnumber cancerous ones, people who have had radiation exposure as children or a close relative with the disease are more at risk.

If a nodule is cancerous, it is usually one of three types of thyroid cancer: papillary, follicular or mixed papillary. Less common types of thyroid cancer include medullary carcinoma, anaplastic carcinoma, and thyroid lymphoma.

Anaplastic carcinoma of the thyroid is the most aggressive thyroid gland malignancy. Although it accounts for less than two per cent of all thyroid cancers, it causes up to 40 per cent of deaths. Patients with medullary carcinoma of the thyroid have a 10-year survival rate of 65 per cent.

Thyroid lymphoma is a form of cancer that develops from white blood cells called lymphocytes. It usually responds well to radiation or chemotherapy.

Papillary and follicular thyroid cancers are usually slow growing, especially if the disease is found only in the neck region. They can remain asymptomatic for many years. Others may cause a lump in the throat that leads to tightness in the neck, coughing and trouble swallowing. In some cases the nodule can grow and cancerous cells can spread to lymph nodes in the neck. While thyroid cancer doesn't usually move quickly, it can metastasize or spread to other organs.

Luckily, more and more cancers are being detected at an early stage due to better medical imaging. Through ultrasound, needle biopsy, computed tomography and magnetic resonance imaging, early thyroid cancers can be identified and treated.

The cure rate is high in the majority of cases. For the most common forms of papillary and papillary-follicular thyroid cancer, the five- and 10-year survival rates are over 95 per cent.

Treatment includes the surgical removal of the thyroid, called a thyroidectomy, and any lymph nodes that have been affected. Sometimes, an injection of radioactive iodine is administered in either a capsule or liquid form usually six weeks after surgery.

Rarely, X-ray radiation from a "cobalt beam" is done when the thyroid cancer cannot be completely removed. It is administered over four to six weeks in small doses to the neck region, killing any cancer cells that may exist.

After surgery, thyroid pills such as Thyroxin are prescribed to replace the hormone lost through the removal of the thyroid. This ensures a person can function normally.

Public awareness low

Though the prevalence is high and rising, thyroid cancer is still largely an unknown entity. There are few marathons or fundraisers for the disease and many people simply don't think of it as a possibility.

"Most people don't known anything about the thyroid," says Rita Banach, president of the Canadian Thyroid Cancer Support Group, Thry'vors. "We have nowhere near the dollar support the other cancers do."

Banach wasn't well acquainted with the disease when she began to feel run down. After a missed diagnosis, she was finally diagnosed with the disease at age 44 and had surgery to remove her thyroid.

"I felt better when I had the surgery," she says, noting that most of her symptoms disappeared rapidly. "Cancer has a profound effect on your life."

Banach's thyroid cancer survivor group has 1,000 members, many of them women seeking information and support about the disease.

Though the prevalence is high and rising, thyroid cancer is still largely an unknown entity. (Adrian Wyld/CP)

Grace Wright is one of them. Diagnosed in 1993 at the age of 19, Wright visited eight doctors before one would pursue an investigation into what was causing her weight gain, lethargy, and the lump in her neck.

A "little" voice in her head telling her that something was wrong, as well as a determined mother, finally got her a shocking diagnosis: thyroid cancer that had spread to two lymph nodes. Wright underwent a thyroidectomy and was treated with radioactive iodine.

She recalls the challenge of being kept in isolation for three days in hospital while the radioactive iodine killed cancer cells. "I remember feeling 'This is worse than prisoners in isolation,'" says Wright. "They would knock on the door, yell at you to stand on the other side of the room and slide your food on the floor.'"

Radioactive iodine treatment makes a person radioactive during the treatment, and for several weeks following. Wright says she was told to stay away from family members, especially children who are vulnerable to radiation.

After her successful treatment, Wright found her life had changed. "I felt out of my peer group. You don't identify with the same concerns they have," she says of her friends, all university students more concerned with cramming than cancer.

She says she's only now leaving her keen sense of mortality behind. "I've now started to realize I might be around for a while. You do value that new appreciation of life."

To treat or not to treat?

Wright says that given the high rate of diagnosis in the last decade, a divide has formed among thyroid specialists. Some believe that treatment at an early stage is critical, others believe if the tumour is tiny, it should just be monitored closely.

"There's this big polemic right now, whether even to consider certain sizes and whether to even label them cancer or not," says Wright.

The divide stems from the fact that many cancers are so slow growing that they have little impact on a person's daily life.

The CCS's Marett says aggressive treatment at a very early stage of thyroid cancer may not be ideal, given that the survival rates are so high and many malignancies can exist for years without spreading. "It's not clear that there's any benefit to early interventions," she says.

But Wright isn't convinced. "The thing is, it still is a cancer — and still does metastasize."

She says advocates of more conservative approaches to thyroid cancer may be basing their opinions on flawed studies. As an example, she cites a study that found a third of people autopsied had small thyroid cancers, leading scientists to hypothesize that a third of the population has thyroid tumours that are inactive.

"The one problem is, they haven't done a random sample of live people — they've done random samples of dead people," Wright explains.

She believes surgery saved her life. With the exception of a few yoga poses that are too challenging and salivary glands that swell up when she's fighting an infection, Wright feels she can do just about anything.

But she acknowledges that it has been a difficult journey that began at a very young age, and that life with cancer is never an easy one.

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