Cancer & Environment
8:55 am
Wed March 7, 2012

Investigating rare childhood cancer cluster in Michigan (Part 3)

This week, we’re bringing you a series of stories on cancer and the environment.

Today, in the third part of our series, we’re going to St. Clair County.

The state of Michigan has confirmed a cancer cluster in the county. Since 2007, eight young children – and a possible ninth – have been diagnosed with a rare kidney cancer called Wilms tumor.  According to the Centers for Disease Control, about 550 children a year are diagnosed with Wilms tumor nationally.

Health officials ran a statistical analysis and found there are more cases of Wilms tumor in kids in the county than you’d expect to find.

Danielle Williams’ (no relation to Rebecca Williams) daughter Erika was the first to be diagnosed. She was seven years old.

“My daughter was playing soccer and she came home that night and we noticed she had a protruding lump on the side of her belly, and to the touch it was hot.”

An ultrasound revealed what looked like a six inch mass in Erika’s kidney. Erika had surgery to remove her left kidney ... and that’s when the doctors discovered the tumor was the size of a football.

“In the hospital, she quit... she didn’t speak. She didn’t really know what was going on but she knew it was serious. Because they’re so little they don’t know the serious(ness) of it, but her seeing me so broken, she just sat there in silence all the time and didn’t talk.”

Williams says after Erika’s surgery, she went through radiation and a year of chemotherapy. Erika is in remission now. Officials with the CDC say more than 90 percent of kids diagnosed with Wilms tumor survive.

A few months after Erika’s diagnosis, another child in the county was diagnosed with Wilms tumor. And then more kids got sick. The youngest was a 6 month old baby girl.

“If children are getting cancer, you know there’s something wrong. There’s something wrong.”

Williams lives in Marine City, on the St. Clair River. It’s downstream from Sarnia, Ontario. That area is nicknamed Chemical Valley because of the complex of petrochemical plants on the river. There have been hundreds of spills in the past two decades. (A 2006 GAO report on the St. Clair River found: "Many spills go unreported by responsible parties because they do not understand or fail to comply with reporting requirements.")

Several cities – including Marine City - pull their drinking water from the river.

Danielle Williams suspects something in the water or the air is making the kids sick.

But health officials say right now... there is no clear connection between any environmental factor and Wilms tumor.  Experts say there are some genetic abnormalities that can be associated with Wilms tumor.

Here's an excerpt from the National Institutes of Health site on Wilms tumor:

Wilms tumor is the most common form of childhood kidney cancer. The exact cause of this tumor in most children is unknown.

A missing iris of the eye (aniridia) is a birth defect that is sometimes associated with Wilms tumor. Other birth defects linked to this type of kidney cancer include certain urinary tract problems and enlargement of one side of the body, a condition called hemihypertrophy.

It is more common among some siblings and twins, which suggests a possible genetic cause.

Tom Sinks is the deputy director of the National Center for Environmental Health at CDC.

"Unfortunately, we do not know how to prevent children from developing a cancer. There are no known preventable causes of childhood cancers including Wilms tumor."

He says it’s believed Wilms tumor could stem from something that happens before a baby is born.

“So if you translate that into doing an epidemiologic study you have to try to recreate what environmental exposures or what the conditions may have been for the mother during pregnancy or possibly before pregnancy .”

The St. Clair County Health Department has been following the Wilms cases for a few years.

Dr. Annette Mercatante is the medical health officer with the health department. 

She says they’re developing detailed survey questions for the families in the cancer cluster.

“Where did they live? What did they eat? Their medical history, their work exposure history, we’re just going to try and be very comprehensive.”

They’re also going to try to track down the placentas of the children. Hospitals often save placentas when babies are born. There’s a research team at the University of Michigan that’s hoping to study the placental tissue to see if they can find any clues about the Wilms tumor cluster.

Dr. Mercatante says it will be difficult to figure out why these kids are getting sick.

“I understand the community and these families' desire to have that answer. But I have to resist the temptation to give them an answer that would make them feel better. I need to be honest. And the honest answer is we don’t know and we very well may not know for a long time to come, if ever. Especially in something as rare as this.”

But she says this cluster of children with cancer deserves a very close look. 

Our series on cancer and environment continues tomorrow. We’ll hear the story of some people who turn to the courts when they think pollution could make them sick.