Four Pocono Mountain-area teenagers have been diagnosed with osteosarcoma since 2006 – and their families want to know if the cancers are a result of a cluster or a coincidence, The Times Tribune reported Monday.

— Alexandria Robbins, known to her friends as Xandi, formerly of Tobyhanna, Pa., died in September 2007 after battling the rare bone cancer for 16 months.

— Thomas Abramouski, 16, who used to live in Tobyhanna, but now lives in Moscow, Pa., has a prosthetic knee as a result of his cancer diagnosis in March 2007.

— Sonya Whitman, 15, who used to be Thomas’ neighbor, has an artificial knee, also the result of the cancer.

— Nakia Irving, 16, who lives 20 minutes from Tobyhanna in Blakeslee, Pa., had her hip and femur replaced. Her knee swelled to the size of a brick in the summer of 2006, around the time she and Xandi were treated at the same Philadelphia hospital.

All four teens attended the same Tobyhanna schools when they were younger.

Osteosarcoma is so rare that it only appears in 400 new cases of American children under the age of 20 each year.

Sonya, Thomas and Nakia are in remission, but Alexandria died after the disease attacked her brain stem.

To determine if the osteosarcoma is a result of a cluster, the state Department of Health is completing a statistical analysis by examining the number of recent rare cancer cases in the area.

The totals will be compared with incidences between 1981 and 2005, the earliest and latest years recorded in the commonwealth’s cancer registry, Dr. Stephen Ostroff, director of the Health Department’s Bureau of Epidemiology, told the Times Tribune.

Researchers develop a baseline rate of how often a type of cancer might occur in a zip code, and if the numbers are unusually high, that is when the state will start testing water, soil and air for cancerous agents, said Dr. Samuel Lesko, medical and research director of the Northeast Regional Cancer Institute.

Stacey Kriedeman, a spokeswoman for the Pennsylvania state Health Department said officials don’t know when the analysis will be ready.

She also noted the state receives 50 to 100 inquiries each year from people suspecting cancer clusters, most of which are coincidences.

“You’re not going to tell me that (an osteosarcoma) cell just starts to abnormally grow in a group of children like this,” said Nakia’s mother, Nannet. “It’s mind-boggling. It makes you question everything. Is it the environment? The food? The water? The air? It has to have some causing factor.”

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