Legal Battle Rages Over Whether to Force 17-Year-Old Cancer Patient to Have Chemo Connecticut Supreme Court to hear case on Thursday.

 -- A court will determine whether a 17-year-old girl, under something called the "mature minor doctrine," can be forced to undergo chemotherapy after she refused treatment for her cancer.

The case will go to the Connecticut Supreme court this week to determine whether the teen, identified in court papers as Cassandra, has "the fundamental right to have a say about what goes on with your [her] body," attorney Michael Taylor, who represents the teen's mother, told ABC News. Taylor was appointed by the public defender's office, and Cassandra has her own court-appointed lawyer, but they've filed joint appeals.

Cassandra was diagnosed with Hodgkin's lymphoma in September, but decided she didn't want to complete the prescribed treatment, according to a court summary. Her mother supported this decision, but the Department of Children and Families stepped in and ordered her mother to comply with the doctor's treatment recommendation.

"It's really for all the reasons you might imagine," said Taylor, adding that he couldn't go into more detail.

Although chemotherapy is a drug that destroys cancer cells, its side effects include hair loss, nausea, pain and fertility changes, according to the National Cancer Institute.

Cassandra underwent two chemotherapy treatments in November and then ran away from home and refused to continue treatments, according to the court summary.

A court hearing ensued in which Cassandra's doctors testified, and she was removed from her mother's home and placed in state custody so that the state could make medical decisions for her.

She has been has been living at Connecticut Children's Medical Center and forced to undergo chemotherapy for about three weeks.

The Hartford Courant reported that Cassandra has an 80 to 85 percent chance of surviving her cancer if she continues with her chemotherapy.

The state Department of Children and Families issued the following statement:

"When experts -- such as the several physicians involved in this case -- tell us with certainty that a child will die as a result of leaving a decision up to a parent, then the Department has a responsibility to take action. Even if the decision might result in criticism, we have an obligation to protect the life of the child when there is consensus among the medical experts that action is required. Much of the improvements in Connecticut's child welfare system have come from working with families voluntarily to realize solutions to family challenges. Unfortunately that can't happen in every situation, especially when the life of a child is at stake."

"No one is disputing that it's very serious," Taylor said. He said there's "a good chance" Cassandra could survive her cancer with treatment, and "there's a good chance she could die if she doesn't. None of us disagree about that."

Taylor said they're trying to argue that because Cassandra is competent, she should be allowed to make this decision for herself through something called the "mature minor doctrine," which has been adopted in Illinois and a few other states but rejected in Texas. The doctrine holds that some children are mature enough to make key life decisions for themselves.