This month the Maine Supreme Court issued a ruling in a medical malpractice lawsuit that some say has big implications for a narrow class of cases involving patient misdiagnosis and treatment. For the first time, the Court has agreed to allow a patient to bring a case of professional negligence against his doctor that extends beyond a three-year statute of limitations.

The case involving Philip Baker and his primary care physician, Dr. Merrill Farrand Jr., is far from over. But attorney Julian Sweet says the Law Court's decision is important because it departs from an absolute three-year statute of limitations.

Sweet is an attorney representing Philip Baker. Until now, he says the Law Court has been rigorous in enforcing the statute of limitations in medical malpractice cases.

"The issue that has always lurked in the background is the situation in which a patient is told to have a test, gets that test and for one reason or another the test is abnormal but the doctor doesn't act on it," Sweet says. "That doctor continues to treat the patient for a period of years, seeing the patient each year, seeing the abnormal test each year but continuing not to act on it."

And that is what Sweet says happened to Philip Baker. Baker saw Dr. Farrand for 20 years, and for the decade between 1996 and 2006 was regularly screened for the prostate-specific antigen known as PSA as part of his annual physical.

PSA tests can reveal evidence of prostate disease such as cancer, and a normal PSA is in the 0-4 range. Baker's results were 3.8 in 2001, 5.7 in 2002 and remained over five until 2006 when he showed a 7.7. At that point Dr. Farrand referred Baker to a urologist who performed a biopsy and diagnosed prostate cancer.

"But by that time his treatment options had changed, and not only that, by the time he filed his notice of claim, the most important time period for treating his cancer was already more than three years in the past," Sweet says.

Defense attorneys representing Dr. Farrand moved for dismissal of the case on the grounds that Baker's claim should be barred because the significant negligence had taken place more than three years earlier in 2002 when he had his first abnormal PSA. A Maine Superior Court judge agreed.

Sweet says that's because in a case where there is a single act of negligence such as a botched surgical procedure the clock starts ticking the moment that occurs. But Baker is asserting that the negligence occurred during a four-year period between 2002-2006.

And now the Maine Supreme Court has vacated the lower court's ruling agreeing that Baker can bring a cause of action under what's known as the "Continuing Negligent Treatment Doctrine" under the Maine Health Security Act.

"I am a bit surprised. It's the first time the court has applied this continuing negligent action doctrine," says Andrew MacLean, general counsel for the Maine Medical Association, a voluntary organization that represents more than 2,000 physicians around the state. He says the act was intended to prevent a flood of malpractice lawsuits and control litigation costs.

"We're concerned about the court's interpretation of the limitations provision in the Maine Health Security Act because it means increased liability exposure for health care practitioners, and that very likely means increased liabilitly insurance costs and litigation expenses," MacLean says.

The Court said a patient can bring a claim based on two or more related negligent acts by a health care provider if some, but not all, of the acts occurred outside the three-year statute of limitations. Neither Maclean nor Julian Sweet say they think a large number of malpractice cases could be affected by the ruling.

Attorneys for Dr. Farrand declined to be interviewed for this story citing pending litigation. But one of them, attorney Christopher Taintor, expressed his disappointment in a written statement and said it will "inevitably have the effect of making medical malpractice litigation more protracted and more expensive."

Meanwhile, Philip Baker will now have the opportunity to take his case to trial. Attorney Julian Sweet says his client, who is now in his 60s, lives with prostate cancer as a chronic disease.