Justice Margaret Cameron heads the inquiry into faulty hormone receptor tests that resumes Tuesday in St. John's (CBC)

A public inquiry investigating how hundreds of breast cancer patients in Newfoundland and Labrador received flawed hormone receptor tests resumes Tuesday in St. John's after a four-week summer break.

The inquiry, headed by Justice Margaret Cameron, has been hearing testimony from patients, doctors, laboratory staff and bureaucrats since March in an effort to understand how 386 breast cancer patients received inaccurate results from pathology laboratories in the province.

The test at the heart of the inquiry, the hormone receptor test, helps determine the type of treatment a patient already diagnosed with breast cancer can receive.

The inquiry began last winter with stunning testimony from breast cancer patients and patients' families, about how the misinformation affected them, their treatment and their lives. Some admitted to Cameron that they learned about the flawed tests in the news, and not from their health-care provider.

After 58 witnesses, a fuller picture has been emerging about what went wrong in the system that allowed such a chain of mistakes.

The public has heard how laboratories in the province did not have the resources many experts deemed necessary to do accurate testing. The labs faced a litany of problems, including understaffing and inadequate training and experience.

Testimony not only shed light on initial problems with laboratory practices, but also turned a microscope on the sometimes chaotic system of how information about the tests made its way through government and how that information was then made available to the public.

Dozens more witnesses, including Premier Danny Williams, are expected to testify before the inquiry, which is expected to wrap up in the fall. Cameron's report on her findings is due February 2009.

On Tuesday, Dr. Ford Elms, a pathologist at St. Clare's Hospital in St. John's, is expected to take the stand.