Why Pathology Is A Necessary and Crucial Step In Clinical Trials

By Jane Meggitt

Many cancer patients are living longer with improved quality of life as the result of medications approved after going through clinical trials. Pathologists play critical roles in the design of such clinical trials. That is especially so when it involves patient eligibility and therapeutic response evaluation. Anatomic pathology focuses on the examination and diagnosis of biopsies and other surgical specimens to identify abnormalities.

Clinical Trials

Pathologists are involved in preclinical drug testing, the earliest step in a clinical trial. Here, they may perform tissue-based research and analyze preclinical drug toxicology studies. Their contributions in this field include:

  • Angiogenesis determination
  • Animal model assessment
  • Micro-vessel density determination
  • Predictive toxicology
  • Protein expression analysis
  • Xenograft assessment

Eligibility for clinical trials involves pathology, as patients are selected based on molecular test results and pathologic findings. Pathologists assess tumor biomarkers for targeted therapy trial eligibility.

Patient participation in clinical trials is always voluntary. Patients must give informed consent to take part in a clinical trial. The doctor explains the purpose of the trial and its risks and possible side effects, as well as the exact procedures. The doctor answers any questions patients have regarding the trial. Patients have the right to stop participating in a clinical trial if they choose.

Pathology plays a key role in every phase of clinical trials. The work of pathologists ranges from trial design, patient recruitment, result analysis and the need for continued monitoring. They play critical parts in later aspects of clinical trials, most notably in evaluating the response to therapy.

Clinical Trial Phases

Clinical trials consist of four phases. Patients generally take part in only one phase of a trial. The goal of the first phase is determining whether a treatment is safe. Physicians also want to know the best way to provide this treatment, such as orally or intravenously. While researchers want to see if there are indications that cancer is responding to this treatment, disease response is not the primary purpose of the phase I study. Phase I studies typically involve patients with different types of cancer. After several months, if it appears the treatment is safe with no severe side effects, the trial moves on to the second phase.

Phase II trials test whether the treatment works in a particular type of cancer. This phase may last up to two years. If the treatment does appear to work, the trial moves on to the third phase.

While the earlier phases involve no more than a few hundred patients, Phase III trials include many more, perhaps thousands. This trial tests whether the new treatment performs better than current, standard treatment. The measurement consists of whether patients live longer on the new treatment than those receiving standard treatment. It also reflects whether the new treatment keeps the cancer from growing for a longer period.

The patients are divided into groups that receive the standard treatment and those receiving the new treatment. Once the Phase III trial concludes in studies lasting up to four years, the FDA conducts a review of the results to ensure whether it is safe and effective. It then decides whether to approve the treatment and make it available for cancer patients.

Phase IV trials involve the continuing study of FDA-approved treatments and long-term side effects. This phase weighs the long-term benefits and risks, as well as how this treatment is integrated into oncological practice.

Pathology plays a key role in every phase of clinical trials. Their work ranges from trial design, patient recruitment, result analysis and the need for continued monitoring.

A Team Approach

Pathologists working on clinical trials for cancer research are an integral part of a team approach also involving oncologists, surgeons and nurses. Their skill sets permit them to aid in the optimization of biomarker implementation, for which they work in conjunction with oncologists.

As pathologists are integral members of multidisciplinary tumor boards, this is where they usually have the ability to recommend testing as per current clinical information. They will explain the advantages and disadvantages of specific testing. Without such crucial input, oncologists may not know what type of molecular oncology test to order for potential trial candidates.

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For over 70 years, Yosemite Pathology’s anatomic pathology laboratory provides top quality and specialized reporting. We now have more than  20 Board Certified Anatomic Pathologists, representing a wide range of specialties. Our expertise assists doctors and their patients in making vital healthcare determinations. The bottom line is always helping doctors provide the most promising treatment outcomes for patients.

For more information about Yosemite Pathology and how we can serve your practice or hospital with our extensive range of testing services, including our many specialties, contact us today