Thursday, December 4, 2014
The most effective cancer treatment starts with an accurate diagnosis. Pathologist Meera Hameed explains the pathologist’s crucial contributions.
Is it cancer? Is it aggressive? Will my disease respond to chemotherapy, hormone therapy, or radiation? Am I a candidate for a targeted therapy? Pathologists are doctors who are specially trained to sleuth out the answers to these and other questions. An accurate pathology report is crucial to getting a precise diagnosis and deciding on the best treatment plan for you.
Patients at Memorial Sloan Kettering benefit from the experience and expertise of our ten teams of disease-specific pathologists, who use state-of-the-art equipment and the most advanced techniques to analyze more than 60,000 tissue samples each year. Some samples are received as a biopsy, which involves the use of a needle to extract tissue from a suspicious mass. Others are actual tumors removed during surgery.
We asked pathologist Meera Hameed to explain why results can change after the first diagnosis, and to give us some more insights into the crucial importance of precise pathology.
A Small Piece of the Puzzle
The most effective cancer treatment starts with an accurate diagnosis. However, a pathologist may come up with different findings after analyzing tissue taken from a biopsy versus analyzing a tumor sample. “It’s unusual for there to be such differences in pathology results, but sometimes it depends on the type of tumor being biopsied or where in the body the biopsy is taken from,” says Dr. Hameed, who is Acting Chief of the Surgical Pathology Service. “Some growths are tumors but may not be cancerous. Others are located in a part of the body that is not easy to access with a biopsy needle, so the pathologist may not receive enough material to run the necessary tests to make a conclusive diagnosis.”
“For example,” she continues, “an interventional radiologist performing a biopsy procedure might only be able to extract a few millimeters of tissue from a tumor that measures five centimeters or more, so you may be getting just a small piece of the puzzle.”
In some instances, the appearance of cancer cells can vary even within a tumor. A biopsy sample may show one thing, “but when you examine a larger tumor sample after surgery there may be more than one possible diagnosis requiring additional studies or, rarely, even a change in diagnosis,” Dr. Hameed explains.
This morphologic and molecular diversity seen in some tumors — known as intra-tumor heterogeneity — can have important consequences for how cancers are diagnosed and treated.Back to top
Looking at the Bigger Picture
Pathologists use a microscope to scrutinize the appearance of cells and run additional tests to ascertain the nature of the cancer and understand how it behaves and whether it’s likely to spread. They are also improving diagnostic accuracy with the use of newer technologies such as genetic sequencing, which can further classify cancers and reveal genetic mutations or alterations in tumors that drive growth and can help guide therapy.
“It’s like putting together pieces of a puzzle in order to clearly see the bigger picture,” says Dr. Hameed. “Pathological diagnosis including molecular information, taken together with what is going on with the patient from a clinical perspective — such as age, other health conditions, imaging tests, and personal and family history of cancer and other diseases — creates the full context in which personalized treatment decisions are made.”
For example, should your surgeon remove any lymph nodes in addition to your tumor? Is chemotherapy or radiation necessary to ensure that no stray cancer cells have been left behind after the operation? Do certain mutations found in your DNA suggest that your cancer will be responsive to a targeted therapy? Or, if your cancer appears to be slow-growing and not aggressive, can you defer treatment and opt for an approach called active surveillance, in which you’d be closely monitored for changes in your disease through imaging and other screening tests? The answers to all these questions begin with a complete and accurate pathology report.Back to top
The Best Care Begins with the Right Diagnosis
Like our clinicians, pathologists at Memorial Sloan Kettering are all sub-specialized and bring extensive experience to their respective fields. “Communication between my group and the treatment team taking care of the patient is an absolute must,” says Dr. Hameed, who notes that she and other pathologists participate in weekly meetings with the clinical team to review complex patient cases.
“This is particularly useful in the diagnosis of rare cancers, such as tumors of the musculoskeletal system, which is my specialty,” she explains. “Most pathologists around the country are not able to get much exposure to rare cancers, but we see these types of diseases often enough that when patients come to MSK, they can be confident that they will receive an accurate diagnosis — and our experts can then offer them the most effective care.”Back to top