Understanding the Biology and Treatment Options for Breast Cancer

by Anthony M Magliocco MD

Breast cancer is a common disease with up to 1 in 8 women receiving this diagnosis in her lifetime. It is more common in older women but it certainly can strike the young and even can occur in men at about 1/100 the rate seen in women.

We have learned a lot about the biology of breast cancer over the years and the condition is becoming easier to detect at an earlier stage and fortunately more effective therapies are now being developed.

We now know that breast cancer is complex and has multiple molecular and biological subtypes. The main types are called Luminal A, Luminal B, HER2 positive, and Triple Negative.

Luminal Cancers – Endocrine responsive tumors

The Luminal types of breast cancer are defined by expressing estrogen receptor. They tend to have better differentiation and generally a more indolent course. The standard treatment is surgery, potentially radiation, and endocrine treatment (an anti estrogen agent) for 5 to 10 years. If the tumor appears more aggressive- ie involves lymph nodes, or has higher grade, chemotherapy may be added to the treatment in an adjuvant way. One of the problems with luminal type breast cancer is it can recur many years after the original cancer has been treated. Its thought the cancer cells can spread and remain dormant in distant organs or bone for many years with some mysterious events causing them to become reactivated.

 

The HER2 positive breast cancers

A subset of breast cancers, about 15% seem driven by the oncogene ERBB2 (which produces the protein HER2).  For some reason this gene can become “amplified” – ie many copies are made in a single cell leading to vast over production of the HER2 protein. This over production seems to drive the cancer cell to proliferate and metastasize.

Fortunately, therapies have been designed for HER2 cancer, these include Trastuzumab and Pertuzumab – antibodies that react and block the function of the HER2 gene. These treatments appear to be able to halt the grow of the cancer and prevent metastases from occurring.

The Triple Negative Breast Cancers (TNBC)

The third main type of breast cancer are the Triple Negative Cancers or TNBC. This group is actually a mixed group of tumors defined by lack of expression of estrogen receptor or HER2.  They frequently occur in younger women, they may be familial, are over represented in African American women and often progress more quickly. Some of them seem to have a high immune infiltrate, some carry the BRCA gene mutation, and some show strange growth characteristics such as bone formation or “metaplasia”.

 

 

The problem with TNBC is they are a generally a diagnosis by exclusion. However there are certain tests a pathologist can order to help prove that a cancer is TNBC such as Nestin.

Because the TNBC is diagnosed by exclusion there is a significant possibility of error. For example some tumors are heterogenous, and only a small portion might be sampled. If the portion is ER negative or HER2 negative the tumor might be erroneously classified as TNBC.

In other cases, TNBC cancers with very low false expression of HER2 or ER may end up being misclassified as HER2 positive or ER positive which could lead to erroneous use of potentially toxic and ineffective anti -HER2 therapy

Use of Second opinion Expert Review Pathology 

A second opinion pathology review by an expert pathologist can help a patient and her oncology be confident that a tumor is indeed a TNBC. The pathologist may order a repeat immunohistochemical stain on additional case material which frequently changes a diagnosis of TNBC to ER positive or HER2 positive. Occasionally a ER positive or HER2 positive will be reclassified as TNBC also.

TNBC is a unique form of breast cancer with subtypes. further classification of TNBC into tumors with BRCA mutation will help with selection of Parp inhibitor or chemotherapy with carboplatinum.

Further, some TNBC tumors have been shown to be sensitive to immunotherapy.

Some TNBC also seem to express androgen receptor, which could be a therapeutic target.

 

Use of Liquid Biopsy

In some patients a liquid biopsy could also be helpful. If a patient has metastatic disease the cancer cells can be isolated and analyzed from a blood sample.  ER and HER2 status can be measured in these circulating tumor cells. In addition fragments of DNA from disintegrating cancer cells can also be measured and classified providing further evidence as to the amount of cancer and whether the cancer is changing or responding to therapy.

Of interest, it seems that breast cancers may undergo biomarker change as they progress or metastasize. for example an ER positive tumor might change and become ER negative or switch to HER2 overexpression.

Patients should seek second opinion pathology review if they have concern regarding the accuracy of their diagnosis or want to ensure that all treatment opportunities are properly considered.

 

 

As treatment options continue to expand, and testing methods improve, it is important that patients with breast cancer have access to the highest quality pathology services and they should also not hesitate to seek second opinion if there is concern regarding the accuracy of diagnosis.

Morsani Molecular Lab at Moffitt Cancer Center is Central to its Personalized Oncology Mission

By Anthony M Magliocco MD

Moffitt Cancer Center, the largest and only NCI designated comprehensive cancer center in Florida and one of the largest in the country has been rapidly expanding its capabilities in molecular diagnostics with a clear focus on supporting its burgeoning personalized oncology programs which are led by internationally recognized expert Dr Howard McLeod.

It became clear several years ago that a huge revolution was coming in the area of personalized oncology and cancer treatments. That revolution is now here.

Explosive advances and numerous FDA approvals for new targeted therapies have emerged for treating and controlling once universal killers such as metastatic melanoma and advanced lung cancer.

These targeted therapy medicines, include vemurafenib targeting mutant BRAF, Erlotinib for EGFR mutant lung cancer, and crizontinib targeting ALK translocations. Further truly dramatic results have been seen with immunotherapy treatments such as the anti PDL-1 immune checkpoint inhibitor pembrolizumab for treatment of a variety of advanced cancers that over express the protein PDL-1 or carry MSI. More recently approvals of NTRK inibitors Larotrectinib and the PARP inhibitor Olaparib for BRCA mutant cancer have further increased demand for specialized testing as both of these treatments have companion diagnostic requirements

 

Immune cells (red and blue) surround a invasive cancer cells (green)

The approval of many new targeted treatments requiring companion biomarker evaluation is providing impetus to develop more advanced diagnostic technology including new cellular imaging methods

These rapid advances in treatment options hinge on the availability of routine, high quality, clinical grade, molecular analysis and diagnosis to properly identify patients who will be most likely to benefit from these costly and frequently toxic treatments.

The Morsani Molecular Laboratories were created to facilitate the rapid development and implementation of new molecular diagnostic assays into the routine CLIA laboratory at Moffitt

Moffitt leadership and its generous philanthropic doners and foundation laid the important cornerstone of the Moffitt Morsani Molecular Laboratories. Under the direction of Dr Magliocco, the laboratories had a singular mission to rapidly develop and deploy the advanced clinical grade diagnostic services necessary to support Moffitts rapidly maturing personalized medicine program.

The Laboratories were initially opened in 2012 and were first equipped with Mass array instruments and conventional Sanger sequencing, pyrosequencing and routine PCR ability. The decision was made to recruit PhD scientists who would help develop the new assays to a CLIA standard and then launch them into a “routine” production laboratory.

The demand from the Moffitt clincal services was high, especially from thoracic oncology, a ground breaking team offering a multitude of clinical trail options for Moffitt patients. This demand required that the assays be CLIA grade, complex and delivered in a rapid way.

This was very challenging. Launching a highly multiplex assay into a CLIA lab is not a trivial matter. The assay must be calibrated to show sensitivity, specificity, analytical performance, range, precision, accuracy and many other technical components. Further, any new assay must also be put through its paces to show its robustness and reproducibility when handled by different scientists and technologists.

Launching new assays into CLIA labs is not trivial and requires extensive expertise and investments

We initially chose to launch the LungCarta (TM) Mass Array Panel from Sequenom. This was very challenging to validate as it contained individual assays run in multiplex to assay over 213 distinct mutations. as these were separate mutations and assays, the decision was made to only validate the most clinically important ones, namely BRAF V600E, KRAS, EGFR, and PIK3CA. The next issue was obtaining appropriate clinical reference materials to validate these assays. Fortunately with Moffitt’s very high clinical volume, previous experience with single-plex testing, and availability of Total Cancer Care Protocol tumor bank which houses data and specimens from over 400,000 patients it was possible to obtain the necessary control and case materials to validate and launch the assays into clinical service.

The development of a CLIA assay requires access to appropriately characterized reference materials to enable clinical validation of the process and assay results.

Although the complete 213 mutation panel was run, only the CLIA validated assay results were reported to the treating physician. The remaining results were ported into Moffitt’s data warehouse for storage and use in properly approved research studies. Following the launch of the LungCarta assay, the Morsani Molecular laboratory also launched assays for melanoma, and a specially constructed Glioma panel assay.

 

In 2014, clinical demands for even more complex sequencing arose for proper management of Myelodysplastic Syndrome (MDS) mounted. The hematology team needed access to over 30 genes and potentially thousands of mutations. It was time for the big guns, time for next generation sequencing. At the same time Moffitt molecular pathologists also saw increasing needs for more complex sequencing for solid tumors as well. After careful discussions and further evaluations it was decided to begin next generation sequencing. Following some debate, the consensus was to start with Illumina, given their long history in next gen sequencing and also the experience with the technology in Moffitt’s core genetic research laboratory. It was decided to develop an off the shelf 26 gene panel TST26 that covered most of the key mutations in lung cancer and in melanoma. In addition Moffitt CLIA scientists, molecular pathologists, and clinicians worked with Illumina to design a 32 gene myeloid NGS panel.

Bringing on NGS brought new challenges of a complex wet lab and also a very complex bioinformatics dry lab. At Moffitt we worked with PierianDx who helped design bioinformatics pipelines and an efficient validation program for both the wet and dry lab as well as an information system – a genome workbench- which allows molecular pathologists to rapidly review cases and access a knowledge database to enable rapid sign out. We also required access to numerous control samples to validate the assays. Again these came from Moffitts vast biospecimen resources and also Horizon Discovery, a company specializing the the provision of reference materials for clinical validations. To date Moffitt has run over 10,000 NGS assays.

By 2017, clinical demands continued to mount for even more complex testing. There were new drugs approved that needed to evaluate fusions, “exon skipping” mutations, and even MSI and tumor mutational burden. With these demands, we turned to illuminas TST170 assay, a new type of sequencing assay that had both DNA and RNA. In addition the assay was designed with “actionable targets” in mind. Meaning, that targeted agents in clinical trials were scrutinized to determine the collection of genes and mutations that would likely be most informative for treatment selection in solid tumor oncology. This approach makes the assay very useful and practical for deployment in a busy cancer center where multiple trials are underway and complex patients with unusual cancers are presenting. Moffitts Morsani molecular team worked hard and spent several months validating the assay to bring it to acceptable CLIA standard finally launching it as “Moffitt STAR” an assay to screen for actionable mutations.

Since its launch, demand has been exceptionally high with hundreds of physician orders in the first week alone.

 

Moffitt laboratories continue to work closely with the worlds leading oncologists and pharma and technology companies to ensure that Moffitt Patients always have access to the latest diagnostic tools to enable them access to the most current treatment options.

That is what makes Moffitt an exceptional hospital for cancer patients seeking innovative treatments and explains why Moffitt has some of the best cancer outcome response rates in the country.

 

A Tale of 2 Biomarkers: CTCs and cfDNA are Key to Managing the Plethora of New Trial Options

By Anthony M Magliocco MD

 

We are currently living in revolutionary times when it comes to cancer therapy and treatment options. There are literally hundreds of clinical trials under way evaluating dozens of new therapeutic compounds and combinations of therapy. In fact there are so many trials that its difficult to always find enough patients for them and also to design them to produce the level of evidence expected in traditional multi-armed phase III trials.

There are hundreds of open clinical trials testing dozens of compounds and combinations of therapy

 

Indeed, we seem to be arriving at the point where cancer therapy really is being tailored and delivered to the individual. This shift from evidence based conventional cancer therapy clinical trials, to newer, matched and “N of One” trials creates new challenges for the oncologist and diagnostic laboratory industry.

In a traditional trial, selection and enrollment would depend on results of a key biomarker such as HER2 overexpression for Trastuzumab therapy

Traditionally a biomarker would be required to select a patient for a specific therapy. For example, in breast cancer, presence of HER2 over expression or amplification was a marker to help select patients for enrollment in a trial. Because the frequency of the biomarker was relatively common in a common disease, it was possible to build a well powered phase III trial to collect convincing evidence that on a population based setting that this was an effective strategy. This led to FDA approval and the development of companion diagnostics such as the Herceptin Test.

Fast forward twenty years or so. Now we have so called “basket trials” where cancers can be tested with complex genomic tests that will evaluate hundreds of genes, for example the Moffitt STAR assay that covers 170 actionable mutations and alterations resulting in detection of relatively rare, but still actionable mutations in many tumors. However the mutations are variable and the choices for treatment complex meaning that more than one combination of therapy could be considered. Whats an oncologist to do?

Going forward, it appears that if patients cannot be managed or enrolled in large trials, there will need to be an approach to effectively manage the so called “N of One” patient. In fact, it could be considered that almost every patient is a now unique in some way and could be classified as a rare disease

With a movement away from classical evidence based clinical trials toward n of one trials, off label therapy, and basket trials new approaches to companion diagnostics are urgently needed

In this situation, it appears that physicians will need to act on “best available evidence” or actual bioinformatics or other predictive models of possible response based on understanding the underlying molecular circuitry in the cancer in question. In this situation a “best guess” is made for assignment of therapy (either in a basket trial or in an off-label situation).

This approach can be problematic and has numerous complications such as the possibility of providing futile or toxic treatment. Fortunately, there are plenty of new advances in technology that might address this problem. The most help may come from the so-called “liquid biopsy”. Which is essentially usually a simple blood test evaluated with a exotic new technology.

Liquid Biopsy

The main components of a liquid Biopsy include circulating normal cells (WBC, Platelets, RBCs) possibly circulating living cancer cells (CTCs) and bits of dying cancer cells (cell free DNA, miRNA etc).

A Story of Two Biomarkers CTCs and cfDNA

CTCs Circulating Tumor Cells

The CTCs are very fragile, rare and hard to detect but give a window into the living cancer in the patient as treatment progresses. These cells can be further evaluated to determine if they are proliferating or if certain signalling pathways are active. In fact they can also be harvested, sequenced, and in some cases grown and expanded in culture.

Cell Free DNA cfDNA

Cell Free DNA or cfDNA gives a more stable read out of the tumor load, and mutation composition of the DNA, or at least the DNA leaking into the blood. It might be expected that when a new treatment begins, cancer cells in the host may undergo death and leak DNA into the blood. Consequently there could be an initial “Spike” in the amount of circulating DNA – this could be a positve signal. In other instances, cfDNA might indicate if there is residual cancer left in a patient after a surgery was completed that was initially intended to remove all disease giving a type of molecular staging. If a therapy is working well we would expect that CTCs and cfDNA would decrease and perhaps become immeasurable. On development of resistance there would be detection of new clones and expansion of the concentration of CTCs and cfDNA fragments.

Liquid biopsy provides a means to monitor tumor response to therapy in a dynamic and real time manner giving unprecedented opportunities to modulate treatment and truly personalize therapy for cancer patients

I expect that the twin technologies of CTC and cfDNA analysis will become more valued by oncologists, patients and payers as these tools will provide a way to dynamically monitor tumor response to treatment and provide immediate evidence of efficacy of a therapy or also of impending relapse potentially allowing a window of opportunity to adjust treatment.

 

Bringing Digital Droplet PCR into the Cancer Clinic for Treating Progressive Lung Cancer

By Anthony M Magliocco MD

Digital Droplet PCR, or ddPCR is a phenomenally sensitive, specific, and most importantly, precise method to measure target DNA.

One important application for this technology that is now reaching the clinical laboratory is the development of tests for monitoring circulating cell free DNA that is released from cancer cells.

The challenge of detecting cfDNA is monumental.  A tube of blood is loaded with a rich variety of complex biomolecules and cells including lymphocytes, neutrophils, platelets, and of course red corpuscles.  These cells, including RBCs, are loaded with nucleic acids and whats worse, they can easily rupture during blood draws or pre analytical handling.

Advanced lung adenocarcinoma, (NSCLC) is probably the single tumor type that has caused the largest advances in personalized oncology of solid tumors. Investigations into the molecular biology of this disease has uncovered the fact that NSCLC is a heterogeneous disease defined by distinct molecular subtypes and clear molecular driving pathways. Further the discovery of targetable driver mutations including presence of EGFR mutations among others has led to pivotal clinical trials proving the efficacy of the Tyrosine Kinase inhibitor Drugs (TKIs).  Further it seems that lung tumors with EGFR mutations are more likely to arise in women and non-smokers.

Despite the remarkable efficacy of TKI therapy in many patients with advanced NSCLC, the disease is relentless and frequently overcomes treatment by developing resistance mechanisms. The commonest mechanism of resistance is acquisition of EGFR T790M mutation which further enhances the activity of the EGFR pathway, driving growth of the lung cancer cells.

 

 

Fortunately, third generation non-competitive inhibitors of EGFR were developed that can overcome the development of T790M resistance -osimertinib or Tagresso from AZD.

When Osimertinib first became available it was necessary to develop an ultra sensitive assay to detect the mutation in tissues and blood.

The Moffitt Cancer Center Morsani Laboratories, when faced with this challenge, decided to use a digital PCR approach because of its superior sensitivity, specificity and reasonable cost of operation.

Dr John Puskas worked diligently to develop and validate a cfDNA assay for EGFR T790M mutation using ddPCR for CLIA at the Moffitt Cancer Center.  Different PCR platforms were evaluated but the Bio-Rad QX200 was eventually selected for use.

The assay was superbly sensitive and precise as well as convenient to run.  The assay can detect mutant EGFR T790M down to 0.1% and can easily monitor blood concentration over time to give assessment of disease progression

 

 

The development of accurate and specific cfDNA assays to precisely monitor cancer progression in the metastatic setting is an important tool to potentially enable oncologists the opportunity to determine more rapidly f tumors are responding to treatment or not and make adjustments.

This novel opportunity to trace tumor evolution in real time, at a molecular level, could play a role in trials and treatments of the future where treatments are carefully adjusted to avoid the inadvertent development of treatment resistance due to over treatment.

 

MOFFITT NGS STAR* Enters Clinical Service

Moffitt’s latest NGS sequencing assay the Moffitt STAR (Solid Tumor Actionable Result) panel was validated by the Moffitt Morsani Molecular Laboratory and launched into service this month at the busy Florida Comprehensive Cancer Center in Tampa.

The assay is based on Illumina’s TruSight Tumor 170 assay which is a next-generation sequencing assay designed to cover 170 genes that are commonly designated as drivers in solid tumors. The assay evaluates both DNA and RNA and focuses on detecting actionable mutations which include SNV, dels, insertions, amplifications, and translocations. Such alterations are the target for many new targetable therapies including anti-EGFR agents, anti BRAF therapies and treatments targeting the Tropomyosin Receptor Kinase fusions (TRK) such as Larotrectinib.

Many key actionable mutations only occur rarely, making detection by single marker tests problematic and wasteful. However, the Moffitt STAR assay now allows the Moffitt molecular laboratory to screen patient tumors for multiple targetable mutations efficiently in a single test using a relatively small amount of nucleic acid extracted from routine formalin fixed, paraffin embedded tissues (FFPE). This important advance enables the Moffitt molecular diagnostic laboratory to effectively evaluate a patient for eligibility to receive treatment with a FDA approved targeted therapy, or be considered for clinical trial enrollment. Moffitt STAR is essentially an “All in one” test that can provide multiple functions.

Moffitt NGS STAR* is an exciting new “all in one” technology advance for Moffitt Cancer Center patients enabling rapid assessment of their tumors for presence of key mutations directing selection of effective approved targeted therapies or for qualification to enroll in the latest generation of clinical trials

Evidence is also emerging the assay, despite its mid size, Moffitt STAR could also reliably measure tumor mutational load and microsatellite instability. These molecular features are often associated with potential response to the latest immune check point inhibitors such as Pembrolizumab which has recently received FDA approval for use in tumors with high microsatellite instability.

Moffitt NGS STAR also provides information on tumor mutational burden and microsatellite instability- key features which may drive patient response to the latest immuno-oncology check point inhibitor therapies

Moffitt NGS STAR can also detect mutations in BRCA genes, a molecular feature that may predict response to parp inhibitors such as olaparib.

Moffitt NGS STAR can be performed on as little as 40ng of input nucleic acid.

Development and launch of Moffitt NGS STAR was made possible through collaboration with industry partners PierianDx and Illumina Inc.

The Moffitt Cancer center is one of the largest in the United States, is consistently ranked in the top cancer centers by U.S. News & World Report. Moffitt Cancer Center has a mission to “contribute to the prevention and cure of cancer” and the vision ” to transform cancer care through service, science, and partnership”

For further details contact anthony.magliocco@moffitt.org