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Thyroid Tumors, BRAF, L597R (c.1790T>G)

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Expand Collapse Thyroid Tumor  - General Description This year about 56,000 people in the U.S. (77% of them women) will be told by a doctor that they have thyroid cancer. About half of these new patients will be at least 50 years old. However, more than 500,000 patients with thyroid cancer remain alive today.

The thyroid is a butterfly-shaped gland found at the base of the throat, near the windpipe (trachea). The 2 wings (lobes) of the thyroid are connected by a thin piece of tissue called the isthmus. The thyroid uses iodine from food and iodized salts to make hormones that control the heart rate, body temperature, the speed with which food is changed into energy (metabolism) and the level of calcium in the blood. Based on their appearance under the microscope, the 4 main types of thyroid cancer are papillary, follicular, medullary and anaplastic. For treatment purposes, thyroid cancers are often classified as differentiated (papillary or follicular) or poorly differentiated (medullary or anaplastic). If a cancer cell is well-differentiated, it has most of the characteristics of a normal cell. On the other hand, poorly differentiated cancer cells don't look like normal cells.

Follicular thyroid cancer is a slow-growing cancer that forms in follicular cells, which are epithelial cells that take up iodine and make certain thyroid hormones. Papillary thyroid cancer, which appears as finger-like shapes under the microscope, also begins in follicular cells and is slow-growing. It is the most common type of thyroid cancer, usually appearing before the age of 45 years. It is more common in women than in men. Medullary thyroid cancer accounts for about 4% of all thyroid cancers. It begins in C cells, which make calcitonin, a hormone that helps keep calcium at the right level in the blood. Anaplastic thyroid cancer is a rare, aggressive form of cancer whose cells don't look at all like normal thyroid cells.

Thyroid cancer (and other tumors) can spread (metastasize) from the place where it started (the primary tumor) in 3 ways. First, it can invade the normal tissue surrounding it. Second, cancer cells can enter the lymph system and travel through lymph vessels to distant parts of the body. Third, the cancer cells can get into the bloodstream and go to other places in the body. In these distant places, the cancer cells cause secondary tumors to grow. The main places to which thyroid cancer spreads are the lungs, liver, and bones.

To find out whether the cancer has entered the lymph system, a surgeon removes all or part of a node near the primary tumor and a pathologist looks at it through a microscope to see if cancer cells are present. Several kinds of imaging can also be performed to determine if the cancer has spread. These include chest x-rays, ultrasound and CT scans.

The FDA has approved the targeted therapy vandetanib (Capreisa) for treatment of medullary thyroid cancer that is locally advanced and can't be removed by surgery or that has metastasized. No targeted therapies are yet available for treatment of anaplastic thyroid cancer. Therefore, novel therapies and treatment strategies are needed.

Source: National Cancer Institute, 2012
Thyroid cancer represents approximately 3% of new malignancies occurring annually in the United States, with an estimated 56,460 cancer diagnoses and 1,780 cancer deaths per year. Of these cancer diagnoses, 2% to 3% are medullary thyroid cancer (MTC).

MTC arises from the calcitonin-secreting parafollicular cells of the thyroid gland. MTC occurs in sporadic and familial forms and may be preceded by C-cell hyperplasia (CCH), although CCH is a relatively common abnormality in middle-aged adults.

Average survival for MTC is lower than that for more common thyroid cancers (e.g., 83% 5-year survival for MTC compared with 90-94% 5-year survival for papillary and follicular thyroid cancer). Survival is correlated with stage at diagnosis. Decreased survival in MTC can be accounted for, in part, by a high proportion of late-stage diagnoses.

In addition to early stage at diagnosis, other factors associated with improved survival in MTC include smaller tumor size, younger age at diagnosis, familial versus sporadic form and diagnosis by biochemical screening (i.e., screening for calcitonin elevation).

A Surveillance, Epidemiology, and End Results (SEER) population-based study of 1,252 MTC patients found that survival varied by extent of local disease. For example, the 10-year survival rates ranged from 95% for disease confined to the thyroid gland to 40% for those with distant metastases.

While the majority of MTC cases are sporadic, approximately 20-25% are hereditary because of mutations in the RET proto-oncogene. Mutations in the RET gene cause multiple endocrine neoplasia type 2 (MEN 2), an autosomal dominant disorder associated with a high lifetime risk of MTC. Multiple endocrine neoplasia type 1 (MEN 1) is an autosomal dominant endocrinopathy that is genetically and clinically distinct from MEN 2. However, the similar nomenclature for MEN 1 and MEN 2 may cause confusion. Of note, there is no increased risk of thyroid cancer for MEN 1.

Historically, MEN 2 has been classified into three subtypes based on the presence or absence of certain endocrine tumors in the individual or family:

- MEN 2A
- Familial medullary thyroid carcinoma (FMTC)
- MEN 2B

All three subtypes impart a high risk of developing MTC. MEN 2A has an increased risk of pheochromocytoma and parathyroid adenoma and/or hyperplasia. MEN 2B has an increased risk of pheochromocytoma and includes additional clinical features such as mucosal neuromas of the lips and tongue, distinctive faces with enlarged lips, ganglioneuromatosis of the gastrointestinal tract and an asthenic Marfanoid body habitus. FMTC has been defined as the presence of at least four individuals with MTC without any other signs or symptoms of pheochromocytoma or hyperparathyroidism in the proband or other family members.

Some families previously classified as FMTC will go on to develop one or more of the MEN 2A-related tumors, suggesting that FMTC is simply a milder variant of MEN 2A. Offspring of affected individuals have a 50% chance of inheriting the gene mutation.

The age of onset of MTC varies in different subtypes of MEN 2. MTC typically occurs in early childhood for MEN 2B, predominantly early adulthood for MEN 2A and middle age for FMTC.

DNA-based germline testing of the RET gene (chromosomal region 10q11.2) identifies disease-causing mutations in more than 95% of individuals with MEN 2A and MEN 2B and in about 88% of individuals with FMTC.

Source: National Cancer Institute, 2012
This year about 56,000 people in the U.S. (77% of them women) will be told by a doctor that they have thyroid cancer. About half of these new patients will be at least 50 years old. However, more than 500,000 patients with thyroid cancer remain alive today.

The thyroid is a butterfly-shaped gland found at the base of the throat, near the windpipe (trachea). The 2 wings (lobes) of the thyroid are connected by a thin piece of tissue called the isthmus. The thyroid uses iodine from food and iodized salts to make hormones that control the heart rate, body temperature, the speed with which food is changed into energy (metabolism) and the level of calcium in the blood. Based on their appearance under the microscope, the 4 main types of thyroid cancer are papillary, follicular, medullary and anaplastic. For treatment purposes, thyroid cancers are often classified as differentiated (papillary or follicular) or poorly differentiated (medullary or anaplastic). If a cancer cell is well-differentiated, it has most of the characteristics of a normal cell. On the other hand, poorly differentiated cancer cells don't look like normal cells.

Follicular thyroid cancer is a slow-growing cancer that forms in follicular cells, which are epithelial cells that take up iodine and make certain thyroid hormones. Papillary thyroid cancer, which appears as finger-like shapes under the microscope, also begins in follicular cells and is slow-growing. It is the most common type of thyroid cancer, usually appearing before the age of 45 years. It is more common in women than in men. Medullary thyroid cancer accounts for about 4% of all thyroid cancers. It begins in C cells, which make calcitonin, a hormone that helps keep calcium at the right level in the blood. Anaplastic thyroid cancer is a rare, aggressive form of cancer whose cells don't look at all like normal thyroid cells.

Thyroid cancer (and other tumors) can spread (metastasize) from the place where it started (the primary tumor) in 3 ways. First, it can invade the normal tissue surrounding it. Second, cancer cells can enter the lymph system and travel through lymph vessels to distant parts of the body. Third, the cancer cells can get into the bloodstream and go to other places in the body. In these distant places, the cancer cells cause secondary tumors to grow. The main places to which thyroid cancer spreads are the lungs, liver, and bones.

To find out whether the cancer has entered the lymph system, a surgeon removes all or part of a node near the primary tumor and a pathologist looks at it through a microscope to see if cancer cells are present. Several kinds of imaging can also be performed to determine if the cancer has spread. These include chest x-rays, ultrasound and CT scans.

The FDA has approved the targeted therapy vandetanib (Capreisa) for treatment of medullary thyroid cancer that is locally advanced and can't be removed by surgery or that has metastasized. No targeted therapies are yet available for treatment of anaplastic thyroid cancer. Therefore, novel therapies and treatment strategies are needed.

Source: National Cancer Institute, 2012
Thyroid cancer represents approximately 3% of new malignancies occurring annually in the United States, with an estimated 56,460 cancer diagnoses and 1,780 cancer deaths per year. Of these cancer diagnoses, 2% to 3% are medullary thyroid cancer (MTC).

MTC arises from the calcitonin-secreting parafollicular cells of the thyroid gland. MTC occurs in sporadic and familial forms and may be preceded by C-cell hyperplasia (CCH), although CCH is a relatively common abnormality in middle-aged adults.

Average survival for MTC is lower than that for more common thyroid cancers (e.g., 83% 5-year survival for MTC compared with 90-94% 5-year survival for papillary and follicular thyroid cancer). Survival is correlated with stage at diagnosis. Decreased survival in MTC can be accounted for, in part, by a high proportion of late-stage diagnoses.

In addition to early stage at diagnosis, other factors associated with improved survival in MTC include smaller tumor size, younger age at diagnosis, familial versus sporadic form and diagnosis by biochemical screening (i.e., screening for calcitonin elevation).

A Surveillance, Epidemiology, and End Results (SEER) population-based study of 1,252 MTC patients found that survival varied by extent of local disease. For example, the 10-year survival rates ranged from 95% for disease confined to the thyroid gland to 40% for those with distant metastases.

While the majority of MTC cases are sporadic, approximately 20-25% are hereditary because of mutations in the RET proto-oncogene. Mutations in the RET gene cause multiple endocrine neoplasia type 2 (MEN 2), an autosomal dominant disorder associated with a high lifetime risk of MTC. Multiple endocrine neoplasia type 1 (MEN 1) is an autosomal dominant endocrinopathy that is genetically and clinically distinct from MEN 2. However, the similar nomenclature for MEN 1 and MEN 2 may cause confusion. Of note, there is no increased risk of thyroid cancer for MEN 1.

Historically, MEN 2 has been classified into three subtypes based on the presence or absence of certain endocrine tumors in the individual or family:

- MEN 2A
- Familial medullary thyroid carcinoma (FMTC)
- MEN 2B

All three subtypes impart a high risk of developing MTC. MEN 2A has an increased risk of pheochromocytoma and parathyroid adenoma and/or hyperplasia. MEN 2B has an increased risk of pheochromocytoma and includes additional clinical features such as mucosal neuromas of the lips and tongue, distinctive faces with enlarged lips, ganglioneuromatosis of the gastrointestinal tract and an asthenic Marfanoid body habitus. FMTC has been defined as the presence of at least four individuals with MTC without any other signs or symptoms of pheochromocytoma or hyperparathyroidism in the proband or other family members.

Some families previously classified as FMTC will go on to develop one or more of the MEN 2A-related tumors, suggesting that FMTC is simply a milder variant of MEN 2A. Offspring of affected individuals have a 50% chance of inheriting the gene mutation.

The age of onset of MTC varies in different subtypes of MEN 2. MTC typically occurs in early childhood for MEN 2B, predominantly early adulthood for MEN 2A and middle age for FMTC.

DNA-based germline testing of the RET gene (chromosomal region 10q11.2) identifies disease-causing mutations in more than 95% of individuals with MEN 2A and MEN 2B and in about 88% of individuals with FMTC.

Source: National Cancer Institute, 2012
Expand Collapse BRAF  - General Description
CLICK IMAGE FOR MORE INFORMATION
The BRAF gene encodes a serine/threonine kinase that activates the growth-promoting MAP kinase signaling cascade. BRAF is commonly activated by somatic point mutations in human cancers, most frequently by mutations located within the kinase domain at amino acid positions G466, G469, L597 and V600.

In regards to treatment, the Food and Drug Administration (FDA) approved the BRAF inhibitor, vemurafenib, for the treatment of unresectable or metastatic melanoma patients harboring specifically the BRAF V600E mutation, as detected by an FDA-approved test. In addition, there are a growing number of targeted agents that are being evaluated for the treatment of various BRAF-mutant advanced cancers, including other RAF kinase inhibitors and/or MEK inhibitors. Recently, the combination of the BRAF inhibitor dabrafenib with the MEK inhibitor trametinib was approved by FDA for the treatment of patients with BRAF V600E or V600K mutations.

Tumor mutation profiling performed clinically at the MGH Cancer Center has identified the highest incidence of BRAF mutations in thyroid cancer (30-40%), melanoma (20-30%) and colon cancer (10-15%).

To read more about the various BRAF based trials ongoing at the MGH Cancer Center, click on the "disease-gene-mutation" tab on the web page, and select relevant information. Current trials will appear as a ist under the posted information.


Source: Genetics Home Reference
The BRAF gene encodes a serine/threonine kinase that activates the growth-promoting MAP kinase signaling cascade. BRAF is commonly activated by somatic point mutations in human cancers, most frequently by mutations located within the kinase domain at amino acid positions G466, G469, L597 and V600.

In regards to treatment, the Food and Drug Administration (FDA) approved the BRAF inhibitor, vemurafenib, for the treatment of unresectable or metastatic melanoma patients harboring specifically the BRAF V600E mutation, as detected by an FDA-approved test. In addition, there are a growing number of targeted agents that are being evaluated for the treatment of various BRAF-mutant advanced cancers, including other RAF kinase inhibitors and/or MEK inhibitors. Recently, the combination of the BRAF inhibitor dabrafenib with the MEK inhibitor trametinib was approved by FDA for the treatment of patients with BRAF V600E or V600K mutations.

Tumor mutation profiling performed clinically at the MGH Cancer Center has identified the highest incidence of BRAF mutations in thyroid cancer (30-40%), melanoma (20-30%) and colon cancer (10-15%).

To read more about the various BRAF based trials ongoing at the MGH Cancer Center, click on the "disease-gene-mutation" tab on the web page, and select relevant information. Current trials will appear as a ist under the posted information.

Source: Genetics Home Reference
PubMed ID's
12068308, 15947100, 20401974, 20425073, 21606968
Expand Collapse L597R (c.1790T>G)  in BRAF
The BRAF L597R mutation arises from a single nucleotide change (c.1790T>G) and results in an amino acid substitution of the leucine (L) at position 597 by an arginine (R).
The BRAF L597R mutation arises from a single nucleotide change (c.1790T>G) and results in an amino acid substitution of the leucine (L) at position 597 by an arginine (R).

Mutation of the BRAF gene is specific to papillary thyroid carcinomas, found in 45% of sporadic adult cases and less frequently in pediatric cases. Almost all BRAF mutations are V600E, with mutations at other BRAF codons being exceedingly rare in this malignancy. BRAF mutations and RET/PTC gne rearrangements are mutually exclusive in papillary thyroid carcinomas.

A recent meta-analysis has reported that the BRAF V600E mutation in papillary thyroid cancer is associated with a number of high-risk factors, including lymph node metastasis and advanced stage of disease. It is therefore not surprising that mutant BRAF has been associated with disease recurrence and reduced or lost radioiodine sensitivity. Therefore, more aggressive treatment may be required.

Targeted therapy in patients with BRAF-mutant papillary thyroid cancer is currently being evaluated in clinical trials. Some have shown positive results. In a phase I study, all 3 patients with BRAF V600E-positive papillary thyroid carcinomas had tumor shrinkage with vemurafenib (a BRAF inhibitor), which was durable for 8-11 months. In a phase II clinical trial evaluating treatment with the MEK inhibitor selumetinib, there was a notable trend for increased progression-free survival in iodine-refractory papillary thyroid cancer patients whose tumors carried a BRAF V600E mutation, compared to patients with non-mutated BRAF (wild-type BRAF). In both studies, only the BRAF V600E mutation was evaluated. Combination therapy with BRAF plus MEK inhibitors, as well as MEK plus PI3K pathway inhibitors, in BRAF-mutant thyroid cancer are promising treatment strategies under investigation.

Interestingly, selumetinib (a MEK inhibitor) was able to produce clinically meaningful increases in iodine uptake and reverse refractoriness to radioiodine in patients with metastatic thyroid cancer. The effectiveness of this approach may be lower in patients with BRAF-mutant disease as compared to RAS-mutant disease.

Mutation of the BRAF gene is specific to papillary thyroid carcinomas, found in 45% of sporadic adult cases and less frequently in pediatric cases. Almost all BRAF mutations are V600E, with mutations at other BRAF codons being exceedingly rare in this malignancy. BRAF mutations and RET/PTC gne rearrangements are mutually exclusive in papillary thyroid carcinomas.

A recent meta-analysis has reported that the BRAF V600E mutation in papillary thyroid cancer is associated with a number of high-risk factors, including lymph node metastasis and advanced stage of disease. It is therefore not surprising that mutant BRAF has been associated with disease recurrence and reduced or lost radioiodine sensitivity. Therefore, more aggressive treatment may be required.

Targeted therapy in patients with BRAF-mutant papillary thyroid cancer is currently being evaluated in clinical trials. Some have shown positive results. In a phase I study, all 3 patients with BRAF V600E-positive papillary thyroid carcinomas had tumor shrinkage with vemurafenib (a BRAF inhibitor), which was durable for 8-11 months. In a phase II clinical trial evaluating treatment with the MEK inhibitor selumetinib, there was a notable trend for increased progression-free survival in iodine-refractory papillary thyroid cancer patients whose tumors carried a BRAF V600E mutation, compared to patients with non-mutated BRAF (wild-type BRAF). In both studies, only the BRAF V600E mutation was evaluated. Combination therapy with BRAF plus MEK inhibitors, as well as MEK plus PI3K pathway inhibitors, in BRAF-mutant thyroid cancer are promising treatment strategies under investigation.

Interestingly, selumetinib (a MEK inhibitor) was able to produce clinically meaningful increases in iodine uptake and reverse refractoriness to radioiodine in patients with metastatic thyroid cancer. The effectiveness of this approach may be lower in patients with BRAF-mutant disease as compared to RAS-mutant disease.

PubMed ID's
20818844, 22241789, 23148184, 17940185, 23406027

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Your Matched Clinical Trials

Trial Matches: (D) - Disease, (G) - Gene, (M) - Mutation
Trial Status: Showing all 2 results Per Page:
Protocol # Title Location Status Match
NCT00585195 A Study Of Oral PF-02341066, A c-Met/Hepatocyte Growth Factor Tyrosine Kinase Inhibitor, In Patients With Advanced Cancer A Study Of Oral PF-02341066, A c-Met/Hepatocyte Growth Factor Tyrosine Kinase Inhibitor, In Patients With Advanced Cancer MGH Open D
NCT02568267 Basket Study of Entrectinib (RXDX-101) for the Treatment of Patients With Solid Tumors Harboring NTRK 1/2/3 (Trk A/B/C), ROS1, or ALK Gene Rearrangements (Fusions) Basket Study of Entrectinib (RXDX-101) for the Treatment of Patients With Solid Tumors Harboring NTRK 1/2/3 (Trk A/B/C), ROS1, or ALK Gene Rearrangements (Fusions) MGH Open D
MGH has many open clinical trials for other cancers not shown on the Targeted Cancer Care website. They can be found on the MassGeneral.org clinical trials search page.

Additional clinical trials may be applicable to your search criteria, but they may not be available at MGH. These clinical trials can typically be found by searching the clinicaltrials.gov website.
Trial Status: Showing all 2 results Per Page:

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