For many years, patients with advanced thyroid cancer faced bleak prospects and no viable treatment options. But now, building on recent discoveries about the genetics and cell signaling pathways of thyroid tumors, researchers are developing exciting new weapons against the disease, using kinase inhibitors that target tumor cell division and blood vessels. Two recent clinical trials led by a researcher from the Perelman School of Medicine at the University of Pennsylvania showcase the great promise of these new approaches. The work will be presented at the European Cancer Congress (ECCO 17 - ESMO 38 - ESTRO 32) in Amsterdam today.
The first study provides additional data from the phase III DECISION trial of the drug sorafenib, a kinase inhibitor already approved for treatment of kidney and liver cancer, which was presented as a plenary during the 2013 annual American Society of Clinical Oncology meeting. In the newly released findings, lead author Marcia Brose, MD, PhD, an assistant professor in the department of Otorhinolarlyngology: Head and Neck Surgery and the division of Hematology/Oncology in the Abramson Cancer Center, and her colleagues examined the effectiveness of sorafenib on thyroid cancers that harbor BRAF and RAS mutations. They previously reported that for patients who received sorafenib, progression free survival was 10.8 months vs. 5.8 months in the placebo arm. Of the 417 patients enrolled in the trial, 256 had tumors collected for genetic analysis. As they expected, the most common mutations were found in the BRAF and RAS genes. However, the analyses show that all groups, regardless of the presence of a BRAF and RAS mutation benefited from treatment with sorafenib.
“Our results are important because they show that regardless of the presence of these two common genetic changes, the group that was treated with sorafenib did better than the placebo,” Brose says. “There was no subgroup that didn’t appear to benefit from the intervention with the sorafenib.” The use of sorafenib for the first line treatment for advanced differentiated thyroid cancer is now being evaluated for approval by the FDA, which would represent the first effective drug for advanced thyroid patients in more than 40 years.
The second study Brose will present during the European Cancer Congress focused on the subgroup of patients with papillary thyroid cancer (PTC), which is the most prevalent form of advanced thyroid cancer.
About half of PTC patients harbor the BRAFV600E mutation, which is also present in melanomas that can be successfully treated with BRAF inhibitor drugs. “In this phase II study, we took the BRAFV600E inhibitor, vemurafenib, and studied it in BRAF-mutated papillary thyroid cancer patients to see if there’s an effect,” Brose explained. Approximately 50 PTC patients with the BRAFV600E mutation were enrolled in the study, all with progressive disease that had failed to respond to radioactive iodine treatment. The patients were divided into two groups: one that had not received sorafenib or other similar kinase inhibitor, and one that had.
The progression free survival of the treatment naïve group was 15.6 months and had a response rate of 35 percent, while the progression free survival in the previously treated group was 6.3 months with a response rate of26 percent. “Our results show that we can effectively treat PTC patients that have progressive disease by targeting a common mutation, and produce clinically meaningful periods of progression free survival,” Brose said.
Thyroid Cancer Facts
Thyroid cancer is one of the few cancers that has increased in incidence rates over recent years. It occurs in all age groups from children through seniors.
The American Cancer Society estimates that there will be about 60,220 new cases of thyroid cancer in the U.S. in 2013. Of these new cases, about 45,310 will occur in women and about 14,910 will occur in men. About 1,850 people (1,040 women and 810 men) will die of thyroid cancer in 2013.
Many patients, especially in the early stages of thyroid cancer, do not experience symptoms. However, as the cancer develops, symptoms can include a lump or nodule in the front of the neck, hoarseness or difficulty speaking, swollen lymph nodes, difficulty swallowing or breathing, and pain in the throat or neck.
There are several types of thyroid cancer: papillary, follicular, medullary, anaplastic, and variants.
Papillary and follicular thyroid carcinomas are referred to as well-differentiated thyroid cancer and account for 80–90% of all thyroid cancers. Variants include tall cell, insular, columnar, and Hurthle cell. Their treatment and management are similar. If detected early, most papillary and follicular thyroid cancer can be treated successfully.
Taken together, the two trials offer substantial new hope for patients with progressive thyroid cancer. “A few years ago there was nothing to offer these patients,” Brose says. “By understanding similarities across different types of cancers, we have been able to show that therapies previously shown to be effective in other cancers, such as liver, kidney and bone, can be effectively used to treat a rare cancer, providing significant hope to these patients.”
Penn Medicine is one of the world’s leading academic medical centers, dedicated to the related missions of medical education, biomedical research, and excellence in patient care. Penn Medicine consists of the Raymond and Ruth Perelman School of Medicine at the University of Pennsylvania (founded in 1765 as the nation’s first medical school) and the University of Pennsylvania Health System, which together form a $4.3 billion enterprise.
The thyroid gland is located at the lower part of the front of the neck. The function of the thyroid gland is to produce hormones that regulate the body’s metabolism.
Of the four main types of thyroid cancer - papillary, follicular, medullary and anaplastic - papillary carcinoma is the most common type. It usually grows slowly and is often curable. Other, less common types of thyroid cancer are more aggressive and can be fatal.
Exposure to high levels of radiation in childhood has been identified as a cause of thyroid cancer. People who as children lived near the Chernobyl nuclear power plant in Ukraine at the time of the 1986 accident have rates of thyroid cancer more than 30 times that of other populations.
Thyroid cancer often appears as a small lump or swelling on the front of the neck. These small lumps, called nodules, are fairly common and are usually benign. Other symptoms of thyroid cancer can include hoarseness, difficulty swallowing, an enlarged neck node or a persistent cough.
A tracheotomy, which was performed on Rehnquist, is a surgical procedure that involves cutting into the trachea (windpipe) and inserting a small tube to assist with breathing.
A tracheotomy is an unusual procedure and is performed in only 2 percent to 10 percent of thyroid cancer surgeries.
A tracheotomy is performed when an invasive tumor has affected the larynx (voice box), trachea or the nerves leading to the larynx. It may also be performed when the surgery is complicated by injury to the vocal cords.
Surgery to remove a malignant thyroid nodule is the most common treatment to manage thyroid cancer. In some cases, the entire thyroid gland may need to be removed.
Some patients may need radioiodine therapy, in which the patient ingests a radioactive iodine solution. Thyroid cells absorb the radioactive iodine, but most other cells in the body do not absorb any of the radioactive iodine.
Depending on the treatment, the patient may need to take thyroid hormone pills to replace the hormones that the thyroid gland no longer produces.
For the majority of patients, life after thyroid cancer treatment can return to normal. In cases where only part of the thyroid was removed, no further treatment is usually necessary.
Thyroid patients are monitored periodically for life. During this monitoring the patient may have radioactive iodine scans, blood tests or ultrasound.
Sources: American Cancer Society; Memorial Sloan Kettering Cancer Center; Paul W. Ladenson, Johns Hopkins Kimmel Cancer Center
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