Thyroid Cancer: Extent of Thyroidectomy
Background: Surgical resection is the key to management of thyroid cancer, but determining the optimal surgical procedure for individual cases has been controversial.
Methods: The author reviews several large data bases that allow examination of prognostic criteria for long-term outcomes.
Results: Patients can be classified into good- or poor-risk groups that assist defining the optimal surgical procedure. Routine use of total thyroidectomy in all patients with thyroid cancer is best avoided; however, patients with medullary cancer generally need total thyroidectomy.
Conclusions: The definition of risk groups has clarified the options regarding choice of primary surgical therapy for differentiated thyroid cancer.
Determining the extent of thyroidectomy in the management of differentiated thyroid cancer is controversial. The principal reason of this controversy is the fact that the majority of patients with differentiated thyroid cancer do extremely well; patients survive for decades. Most patients present at a low-risk stage, where survival is excellent. Statistically, it would be impossible to detect any meaningful impact of the routine use of radioactive iodine (RAI) therapy in low-risk patients. The routine application of total thyroidectomy in all patients with differentiated thyroid cancer is likely to lead to significant incidence of complications, with considerable long-term morbidity. No randomized, prospective trials have been conducted regarding the extent of thyroidectomy in differentiated thyroid cancer. This is mainly due to the excellent survival and the need of a large number of patients to be followed for a considerable period of time. A study of this kind would be almost impossible to conduct, especially in good-risk thyroid cancer patients.
Approximately 18,000 new cases of thyroid cancer will occur in the United States in the year 2000. Of these, only 200 to 300 patients are expected to die of differentiated thyroid cancer. The majority of the mortality in thyroid cancer is related to either anaplastic thyroid cancer or medullary thyroid cancer. Currently, thyroid surgery is considered to be the safest surgical procedure, with minimal morbidity and rare mortality.
In 1909, Emil Theodor Kocher became the first surgeon to win the Nobel Prize in Medicine for his contributions to the understanding of thyroid physiology and for perfecting the technique of thyroidectomy. In the past two decades, we have learned a great deal about the biology of thyroid cancer, the prognostic factors, the risk groups, and the application of risk groups to the extent of thyroidectomy and adjuvant therapy. The National Cancer Data Base reported a large series of 53,856 patients with thyroid carcinoma between 1985 and 1995. The 10-year overall relative survival rates for patients with papillary, follicular, Hürthle cell, medullary, and undifferentiated/anaplastic carcinoma was 93%, 85%, 76%, 75%, and 14%, respectively. Their large data base at 5 years did not translate into compelling differences in survival for any subgroup of papillary or follicular carcinoma based on extent of surgery. The percentage distribution of various types of thyroid carcinoma, by histologic subgroups, was papillary (79.9%), follicular (14.2%), medullary (3.7%), Hürthle cell (2.7%), and undifferentiated/anaplastic (1.6%).
Background: Surgical resection is the key to management of thyroid cancer, but determining the optimal surgical procedure for individual cases has been controversial.
Methods: The author reviews several large data bases that allow examination of prognostic criteria for long-term outcomes.
Results: Patients can be classified into good- or poor-risk groups that assist defining the optimal surgical procedure. Routine use of total thyroidectomy in all patients with thyroid cancer is best avoided; however, patients with medullary cancer generally need total thyroidectomy.
Conclusions: The definition of risk groups has clarified the options regarding choice of primary surgical therapy for differentiated thyroid cancer.
Determining the extent of thyroidectomy in the management of differentiated thyroid cancer is controversial. The principal reason of this controversy is the fact that the majority of patients with differentiated thyroid cancer do extremely well; patients survive for decades. Most patients present at a low-risk stage, where survival is excellent. Statistically, it would be impossible to detect any meaningful impact of the routine use of radioactive iodine (RAI) therapy in low-risk patients. The routine application of total thyroidectomy in all patients with differentiated thyroid cancer is likely to lead to significant incidence of complications, with considerable long-term morbidity. No randomized, prospective trials have been conducted regarding the extent of thyroidectomy in differentiated thyroid cancer. This is mainly due to the excellent survival and the need of a large number of patients to be followed for a considerable period of time. A study of this kind would be almost impossible to conduct, especially in good-risk thyroid cancer patients.
Approximately 18,000 new cases of thyroid cancer will occur in the United States in the year 2000. Of these, only 200 to 300 patients are expected to die of differentiated thyroid cancer. The majority of the mortality in thyroid cancer is related to either anaplastic thyroid cancer or medullary thyroid cancer. Currently, thyroid surgery is considered to be the safest surgical procedure, with minimal morbidity and rare mortality.
In 1909, Emil Theodor Kocher became the first surgeon to win the Nobel Prize in Medicine for his contributions to the understanding of thyroid physiology and for perfecting the technique of thyroidectomy. In the past two decades, we have learned a great deal about the biology of thyroid cancer, the prognostic factors, the risk groups, and the application of risk groups to the extent of thyroidectomy and adjuvant therapy. The National Cancer Data Base reported a large series of 53,856 patients with thyroid carcinoma between 1985 and 1995. The 10-year overall relative survival rates for patients with papillary, follicular, Hürthle cell, medullary, and undifferentiated/anaplastic carcinoma was 93%, 85%, 76%, 75%, and 14%, respectively. Their large data base at 5 years did not translate into compelling differences in survival for any subgroup of papillary or follicular carcinoma based on extent of surgery. The percentage distribution of various types of thyroid carcinoma, by histologic subgroups, was papillary (79.9%), follicular (14.2%), medullary (3.7%), Hürthle cell (2.7%), and undifferentiated/anaplastic (1.6%).
SHARE
![Breast Cancer Screening (PDQ®): Screening - Health Professional Information [NCI]-Special Population](https://cdnus.oss-us-west-1.aliyuncs.com/libs/images/NewsJpg/cate_6/039_215x160.jpg)
