Parathyroid adenomas represent a common endocrine problem, whereas parathyroid carcinomas are very rare tumors. With an estimated incidence of 0.015 per 100,000 population and an estimated prevalence of .005% in the United States, parathyroid cancer is one of the rarest of all human cancers.[1,2] In Europe, the United States, and Japan, parathyroid carcinoma has been estimated to cause hyperparathyroidism (HPT) in .017% to 5.2% of the cases; however, many series report this entity to account for less than 1% of patients with primary HPT.[1,3,4,5] The median age in most series is between 45 and 51 years. The ratio of affected women to men is 1:1 in contrast to primary HPT in which there is a significant female predominance (ratio of 3-4:1).
The etiology of parathyroid carcinoma is unknown; however, an increased risk of parathyroid cancer has been associated with multiple endocrine neoplasia 1 and with autosomal dominant familial isolated hyperparathyroidism.[6,7,8] Parathyroid cancer has also been associated with external radiation exposure; however, most reports describe an association between radiation and the more common parathyroid adenoma.[1,5]
Coenzyme Q10 (commonly known as CoQ10) is a compound that is made naturally in the body. The body uses it for cell growth and to protect cells from damage that could lead to cancer (see Question 1).
Animal studies have shown that CoQ10 helps the immune system work better and makes the body better able to resist certain infections and types of cancer (see Question 5).
Clinical trials have shown that CoQ10 helps protect the heart from the damaging side effects of doxorubicin, a drug...
Parathyroid cancer typically runs an indolent, albeit tenacious, course because the tumor has a rather low malignant potential. At initial presentation, very few patients with parathyroid carcinoma have metastases either to regional lymph nodes (<5%) or distant sites (<2%). In the National Cancer Database series of 286 patients, only 16 (5.6%) had lymph node metastases noted at the time of initial surgery. A higher proportion of parathyroid cancers locally invade the thyroid gland, overlying strap muscles, recurrent laryngeal nerve, trachea, or esophagus. Some patients are not identified preoperatively or intraoperatively as having parathyroid carcinoma and undergo parathyroid procedures devised to treat parathyroid adenoma. Only after review of the postsurgical pathology, or when these patients experience local or distant recurrence, is a correct diagnosis of parathyroid carcinoma made. Parathyroid carcinoma tends to be localized in the inferior parathyroid glands; one series reported that the primary tumor originating in the inferior parathyroid glands was found in 15 of 19 cases involving local invasion.[9,10]