Early detection and treatment of cancer is usually a good thing. In the case of thyroid cancer, however, some physicians worry that treatments for patients may be too aggressive, particularly when small tumors have been detected in only part of the thyroid.
The thyroid is a small butterfly shaped gland straddling the front of the neck, just below the “adam’s apple.” When a thyroid tumor is detected on one side, or lobe, doctors and patients must decide how much of the thyroid to remove in order to arrest the cancer.
Up to 90% of surgeries for thyroid cancer involve total thyroidectomies where the entire gland is removed. More conservative options involve a “lumpectomy” or “lobectomy” where only part or half of the thyroid is excised. The debate among physicians is over which surgical approach provides the best outcome for patient survival and quality of life.
One study in 2006 from Northwestern University in Chicago, Illinois looked at the results from more than 50,000 thyroid cancer patients who had surgery in 1985 to 1998. The researchers found that tumor size was critical in determining the best surgical choice.
For thyroid tumors less than one centimeter the extent of surgery—total or partial removal of the thyroid--did not affect patient long-term survival or tumor recurrence. But “total thyroidectomy results in lower recurrence rates and improved survival for papillary thyroid cancers greater or equal to one centimeter compared to lobectomy,” the authors concluded.
When small tumors are confined to one lobe, "there is no rationale for taking out the whole thyroid. You are punishing the patient, more or less, for their whole life," argues Dr. Ashok R. Shaha, a professor of surgery at Memorial Sloan-Kettering Cancer Center, quoted in the National Cancer Institute Bulletin.
The punishment, Dr. Shaha explains, is that patients who undergo total thyroidectomy require life long thyroid hormone replacement in addition to regular doctor visits to ensure the proper dosage. There are also potential long-term problems with maintaining sufficient calcium and phosphorous in the body and a small risk of permanent nerve damage during total thyroidectomy surgeries. Other experts say these risks are minimal and prefer complete removal of the thyroid, even when tumors are small, to better avoid possible tumor recurrence and spread.
"The problem is that these very small cancers, most of them have a good outcome, but not all of them," says Dr. Ernest Mazzaferri, chair of medicine at The Ohio State University, a long-standing proponent of more aggressive treatment who was quoted in the National Cancer Institute Bulletin.
Patients with thyroid cancer can live for decades after surgery, but even those with small tumors in the end "don't always do so well," Dr. Mazzaferri says in the National Cancer Institute Bulletin article. "They can die from pulmonary or brain metastases. A small number, 1 percent, will die. None of us want to miss those."
In another controversy related to thyroid cancer treatment, physicians are not in agreement about who should receive radiation therapy following surgery. Some believe all patients should get radiation treatments regardless of the initial size of the tumor or how much of the thyroid was removed.
Others think that radiation is unnecessary in low risk patients and cite studies that show radiation treatments produce no additional benefit to long-term survival in this patient population. Proponents argue that the current smaller radiation doses and single treatments used in thyroid cancer patients today greatly reduce side effects while increasing assurances that tumors won’t reoccur.
Because thyroid tumor size, location and propensity to spread can vary greatly among patients, there is no “one size fits all” approach to treatments. Until physicians can better predict which type of tumor to treat most aggressively, treatment decisions will have to be determined by careful discussions between patients and their doctors.
Article Links:
Philips, C., 2008. “Tiny Nodules, Big Dilemma,” National Cancer Institute Bulletin, http://www.cancer.gov/ncicancerbulletin/NCI_Cancer_Bulletin_030408/page6
BIlimoria, K.Y., et al., 2007. “Extent of Surgery Affects Survival for Papillary Thyroid Cancer,” Ann. Surgery, http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&pubmedid=17717441
Related Links:
Papillary Cancer: The Most Common Type of Thyroid Cancer, Endocrine web
http://www.endocrineweb.com/capap.html
Bilimoria, K.Y. et al., 2008. “Impact of Surgical Treatment on Outcomes for Papillary Thyroid Cancer,” Adv. Surgery,
http://www.ncbi.nlm.nih.gov/pubmed/18953806?ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DiscoveryPanel.Pubmed_Discovery_RA&linkpos=1&log$=relatedreviews&logdbfrom=pubmed