Thyroid Cancer in New Mexico

Transcription

1 Thyroid Cancer in New Mexico Time Trends and Surgical Treatment Preferences Ihsan Mahdi MD MPH

2 Introduction The incidence of thyroid cancer incidence is increasing more rapidly than any other malignancy except liver cancer, rising nearly threefold from 198 to 26(Mangano, 29). The predominant hypothesis explaining the increase in thyroid cancer rates, has been improved surveillance and diagnostics (Morris et al, 213), (Cramer et al., 21), and (Lim et al, 217). Surgery is the mainstay of thyroid cancer treatment with considerable controversy existing about the most appropriate surgical procedures (Donn et al., 1986). The choice of procedure has its effects on individual patients, and on health care systems in terms of associated complications and potential costs (Corso et al., 214).

3 Methods Study population: 5,325 incident primary thyroid cancers diagnosed among New Mexico residents between 1981 and 213. Data source: SEER data base of the New Mexico Tumor Registry. Variables: Tumor size: 4 categories according to cancers greatest dimension as recorded on surgical pathology reports. Treatment options defined as : 1) no surgery, 2) lobectomy/isthmectomy, 3) subtotal thyroidectomy, 4) total thyroidectomy, and 5) surgery not otherwise specified. Race/Ethnicity: Non-Hispanic White, Hispanic, Native American Data Analysis: All data analyses were done using SEER*Stat version and standard modules of the Statistical Analysis System, version 9.4. Temporal trends were assessed using JoinPoint regression analysis.

4 Trends in Thyroid Cancer Age-Adjusted Incidence Rates Among New Mexico Residents, Rate per 1, Population (US 2 Standard) APC=2.5* 95%CI (1., 4.) APC=1.2* 95%CI (1.4, 19.8) APC=2.4* 95%CI (1., 3.8) Year at Diagnosis *Annual percent change (APC) significantly different from zero at α =.5

5 Thyroid Cancer Age-Adjusted Incidence Rates Among Residents of New Mexico, by Gender, and Race/Ethnicity, Rate per 1, Population (US 2 Standard) Males Non-Hispanic White Hispanic Native American Females

6 Rate per 1, Population (US 2 Standard) Trends in Thyroid Cancer Age-Adjusted Incidence Rates Among New Mexico Residents by Race/Ethnicity, APC=4.1* 95%CI (2.3, 5.9) APC=19 95%CI (-18.8, 74.6) APC=1.6 95%CI (-1., 3.3) Non-Hispanic White Hispanic Native American * Annual percent change significantly different from zero at α = APC=3.5* 95%CI (2.2, 4.2) APC=2* 95%CI (-1.3, 5.3) Year of Diagnosis

7 Trends in Thyroid Cancer Age-Adjusted Incidence Rates Among New Mexico Residents, by Tumor Histology, Rate per 1, Population (US 2 Standard) Papillary Follicular Medullary APC=4.5* 95%CI (4., 5.1) APC=1.3* 95%CI (.3, 2.4) APC=2.3 95%CI (-4.9, 9.7) The Anaplastic variety was excluded from the analysis due to low counts. *Annual percent change is significantly different from zero at α =.5 Year of Diagnosis

8 Trends in Papillary Thyroid Cancer Age-Adjusted Incidence Rates Among New Mexico Residents, by Tumor Size, Rates per 1, Population (US 2 Standrad) Males 1 cm or Less cm cm 5+ cm APC=4.7* 95%CI (2.8, 6.6) APC=6.5* 95%CI (4.6, 8.4) APC=3.8* 95%CI (2.1, 5.6) APC=11.5* 95%CI (1.4, 22.7) Rates per 1, Population (US 2 Standard) Females cm or Less cm cm 5+ cm APC=3.8* 95%CI (2.8, 4.9) APC=11.9* 95%CI (2.4, 22.3) APC=8.8* 95%CI (5.9, 11.7) APC=2.3 95%CI (-.7, 5.5) APC=4.9* 95%CI (3.8, 6.1) *Annual percent change is significantly different from zero at α =.5 *Annual percent change is significantly different from zero at α =.5

9 The Percentage of Total Thyroidectomies Performed Among Patients of Thyroid Cancer in New Mexico, % Percentage of Total Thyroidectomies 9% 8% 7% 6% 5% 4% 3% 2% 1% % 85% 84% 8% 81% 8% 77% 76% 72% 71% 7% 66% 63% 57% 56% 53% 49% Year at diagnosis

10 The Percentage of Patients of Papillary Thyroid Cancer (Measuring 1 cm or Less) Treated With Total Thyroidectomy Vs. Other Treatment Options, in New Mexico, Thyroidectomy Other Percentage P(trend)< Time Period of Diagnosis

11 The Percentage of Patients of Papillary Thyroid Cancer (Measuring 1 cm or Less) Treated With Total Thyroidectomy Vs. Other Treatment Options, in New Mexico, by Age Group, P(trend)<.1 Under 65 Years of Age P(trend)= Years or Older Thyroidectomy Other Thyroidectomy Other 1 1 Percentage Percentage Time Period at Diagnosis Time Period at Diagnosis

12 The Percentage of Patients of Papillary Thyroid Cancer Measuring 1 cm or Less, Treated With Total Thyroidectomy Vs. Other Treatment Options, in New Mexico, by Race/Ethnicity, P(trend)<.1 Non-Hispanic White Thyroidectomy Other Percentage Time Period at Diagnosis

13 The Percentage of Patients of Papillary Thyroid Cancer Measuring 1 cm or Less, Treated With Total Thyroidectomy Vs. Other Treatment Options, in New Mexico, by Race/Ethnicity, P(trend)=.5 Hispanic Thyroidectomy Other Percentage Time period at Diagnosis

14 The Percentage of Patients of Papillary Thyroid Cancer (Measuring 1 cm or Less) Treated With Total Thyroidectomy Vs. Other Treatment Options, in New Mexico, by Race/Ethnicity, P(trend)=.7 Native American Thyroidectomy Other Percentage Time period at Diagnosis

15 Conclusions Thyroid cancer incidence rates have nearly tripled in New Mexico over the last thirty years. The epidemiology of thyroid cancer in New Mexico is similar to the national picture in terms of distribution by gender, age, race/ethnicity, and tumor histology. The major difference was that rates in New Mexico increased across all size groups. The increasing rates of large tumors cannot be explained by increased detection. A true disease occurrence is a possible explanation. Low risk papillary thyroid cancer patients in New Mexico are being over treated with the most extensive surgical procedure of total thyroidectomy despite national guidelines that advocate an active surveillance management approach for such patients. Younger patients under the age of 65 years are most likely to be targeted by this overtreatment phenomenon, with no difference across ethnic groups.

16 Thank you! Questions?