分化型甲状腺癌英文文献一篇
这个帖子发布于 20 年零 290 天前，其中的信息可能已发生改变或有所发展。
分化型甲状腺癌国内报道很多，但象香港这样报道1348例且从发病率、诊断到治疗均有分析评价的还未见到。通过这篇文献大家对分化型甲状腺癌会有一个大致的了解。其发病率与乏碘，富碘有关的结论早有报道，但其认为分化型甲状腺癌的发病率近年来呈增高趋势。治疗上倾向于西方的观点，主张行双侧腺叶切除术。强调了肿瘤最初的大小、淋巴结情况、切缘、是否多中心及有无腺外侵犯是判断预后和下一步治疗重要因素。我觉得值得一看，推荐给大家。
Clinical Oncology
Volume 15, Issue 6 , September 2003, Pages 329-336
doi:10.1016/S0936-6555(03)00066-9
Copyright © 2003 Elsevier Science Ltd. All rights reserved.
Original Article
Changes in Clinical Presentation, Management and Outcome in 1348 Patients with Differentiated Thyroid Carcinoma: Experience in a Single Institute in Hong Kong, 1960–2000
S. -M. Chow, , *, S. C. K. Law*, S. -K. Au*, O. Mang†, S. Yau*, K. -T. Yuen* and W. -H. Lau†
* Department of Clinical Oncology, Queen Elizabeth Hospital, Kowloon, Hong Kong, People's Republic of China
† Hong Kong Cancer Registry, Hong Kong, People's Republic of China
Received 28 October 2002; revised 24 February 2003; accepted 26 February 2003. ; Available online 4 September 2003.
Abstract
The clinical features, management and outcome of 1348 patients diagnosed with differentiated thyroid carcinoma in Queen Elizabeth Hospital, Hong Kong, were analysed according to the period of diagnosis: A (before 1980), B (1981–1990) and C (1991–2000). As time advanced, ratio of papillary carcinoma (PTC) to follicular carcinoma (FTC) increased (A:B:C=1.6: 3.1: 7.2). The mean size of the primary tumour decreased (A:B:C=3.5 cm: 2.8 cm: 2.5 cm), with a greater percentage of microcarcinoma of 1 cm or less (A:B:C=5.1%: 16.1%: 21.7%). At presentation, the incidence of lymph-node metastasis decreased (A:B:C=32.7%: 31.6%: 24.8%) and that of distant metastasis decreased (A:B:C=9%: 6.1%: 5.3%). Bilateral surgical resection was more commonly used (A:B:C=62.8%: 89.1%: 94.8%) than lobectomy (A:B:C=26.3%: 2.8%: 1.8%). Radiation treatment, radioactive iodine (131I; RAI) and external radiotherapy (EXT), was more commonly used (A:B:C=53.2%: 74.7%: 85.1%). RAI was used in 84.3% (A:B:C=50%: 71.2%: 84.3%) and EXT in 14.5% of patients in the past decade (A:B:C=10.9%: 8.7%: 14.5%). The proportion of patients who adopted a bilateral surgery and RAI treatment increased gradually with time (A:B:C=33%: 68%: 83.8%). The 5-year cause-specific survival (A:B:C=90.2%: 93.7%: 95.7%), locoregional failure-free survival (A:B:C=72.6%: 82.9%: 91.6%) and distant metastasis failure-free survival (A:B:C=84.5%: 89.1%: 92.6%) were improved. However, the period of diagnosis was not found to be an important explanatory variable (i.e. P>0.05) in Cox regression after adjusting for other factors, indicating that the improvement was probably related to the temporal trend of other factors: presentation at earlier stage, increased ratio of PTC:FTC and more aggressive management by bilateral surgery and radiation therapy.
Author Keywords: Differentiated thyroid carcinoma; papillary carcinoma; follicular carcinoma; presentation; outcome
1. Introduction
Differentiated thyroid carcinoma (DTC) is an uncommon malignancy worldwide with an incidence of 0.5 to 10 per 100000 population [1]. Differences exist in incidence rates, gender distribution, histological subtypes, ethnic and age distribution in different areas. The world age-standardised incidence rate of thyroid cancer in Hong Kong in 1998–1999 was 2.5 per 100000 for men and 6.5 per 100000 for women, respectively [2]. Papillary and follicular histology accounted for 77.4% and 12.6% (i.e. 90%) of all our cases. The prognosis is very good. The analyses in our hospital revealed a 10- year cause-specific survival of 92.1% for papillary thyroid carcinoma (PTC) [3]and 81% for follicular thyroid carcinoma (FTC) [4]. Although PTC and FTC were often analysed as a single entity of DTC, there is observed difference in the clinical behaviour and outcome. PTC had a higher incidence, younger age at presentation, higher female : male ratio, smaller tumour size, higher incidence of multifocal disease, extrathyroidal extension and lymph-node metastases, and lower incidence of distant metastases [5].
DTC is well known to have an indolent clinical course and late relapses. Not surprisingly, the low incidence and slow growth rate of this peculiar tumour render it very difficult to perform prospective randomised trials. Consequently, most of the current literature came from retrospective analyses. Only studies with a long follow-up period could reveal the natural history and outcome in this cancer. Certain changes in epidemiology were observed: increased incidence in Australia [6], USA, Israel, Nordic countries, Japan [1], decreased size of tumour [7], decreased mortality in Switzerland, Austria [1]and Japan [7], increased frequency of PTC relative to FTC [8 and 9], and decreased anaplastic carcinoma [10 and 11]. The department of Clinical Oncology, Queen Elizabeth Hospital, is a tertiary referral centre for management of cancer. We receive about a quarter of the thyroid cancer patients in the territory. This study aims to document the changes in presentation, management and outcome of DTC diagnosed in the past decades.
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4. Discussion
4.1. Changes in General Epidemiology
Increased incidence of thyroid cancer was observed in some cancer registries, including the U.S.A., Canada, Japan, and Nordic countries [1]. According to the Hong Kong Cancer Registry data 1998–1999, the age-adjusted incidence of thyroid cancers increased, but did not reach statistical significance, in both men and women from 1990 to 1999. Despite its overall low ranking as the eleventh most common cancer among women in Hong Kong, it was the second most common malignancy for women aged between 15–34 years (15.7% incidence compared with 18.7% of breast cancer) [2].
The worldwide observation of an increased frequency of PTC relative to FTC, less advanced tumour stages and reduction in mortality in DTC [7 and 11]was also found in our patients. Papillary microcarcinoma was characterised by low metastatic potential as evidenced by its high prevalence in autopsy studies (6–35%) [11]and excellent prognosis. The rate of distant metastasis and mortality was reported to be 6.8% and 1.4% in a Chinese population in Taiwan [ [20]]. In a surgical series from Canada [ [21]], the incidence of papillary microcarcinoma was 16.7% if the surgical specimens were examined in thin sections of 2–3 mm intervals. In our study, there was a reduction of mean size of tumour and increased frequency of microcarcinoma (of 1 cm or less) up to one-fifth incidence in period C. This might reflect a higher operation rate of benign disease leading to incidental finding of occult malignancy. Occult and non-occult microcarcinoma should be managed in the same manner [20 and 22].
4.2. Changes in Management
The recommendation for thyroid cancer surgery varies in different regions and countries. A number of guidelines have been published [23, 24, 25 and 26]. For small intrathyroidal tumours of 1 cm diameter or less (both PTC and FTC) without enlarged lymph nodes or other unfavourable factors (multifocal disease), the recommendations are usually lobectomy or subtotal thyroidectomy followed by thyroid hormone suppression[23, 24 and 25]. For other stages, definitive surgery is usually total thyroidectomy followed by RAI and TSH suppression [23]. Considerable difference in practice was found between U.S.A. and Germany in a comparative study [27].
In Hong Kong, the trend has been to use more bilateral surgical procedures, RAI and EXT were used in thyroid cancer management. The use of combined bilateral surgery and RAI increased to 83.8% in period C. With advances in surgical techniques, gross total removal of tumour could often be achieved. There was also more accurate reporting of extent of disease recorded in operative and pathology reports. The sites of extrathyroidal extension, presence of residual disease, resection margins, and multifocal disease were more clearly stated.
4.3. Outcome
We observed that the outcome parameters in survival, locoregional control and distant metastasis were all improved (Table 3). For those who completed primary treatment, the median time to logoregional relapse and distant metastasis were 3.5 and 4.8 years, respectively. However, 13% of locoregional relapse and 26% at distant sites occurred after 10 years. As DTC is well known to have delayed recurrences, the data in period C would be more mature if the follow-up time was longer.
Table 3. Outcome of patients treated in the three different periods
5. Conclusion
The worldwide distribution of histological subtypes shows an increase in PTC and a decrease in anaplastic carcinoma [9, 28 and 29]. Epidemiology studies demonstrate a relationship of iodine deficiency to FTC whereas dietary iodine supplements increase the incidence of PTC but FTC remains constant [11 and 30]. In this study, the incidence of FTC was quite constant throughout the three periods, whereas PTC had a slight rise in incidence. This finding is in accordance with others because Hong Kong is an iodine-sufficient area as it is situated on the coast and local people have seafood in their diet.
The pattern of practice has changed considerably during the past decades in Hong Kong: there has been an increase in bilateral thyroid surgery compared with unilateral resection and increased application of RAI and EXT. Bilateral resection has resulted in less local relapse [31 and 32], although the survival was not better [33 and 34]. Improvement in pathology reporting has also been observed. Accurate description of size of primary thyroid tumour, lymph-node status, resection margins, multifocality and extrathyroidal extension, all help to guide prognosis and subsequent management. Despite a few negative reports of RAI on thyroid cancer management [35 and 36], the use of RAI was more frequently applied, probably related to the much greater number of positive studies supporting its role in preventing relapses [3, 4, 37, 38, 39, 40 and 41], treatment of metastasis [42, 43, 44 and 45]and increased survival [4, 31, 37, 38 and 41]. EXT was shown to be effective in reducing locoregional relapses especially in patients with gross disease after incomplete surgery [3, 46, 47, 48 and 49], microscopic positive margins [40 and 50], and pT4 disease with age older than 40 years [51]. With the better-defined role of EXT, it is not surprising that EXT has been more frequently applied in DTC.
Studies from Japan [7], Austria [52]and the U.S.A. [53]have shown that the prognosis of DTC has improved. It is not clear whether improved outcome is attributable to improvement in diagnostic tools (ultrasonography and fine-needle aspiration cytology) [54 and 55]leading to diagnosis at earlier stage, more aggressive treatment methods (more application of bilateral surgery, RAI or EXT), shifting of histological subtypes to PTC (which has better survival and less distant metastasis compared with FTC) or earlier detection of recurrence by thyroglobulin measurement [54 and 55], computed tomography or magnetic resonance imaging. This study shows that period of diagnosis is not an independent prognostic factor in CSS, locoregional control and distant metastasis. Therefore, the improvement in outcome is probably a result of a conjoint effect of the above factors. Some other possible factors include better control of benign thyroid disease [56]and avoidance of childhood radiation exposure.
Although DTC has a very good prognosis, its rising incidence and psychosocial implication in young patients deserve better understanding of its natural history and changing temporal trends.
References
..........
Clinical Oncology
Volume 15, Issue 6 , September 2003, Pages 329-336
doi:10.1016/S0936-6555(03)00066-9
Copyright © 2003 Elsevier Science Ltd. All rights reserved.
Original Article
Changes in Clinical Presentation, Management and Outcome in 1348 Patients with Differentiated Thyroid Carcinoma: Experience in a Single Institute in Hong Kong, 1960–2000
S. -M. Chow, , *, S. C. K. Law*, S. -K. Au*, O. Mang†, S. Yau*, K. -T. Yuen* and W. -H. Lau†
* Department of Clinical Oncology, Queen Elizabeth Hospital, Kowloon, Hong Kong, People's Republic of China
† Hong Kong Cancer Registry, Hong Kong, People's Republic of China
Received 28 October 2002; revised 24 February 2003; accepted 26 February 2003. ; Available online 4 September 2003.
Abstract
The clinical features, management and outcome of 1348 patients diagnosed with differentiated thyroid carcinoma in Queen Elizabeth Hospital, Hong Kong, were analysed according to the period of diagnosis: A (before 1980), B (1981–1990) and C (1991–2000). As time advanced, ratio of papillary carcinoma (PTC) to follicular carcinoma (FTC) increased (A:B:C=1.6: 3.1: 7.2). The mean size of the primary tumour decreased (A:B:C=3.5 cm: 2.8 cm: 2.5 cm), with a greater percentage of microcarcinoma of 1 cm or less (A:B:C=5.1%: 16.1%: 21.7%). At presentation, the incidence of lymph-node metastasis decreased (A:B:C=32.7%: 31.6%: 24.8%) and that of distant metastasis decreased (A:B:C=9%: 6.1%: 5.3%). Bilateral surgical resection was more commonly used (A:B:C=62.8%: 89.1%: 94.8%) than lobectomy (A:B:C=26.3%: 2.8%: 1.8%). Radiation treatment, radioactive iodine (131I; RAI) and external radiotherapy (EXT), was more commonly used (A:B:C=53.2%: 74.7%: 85.1%). RAI was used in 84.3% (A:B:C=50%: 71.2%: 84.3%) and EXT in 14.5% of patients in the past decade (A:B:C=10.9%: 8.7%: 14.5%). The proportion of patients who adopted a bilateral surgery and RAI treatment increased gradually with time (A:B:C=33%: 68%: 83.8%). The 5-year cause-specific survival (A:B:C=90.2%: 93.7%: 95.7%), locoregional failure-free survival (A:B:C=72.6%: 82.9%: 91.6%) and distant metastasis failure-free survival (A:B:C=84.5%: 89.1%: 92.6%) were improved. However, the period of diagnosis was not found to be an important explanatory variable (i.e. P>0.05) in Cox regression after adjusting for other factors, indicating that the improvement was probably related to the temporal trend of other factors: presentation at earlier stage, increased ratio of PTC:FTC and more aggressive management by bilateral surgery and radiation therapy.
Author Keywords: Differentiated thyroid carcinoma; papillary carcinoma; follicular carcinoma; presentation; outcome
1. Introduction
Differentiated thyroid carcinoma (DTC) is an uncommon malignancy worldwide with an incidence of 0.5 to 10 per 100000 population [1]. Differences exist in incidence rates, gender distribution, histological subtypes, ethnic and age distribution in different areas. The world age-standardised incidence rate of thyroid cancer in Hong Kong in 1998–1999 was 2.5 per 100000 for men and 6.5 per 100000 for women, respectively [2]. Papillary and follicular histology accounted for 77.4% and 12.6% (i.e. 90%) of all our cases. The prognosis is very good. The analyses in our hospital revealed a 10- year cause-specific survival of 92.1% for papillary thyroid carcinoma (PTC) [3]and 81% for follicular thyroid carcinoma (FTC) [4]. Although PTC and FTC were often analysed as a single entity of DTC, there is observed difference in the clinical behaviour and outcome. PTC had a higher incidence, younger age at presentation, higher female : male ratio, smaller tumour size, higher incidence of multifocal disease, extrathyroidal extension and lymph-node metastases, and lower incidence of distant metastases [5].
DTC is well known to have an indolent clinical course and late relapses. Not surprisingly, the low incidence and slow growth rate of this peculiar tumour render it very difficult to perform prospective randomised trials. Consequently, most of the current literature came from retrospective analyses. Only studies with a long follow-up period could reveal the natural history and outcome in this cancer. Certain changes in epidemiology were observed: increased incidence in Australia [6], USA, Israel, Nordic countries, Japan [1], decreased size of tumour [7], decreased mortality in Switzerland, Austria [1]and Japan [7], increased frequency of PTC relative to FTC [8 and 9], and decreased anaplastic carcinoma [10 and 11]. The department of Clinical Oncology, Queen Elizabeth Hospital, is a tertiary referral centre for management of cancer. We receive about a quarter of the thyroid cancer patients in the territory. This study aims to document the changes in presentation, management and outcome of DTC diagnosed in the past decades.
...............
..............
4. Discussion
4.1. Changes in General Epidemiology
Increased incidence of thyroid cancer was observed in some cancer registries, including the U.S.A., Canada, Japan, and Nordic countries [1]. According to the Hong Kong Cancer Registry data 1998–1999, the age-adjusted incidence of thyroid cancers increased, but did not reach statistical significance, in both men and women from 1990 to 1999. Despite its overall low ranking as the eleventh most common cancer among women in Hong Kong, it was the second most common malignancy for women aged between 15–34 years (15.7% incidence compared with 18.7% of breast cancer) [2].
The worldwide observation of an increased frequency of PTC relative to FTC, less advanced tumour stages and reduction in mortality in DTC [7 and 11]was also found in our patients. Papillary microcarcinoma was characterised by low metastatic potential as evidenced by its high prevalence in autopsy studies (6–35%) [11]and excellent prognosis. The rate of distant metastasis and mortality was reported to be 6.8% and 1.4% in a Chinese population in Taiwan [ [20]]. In a surgical series from Canada [ [21]], the incidence of papillary microcarcinoma was 16.7% if the surgical specimens were examined in thin sections of 2–3 mm intervals. In our study, there was a reduction of mean size of tumour and increased frequency of microcarcinoma (of 1 cm or less) up to one-fifth incidence in period C. This might reflect a higher operation rate of benign disease leading to incidental finding of occult malignancy. Occult and non-occult microcarcinoma should be managed in the same manner [20 and 22].
4.2. Changes in Management
The recommendation for thyroid cancer surgery varies in different regions and countries. A number of guidelines have been published [23, 24, 25 and 26]. For small intrathyroidal tumours of 1 cm diameter or less (both PTC and FTC) without enlarged lymph nodes or other unfavourable factors (multifocal disease), the recommendations are usually lobectomy or subtotal thyroidectomy followed by thyroid hormone suppression[23, 24 and 25]. For other stages, definitive surgery is usually total thyroidectomy followed by RAI and TSH suppression [23]. Considerable difference in practice was found between U.S.A. and Germany in a comparative study [27].
In Hong Kong, the trend has been to use more bilateral surgical procedures, RAI and EXT were used in thyroid cancer management. The use of combined bilateral surgery and RAI increased to 83.8% in period C. With advances in surgical techniques, gross total removal of tumour could often be achieved. There was also more accurate reporting of extent of disease recorded in operative and pathology reports. The sites of extrathyroidal extension, presence of residual disease, resection margins, and multifocal disease were more clearly stated.
4.3. Outcome
We observed that the outcome parameters in survival, locoregional control and distant metastasis were all improved (Table 3). For those who completed primary treatment, the median time to logoregional relapse and distant metastasis were 3.5 and 4.8 years, respectively. However, 13% of locoregional relapse and 26% at distant sites occurred after 10 years. As DTC is well known to have delayed recurrences, the data in period C would be more mature if the follow-up time was longer.
Table 3. Outcome of patients treated in the three different periods
5. Conclusion
The worldwide distribution of histological subtypes shows an increase in PTC and a decrease in anaplastic carcinoma [9, 28 and 29]. Epidemiology studies demonstrate a relationship of iodine deficiency to FTC whereas dietary iodine supplements increase the incidence of PTC but FTC remains constant [11 and 30]. In this study, the incidence of FTC was quite constant throughout the three periods, whereas PTC had a slight rise in incidence. This finding is in accordance with others because Hong Kong is an iodine-sufficient area as it is situated on the coast and local people have seafood in their diet.
The pattern of practice has changed considerably during the past decades in Hong Kong: there has been an increase in bilateral thyroid surgery compared with unilateral resection and increased application of RAI and EXT. Bilateral resection has resulted in less local relapse [31 and 32], although the survival was not better [33 and 34]. Improvement in pathology reporting has also been observed. Accurate description of size of primary thyroid tumour, lymph-node status, resection margins, multifocality and extrathyroidal extension, all help to guide prognosis and subsequent management. Despite a few negative reports of RAI on thyroid cancer management [35 and 36], the use of RAI was more frequently applied, probably related to the much greater number of positive studies supporting its role in preventing relapses [3, 4, 37, 38, 39, 40 and 41], treatment of metastasis [42, 43, 44 and 45]and increased survival [4, 31, 37, 38 and 41]. EXT was shown to be effective in reducing locoregional relapses especially in patients with gross disease after incomplete surgery [3, 46, 47, 48 and 49], microscopic positive margins [40 and 50], and pT4 disease with age older than 40 years [51]. With the better-defined role of EXT, it is not surprising that EXT has been more frequently applied in DTC.
Studies from Japan [7], Austria [52]and the U.S.A. [53]have shown that the prognosis of DTC has improved. It is not clear whether improved outcome is attributable to improvement in diagnostic tools (ultrasonography and fine-needle aspiration cytology) [54 and 55]leading to diagnosis at earlier stage, more aggressive treatment methods (more application of bilateral surgery, RAI or EXT), shifting of histological subtypes to PTC (which has better survival and less distant metastasis compared with FTC) or earlier detection of recurrence by thyroglobulin measurement [54 and 55], computed tomography or magnetic resonance imaging. This study shows that period of diagnosis is not an independent prognostic factor in CSS, locoregional control and distant metastasis. Therefore, the improvement in outcome is probably a result of a conjoint effect of the above factors. Some other possible factors include better control of benign thyroid disease [56]and avoidance of childhood radiation exposure.
Although DTC has a very good prognosis, its rising incidence and psychosocial implication in young patients deserve better understanding of its natural history and changing temporal trends.
References
..........
