影響乳癌預後的相關研究－ 探討缺氧誘導因子1α在乳癌病患的表現與放射線治療在乳癌患者接受乳房全切除術後所扮演的角色

Correlation Studies of the Prognosis for Breast Cancer--- The Investigation of HIF-1α Expression and the Role of Adjuvant Radiation Therapy for the Patients with Breast Cancer after Modified Radical Mastectomy

黃志仁(Chih-Jen Huang)

指導教授 ： 林勝豐

高雄醫學大學/醫學院/醫學研究所/博士(2012年)

摘要

【研究題目一】乳癌病患缺氧誘導因子1α的過度表現

研究背景：
缺氧誘導因子1α (Hypoxia inducible factor -1α, 以下簡稱HIF-1α)是細胞面臨氧氣缺乏時，會表現的重要轉錄因子。本研究假設HIF-1α的過度表現會增加血管內皮生長因子 (Vascular Endothelium Growth Factor, 以下簡稱VEGF)的表現，進而增加血管新生(Neo- angiogenesis)，再進一步在臨床上會影響乳癌病患的腫瘤控制及存活期。
研究方法：
本研究收集有240位長期追蹤的乳癌病人之病理組織，使用免疫組織染色法，定出乳癌HIF-1α與VEGF的表現；用CD31染色法，測量腫瘤微小血管密度(Micro-vessel density, 以下簡稱MVD)。統計學上用Chi-square方法分析HIF-1α、VEGF、腫瘤微小血管密度、臨床期別、病理特徵、與腫瘤控制之間的關係。再使用Kaplan-Meier 存活曲線分析乳癌病患影響存活期的危險因子。
研究結果：
在240位患者中，HIF-1α高表現者為73人(30%)，低度表現者為167人(70%)。以年齡而言，≦46歲vs. ＞46歲，HIF-1α高度表現分別為34% vs. 27%；低度表現分別為66% vs.73%，p = 0.229，未呈現統計學上顯著的差異。HIF-1α的高度表現、VEGF的高度表現（p < 0.001）與微小血管MVD的高密度（p = 0.001）均呈現正相關性，且具統計學上顯著的意義；另外， HIF-1α的高度表現也與局部復發（p < 0.001）與遠處轉移（p < 0.001）呈現顯著的正相關性。經由多變異數分析，我們發現癌症期別， HIF-1α表現及腫瘤微小血管密度是影響無疾病存活期最主要的預後因子。以Kaplain-Meier存活分析240位乳癌患者在無疾病存活期與整體存活期， HIF-1α過度表現者與與血管內皮生長因子的高度表現者的臨床預後較差。
結論：
本研究的結果發現HIF-1α的高度表現與乳癌腫瘤的血管內皮生長因子的表現及微血管的密度呈現正相關，我們的研究結果顯示乳癌局部復發或遠處轉移者，其乳癌細胞的HIF-1α表現較強。HIF-1α過度表現者，可視為腫瘤的預後不良的危險因子。

【研究題目二】乳房原發腫瘤小於5公分合倂1至3顆腋下淋巴結轉移之乳癌病患接受乳房全切除術後有無放射線治療的臨床預後比較分析
研究背景：
針對腫瘤小於5公分合倂腋下淋巴結1-3顆轉移 (簡稱T1-2N1)的乳癌患者，進行乳房切除術後放射線治療( Post-Mastectomy Radiation Therapy, 以下簡稱PMRT)的臨床治療價值仍未定論，本研究的目的在比較此一期別乳癌病人是否有必要接受PMRT與臨床預後之關係，進而找出其高復發之危險因子。
研究方法：
於西元1990年5月到西元2008年6月，共有318位T1-2N1的乳癌患者接受改良式乳房全切除術治療，其中163位接受手術後放射線治療，155位則無。針對此二組患者的臨床及病理上的特徵進行分析比較，並針對其局部復發率、遠處轉移率、無疾病存活率及整體存活率等臨床預後，進行分析研究。
研究結果：
在平均102個月的研究期間，這些患者的臨床預後(以PMRT組vs.無PMRT組做比較) 如下：局部復發率是3.1％ vs. 11.0％ (p = 0.006)；遠處轉移率是20.9％ vs. 27.7％ (p = 0.152)；10年無疾病存活率是73.8％ vs. 61.3％ (p = 0.001)；與10年整體存活率是82.1％ vs. 76.1％（p = 0.239)。以多變異數分析發現：淋巴結陽性比率≧25％ (HR = 4.571， p = 0.003)與腫瘤侵犯淋巴血管者(HR = 2.738， p = 0.028)，是預測局部復發之不良預後的獨立預測因子；而PMRT可以減少局部復發率(HR = 0.208，p = 0.004)並改善乳癌的無疾病存活率(HR = 0.445，p = 0.001)，達統計學上有顯著意義。
結論：
此次研究結果，提供ㄧ些臨床證據：建議PMRT可使用於T1-2N1的乳癌患者；尤其是具有淋巴結陽性比率≧25％與腫瘤侵犯淋巴血管者之較高風險特徵的患者。同時PMRT可以顯著地減少乳癌的局部復發率，並改善乳癌的無疾病存活期。

【研究題目三】放射線治療對乳癌病患接受乳房全切除術後有無立 即性腹直肌皮瓣重建乳房的臨床結果分析
研究背景：
此研究的目的為比較乳癌患者在乳癌切除後，有無接受同時立即性腹直肌皮瓣(Transverse Rectus Abdominis Musculocutaneous, 以下簡稱TRAM Flap)乳房重建術，再接受手術後放射線治療(Post-Mastectomy Radiation Therapy, 以下簡稱PMRT)之影響局部復發、遠處轉移、急性皮膚炎與慢性併發症等的臨床結果分析。
研究方法：
在1997年3月到2001年10月，共有191位乳癌患者接受PMRT：其中82位患者已先接受立即性TRAM Flap的乳房重建手術(以下簡稱TRAM flap組)，與109位患者未接受乳房重建手術(以下簡稱non-TRAM flap組)。放射線治療對前胸壁、TRAM Flap腹直肌皮瓣、腋下及下頸部等區域淋巴結的照射，平均放射線治療劑量為50 Gy (介於48 Gy到54 Gy)，平均追踪期為40個月。
研究結果：
分析TRAM flap組及non-TRAM flap組的臨床結果：患者在胸壁的局部復發率分別是3.7％(3/82)及1.8％(2/109) (p = 0.653)；在遠處轉移的比例分別是12. 2％(10/82)及15.6％(17/109) (p = 0.67)。患者在放射線治療後的急性皮膚炎反應，是根據Radiation Therapy Oncology Group Scoring Criteria(簡稱RTOG分數)來評估，TRAM flap組及non-TRAM flap組對應的急性皮膚炎反應分別如下：第一度反應是90％(74/82) 及85％(93/109)；第二度反應是9％(7/82) 及12％(13/109)；第三度反應是1％(1/82) 及3％(3/109) (p = 0.558)。另外放射線治療後慢性併發症，在TRAM組雖會增加8％的脂肪壞死比率，但該組所有患者皆沒有因放射線治療而失去重建的皮瓣。
結論：
放射線治療對乳癌患者在TRAM flap組與non-TRAM flap組之間不論在急性皮膚反應、局部復發與遠處轉移的方面皆未有顯著差別，所以我們建議：對於乳癌病患，在接受乳房切除術後需要放射線治療的患者，先同時接受「立即性腹直肌皮瓣TRAM flap」的乳房重建手術是合適的治療。

關鍵字

缺氧誘導因子1α ； 乳癌 ； 乳房全切除術 ； 放射線治療

並列摘要

Topic 1: Expression of Hypoxia Inducible Factor -1α of Breast Cancer
Background:
Tumor angiogenesis is essential for solid tumor development, progression and metastases. The purpose of this study is to investigate the relationship between hypoxia inducible factor 1 α (HIF-1α), vascular endothelial growth factor (VEGF) and microvessel density (MVD) as well as their prognostic impacts on patients with breast cancer.
Methods and Materials:
We collected the clinical data of 240 female patients with breast cancer between January, 1991 and July, 2001. The immunohistochemical expression of HIF-1 α, VEGF and CD31 endothelial cell marker of microvessel density (MVD) was evaluated in formalin-fixed paraffin-embedded breast cancer tissue samples. Data of the immunohistochemical expression were analyzed by chi-square test. The overall survival and disease-free survival were analyzed by Kaplan-Meier method and log rank test.
Results:
High expression of HIF- 1α, VEGF and MVD was found in 73 patients (30%), 163 patients (68%) and 112 patients (47%), respectively. Expression of HIF-1α was significantly correlated with VEGF (p < 0.001), MVD (p = 0.001). In univariate analysis, high MVD is the significant poor prognostic factor of local recurrenace (p < 0.001). Advanced stage of T and N stage，high expression of HIF-1α、VEGF and high MVD were the poor prognostic factors of distant metastasis significantly (p < 0.001). By multivariate analysis, high expression of HIF-1α，advanced tumor stage and high MVD (p < 0.001) would had significantly poor impacts on clinical outcome of disease-free survival. From Kaplan-Meier analysis, the patients characterized with HIF-1α over-expression showed worse overall survival (p < 0.001).
Conclusion:
These findings suggest that HIF-1α may play an important role in angiogenesis, tumor progression via regulation of VEGF and microvessel development. The high expression of HIF-1α might be considered as one poor prognostic factor in patients with breast cancer.

Topic 2：Comparison of Clinical Outcomes of Breast Cancer Patients with T1-2 Tumor and 1-3 Positive Nodes with or without Post-Mastectomy Radiation Therapy

Paper in print, Japanese Journal of Clinical Oncology, accepted on April 26, 2012.

Background: The value of postmastectomy radiation therapy (PMRT) for breast cancer patients with T1-2 and 1-3 positive nodes remains controversial. The purpose of this retrospective study was to compare the clinical outcome of breast cancer patients with T1-2 and 1-3 positive nodes with and without PMRT.
Methods: Between May 1990 and June 2008, 318 breast cancer patients with T1-2 and 1-3 positive nodes who had undergone modified radical mastectomy received PMRT (n = 163) and no PMRT (n = 155). The clinico-pathologic characteristics were analyzed for clinical outcomes including loco-regional recurrence, distant metastasis, disease-free survival and overall survival.
Results: During the median follow-up period of 102 months, the clinical outcome in PMRT vs. no-PMRT groups was as follows: loco-regional recurrence rate (3.1% vs. 11.0%, p = 0.006); distant metastasis rate (20.9% vs. 27.7%, p = 0.152); 10-year disease-free survival rate (73.8% vs. 61.3%, p= 0.001) and 10-year overall survival rate (82.1% vs. 76.1%, p = 0.239). In multivariate analysis, positive nodal ratio ≥ 25% (HR = 4.571, p = 0.003) and positive lymphovascular invasion (HR = 2.738, p = 0.028) were the independent poor prognostic predictors of LRR. The PMRT had significant improvement in reducing loco-regional recurrence (HR = 0.208, p = 0.004).
Conclusions: Our results provide some evidence that PMRT be strongly recommended for breast cancer patients with T1-2 and 1-3 positive nodes, especially for high-risk subgroups with positive nodal ratio ≥ 25% and positive lymphovascular invasion, not only for reducing the loco-regional recurrence but also for having benefits on improving disease-free survival.

Topic 3: Comparison of Local Recurrence and Distant Metastasis between Breast Cancer Patient after PMRT with and without Immediate TRAM Flap Reconstruction
Published at Plastic and Reconstruction Surgery. Vol. 118, No5, 2006, P. 1079-1086

Background：The purpose of this study was to compare the local recurrence and distant metastasis of postmastectomy radiotherapy （PMRT）for breast cancer patients with and without immediate transverse rectus abdominis musculocutaneous (TRAM) flap reconstruction.
Methods：Between March of 1997 and October of 2001, 191 breast cancer patients received postmastectomy radiotherapy（PMRT）: 82 patients had TRAM flap reconstruction (TRAM flap group) and 109 patients did not (non-TRAM flap group). The mean radiation dose to the chest wall or entire TRAM flap, axillary area, and lower neck was 50 Gy (range, 48 to 54 Gy). The median follow-up period was 40 months.
Results：The percentages of chest wall recurrence were 3.7 percent (three of 82) in the TRAM flap group and 1.8 percent (two of 109) in the non-TRAM flap group (p = 0.653). The percentages of distant metastases were 12.2 percent (10 of 82) in the TRAM group and 15.6 percent (17 of 109) for the non-TRAM group (p = 0.67). The percentages of acute radiation dermatitis according to Radiation Therapy Oncology Group scoring criteria (TRAM flap group versus non-TRAM flap group) were as follows: grade I, 74 of 82 (90 percent) versus 93 of 109 (85 percent); grade II, seven of 82 (9 percent) versus 13 of 109 (12 percent); grade III, one of 82 (1 percent) versus three of 109 (3 percent) (p = 0.558). In the TRAM flap group, the increased percentage of fat necrosis was 8 percent. No flap loss was detected.
Conclusions：There were no significant differences in the incidences of complication, locoregional recurrence, and distant metastasis between the TRAM flap and non-TRAM flap patients. The authors’ results suggest that immediate TRAM flap reconstruction can be considered a feasible treatment for breast cancer patients requiring postmastectomy radiotherapy （PMRT）.

並列關鍵字

HIF-1α Expression ； Breast Cancer ； Radiation Therapy ； Modified Radical Mastectomy

參考文獻

第一節 研究題目一（第四章）的參考文獻

Reference ( Expression of HIF -1α of Breast Cancer )

Aebersold DM, Burri P, Beer KT, et al. Expression of hypoxia-inducible factor-1alpha: a novel predictive and prognostic parameter in the radiotherapy of oropharyngeal cancer. Cancer Res 61: 2911-2916, 2001.

Bachtiary B, Schindl M, Potter R, et al. Overexpression of hypoxia-inducible factor 1alpha indicates diminished response to radiotherapy and unfavorable prognosis in patients receiving radical radiotherapy for cervical cancer. Clin Cancer Res 9: 2234-2240, 2003.

Bos, R., van der Groep, P., Greijer, A.E., Shvarts, A., Meijer, S., Pinedo, H.M., Semenza, G.L., van Diest, P.J. and van der Wall, E. Levels of hypoxia-inducible factor-1alpha independently predict prognosis in patients with lymph node negative breast carcinoma. Cancer 97: 1573-81, 2003.