vicky3 2009-10-16 11:37
荷爾蒙替代療法與肺癌死亡風險有關
作者：Laurie Barclay, MD
出處：WebMD醫學新聞
September 29, 2009 — 根據9月20日線上初版The Lancet期刊中對「Women's Health Initiative (WHI)」試驗之資料分析結果，使用雌激素和黃體素的荷爾蒙替代療法(HRT)與增加肺癌死亡風險有關。Medscape Oncology報導了初步發表於美國臨床腫瘤協會第45屆年會中的這些結果。
加州大學洛杉磯分校、洛杉磯生物醫學研究中心的Rowan T. Chlebowski與WHI的研究夥伴寫道，在WHI試驗的後介入期中，指派接受雌激素加黃體素治療的女性，發生癌症的風險高於安慰劑組；結果也顯示，併用兩種荷爾蒙治療會增加肺癌死亡率。為了評估此關聯是否存在，我們對於該試驗完整追蹤期間有肺癌診斷者進行事後分析。
WHI研究是一個在美國40個中心進行的隨機、雙盲、安慰劑控制試驗，因為發現HRT對於健康的風險超過利益而提早停止。根據電腦化分類塊狀排列演算，16,608名年紀50至79歲、有完整子宮的婦女，被隨機指派接受每天1錠、0.625-mg的共軛馬黃體素以及2.5-mg的medroxyprogesterone acetate (n = 8506人)或相對的安慰劑(n=8102人)。根據治療期和後介入追蹤期的資料，採用治療意向分析，確認所有肺癌、小細胞肺癌以及非小細胞肺癌的發生率和死亡率；平均治療期間為5.6 ± 1.3年，平均額外追蹤期間為2.4 ± 0·4年。
併用兩種荷爾蒙治療這一組有109名婦女診斷出肺癌，安慰劑組有85人(每年發生率分別是0.16% vs 0.13%；風險比[HR]，1.23；95% CI，0.92 - 1.63；P= .16)。HRT組有96名婦女診斷有非小細胞肺癌，安慰劑組有72人(0.14% vs 0.11%；HR，1.28；95% CI，0.94 - 1.73；P = .12)。併用兩種荷爾蒙治療這一組的肺癌死亡率大於安慰劑組(死亡數為73 vs 40；死亡率0.11% vs 0.06%；HR，1.71；95% CI，1.16 - 2.52；P = .01)。
HRT組死亡率較高，主要是有較多因非小細胞肺癌而死亡者(死亡數為62 vs 31；0.09% vs 0.05%; HR, 1.87; 95% CI, 1.22 - 2.88; P = .004)；兩組的小細胞肺癌發生率和死亡率相似。
研究作者寫道，雖然停經後婦女使用雌激素加黃體素治療並未增加肺癌發生率，但是增加了因肺癌死亡的人數，特別是死於非小細胞肺癌者。這些發現應整合到併用兩種荷爾蒙之婦女的風險與利益討論中，特別是那些有肺癌風險高者。
研究限制包括，採用事後分析、肺癌與小細胞肺癌病患數少、缺乏診斷後的治療資訊。此外，結果無法外推到其他口服或外用荷爾蒙治療或其他治療期間。
研究作者結論表示，併用兩種荷爾蒙組的確比安慰劑組有更多的分化不佳的癌症以及轉移癌症。這些以及非小細胞肺癌診斷後死亡率增加的發現，認為併用兩種荷爾蒙治療主要會刺激已有的非小細胞肺癌成長。
內布拉斯加大學醫學中心的Apar Kishor Ganti醫師，在評論中討論這些發現對於考慮使用HRT治療停經期間症狀之婦女的臨床影響。
Ganti醫師寫道，因為荷爾蒙替代治療在肺癌存活這方面的適當安全期間還不清楚，有發生肺癌高風險的婦女，特別是有抽菸史者，或許應避免此類治療。這些結果以及之前對於冠心症沒有保護力的發現，嚴重質疑了荷爾蒙替代治療在今日醫療的角色。難以假設規律使用這類治療對於停經症候群的利益會大於死亡率增加的風險，特別是生活品質也未能改善。
國家心肺與血液研究中心、國家健康研究中心資助本研究。有些研究作者與AstraZeneca、Novartis、Lilly、Amgen、Pfizer、國家健康研究中心、加拿大國家癌症研究中心和/或Wyeth藥廠有各種財務關係。Ganti醫師宣告沒有相關資金上的往來。
Lancet.線上發表於2009年9月20日。
Hormone Replacement Therapy Linked to Risk for Death From Lung Cancer
By Laurie Barclay, MD
Medscape Medical News
September 29, 2009 — Hormone replacement therapy (HRT) using estrogen and progestin is associated with an increased risk for death from lung cancer, according to the results of an analysis of data from the Women's Health Initiative (WHI) trial reported in the September 20 Online First issue of The Lancet. These results were initially presented at the American Society of Clinical Oncology 45th Annual Meeting as reported by Medscape Oncology.
"In the post-intervention period of the...WHI trial, women assigned to treatment with oestrogen plus progestin had a higher risk of cancer than did those assigned to placebo," write Rowan T. Chlebowski, from Los Angeles Biomedical Research Institute at Harbour-University of California, Los Angeles, Medical Center, Torrance, California, and colleagues from the WHI Investigators. "Results also suggested that the combined hormone therapy might increase mortality from lung cancer. To assess whether such an association exists, we undertook a post-hoc analysis of lung cancers diagnosed in the trial over the entire follow-up period."
The WHI study, which was a randomized, double-blind, placebo-controlled trial performed at 40 US centers, was stopped early when health risks of HRT were found to exceed benefits. With use of a computerized, stratified, permuted block algorithm, 16,608 postmenopausal women aged 50 to 79 years with an intact uterus were randomly assigned to receive a once-daily tablet of 0.625-mg conjugated equine estrogen plus 2.5-mg medroxyprogesterone acetate (n = 8506) or matching placebo (n = 8102). Data from treatment and postintervention follow-up periods allowed determination of incidence and mortality rates for all lung cancer, small-cell lung cancer, and non–small-cell lung cancer, with analysis by intent-to-treat. Mean treatment duration was 5.6 ± 1.3 years, and mean additional follow-up duration was 2.4 ± 0·4 years.
Lung cancer was diagnosed in 109 women in the combined hormone therapy group vs 85 in the placebo group (incidence per year, 0.16% vs 0.13%; hazard ratio [HR], 1.23; 95% CI, 0.92 - 1.63; P = .16). Non–small-cell lung cancer was diagnosed in 96 women in the HRT group vs 72 in the placebo group (0.14% vs 0.11%; HR, 1.28; 95% CI, 0.94 - 1.73; P = .12).
Mortality rate from lung cancer was greater in the combined hormone therapy group vs the placebo group (73 vs 40 deaths; 0.11% vs 0.06%; HR, 1.71; 95% CI, 1.16 - 2.52; P = .01). This excess mortality rate in the HRT group was primarily attributed to more deaths from non–small-cell lung cancer (62 vs 31 deaths; 0.09% vs 0.05%; HR, 1.87; 95% CI, 1.22 - 2.88; P = .004). Both groups had similar incidence and mortality rates of small-cell lung cancer.
"Although treatment with oestrogen plus progestin in postmenopausal women did not increase incidence of lung cancer, it increased the number of deaths from lung cancer, in particular deaths from non-small-cell lung cancer," the study authors write. "These findings should be incorporated into risk–benefit discussions with women considering combined hormone therapy, especially those with a high risk of lung cancer."
Limitations of this study include post hoc analysis, small number of lung cancers and small-cell lung cancers, and absence of information on treatment after diagnosis. In addition, the results cannot be extrapolated to other oral or topical hormone treatments or other treatment durations.
"There were significantly more poorly differentiated cancers and cancers with metastatic spread in the combined hormone therapy group than in the placebo group," the study authors conclude. "These findings, together with the substantial increase in mortality after a diagnosis of non-small-cell lung cancer, suggest that the main effect of combined hormone therapy might be on stimulating growth of already established non-small-cell lung cancers."
In an accompanying comment, Apar Kishor Ganti, MD, from the University of Nebraska Medical Center in Omaha, discusses the clinical implications of these findings for women considering use of HRT for perimenopausal symptoms.
"Because the optimum safe duration of hormone-replacement therapy in terms of lung-cancer survival is unclear, such therapy should probably be avoided in women at a high risk of developing lung cancer, especially those with a history of smoking," Dr. Ganti writes. "These results, along with the findings showing no protection against coronary heart disease, seriously question whether hormone-replacement therapy has any role in medicine today. It is difficult to presume that the benefits of routine use of such therapy for menopausal symptoms outweigh the increased risks of mortality, especially in the absence of improvement in the quality of life."
The National Heart, Lung and Blood Institute, National Institutes of Health, funded this study. Some of the study authors have disclosed various financial relationships with AstraZeneca, Novartis, Lilly, Amgen, Pfizer, the National Institutes of Health, the National Cancer Institute of Canada, and/or Wyeth. Dr. Ganti has disclosed no relevant financial relationships.
Lancet. Published online September 20, 2009.