作者：Laurie Barclay, MD 齣處：WebMD醫學新聞 　　February 9, 2009 — 根據美國預防醫學服務工作小組(USPSTF)發錶於2月3日內科醫學檔案期刊的一篇聲明 目前的證據不足以支持由一綫照護醫師篩檢皮膚癌 - 趣味新聞網

發表日期 2009-02-22T13:53:09+08:00

     作者：Laurie Barclay, MD
齣處：WebMD醫學新聞

February 9, 2009 — 根據美國預防醫學服務工作小組(USPSTF)發錶於2月3日內科醫學檔案期刊的一篇聲明，目前的證據不足以評估由一綫照護醫師或者病患自我檢查皮膚來篩檢皮膚癌的利弊；USPSTF建議，進行任何篩檢前，需告知病患有關篩檢之利弊的不確定性。

科羅拉多公共衛生與環境部的Ned Calonge醫師與USPSTF、照護研究與品質中心的研究者寫道，皮膚癌是美國最常被診斷的癌癥；沒有直接針對醫師篩檢是否會改善臨床結果如降低皮膚癌的發病率或死亡率的隨機研究，篩檢而及早治療以改善健康結果的可能性需依賴間接證據。

USPSTF此次的建議聲明是2001年皮膚癌篩檢指引的更新版，根據2001年後發錶的有關篩檢效果、篩檢的偵測分期、一綫照護醫師全身檢查與病患自我檢查之準確度的研究證據迴顧。

根據此一迴顧，USPSTF結論錶示，目前的證據不足以確認由一綫照護醫師或者一般成年病患自我檢查皮膚來及早偵測皮膚黑色素瘤、基底細胞癌或者鱗狀細胞皮膚癌的利弊 。

這是一種「自我聲明」，意思是因為缺乏證據、證據品質不佳或有矛盾，利弊之平衡無法被充分評價。

此聲明隻可運用於沒有癌前病變或惡性皮膚病竈的成人；USPSTF並未評估極高風險之病患，例如有傢族癥狀(即傢族非典型痣與黑色素瘤癥候群)者的監控結果。

由醫師篩檢黑色素瘤具適度準確度的現有證據尚可。第一綫照護醫師評估診斷黑色素瘤有42%至100%的敏感度以及70%至98%的專一度。

現有的證據不足以評價哪種程度的病患自我檢查篩檢可以準確偵測皮膚癌。

有關及早偵測皮膚癌是否與降低皮膚癌的發病率或死亡率有關的證據有極大的闕漏，特彆是缺乏針對及早偵測與這些結果間關係的研究。

平均來說，篩檢確認的黑色素瘤少於一般照護時所發現的，也不清楚偵測這些病竈是否與降低發病率或死亡率有關。

因為缺乏評價皮膚癌篩檢之利弊大小的研究，作者在建議聲明中也結論錶示，皮膚癌篩檢相關可能傷害的證據也有極大闕漏，這些包括誤診、過度診斷、切片與過度治療導緻的後續傷害。

聲明作者寫道，USPSTF結論錶示，目前的證據不足以評價由一綫照護醫師或者病患自我檢查皮膚來篩檢皮膚癌的利弊。如果提供這類服務，病患需知道利弊之間尚有不確定性。

有關USPSTF對於一般成人皮膚癌篩檢的特殊臨床建議如下：
* 風險估計：皮膚癌風險包括傢族皮膚癌病史，反覆和/或嚴重日曬和曬傷病史。黑色素瘤風險增加的病患包括：
o 65歲以上皮膚白皙者
o 有非典型痣的病患
o 有50個以上的痣的病患
* 篩檢檢測：證據不足以確認由醫師全身皮膚檢查或者病患皮膚自我檢查來早期偵測皮膚癌的利弊。
* 即使是高風險病患，篩檢的利益依舊不確定。
* 因其他原因進行體檢時，醫師依舊須對惡性皮膚病竈有所警覺。
* 增加惡性病徵風險的病竈包括不對稱(asymmetry)、不規則邊緣(border)、顔色(color)改變、直徑(diameter)大於6 mm等，這些特徵可以用首字母縮略字「ABCD」來記憶。
* 疑似病竈需進行切片。

聲明作者結論錶示，USPSTF認為臨床或政策製定者在證據之外納入更多考量；醫師和政策製定者應瞭解證據，但是這不同於特定病患或狀況的個彆決定。

USPSTF是一個獨立的自主機構，接受美國國會指派的健康照護研究與品質中心的支持。聲明作者宣稱沒有相關財務關係。聲明指齣，USPSTF所做的建議不代錶美國政府官方，不應被解釋為健康照護研究與品質中心或者美國健康與人類服務部的官方立場。

Current Evidence Insufficient to Support Skin Cancer Screening by Primary Care Clinicians

By Laurie Barclay, MD
Medscape Medical News

February 9, 2009 — Current evidence is insufficient to evaluate the balance of benefits and harms of screening for skin cancer by primary care clinicians or by patient skin self-examination, according to a statement by the US Preventive Services Task Force (USPSTF) published in the February 3 issue of the Annals of Internal Medicine. The USPSTF recommends that patients be counseled regarding the uncertainty about the balance of benefits and harms before any screening is performed.

"Skin cancer is the most commonly diagnosed cancer in the United States," write Ned Calonge, MD, MPH, from the Colorado Department of Public Health and Environment in Denver, and colleagues from the USPSTF, Agency for Healthcare Research and Quality, in Rockville, Maryland. "No randomized studies have directly examined whether screening by clinicians is associated with improved clinical outcomes, such as reduced morbidity or mortality from skin cancer. The possibility that earlier treatment as a result of screening improves health outcomes must rely on indirect evidence."

This USPSTF recommendation statement is an update of the 2001 guidelines regarding screening for skin cancer, based on a review of evidence published since 2001 on studies on screening effectiveness, the stage of detection by screening, and the accuracy of whole-body examination by primary care clinicians and of self-examination by patients.

Based on this review, the USPSTF concluded that the current evidence is insufficient to determine the balance of benefits and harms of screening for skin cancer by primary care clinicians or by patient skin self-examination for the early detection of cutaneous melanoma, basal cell cancer, or squamous cell skin cancer in the adult general population.

This is an "I" statement, meaning that because the evidence is lacking, is of poor quality, or is conflicting, the balance of benefits and harms cannot be adequately assessed.

The statement applies only to adults with no history of premalignant or malignant skin lesions. The USPSTF did not evaluate outcomes associated with surveillance of patients at extremely high risk, such as those with familial syndromes (eg, familial atypical mole and melanoma syndrome).

Available evidence is fair that screening by clinicians is moderately accurate in detecting melanoma. Evaluation by primary care clinicians is 42% to 100% sensitive and 70% to 98% specific in the diagnosis of melanoma.

Available evidence is insufficient to assess the degree to which screening by patient self-examination is able to accurately detect skin cancer.

There is a critical gap in the evidence regarding whether early detection of skin cancer is associated with decreased mortality or morbidity rates from skin cancer. Specifically, there is an absence of studies that looked at the relationship of early detection with these outcomes.

On average, melanomas identified by screening are thinner than those found during usual care, and it is unknown whether detection of these lesions is associated with decreased morbidity or mortality rates.

Because there is also an absence of studies assessing the magnitude of harms from screening for skin cancer, the authors of the recommendation statement also concluded that there is a critical gap in the evidence regarding potential harms of screening for skin cancer. These include misdiagnosis, overdiagnosis, and subsequent harms resulting from biopsies and overtreatment.

"The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of screening for skin cancer by primary care clinicians or by patient skin self-examination," the authors of the statement write. "If this service is used, patients should be made aware of the uncertainty about the balance of benefits and harms."

Specific clinical recommendations of the USPSTF regarding screening for skin cancer in the adult general population are as follows:


Risk assessment: Skin cancer risks include a family history of skin cancer and a history of repeated and/or severe sun exposure and sunburn. Patients at increased risk for melanoma include:
Fair-skinned adults older than 65 years
Patients with atypical moles
Patients with more than 50 moles
Screening tests: Evidence is insufficient to determine the balance of benefits and harms of whole-body skin examination by a clinician or of patient skin self-examination to detect skin cancer early.
Even for high-risk patients, benefits from screening are uncertain.
While performing physical examinations for other purposes, clinicians should remain vigilant for skin lesions with malignant features.
Lesions with increased risk for malignant process include those with asymmetry, border irregularity, variability in color, or size greater than 6 mm in diameter. These features can be remembered by the acronym ABCD.
A biopsy should be performed for suspicious lesions.

"The USPSTF recognizes that clinical or policy decisions involve more considerations than this body of evidence alone," the authors of the statement conclude. "Clinicians and policymakers should understand the evidence but individualize decision making to the specific patient or situation."

The USPSTF is an independent, voluntary body, with support from the Agency for Healthcare Research and Quality mandated by the US Congress. The statement authors have disclosed no relevant financial relationships. The statement notes that recommendations made by the USPSTF are independent of the US government and should not be construed as an official position of the Agency for Healthcare Research and Quality or the US Department of Health and Human Services.

Ann Intern Med. 2009;150:188-193.

[ 本帖最後由 lsc0019 於 2009-2-23 23:25 編輯 ]

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