狗能幫助診斷結腸癌

Who says you can’t teach an old dog new tricks? Japanese researchers say they’ve successfully trained an 8-year-old female black Labrador retriever to sniff out colon cancer on the breath of a patient.

Published Monday by the digestive health journal Gut, the study adds to previous research suggesting that dogs can be useful for cancer detection. Studies over the past few years have shown that dogs can detect melanoma, bladder, lung, ovarian, and breast cancer, also by sniffing the breath of cancer patients.

Their amazing sense of smell allows dogs to identify chemicals that are diluted as low as a few parts per trillion. It’s why we rely on man’s best friend to sniff out bombs and drugs at airports.

In the current study, the black Lab sniffed 33 breath samples from patients with colon cancer and 132 samples from healthy controls, about half of whom had benign colon polyps. The dog sniffed each sample, five to a group, and was trained to sit in front of the one that had cancer.

She correctly identified those who had cancer 91 percent of the time — correctly distinguishing between cancerous and benign polyps — and was correct in excluding healthy samples 99 percent of the time when compared with findings on a colonoscopy.

When the dog was given watery stool samples to sniff instead, she was able to find 97 percent of the cancers with the same specificity rate of 99 percent. The fecal occult blood test, another routine colon cancer screening method that checks for blood in the stool, detected about 70 percent of the cancers and had a specificity rate of 85 percent.

If you’re looking to get out of a colonoscopy, however, no such luck — at least for a while. The dog-sniffing method is hardly ready for prime time, given the small amount of samples that have been tested.

There’s also the matter of training the dogs. “It may be difficult to introduce canine scent judgment into clinical practice,’’ write the study authors, led by Dr. Hideto Sonoda of Kyushu University at Fukuoka, “owing to the expense and time required for the dog trainer and for dog education.’’

- By Deborah Kotz （The Boston Globe）

訓練的狗嗅著了98％的準確度與結腸癌

一項新的研究表明，這是一個訓練有素的拉布拉多獵犬嗅出癌症能夠檢測為大腸癌結腸鏡檢查幾乎準確。

在這項研究中，九州大學的研究人員訓練一個8歲的女拉布拉多獵犬名為海洋誰是給予306例呼吸和糞便樣本，收集他們接受結腸鏡檢查前的權利。最近有48例被診斷出患有腸癌，其他258人無論是從另一個大腸疾病的痛苦或已經戰勝了癌症，或者是健康的。在她的評估，海洋，至少95％是確定準確的大腸鏡檢查癌症，98％的正確嗅糞便樣本時，研究人員發現。她最能當場早期癌症，並能辨別惡性腫瘤，其中甚至不能做結腸鏡檢查息肉。這項研究發表在醫學雜誌腸道 。

特雷弗洛基特，與英聯邦科學和工業研究組織在澳大利亞腸癌研究員說，“早期癌症的檢測是真正的腸癌診斷的聖杯，因為手術可以治愈多達90％的患者早期誰現在的舞台疾病。“雖然狗不能用於這一目的，研究人員認為，電子氣味探測器可開發基於這一原則。 “這項研究表明，特定癌症的氣味確實存在，”研究人員寫道，在“這些氣味物質可能成為篩選的有效工具。”

根據主要從手術在醫學研究生院在九州福岡大學，目的是找出氣味是否可以成為大腸癌篩檢的有效工具研究部研究員博士Hideto園田。如乳腺癌，胃癌和前列腺癌等癌症時，園田說，“犬產生氣味的判斷，以及這些癌症患者的正確答案，這表明可能存在著共同的氣味不同癌症類型。”

這項研究發表評論，博士特德Gansler，醫療內容主管在美國癌症協會說，“這項研究增加了一個展示的其他出版關於膀胱癌，肺癌和乳腺癌的文章類似的結果少數”，為最近會議介紹有關前列腺癌。下一步是發現特定化學物質與結腸癌有關，或與其他類型的癌症，Gansler說補充說，“一旦做到這一點，科學家將嚐試開發實驗室測試，檢測為癌症篩查方法，這些化學品的潛力。 “

博士弗洛裏亞努馬爾凱蒂，是臨床外科助理教授，結腸和直腸外科住院醫師項目主任米勒在美國邁阿密大學醫學院，他說，“方向應該是在尋找刺激的那隻有機化合物反應的研究來。“


[論文摘要] Sonoda H, Kohnoe S, Yamazato T, Satoh Y, Morizono G, Shikata K, Morita M, Watanabe A, Morita M, Kakeji Y, Inoue F, Maehara Y.  Colorectal cancer screening with odour material by canine scent detection. Gut. 2011 Jan 31

Objective Early detection and early treatment are of vital importance to the successful treatment of various cancers. The development of a novel screening method that is as economical and non-invasive as the faecal occult blood test (FOBT) for early detection of colorectal cancer (CRC) is needed. A study was undertaken using canine scent detection to determine whether odour material can become an effective tool in CRC screening. Design Exhaled breath and watery stool samples were obtained from patients with CRC and from healthy controls prior to colonoscopy. Each test group consisted of one sample from a patient with CRC and four control samples from volunteers without cancer. These five samples were randomly and separately placed into five boxes. A Labrador retriever specially trained in scent detection of cancer and a handler cooperated in the tests. The dog first smelled a standard breath sample from a patient with CRC, then smelled each sample station and sat down in front of the station in which a cancer scent was detected. Results 33 and 37 groups of breath and watery stool samples, respectively, were tested. Among patients with CRC and controls, the sensitivity of canine scent detection of breath samples compared with conventional diagnosis by colonoscopy was 0.91 and the specificity was 0.99. The sensitivity of canine scent detection of stool samples was 0.97 and the specificity was 0.99. The accuracy of canine scent detection was high even for early cancer. Canine scent detection was not confounded by current smoking, benign colorectal disease or inflammatory disease. Conclusions This study shows that a specific cancer scent does indeed exist and that cancer-specific chemical compounds may be circulating throughout the body. These odour materials may become effective tools in CRC screening. In the future, studies designed to identify cancer-specific volatile organic compounds will be important for the development of new methods for early detection of CRC.