肥胖女性比較可能在乳癌晚期才診斷且腫瘤較大
作者：Carole VanSickle
出處：WebMD醫學新聞
May 3, 2010 (拉斯維加斯) — 一篇發表於美國乳房外科醫師協會第11屆年會的研究發現，許多醫師和研究者懷疑，肥胖婦女不只乳癌風險增加，更可能在比較後期才發現乳癌且發現時的腫瘤較大。
亞利桑那州鳳凰城梅約診所外科住院醫師Danielle Haakinson等研究者將1352名病患分成肥胖組(n = 327人)與非肥胖組(n = 1026人)，Haakinson醫師在摘要中指出，兩組的平均年紀沒有差異，但是肥胖病患較少在年輕時發現乳癌，再者，她在發表時表示，多數肥胖婦女是藉由乳房攝影診斷出乳癌，而非透過觸診(67%vs 56%；P = .0006)，這表示較少婦女是在自我檢查時發現腫塊，肥胖婦女藉由臨床檢查發現的比率為5%，非肥胖婦女為6% (P = .0066)。
Haakinson醫師在發表時指出，同樣令人困擾的是，肥胖婦女發現時的腫瘤較大，肥胖組中，71%的腫瘤小於2公分，非肥胖組則是有79%的腫瘤小於2公分，肥胖病患比較可能有淋巴結轉移(31% vs 25%；P = .026)，兩組在輔助治療、復發、家族史、腫瘤標記等沒有差異，但是根據多變項分析，肥胖病患傾向有較差的整體存活率，風險比為1.53(95%信心區間為0.97 - 2.53)。
美國乳房外科協會溝通委員會主席、美國外科委員會專科醫師、Center for Breast Care公司主任Deanne Attai醫師向Medscape Ob/Gyn Women's Health表示，這再度證明肥胖是公共衛生問題，我們知道，這些病患的中風、糖尿病、心臟病風險較高，現在，我們發現他們的乳癌風險較高且腫瘤較大。
同樣來自梅約診所的研究者Barbara Pockaj醫師表示，研究者相信，根據他們的分析，肥胖婦女比較不會進行一般的健康維持行動，包括進行年度健康檢查。她向Medscape Ob/Gyn Women's Health表示，缺乏健康維持行動也經常忽略將乳房攝影納入，此外，肥胖婦女也較難觸摸到乳房腫瘤，導致她們在腫瘤變大之後才發現。
Haakinson醫師在記者會中表示，這個健康維持行動議題有其重要性，因為肥胖婦女只是比較難檢查乳房或者檢查不完整，也可能是她們對自己的體型不滿意而羞於檢查，不過，她向Medscape Ob/Gyn Women's Health表示，不論這些婦女為何不參加檢查，醫師們需暸解，這些婦女忽略了健康維持行動，應鼓勵這些婦女參與自我健康照護。晚期腫瘤有其風險存在，藉由年度乳房攝影以及年度檢查，讓這些婦女可以自己主掌自我健康保護。
Pockaj醫師指出，結果顯示，肥胖婦女的腫瘤較大這有點令人驚訝，因為她們應該因為風險較高而提高警覺，該團隊同意，更積極的健康維持行動可以對肥胖婦女的乳癌死亡率有正面影響。
該研究並未接受商業補助，Haakinson醫師與Pockaj醫師皆宣告沒有相關財務關係。
美國乳房外科醫師協會第11屆年會：「前線簡報；肥胖病患有較後期的癌症：肥胖對乳癌的影響」，發表於2010年4月30日。
Obese Women at Risk for Larger Tumors, Later-Stage Diagnosis of Breast Cancer
By Carole VanSickle
Medscape Medical News
May 3, 2010 (Las Vegas, Nevada) — A study released here at the American Society of Breast Surgeons 11th Annual Meeting in Las Vegas revealed that obese women not only are at an increased risk for breast cancer, as was already suspected by many physicians and researchers, but are also more likely to have that breast cancer detected at a later stage and to have larger tumors at the time of detection.
The study, headed by Danielle Haakinson, MD, surgical resident at the Mayo Clinic in Phoenix, Arizona, divided 1352 patients into obese (n = 327) and nonobese (n = 1026) groups. There was no difference in the mean ages of the groups, but fewer obese patients presented with breast cancer at younger ages, noted Dr. Haakinson in her abstract. Furthermore, as she said in her presentation, the majority of obese women who were diagnosed with cancer found their tumors through mammography, rather than through palpation (67% vs 56%; P = .0006). This was largely a result of the lower rate of patients who detected their lumps during self examination, as detection by clinical exam was 5% for obese patients and 6% for nonobese patients (P = .0066).
Also troubling, noted Dr. Haakinson during her presentation, was that obese women presented larger tumors once they were detected. Of the obese group, 71% had tumors smaller than 2 cm, whereas in the nonobese group, 79% of participants had tumors 2 cm or less in size, and obese patients were more likely to have lymph node metastases (31% vs 25%; P = .026). The groups did not have differences in adjuvant therapy, recurrence, family history, or tumor markers, but according to multivariate analysis, obese patients did tend to have a worse overall survival rate, with a hazard ratio of 1.53 (95% confidence interval, 0.97 - 2.53), wrote the research team in their abstract.
"This is just one more example of how obesity is a public health problem," Dr. Deanna Attai, MD, director of the Center for Breast Care, Inc, diplomate for the American Board of Surgery, and chair of the Communications Committee for the American Society of Breast Surgeons, told Medscape Ob/Gyn & Women's Health. "We know that these patients are more at risk for stroke, diabetes, [and] heart disease, and also now we see that they are at increased risk for breast cancer and that their tumors are larger."
The researchers believe based on their analysis that obese women are less likely to perform usual health maintenance, "including going to yearly health checkups," said Barbara Pockaj, MD, also from the Mayo Clinic and part of the research team. She told Medscape Ob/Gyn & Women's Health that these failures in health maintenance also frequently include neglecting yearly mammograms. As it is more difficult to palpate a breast tumor in a larger woman, this delay allows the tumor to get bigger before it is detected.
In the team's press release, Dr. Haakinson commented that this health maintenance issue might be "because obese women simply are less likely to examine their breasts or to examine them thoroughly, possibly because they are uncomfortable with their body image." However, she told Medscape Ob/Gyn & Women's Health, "regardless of the reasons these women are not participating, [physicians] need to understand [that the women are neglecting health maintenance] and encourage these women to be participants in their own healthcare. There is a risk out there of this group presenting late-stage tumors. By having their yearly mammograms and coming in for yearly checkups these women can put themselves in the driver's seat in terms of protecting their own health," she said.
Dr. Pockaj added that the results indicating that obese women present with larger tumors were "a little surprising[, as] there should be a heightened awareness already because they are at a heightened risk." The team agreed that more aggressive health maintenance could affect obese women's mortality by breast cancer in a positive direction.
The study did not receive commercial support. Dr. Haakinson and Dr. Pockaj have disclosed no relevant financial relationships.
American Society of Breast Surgeons 11th Annual Meeting: "Press Briefing from the Front Lines; Obese Patients Present with More Advanced Cancers: The Impact of Obesity on Breast Cancer." Presented April 30, 2010.
