卵巢癌標靶藥物誕生 點燃患者抗癌新希望 (下)

 
標靶藥物PARP抑制劑帶來新希望

PARP參與DNA修復，不但在調節細胞存活和死亡過程中具有關鍵作用，同時也是腫瘤發展和炎症發生過程中的主要蛋白質。但PARP也能幫助卵巢腫瘤修復變異的BRCA細胞，以至於患者進行化療後，都無法完全破壞病變的細胞，而標靶藥物PARP抑制劑能令卵巢癌病變細胞中的PARP不再進行修復工作。

當卵巢腫瘤中BRCA突變癌細胞失去PARP修復功能時，基因組就會變得支離破碎，DNA修復機器發現沒法再修補病變的BRCA基因時，便會啟動細胞固有的自殺信號，引起細胞的程式性死亡，令即使看似強大的癌細胞也逃不過死亡的宿命。同時，PARP抑制劑只會抑制人體中大部分PARP基因的修復，並不會抑制人體其他健康細胞中的BRCA基因修復功能，其他細胞還是能正常進行修復工作。由於PARP抑制劑對癌症細胞的較高針對性，醫學界稱之為「標靶藥物」。

陳亮祖醫生表示，根據近期公佈的晚期卵巢癌二線藥物臨床硏究報告，若在鉑類化療後堅持每日使用PARP抑制劑「奧拉帕利」的BRCA基因突變患者，其「無惡化存活期」為11.2個月（「無惡化存活期」描述的並不是病人總生存時間，而是有效控制腫瘤的時間），對照未使用PARP抑制劑的病人，只有4.3個月。疾病控制的時間增加了近7個月，這對復發的晚期卵巢癌病人來說，絕對是福音。

陳亮祖醫生告訴記者，它的最大好處在於它是一種口服藥物，患者按時在家服用即可，無需再奔波於醫院和家之間進行化療。此外，臨床測試證明該類藥物嚴重副作用基本上小於5％，且效果明確，令腫瘤的控制更加長遠。

內地市民赴港亦可使用口服標靶藥進行持效治療

陳亮祖醫生告訴記者，PARP抑制劑已於今年8月初在香港正式註冊，有望在未來為香港抗癌事業作貢獻。此外，內地患者亦可攜帶BRCA基因測試報告赴港就醫，醫生會根據病情考慮使用標靶藥物PARP抑制劑進行治療。


醫生小囑咐
陳亮祖醫生最後囑咐廣大市民，由於卵巢癌的症狀始終不太明顯，市民一定要留意自己的身體變化，有什麼不舒服一定要盡早看醫生，早發現、早做手術進行腫瘤切除，令康復的機會增加。

此外，卵巢癌始終都是一種比較惡性的腫瘤，若卵巢癌不幸復發了，患者也不必擔心，因為隨着現代科技的進步，除了化療外，患者如果是攜帶BRCA突變基因，是可以通過服用標靶藥物PARP抑制劑去控制腫瘤。







參考資料: 文匯報
以上所提供的資訊僅作為教育及參考用途，如果你有任何醫療問題，
應向自己的腫瘤科專科醫生查詢，而不應單倚賴以上提供的資料。

卵巢癌標靶藥物誕生 點燃患者抗癌新希望 (上)

強力提升患者病控時間至11.2個月

香港中文大學內外全科醫學士、英國皇家放射科學醫學院院士、香港臨床腫瘤專科陳亮祖醫生接受本報採訪時表示，卵巢癌目前為香港女性10大癌症之一，排女性癌症第6位。全港每年新增卵巢癌患者約570名，其中每年有接近200個死亡個案，死亡率排在女性癌症第7名，死亡對發病比率約30%。

卵巢癌症知多少

數據顯示，香港卵巢癌患者確診時屬於第一期的佔41%，第二期佔9％，第三期佔22.6%、第四期佔11.6%，其餘一些個案未能分期。由此可見約三分一的卵巢癌患者就醫時，已處於較為嚴重的晚期。但為何會有三分一的患者，在患上卵巢癌初期時不能自行發現身體的異樣？

陳亮祖醫生告訴記者：「卵巢癌不易被發現，尤其是初期的症狀不明顯，患者未必會出現下體流血等症狀，有時只會像得了其他例如胃痛，肚脹等病症。所以有些婦女就覺得可能是經期不舒服、胃痛或者是吃了變壞的食物，最終忽略了非常隱蔽的卵巢癌病症。」

就如何治療卵巢癌，陳亮祖醫生表示，目前的治療方案主要通過外科手術，隨後進行化療來抑制卵巢癌腫瘤生長。若卵巢癌患者在第一或第二期接受治療，他們的五年存活率是比較高的。但若到了第三期才進行治療，術後五年存活率會相對較低，只有約50％。而到了第四期進行治療的五年存活率就會低於20％。因此，盡早發現卵巢癌並進行治療尤其重要。但如何才能及早判斷自己是卵巢癌高危一族？

陳亮祖醫生表示，卵巢癌的成因分先天性與後天性。其中女性若沒有生育經歷或沒有母乳餵哺，有較高風險患上後天性卵巢癌；若女性的家族成員中有乳癌、卵巢癌、腹膜癌、前列腺、胰腺癌等家族遺傳病史，這類女性由於遺傳基因，患上先天性卵巢癌的機會較高。而這種先天的遺傳性卵巢癌，與一種叫BRCA的遺傳基因有很大關係，若女性攜帶變異的「BRCA」基因，就有較高風險患上卵巢癌。

人體BRCA基因突變 喪失抑制腫瘤功能

BRCA是抑癌基因，在調節細胞複製、DNA損傷修復、細胞正常生長方面有重要作用。如果BRCA基因突變，人體就喪失了抑制腫瘤的功能。陳亮祖醫生解釋，BRCA突變類型達數百種之多，與人體的很多癌症都有關係，比如大腸癌、前列腺癌等，其中關係最緊密的是乳腺癌，其次就是卵巢癌。如果家族中有人攜帶BRCA基因有機會，就有機會傳給下一代，而攜帶BRCA基因的人出現腫瘤的機率較一般人高出很多。

然而，世界卵巢癌的最新數據顯示，卵巢癌患者中因先天遺傳帶有BRCA基因突變的概率約為14％，相當於每七位卵巢癌患者中便有一位出現遺傳性BRCA基因突變，有部分患者的BRCA基因突變並不是通過先天遺傳的，而是通過偶發性的後天變異引起BRCA基因突變。

現時醫生會為第四期或復發性卵巢癌的患者，安排BRCA基因測試。而全球不同的癌症權威組織亦建議卵巢癌患者接受BRCA基因測試，如美國全國國家綜合癌症網絡（NCCN）和美國臨床腫瘤科學會（ASCO）等。陳亮祖醫生建議部分乳癌或卵巢癌患者的女性家屬也可一起進行該測試，以排除BRCA基因和患乳癌或卵巢癌的風險，以便可以更緊密監察，盡早發現腫瘤，盡早醫治。一般女性可通過化驗血液、口腔粘膜細胞做遺傳性的BRCA基因測試。

如果已是對鉑化療有反應而復發的卵巢癌患者，醫生又通過測試檢測出患者屬於BRCA基因突變，此時就能用另一種治療方式——標靶藥物PARP抑制劑來控制患者卵巢癌細胞的擴散。陳亮祖醫生解釋：「若不是BRCA基因突變引起的卵巢癌，使用PARP抑制劑的效果微乎其微，因PARP抑制劑只精準地針對存在BRCA突變癌細胞的患者。」

...........續

參考資料: 文匯報
以上所提供的資訊僅作為教育及參考用途，如果你有任何醫療問題，
應向自己的腫瘤科專科醫生查詢，而不應單倚賴以上提供的資料。

Nutritional support essential for cancer patients: Experts

HONG KONG - Oral mucositis, a common complication which inhibits eating that is induced by radiotherapy and chemotherapy, could significantly upset the course of cancer treatment and lead to higher tumor recurrence rates, Chan Leung-cho, a specialist in clinical oncology, said on Tuesday.

Patients suffering from oral mucositis induced by chemotherapy could lose their appetite and become too weak to continue the treatment. Normally a course of chemotherapy takes seven weeks. If oral mucositis interrupts and suspends the treatment, the chemotherapy cannot perform its best result, and the recurrent rate of the cancer might increase 3 to 5 percent for every postponed week of treatment, Chan said.

Chemotherapy, a cancer treatment intended to hinder or cease the growth of cancer cells, might also damage healthy, rapidly divided epithelial cells lining in the mouth. This later gives rise to ulcerations, a prominent symptom of oral mucositis, he said.

Patients who have oral mucositis will find themselves in great oral pain, and have difficulty when eating and swallowing. Reddened, bleeding and swollen mouth and gums are the visible indicators. Such conditions normally develop around four to five days from the onset of the chemotherapy.

Nutritional support is a crucial component of cancer treatment to help patients regain and maintain normal body weight and be physically strong enough to fight against cancer, said Sylvia Lam See-way, a senior registered dietician.

“Generally, a cancer patient has to consume a special diet, which contains higher calories and protein content than usual,” Lam said.

Lorena Cheung Tsui-fun, a registered dietician who is experienced in mapping out individualized diets for cancer patients, said that patients will have a bolstered immune system and be more tolerant of chemotherapy-induced side effects if they have sufficient immunonutrition.

The notion that the sugar in food might promote the growth of cancer cells is a fallacy, Lam and Cheung contended. They warn that cancer patients should not overly abstain from eating a wide range of food.

Cheung suggested eating extra amounts of quality oil, such as olive oil, to boost energy content in patients’ diets. Cancer patients should also snack between meals and consume food which is easy to chew and swallow to enhance their appetite.

“Nutrition modification is important during treatments, but optimizing a patient’s nutrition before the start of chemotherapy is also crucial,” Chan told China Daily, adding that he often recommends that cancer patients load up on nutrients in advance. In such a way they can be better prepared to deal with the damaging outcomes caused by oral mucositis.

According to the European Oncology Nursing Society, the average occurrence rate of oral mucositis among patients who receive chemotherapy is around 40 percent. For those who suffer from head and neck cancer, the rate reaches 100 percent.

As stated by the Department of Health, cancer has become the number one killer in Hong Kong, accounting for 30.2 percent of all registered deaths in 2014.






Reference information:  China Daily Asia
The information aims to provide educational purpose only. Anyone reading it should consult Oncologist before considering treatment and should not rely on the information above

癌症篩查或出現假陽／陰性結果

全球每年有1,100萬人證實患上癌症 ，而且發病率有上升的趨勢，而各類癌症篩查亦愈見普及。癌症篩查是以有系統的方法，透過不同的檢測工具向沒有癌症病徵的人士進行檢測，目的希望能從沒有癌症病徵的人群中找出患癌的人，以便能及早進行治癒，減少癌症死亡率。然而，不同癌症的癌症普查也有利與弊，當中更有機會出現假陽性或假陰性的結果，故市民進行檢查前應先考慮自己的需要，再諮詢醫生的建議。

目前，大腸癌、子宮頸癌、乳腺癌、及前列腺癌的普查最為常見，大腸癌可使用大便隱血測試或大腸內窺鏡檢查;子宮頸癌用子宮頸抹片;乳腺癌使用乳房X光造影進行檢查，而前列腺癌使用前列腺抗原(PSA)抽血測試，雖然上述各項普查的風險很低且對檢測早期癌症有一定成效，但仍有機會出現一些併發症，如進行大腸鏡檢查前需服用瀉藥以助檢測，或會令檢查者因腹瀉而出現脫水或電解質不平衡的情形。

另一方面，各項的普查均有機會出現假陽性或假陰性結果。以乳房X光造影為例，曾有研究指出10萬名婦女連續10年進行普查，當中發現近9000宗假陽性的結果，故檢查者一旦發現普查結果為陽性時不用過份擔心，應立即跟醫生商量並進行局部且更深入的抽取組織檢測以確定是否患病。同時，市民或會認為檢查結果正常便不用理會，但同樣地有機會是假陰性結果，引致潛伏危機而不自知；因此就算普查結果正常亦應定期進行下次普查，如每年進行一次大便隱血測試、10年一次大腸內窺鏡檢查、2年一次乳房X光造影等；同時市民若於進行下次普查前發現身體出現懷疑是癌症的病徵時，亦應盡快找醫生，不要留待下次檢查。

此外，作息定時和適量的運動都是預防癌症的方法；至於近親曾患癌症的市民更須多加注意，並因應自己的需要及醫生的建議來決定是否做癌症普查，同時應先向醫生了解有關檢查事項的益處、風險和限制。

臨牀腫瘤科專科醫生

陳亮祖

參考資料: 信報
以上所提供的資訊僅作為教育及參考用途，如果你有任何醫療問題，
應向自己的腫瘤科專科醫生查詢，而不應單倚賴以上提供的資料。

Managing pain in a patient with pancreatic cancer (2) pancreatic cancer (2)

Discussion

Pain is one of the most common symptoms experienced by cancer patients. It has been estimated that approximately 50 to 70 percent of patients with cancer experience some degree of pain, which usually progresses and intensifies as the disease progresses.¹ One study noted that the incidence of pain in patients with advanced stages of invasive cancer may be as high as 80 percent. The incidence can be as high as 90 percent for those with metastases in osseous structures.² However, more than half of cancer patients have insufficient pain control. Severe pain can significantly impair patients’ quality of life and interfere with their physical rehabilitation, nutrition and mobility. Furthermore, a large number of cancer patients suffer from depression.³

Several practice guidelines on pain control have been formulated. The most widely used algorithm in the management of cancer pain is probably the one formulated by the WHO, called the WHO cancer pain treatment step ladder. These guidelines recommend the use of paracetamol or NSAIDs as an initial step in pain management, followed by opioid analgesic for mild to moderate pain, and strong opioids for moderate to severe pain.⁴ (Figure 2) However, some experts have stated that the WHO guidelines may be inadequate to address current needs and suggested the addition of a fourth interventional step in the form of nerve blocks, intrathecal delivery systems, or surgical procedures.⁵

Oxycodone is a synthetic opioid metabolized to its active metabolite, oxymorphone, in the liver. A comparison of oxycodone CR and morphine demonstrated similar analgesic effects between the two drugs. However, there were significant differences in pain control for patients with underlying renal or hepatic impairment receiving oxyvodone.⁶ although oxycodone is generally more expensive than morphine, it has proven efficacy in treating moderate to severe pain, and its CR formulation allows for the convenience of 12-hour dosing intervals.⁷

The use of opioids, though often perceived to be associated with palliative care, plays and important role in pain management. In the case of our patient, it resulted in satisfactory pain control and improved quality of life, enabling him to undergo and tolerate subsequent chemotherapy, which can potentially control the disease and prolong survival.
Dr Leung-Cho Chan        

                                       
Specialist in Clinical Oncology Private practice Hong Kong





Reference information:  oncologytribune
The information aims to provide educational purpose only. Anyone reading it should consult Oncologist before considering treatment and should not rely on the information above

Managing pain in a patient with pancreatic cancer (1)

Presentation and management

This is the case of a 53-year-old married male with children who sought consultation for progressive abdominal pain in April 2014. The pain had been present for 1 to 2 months prior to the consultation, and was previously diagnosed by other doctors as pain due to gastritis.

The patient described the pain as severe, giving it a score of 7 to 8 on a numerical rating scale of 1 to 10. Esophagogastroduodenoscopy was unremarkable, but CT scan revealed a pancreatic tumor with liver metastasis and mild ascites, which was inoperable due to celiac plexus infiltration and secondary lesions in the liver. Pain management was initiated using oxycodone 10 mg controlled-release (CR) tablets twice daily and oxycodone 5 mg capsules as needed.

The patient was informed of possible side effects such as dizziness, nausea, vomiting and constipation. Metoclopramide and a senna-based laxative were prescribed for nausea and vomiting, and constipation, respectively.

The patient then underwent intensity-modulated radiotherapy, receiving 3.0 Gy per fraction at the tumor area, 2.8 Gy at the 0.7 cm tumor margin, and 2.5 Gy at the 1.0 cm tumor margin for a total of 15 fractions given over 3 weeks. (Figure 1)

Pain intensity improved from a score of 7 to 8 initial consultation to 4 after 3 to 4 days of treatment with oxycodone. Two weeks after radiotherapy, pain intensity further reduced to a score of 2. The dose of oxycodone was reduced to one 10 mg CR tablet daily at night time. Oxycodone 5 mg capsule was discontinued and replaced by an NSAID taken as needed during daytime.

During follow-up visits every 1 to 2 months, the patient reported only mild pain. He is now receiving gemcitabine as single-agent chemotherapy at a public hospital.

Dr Leung-Cho Chan                                                
Specialist in Clinical Oncology Private practice Hong Kong











Reference information:  oncologytribune
The information aims to provide educational purpose only. Anyone reading it should consult Oncologist before considering treatment and should not rely on the information above.